Date   

Re: Synchronome contacts pitted

Andrew Nahum
 


A supply for the glass rollers for the ‘back stop’ or detent that runs on the count wheel would be great. Has anyone any news on a source for them?  I think I recall Jan Wright produced some a few years ago and they all sold out like hot cakes. I am currently using a delrin one kindly made by a friend but I fancy glass would have the lowest friction in that application. 

Andrew 


On 18 Feb 2021, at 20:46, Stephen Hibbs <oldtimemachines@...> wrote:

Hi, Naing,

There are reproduction gathering arms for sale right now on eBay for 25 US dollars plus a nominal shipping cost. Just enter the search term “Synchronome”. Making one would be an interesting challenge, but if you want one right now, here you go.

Stephen Hibbs
PO Box 536
Markleeville, CA 96120
530-694-1045




On Feb 18, 2021, at 12:19 PM, bailey.services via groups.io <bailey.services@...> wrote:

Hi pallet design drawing is on NAWCC clock forum website dated 17 sept 2007 posted by fdew


Re: Count wheel & backstop roller

John Hubert
 

Glass is correct.  I have also used perspex (glass is relatively difficult to drill) with success.  The keys to the clock running well are that;

  1. The teeth of the count wheel are clean and dry (it runs with the teeth dry NOT oiled)
  2. The gathering jewel engages the teeth JUST enough to gather a tooth and allow the backstop roller to drop - not more.  Having the jewel set too low looses energy and the Synchronome is pretty ’tight’ on energy.
  3. The slope of the pallet down which the roller rolls must also be clean and dry - as must the surfaces of the roller itself.  It should drop just on the corner of the slope.

Bob's book should enable you to get it running fine.  The clock pictured has run well for many years for me without anything more than an occasional clean and keeps excellent time.

John

On 22 Feb 2021, at 16:07, Chris Wollaston <chris@...> wrote:

Hi John, many tks for that and excellent picture. I'm going to require a steady pair of hands to get it set up.  Any preference as to which bead to use, glass or alloy? The alloy one has a raised edge both sides.  Also, I've been avidly studying Bob Miles tome Ch 13 on setting up the pendulum and impulse pallet under the roller and am now awaiting a replacement suspension spring as the one that came with the clock is twice as long as the correct version shown on p.236 plus it has a crimp in the metal. This will be the next challenge. Chris


Re: Count wheel & backstop roller

Chris Wollaston
 

Hi John, many tks for that and excellent picture. I'm going to require a steady pair of hands to get it set up.  Any preference as to which bead to use, glass or alloy? The alloy one has a raised edge both sides.  Also, I've been avidly studying Bob Miles tome Ch 13 on setting up the pendulum and impulse pallet under the roller and am now awaiting a replacement suspension spring as the one that came with the clock is twice as long as the correct version shown on p.236 plus it has a crimp in the metal. This will be the next challenge. Chris


Re: Count wheel & backstop roller

John Hubert
 

In fact it cannot ‘fall off’ because the K shaped bridge is ‘in the way’.  Photo of a slightly earlier clock (which has been running for many years) attached.


John

On 22 Feb 2021, at 15:41, Chris Wollaston <chris@...> wrote:

Dear All, I've just joined the forum and in the process of setting up my 1920s Synchronome master (Serial 1152) in mahogany case and have carefully dismounted the Y-shaped brass bracket that holds the count wheel and latch because the pivot pins were bent and the wheel gummed up with old sticky oil.  Now cleaned and straightened I'm poised to re-assemble but see that I've been supplied with either a wee glass or solid alloy roller bead to fit on the backstop wire.  However, there doesn't seem to be a way of preventing the bead falling off the wire so is it just held in place by the brass Y or should I drop a spot of glue on the end to prevent it falling off? Bests, Chris in E Sussex


Count wheel & backstop roller

Chris Wollaston
 

Dear All, I've just joined the forum and in the process of setting up my 1920s Synchronome master (Serial 1152) in mahogany case and have carefully dismounted the Y-shaped brass bracket that holds the count wheel and latch because the pivot pins were bent and the wheel gummed up with old sticky oil.  Now cleaned and straightened I'm poised to re-assemble but see that I've been supplied with either a wee glass or solid alloy roller bead to fit on the backstop wire.  However, there doesn't seem to be a way of preventing the bead falling off the wire so is it just held in place by the brass Y or should I drop a spot of glue on the end to prevent it falling off? Bests, Chris in E Sussex


Re: Synchronome contacts pitted

John Hubert
 

If you search eBay - there is an un-machined impulse pallet casting listed in the UK.  (I am not and have no connection with the seller - nor have I ever seen or examined the part.)

John

On 20 Feb 2021, at 13:02, N Linn <naingtlin@...> wrote:

Dear Stephen,

Your advices are very much appreciated and giving me a lot to think about recreating a part to work with. That helps expanding the idea by various perspectives and thank you so much. 

It would be great if you can examine the picture provided by Norman. Let me send you the file attached.

Best wishes,
Naing

On Sat, Feb 20, 2021, 3:21 AM Stephen Hibbs <oldtimemachines@...> wrote:
Hi, Naing,

I can’t seem to get Norman’s .jpg to download. Wish I could see it. But as a mechanical engineer who has designed thousands of parts for manufacturing, I have some comments about the .pdf from bailey.services that might simplify its fabrication with no loss of functionality.

