Re: DC Power sources for a 1920's Synchronome master & Current Regulation?

James

Hi Ian,

In your thoughts below you comment There is something to be said for using a voltage higher than the minimum required and controlling the current with an appropriate series resistor”  For my system (Master with ten slave dials) I have used a buck converter to adjust the voltage and don’t adjust the resistance.  As we all know, using ohms law, we can get 330mA by adjusting either voltage or resistance.  I have gone with voltage adjustment and have no added resistance in the circuit.

If I was to increase the voltage and then adjust the resistance what differences/benefits would their be?

Thanks,

James G

Somewhere in New Zealand

Sent from Mail for Windows 10

From: Ian Richardson via groups.io
Sent: Wednesday, 3 March 2021 7:53 am
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] DC Power sources for a 1920's Synchronome master & Current Regulation?

I may be preaching to the converted, but clock systems such as the Synchronome are current controlled, and the recommended current through the system is 330mA.  The voltage applied will be dependent upon the number (and type) of slave dials in the series circuit. There is something to be said for using a voltage higher than the minimum required, and controlling the current with an appropriate series resistor.  In my