1. The curved ramp is shown as a segment of the developed surface of a toroid. Again, this could be simplified. If it was simply the surface of a cylinder instead, it could be generated by the simple motion of a milling cutter instead of a complex motion, if you follow me. The roller on the Synchronome’s gravity arm won’t know the difference if it is truly rolling instead of sliding (which it might do if its pivots aren’t sufficiently lubricated). There might be a very slight tendency to twist the pendulum if it rolls down either edge rather than the surface, but I think that would be negligible. If the correct suspension spring is used, it has considerable torsional stiffness and the pendulum bob has huge torsional inertia.
      And I still suspect a straight ramp is as good as a curved one. If I were making this part, I’d make the flat ramp long enough that the roller would land below the top of the ramp and be lifted off before reaching the bottom. This is what Gents’ does and it extracts all the potential energy available in the time the roller and pallet are in contact with each other.

2.  I believe the 45-degree facets are intended to act as elastic hinges where thin material embraces the pendulum rod. But they are so long that I’m not convinced that a single 4-40NC screw in brass will be able to generate adequate clamping force around the rod. And the effort to generate enough clamping force will likely strip the female thread, leaving you with no clamping force at all. The safe way out is two screws, though there is still risk of stripping one of the female threads if they are tightened unevenly.
     You’ll likely be starting with .50-inch thick stock, or maybe the nearest metric equivalent. There’s really no need to machine it down to .44 inch thick, nor is there a functional need to machine the two 45-degree facets on the end opposite the ramp; only an aesthetic one. Nor is there a need for the counterbore if those facets are omitted.

3.   The .035 dia. thru hole gives the gathering arm a place to be, but I don’t see what keeps it there unless the 2-56NC hole below it is part of a retaining scheme not shown. The original pallet part, of course, has an elegant but complex retaining scheme machined into it that was wisely avoided in this design.

4.   The .38 radius on the underside can actually be any radius that’s convenient. It does happen to match the specified radius of the ramp.

Kind regards,
Steve

Stephen Hibbs
PO Box 536
Markleeville, CA 96120
530-694-1045




On Feb 19, 2021, at 1:29 AM, Norman Heckenberg <heckenberg@...> wrote:

<pallet.jpg>




-- 
Naing<pallet.jpg>


Re: Synchronome contacts pitted

Stephen Hibbs
 

Hi, Naing,

Thanks for re-sending me Norman’s picture. It is very much more like the Synchronome original part. It differs only, as far as I can see, in the way it retains the gathering arm. The very thin wall embracing the pendulum rod makes for easy clamping with a small screw. This part would also be difficult to fabricate. The text further up the page isn’t visible, but I expect it mentions that making this part begins as a casting. Achieving that thin, circular outer shape would be difficult even by that method, almost impossible by any other. My other comments as to the importance of curves vs. straight lines, etc. would still apply to the making of this part. The dimensioning convention used here only alludes to the formation of the ramp as a section of the surface of a torus; it’s not explicit. That would be complex to set up for machining, someone one would only do if it was thought to be truly necessary (and I don’t think so), and was going to be made in quantity.

An additional comment about the other design:

5.   Unless I’m missing something, it would put the gathering arm off center. That is, it would miss the count wheel. Perhaps it’s intended to work with a gathering arm of a different design, one with a jog in it that puts the gathering jewel back on the centerline.

Best regards,
Steve

Stephen Hibbs
PO Box 536
Markleeville, CA 96120
530-694-1045




On Feb 20, 2021, at 5:02 AM, N Linn <naingtlin@...> wrote:

Dear Stephen,

Your advices are very much appreciated and giving me a lot to think about recreating a part to work with. That helps expanding the idea by various perspectives and thank you so much. 

It would be great if you can examine the picture provided by Norman. Let me send you the file attached.

Best wishes,
Naing

On Sat, Feb 20, 2021, 3:21 AM Stephen Hibbs <oldtimemachines@...> wrote:
Hi, Naing,

I can’t seem to get Norman’s .jpg to download. Wish I could see it. But as a mechanical engineer who has designed thousands of parts for manufacturing, I have some comments about the .pdf from bailey.services that might simplify its fabrication with no loss of functionality.

1. The curved ramp is shown as a segment of the developed surface of a toroid. Again, this could be simplified. If it was simply the surface of a cylinder instead, it could be generated by the simple motion of a milling cutter instead of a complex motion, if you follow me. The roller on the Synchronome’s gravity arm won’t know the difference if it is truly rolling instead of sliding (which it might do if its pivots aren’t sufficiently lubricated). There might be a very slight tendency to twist the pendulum if it rolls down either edge rather than the surface, but I think that would be negligible. If the correct suspension spring is used, it has considerable torsional stiffness and the pendulum bob has huge torsional inertia.
      And I still suspect a straight ramp is as good as a curved one. If I were making this part, I’d make the flat ramp long enough that the roller would land below the top of the ramp and be lifted off before reaching the bottom. This is what Gents’ does and it extracts all the potential energy available in the time the roller and pallet are in contact with each other.

2.  I believe the 45-degree facets are intended to act as elastic hinges where thin material embraces the pendulum rod. But they are so long that I’m not convinced that a single 4-40NC screw in brass will be able to generate adequate clamping force around the rod. And the effort to generate enough clamping force will likely strip the female thread, leaving you with no clamping force at all. The safe way out is two screws, though there is still risk of stripping one of the female threads if they are tightened unevenly.
     You’ll likely be starting with .50-inch thick stock, or maybe the nearest metric equivalent. There’s really no need to machine it down to .44 inch thick, nor is there a functional need to machine the two 45-degree facets on the end opposite the ramp; only an aesthetic one. Nor is there a need for the counterbore if those facets are omitted.

3.   The .035 dia. thru hole gives the gathering arm a place to be, but I don’t see what keeps it there unless the 2-56NC hole below it is part of a retaining scheme not shown. The original pallet part, of course, has an elegant but complex retaining scheme machined into it that was wisely avoided in this design.

4.   The .38 radius on the underside can actually be any radius that’s convenient. It does happen to match the specified radius of the ramp.

Kind regards,
Steve

Stephen Hibbs
PO Box 536
Markleeville, CA 96120
530-694-1045




On Feb 19, 2021, at 1:29 AM, Norman Heckenberg <heckenberg@...> wrote:

<pallet.jpg>




--
Naing <pallet.jpg>


Re: Synchronome contacts pitted

N Linn
 
Edited

Hi Neville,

Good to know you have those. I'm not sure which one would fit to my movement. Will you consider selling one for me? 

Best regards,
Naing


On Sat, Feb 20, 2021, 12:28 PM Neville Michie via groups.io <neville_michie=yahoo.com@groups.io> wrote:
Hi Naing,
I have an early Synchronome with an obscure history.
It has without doubt been made in the Synchronome factory,
but was probably sold as the movement alone. It has no serial number.
It has been fitted in a hardwood case with bevelled glass.
The latch dates the unit as quite early, about 1917 is my best guess.
The point of interest here is that the pallet design was different.
I am attaching photos of the original pallet with a set screw and 
another pallet with a clamp fixing. The setscrew model was on the 
unit when I got it.
cheers, 
Neville Michie


On 20 Feb 2021, at 08:02, Odell, Edward via groups.io <edward.odell=kcl.ac.uk@groups.io> wrote:

Hi Naing, 
 
In the picture you sent with your first post, the movement that you have looks to be an interesting and early example. It does not have an overthrow damper for the gravity arm and it has the early type of latch. These early clocks did not have the later standardised impulse pallet, they had a much shorter curve which was less efficient. It probably does not matter exactly which curve you make for your clock so long as the contacts close before the roller reaches the end of the curve.
However, it would be interesting to know the serial number of your clock. This is stamped into the bottom of the NRA plate. I can make out a 0 in the number but I cannot see the exact number. If the number is very low this could be an interesting movement historically and it would be good if you could let us know the serial number. We might then be able to tell you which design of impulse pallet match the date of your clock
 
Eddy Odell 
 
From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of Stephen Hibbs via groups.io
Sent: 19 February 2021 20:51
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted
 
Hi, Naing,
 
I can’t seem to get Norman’s .jpg to download. Wish I could see it. But as a mechanical engineer who has designed thousands of parts for manufacturing, I have some comments about the .pdf from bailey.services that might simplify its fabrication with no loss of functionality.
 
1. The curved ramp is shown as a segment of the developed surface of a toroid. Again, this could be simplified. If it was simply the surface of a cylinder instead, it could be generated by the simple motion of a milling cutter instead of a complex motion, if you follow me. The roller on the Synchronome’s gravity arm won’t know the difference if it is truly rolling instead of sliding (which it might do if its pivots aren’t sufficiently lubricated). There might be a very slight tendency to twist the pendulum if it rolls down either edge rather than the surface, but I think that would be negligible. If the correct suspension spring is used, it has considerable torsional stiffness and the pendulum bob has huge torsional inertia.
      And I still suspect a straight ramp is as good as a curved one. If I were making this part, I’d make the flat ramp long enough that the roller would land below the top of the ramp and be lifted off before reaching the bottom. This is what Gents’ does and it extracts all the potential energy available in the time the roller and pallet are in contact with each other.
 
2.  I believe the 45-degree facets are intended to act as elastic hinges where thin material embraces the pendulum rod. But they are so long that I’m not convinced that a single 4-40NC screw in brass will be able to generate adequate clamping force around the rod. And the effort to generate enough clamping force will likely strip the female thread, leaving you with no clamping force at all. The safe way out is two screws, though there is still risk of stripping one of the female threads if they are tightened unevenly.
     You’ll likely be starting with .50-inch thick stock, or maybe the nearest metric equivalent. There’s really no need to machine it down to .44 inch thick, nor is there a functional need to machine the two 45-degree facets on the end opposite the ramp; only an aesthetic one. Nor is there a need for the counterbore if those facets are omitted.
 
3.   The .035 dia. thru hole gives the gathering arm a place to be, but I don’t see what keeps it there unless the 2-56NC hole below it is part of a retaining scheme not shown. The original pallet part, of course, has an elegant but complex retaining scheme machined into it that was wisely avoided in this design.
 
4.   The .38 radius on the underside can actually be any radius that’s convenient. It does happen to match the specified radius of the ramp.
 
Kind regards,
Steve
 
Stephen Hibbs
PO Box 536
Markleeville, CA 96120
530-694-1045
oldtimemachines@...
 
 



On Feb 19, 2021, at 1:29 AM, Norman Heckenberg <heckenberg@...> wrote:
 
<pallet.jpg>
 


--
Naing


Re: Synchronome contacts pitted

John Hubert
 

For your information, clock 707 would date to about 1919 and would (probably) have originally been in a 'false pediment’ type case, found (mainly) between the approximate serial number range of 680 (around 1918/9) and 900 (1922).  I say approximate, because there is no exact transition with some overlapping of the case styles.  It is therefore over 100 years old.

John

On 20 Feb 2021, at 13:06, N Linn <naingtlin@...> wrote:

Hi Eddy,

Thanks for the message.  The serial no. reads 707. Kindly see in attach for your reference. I'm not very well understand about these parts. But i saw some videos on youtube similar to this clock. 

Best regards,
Naing

On Sat, Feb 20, 2021, 3:32 AM Odell, Edward via groups.io <edward.odell=kcl.ac.uk@groups.io> wrote:

Hi Naing,

 

In the picture you sent with your first post, the movement that you have looks to be an interesting and early example. It does not have an overthrow damper for the gravity arm and it has the early type of latch. These early clocks did not have the later standardised impulse pallet, they had a much shorter curve which was less efficient. It probably does not matter exactly which curve you make for your clock so long as the contacts close before the roller reaches the end of the curve.

However, it would be interesting to know the serial number of your clock. This is stamped into the bottom of the NRA plate. I can make out a 0 in the number but I cannot see the exact number. If the number is very low this could be an interesting movement historically and it would be good if you could let us know the serial number. We might then be able to tell you which design of impulse pallet match the date of your clock

 

Eddy Odell

 

From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of Stephen Hibbs via groups.io
Sent: 19 February 2021 20:51
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

 

Hi, Naing,

 

I can’t seem to get Norman’s .jpg to download. Wish I could see it. But as a mechanical engineer who has designed thousands of parts for manufacturing, I have some comments about the .pdf from bailey.services that might simplify its fabrication with no loss of functionality.

 

1. The curved ramp is shown as a segment of the developed surface of a toroid. Again, this could be simplified. If it was simply the surface of a cylinder instead, it could be generated by the simple motion of a milling cutter instead of a complex motion, if you follow me. The roller on the Synchronome’s gravity arm won’t know the difference if it is truly rolling instead of sliding (which it might do if its pivots aren’t sufficiently lubricated). There might be a very slight tendency to twist the pendulum if it rolls down either edge rather than the surface, but I think that would be negligible. If the correct suspension spring is used, it has considerable torsional stiffness and the pendulum bob has huge torsional inertia.

      And I still suspect a straight ramp is as good as a curved one. If I were making this part, I’d make the flat ramp long enough that the roller would land below the top of the ramp and be lifted off before reaching the bottom. This is what Gents’ does and it extracts all the potential energy available in the time the roller and pallet are in contact with each other.

 

2.  I believe the 45-degree facets are intended to act as elastic hinges where thin material embraces the pendulum rod. But they are so long that I’m not convinced that a single 4-40NC screw in brass will be able to generate adequate clamping force around the rod. And the effort to generate enough clamping force will likely strip the female thread, leaving you with no clamping force at all. The safe way out is two screws, though there is still risk of stripping one of the female threads if they are tightened unevenly.

     You’ll likely be starting with .50-inch thick stock, or maybe the nearest metric equivalent. There’s really no need to machine it down to .44 inch thick, nor is there a functional need to machine the two 45-degree facets on the end opposite the ramp; only an aesthetic one. Nor is there a need for the counterbore if those facets are omitted.

 

3.   The .035 dia. thru hole gives the gathering arm a place to be, but I don’t see what keeps it there unless the 2-56NC hole below it is part of a retaining scheme not shown. The original pallet part, of course, has an elegant but complex retaining scheme machined into it that was wisely avoided in this design.

 

4.   The .38 radius on the underside can actually be any radius that’s convenient. It does happen to match the specified radius of the ramp.

 

Kind regards,

Steve

 

Stephen Hibbs

PO Box 536

Markleeville, CA 96120

530-694-1045

 

 



On Feb 19, 2021, at 1:29 AM, Norman Heckenberg <heckenberg@...> wrote:

 

<pallet.jpg>

 




--
Naing <IMG_20210220_191411.jpg>


Re: Synchronome contacts pitted

N Linn
 

Hi Eddy,

Thanks for the message.  The serial no. reads 707. Kindly see in attach for your reference. I'm not very well understand about these parts. But i saw some videos on youtube similar to this clock. 

Best regards,
Naing

On Sat, Feb 20, 2021, 3:32 AM Odell, Edward via groups.io <edward.odell=kcl.ac.uk@groups.io> wrote:

Hi Naing,

 

In the picture you sent with your first post, the movement that you have looks to be an interesting and early example. It does not have an overthrow damper for the gravity arm and it has the early type of latch. These early clocks did not have the later standardised impulse pallet, they had a much shorter curve which was less efficient. It probably does not matter exactly which curve you make for your clock so long as the contacts close before the roller reaches the end of the curve.

However, it would be interesting to know the serial number of your clock. This is stamped into the bottom of the NRA plate. I can make out a 0 in the number but I cannot see the exact number. If the number is very low this could be an interesting movement historically and it would be good if you could let us know the serial number. We might then be able to tell you which design of impulse pallet match the date of your clock

 

Eddy Odell

 

From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of Stephen Hibbs via groups.io
Sent: 19 February 2021 20:51
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

 

Hi, Naing,

 

I can’t seem to get Norman’s .jpg to download. Wish I could see it. But as a mechanical engineer who has designed thousands of parts for manufacturing, I have some comments about the .pdf from bailey.services that might simplify its fabrication with no loss of functionality.

 

1. The curved ramp is shown as a segment of the developed surface of a toroid. Again, this could be simplified. If it was simply the surface of a cylinder instead, it could be generated by the simple motion of a milling cutter instead of a complex motion, if you follow me. The roller on the Synchronome’s gravity arm won’t know the difference if it is truly rolling instead of sliding (which it might do if its pivots aren’t sufficiently lubricated). There might be a very slight tendency to twist the pendulum if it rolls down either edge rather than the surface, but I think that would be negligible. If the correct suspension spring is used, it has considerable torsional stiffness and the pendulum bob has huge torsional inertia.

      And I still suspect a straight ramp is as good as a curved one. If I were making this part, I’d make the flat ramp long enough that the roller would land below the top of the ramp and be lifted off before reaching the bottom. This is what Gents’ does and it extracts all the potential energy available in the time the roller and pallet are in contact with each other.

 

2.  I believe the 45-degree facets are intended to act as elastic hinges where thin material embraces the pendulum rod. But they are so long that I’m not convinced that a single 4-40NC screw in brass will be able to generate adequate clamping force around the rod. And the effort to generate enough clamping force will likely strip the female thread, leaving you with no clamping force at all. The safe way out is two screws, though there is still risk of stripping one of the female threads if they are tightened unevenly.

     You’ll likely be starting with .50-inch thick stock, or maybe the nearest metric equivalent. There’s really no need to machine it down to .44 inch thick, nor is there a functional need to machine the two 45-degree facets on the end opposite the ramp; only an aesthetic one. Nor is there a need for the counterbore if those facets are omitted.

 

3.   The .035 dia. thru hole gives the gathering arm a place to be, but I don’t see what keeps it there unless the 2-56NC hole below it is part of a retaining scheme not shown. The original pallet part, of course, has an elegant but complex retaining scheme machined into it that was wisely avoided in this design.

 

4.   The .38 radius on the underside can actually be any radius that’s convenient. It does happen to match the specified radius of the ramp.

 

Kind regards,

Steve

 

Stephen Hibbs

PO Box 536

Markleeville, CA 96120

530-694-1045

 

 



On Feb 19, 2021, at 1:29 AM, Norman Heckenberg <heckenberg@...> wrote:

 

<pallet.jpg>

 


--
Naing


Re: Synchronome contacts pitted

N Linn
 

Dear Stephen,

Your advices are very much appreciated and giving me a lot to think about recreating a part to work with. That helps expanding the idea by various perspectives and thank you so much. 

It would be great if you can examine the picture provided by Norman. Let me send you the file attached.

Best wishes,
Naing


On Sat, Feb 20, 2021, 3:21 AM Stephen Hibbs <oldtimemachines@...> wrote:
Hi, Naing,

I can’t seem to get Norman’s .jpg to download. Wish I could see it. But as a mechanical engineer who has designed thousands of parts for manufacturing, I have some comments about the .pdf from bailey.services that might simplify its fabrication with no loss of functionality.

1. The curved ramp is shown as a segment of the developed surface of a toroid. Again, this could be simplified. If it was simply the surface of a cylinder instead, it could be generated by the simple motion of a milling cutter instead of a complex motion, if you follow me. The roller on the Synchronome’s gravity arm won’t know the difference if it is truly rolling instead of sliding (which it might do if its pivots aren’t sufficiently lubricated). There might be a very slight tendency to twist the pendulum if it rolls down either edge rather than the surface, but I think that would be negligible. If the correct suspension spring is used, it has considerable torsional stiffness and the pendulum bob has huge torsional inertia.
      And I still suspect a straight ramp is as good as a curved one. If I were making this part, I’d make the flat ramp long enough that the roller would land below the top of the ramp and be lifted off before reaching the bottom. This is what Gents’ does and it extracts all the potential energy available in the time the roller and pallet are in contact with each other.

2.  I believe the 45-degree facets are intended to act as elastic hinges where thin material embraces the pendulum rod. But they are so long that I’m not convinced that a single 4-40NC screw in brass will be able to generate adequate clamping force around the rod. And the effort to generate enough clamping force will likely strip the female thread, leaving you with no clamping force at all. The safe way out is two screws, though there is still risk of stripping one of the female threads if they are tightened unevenly.
     You’ll likely be starting with .50-inch thick stock, or maybe the nearest metric equivalent. There’s really no need to machine it down to .44 inch thick, nor is there a functional need to machine the two 45-degree facets on the end opposite the ramp; only an aesthetic one. Nor is there a need for the counterbore if those facets are omitted.

3.   The .035 dia. thru hole gives the gathering arm a place to be, but I don’t see what keeps it there unless the 2-56NC hole below it is part of a retaining scheme not shown. The original pallet part, of course, has an elegant but complex retaining scheme machined into it that was wisely avoided in this design.

4.   The .38 radius on the underside can actually be any radius that’s convenient. It does happen to match the specified radius of the ramp.

Kind regards,
Steve

Stephen Hibbs
PO Box 536
Markleeville, CA 96120
530-694-1045




On Feb 19, 2021, at 1:29 AM, Norman Heckenberg <heckenberg@...> wrote:

<pallet.jpg>


--
Naing


Re: Synchronome contacts pitted

Neville Michie
 

Hi Naing
The clock being discussed has a latch and fittings that
place it about 1917.
I base this on other clocks with the previous model latch and
the later latch that followed. None of these clocks had the
gravity arm buffer.

cheers,
Neville Michie


Re: Synchronome contacts pitted

Neville Michie
 
Edited

Hi Naing,
I have an early Synchronome with an obscure history.
It has without doubt been made in the Synchronome factory,
but was probably sold as the movement alone. It has no serial number.
It has been fitted in a hardwood case with bevelled glass.
The latch dates the unit as quite early, about 1917 is my best guess.
The point of interest here is that the pallet design was different.
I am attaching photos of the original pallet with a set screw and 
another pallet with a clamp fixing. The setscrew model was on the 
unit when I got it.
cheers, 
Neville Michie


On 20 Feb 2021, at 08:02, Odell, Edward via groups.io <edward.odell@...> wrote:

Hi Naing, 
 
In the picture you sent with your first post, the movement that you have looks to be an interesting and early example. It does not have an overthrow damper for the gravity arm and it has the early type of latch. These early clocks did not have the later standardised impulse pallet, they had a much shorter curve which was less efficient. It probably does not matter exactly which curve you make for your clock so long as the contacts close before the roller reaches the end of the curve.
However, it would be interesting to know the serial number of your clock. This is stamped into the bottom of the NRA plate. I can make out a 0 in the number but I cannot see the exact number. If the number is very low this could be an interesting movement historically and it would be good if you could let us know the serial number. We might then be able to tell you which design of impulse pallet match the date of your clock
 
Eddy Odell 
 
From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of Stephen Hibbs via groups.io
Sent: 19 February 2021 20:51
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted
 
Hi, Naing,
 
I can’t seem to get Norman’s .jpg to download. Wish I could see it. But as a mechanical engineer who has designed thousands of parts for manufacturing, I have some comments about the .pdf from bailey.services that might simplify its fabrication with no loss of functionality.
 
1. The curved ramp is shown as a segment of the developed surface of a toroid. Again, this could be simplified. If it was simply the surface of a cylinder instead, it could be generated by the simple motion of a milling cutter instead of a complex motion, if you follow me. The roller on the Synchronome’s gravity arm won’t know the difference if it is truly rolling instead of sliding (which it might do if its pivots aren’t sufficiently lubricated). There might be a very slight tendency to twist the pendulum if it rolls down either edge rather than the surface, but I think that would be negligible. If the correct suspension spring is used, it has considerable torsional stiffness and the pendulum bob has huge torsional inertia.
      And I still suspect a straight ramp is as good as a curved one. If I were making this part, I’d make the flat ramp long enough that the roller would land below the top of the ramp and be lifted off before reaching the bottom. This is what Gents’ does and it extracts all the potential energy available in the time the roller and pallet are in contact with each other.
 
2.  I believe the 45-degree facets are intended to act as elastic hinges where thin material embraces the pendulum rod. But they are so long that I’m not convinced that a single 4-40NC screw in brass will be able to generate adequate clamping force around the rod. And the effort to generate enough clamping force will likely strip the female thread, leaving you with no clamping force at all. The safe way out is two screws, though there is still risk of stripping one of the female threads if they are tightened unevenly.
     You’ll likely be starting with .50-inch thick stock, or maybe the nearest metric equivalent. There’s really no need to machine it down to .44 inch thick, nor is there a functional need to machine the two 45-degree facets on the end opposite the ramp; only an aesthetic one. Nor is there a need for the counterbore if those facets are omitted.
 
3.   The .035 dia. thru hole gives the gathering arm a place to be, but I don’t see what keeps it there unless the 2-56NC hole below it is part of a retaining scheme not shown. The original pallet part, of course, has an elegant but complex retaining scheme machined into it that was wisely avoided in this design.
 
4.   The .38 radius on the underside can actually be any radius that’s convenient. It does happen to match the specified radius of the ramp.
 
Kind regards,
Steve
 
Stephen Hibbs
PO Box 536
Markleeville, CA 96120
530-694-1045
oldtimemachines@...
 
 



On Feb 19, 2021, at 1:29 AM, Norman Heckenberg <heckenberg@...> wrote:
 
<pallet.jpg>
 


Re: Synchronome contacts pitted

Odell, Edward
 

Hi Naing,

 

In the picture you sent with your first post, the movement that you have looks to be an interesting and early example. It does not have an overthrow damper for the gravity arm and it has the early type of latch. These early clocks did not have the later standardised impulse pallet, they had a much shorter curve which was less efficient. It probably does not matter exactly which curve you make for your clock so long as the contacts close before the roller reaches the end of the curve.

However, it would be interesting to know the serial number of your clock. This is stamped into the bottom of the NRA plate. I can make out a 0 in the number but I cannot see the exact number. If the number is very low this could be an interesting movement historically and it would be good if you could let us know the serial number. We might then be able to tell you which design of impulse pallet match the date of your clock

 

Eddy Odell

 

From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of Stephen Hibbs via groups.io
Sent: 19 February 2021 20:51
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

 

Hi, Naing,

 

I can’t seem to get Norman’s .jpg to download. Wish I could see it. But as a mechanical engineer who has designed thousands of parts for manufacturing, I have some comments about the .pdf from bailey.services that might simplify its fabrication with no loss of functionality.

 

1. The curved ramp is shown as a segment of the developed surface of a toroid. Again, this could be simplified. If it was simply the surface of a cylinder instead, it could be generated by the simple motion of a milling cutter instead of a complex motion, if you follow me. The roller on the Synchronome’s gravity arm won’t know the difference if it is truly rolling instead of sliding (which it might do if its pivots aren’t sufficiently lubricated). There might be a very slight tendency to twist the pendulum if it rolls down either edge rather than the surface, but I think that would be negligible. If the correct suspension spring is used, it has considerable torsional stiffness and the pendulum bob has huge torsional inertia.

      And I still suspect a straight ramp is as good as a curved one. If I were making this part, I’d make the flat ramp long enough that the roller would land below the top of the ramp and be lifted off before reaching the bottom. This is what Gents’ does and it extracts all the potential energy available in the time the roller and pallet are in contact with each other.

 

2.  I believe the 45-degree facets are intended to act as elastic hinges where thin material embraces the pendulum rod. But they are so long that I’m not convinced that a single 4-40NC screw in brass will be able to generate adequate clamping force around the rod. And the effort to generate enough clamping force will likely strip the female thread, leaving you with no clamping force at all. The safe way out is two screws, though there is still risk of stripping one of the female threads if they are tightened unevenly.

     You’ll likely be starting with .50-inch thick stock, or maybe the nearest metric equivalent. There’s really no need to machine it down to .44 inch thick, nor is there a functional need to machine the two 45-degree facets on the end opposite the ramp; only an aesthetic one. Nor is there a need for the counterbore if those facets are omitted.

 

3.   The .035 dia. thru hole gives the gathering arm a place to be, but I don’t see what keeps it there unless the 2-56NC hole below it is part of a retaining scheme not shown. The original pallet part, of course, has an elegant but complex retaining scheme machined into it that was wisely avoided in this design.

 

4.   The .38 radius on the underside can actually be any radius that’s convenient. It does happen to match the specified radius of the ramp.

 

Kind regards,

Steve

 

Stephen Hibbs

PO Box 536

Markleeville, CA 96120

530-694-1045

 

 



On Feb 19, 2021, at 1:29 AM, Norman Heckenberg <heckenberg@...> wrote:

 

<pallet.jpg>

 


Re: Synchronome contacts pitted

Stephen Hibbs
 

Hi, Naing,

I can’t seem to get Norman’s .jpg to download. Wish I could see it. But as a mechanical engineer who has designed thousands of parts for manufacturing, I have some comments about the .pdf from bailey.services that might simplify its fabrication with no loss of functionality.

1. The curved ramp is shown as a segment of the developed surface of a toroid. Again, this could be simplified. If it was simply the surface of a cylinder instead, it could be generated by the simple motion of a milling cutter instead of a complex motion, if you follow me. The roller on the Synchronome’s gravity arm won’t know the difference if it is truly rolling instead of sliding (which it might do if its pivots aren’t sufficiently lubricated). There might be a very slight tendency to twist the pendulum if it rolls down either edge rather than the surface, but I think that would be negligible. If the correct suspension spring is used, it has considerable torsional stiffness and the pendulum bob has huge torsional inertia.
      And I still suspect a straight ramp is as good as a curved one. If I were making this part, I’d make the flat ramp long enough that the roller would land below the top of the ramp and be lifted off before reaching the bottom. This is what Gents’ does and it extracts all the potential energy available in the time the roller and pallet are in contact with each other.

2.  I believe the 45-degree facets are intended to act as elastic hinges where thin material embraces the pendulum rod. But they are so long that I’m not convinced that a single 4-40NC screw in brass will be able to generate adequate clamping force around the rod. And the effort to generate enough clamping force will likely strip the female thread, leaving you with no clamping force at all. The safe way out is two screws, though there is still risk of stripping one of the female threads if they are tightened unevenly.
     You’ll likely be starting with .50-inch thick stock, or maybe the nearest metric equivalent. There’s really no need to machine it down to .44 inch thick, nor is there a functional need to machine the two 45-degree facets on the end opposite the ramp; only an aesthetic one. Nor is there a need for the counterbore if those facets are omitted.

3.   The .035 dia. thru hole gives the gathering arm a place to be, but I don’t see what keeps it there unless the 2-56NC hole below it is part of a retaining scheme not shown. The original pallet part, of course, has an elegant but complex retaining scheme machined into it that was wisely avoided in this design.

4.   The .38 radius on the underside can actually be any radius that’s convenient. It does happen to match the specified radius of the ramp.

Kind regards,
Steve

Stephen Hibbs
PO Box 536
Markleeville, CA 96120
530-694-1045




On Feb 19, 2021, at 1:29 AM, Norman Heckenberg <heckenberg@...> wrote:

<pallet.jpg>


Re: Synchronome contacts pitted

N Linn
 

Dear Stephen,

Thanks so much for helping me with ideas. 

And to Norman, you provided me a drawing I couldn't find anywhere and that will definitely help me able to make a copy. 

Thanks again dears!

Best wishes,
Naing

On Fri, Feb 19, 2021, 3:59 PM Norman Heckenberg <heckenberg@...> wrote:

Dear Naing,

I have attached a photo of the diagram in F. Hope-Jones, ‘Electric Clocks and how to make them’, Percival Marshall, London, n.d., that shows how to make the pallet.

That book could probably answer many questions for you as it describes how to make the whole clock, and some others.

I hope that helps.

Norman

 

From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of N Linn
Sent: Friday, 19 February 2021 2:59 PM
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

 

Hi Eddy and Stephen,

 

Thank you so much for your kind help and sharing information. I think you are talking about the gathering arm. I also noticed there are listings of the arm and suspension spring on ebay. What i actually needed is the the whole pallet attached to the pensulum rod. I realized it is not easy to get such replacement part and I'm considering to make one by myself and looking for detailed measurement.

 

Attached is the movement which i only have. 

 

Best regards,

Naing

 

 

On Fri, Feb 19, 2021, 12:38 AM Odell, Edward via groups.io <edward.odell=kcl.ac.uk@groups.io> wrote:

Hi Naing,

 

It doesn’t look as though anyone can help you with a CAD drawing, so perhaps this is useful.  The wire is 1/32 inch or 0.8mm steel, one end hammered flat and bent into a loop with 2mm diameter.  The jewel is a 2mm brocot jewel fitted into the loop. The other end is bent at 90 degrees  and the distance between the flat face of the jewel and the centre of the bent wire is 35mm (in most standard clocks).  The bent part is ¼ inch long.

Hope that makes sense without a diagram, I assume you have  a broken one or a picture to copy

 

Eddy Odell

 

 

From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of N Linn via groups.io
Sent: 17 February 2021 05:28
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

 

Dear guys,

 

I'm looking for synchronome pallet details.  Is there any CAD drawing of pallet with the detailed measurements. I need to make a new one as i could get replcement part around me. I'm from Burma. Apologies if my query not related to this discussion but I believed this community can help me huge.

 

Best regards,

Naing 

 

 


--
Naing


--
Naing


Re: Synchronome contacts pitted

Norman Heckenberg
 
Edited

Dear Naing,

I have attached a photo of the diagram in F. Hope-Jones, ‘Electric Clocks and how to make them’, Percival Marshall, London, n.d., that shows how to make the pallet.

That book could probably answer many questions for you as it describes how to make the whole clock, and some others.

I hope that helps.

Norman

 

From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of N Linn
Sent: Friday, 19 February 2021 2:59 PM
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

 

Hi Eddy and Stephen,

 

Thank you so much for your kind help and sharing information. I think you are talking about the gathering arm. I also noticed there are listings of the arm and suspension spring on ebay. What i actually needed is the the whole pallet attached to the pensulum rod. I realized it is not easy to get such replacement part and I'm considering to make one by myself and looking for detailed measurement.

 

Attached is the movement which i only have. 

 

Best regards,

Naing

 

 

On Fri, Feb 19, 2021, 12:38 AM Odell, Edward via groups.io <edward.odell=kcl.ac.uk@groups.io> wrote:

Hi Naing,

 

It doesn’t look as though anyone can help you with a CAD drawing, so perhaps this is useful.  The wire is 1/32 inch or 0.8mm steel, one end hammered flat and bent into a loop with 2mm diameter.  The jewel is a 2mm brocot jewel fitted into the loop. The other end is bent at 90 degrees  and the distance between the flat face of the jewel and the centre of the bent wire is 35mm (in most standard clocks).  The bent part is ¼ inch long.

Hope that makes sense without a diagram, I assume you have  a broken one or a picture to copy

 

Eddy Odell

 

 

From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of N Linn via groups.io
Sent: 17 February 2021 05:28
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

 

Dear guys,

 

I'm looking for synchronome pallet details.  Is there any CAD drawing of pallet with the detailed measurements. I need to make a new one as i could get replcement part around me. I'm from Burma. Apologies if my query not related to this discussion but I believed this community can help me huge.

 

Best regards,

Naing 

 

 


--
Naing


Re: Synchronome contacts pitted

bailey.services@...
 

http://lbpinc.com/Synchronome/78%20Brass%20Impulse%20Pallet%20Machined.PDF

Taken from fdew post 17 Sept 2007 on NAWCC electric clock forum. Links to other drawings also referred to on that web site


Re: Synchronome contacts pitted

Stephen Hibbs
 

Hi again, Naing,

Keep an eye on the “Synchronome" search term on eBay. I have seen the part you need, though it's not there currently.

I’ve also seen much discussion of the profile of the pallet on this forum—the “ramp” that’s engaged by the roller on the gravity arm when it drops. I wonder myself if the exact curve of the profile is really important at all. What made me wonder is that the Gents Pul-Sy-Etic uses a perfectly straight ramp with no curvature at all and it works perfectly well. The fundamental idea, after all, is to transfer a certain amount of potential energy to the pendulum in the available engagement time. I suspect Frank Hope-Jones would strenuously disagree with me, but I really doubt that the profile makes enough difference to justify the complication of a curve. The takeaway for you is that, if you end up making your own pallet, you can at least start making it with a straight ramp instead of a curved one and see how it works. It will simplify the fabrication, as it did for Gents. If it does work and you’re not further concerned with originality, your pallet is finished. If it doesn’t work, you can still convert the ramp to the curve.

And if you pursue this suggestion, I’d like to know how it turns out.

Steve

Stephen Hibbs
PO Box 536
Markleeville, CA 96120
530-694-1045




On Feb 18, 2021, at 7:58 PM, N Linn <naingtlin@...> wrote:

Hi Eddy and Stephen,

Thank you so much for your kind help and sharing information. I think you are talking about the gathering arm. I also noticed there are listings of the arm and suspension spring on ebay. What i actually needed is the the whole pallet attached to the pensulum rod. I realized it is not easy to get such replacement part and I'm considering to make one by myself and looking for detailed measurement.

Attached is the movement which i only have. 

Best regards,
Naing


On Fri, Feb 19, 2021, 12:38 AM Odell, Edward via groups.io <edward.odell=kcl.ac.uk@groups.io> wrote:

Hi Naing,

 

It doesn’t look as though anyone can help you with a CAD drawing, so perhaps this is useful.  The wire is 1/32 inch or 0.8mm steel, one end hammered flat and bent into a loop with 2mm diameter.  The jewel is a 2mm brocot jewel fitted into the loop. The other end is bent at 90 degrees  and the distance between the flat face of the jewel and the centre of the bent wire is 35mm (in most standard clocks).  The bent part is ¼ inch long.

Hope that makes sense without a diagram, I assume you have  a broken one or a picture to copy

 

Eddy Odell

 

 

From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of N Linn via groups.io
Sent: 17 February 2021 05:28
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

 

Dear guys,

 

I'm looking for synchronome pallet details.  Is there any CAD drawing of pallet with the detailed measurements. I need to make a new one as i could get replcement part around me. I'm from Burma. Apologies if my query not related to this discussion but I believed this community can help me huge.

 

Best regards,

Naing 

 

 




-- 
Naing<IMG_20210213_163633.jpg>


Re: Synchronome contacts pitted

N Linn
 

Hi Eddy and Stephen,

Thank you so much for your kind help and sharing information. I think you are talking about the gathering arm. I also noticed there are listings of the arm and suspension spring on ebay. What i actually needed is the the whole pallet attached to the pensulum rod. I realized it is not easy to get such replacement part and I'm considering to make one by myself and looking for detailed measurement.

Attached is the movement which i only have. 

Best regards,
Naing


On Fri, Feb 19, 2021, 12:38 AM Odell, Edward via groups.io <edward.odell=kcl.ac.uk@groups.io> wrote:

Hi Naing,

 

It doesn’t look as though anyone can help you with a CAD drawing, so perhaps this is useful.  The wire is 1/32 inch or 0.8mm steel, one end hammered flat and bent into a loop with 2mm diameter.  The jewel is a 2mm brocot jewel fitted into the loop. The other end is bent at 90 degrees  and the distance between the flat face of the jewel and the centre of the bent wire is 35mm (in most standard clocks).  The bent part is ¼ inch long.

Hope that makes sense without a diagram, I assume you have  a broken one or a picture to copy

 

Eddy Odell

 

 

From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of N Linn via groups.io
Sent: 17 February 2021 05:28
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

 

Dear guys,

 

I'm looking for synchronome pallet details.  Is there any CAD drawing of pallet with the detailed measurements. I need to make a new one as i could get replcement part around me. I'm from Burma. Apologies if my query not related to this discussion but I believed this community can help me huge.

 

Best regards,

Naing 

 

 


--
Naing

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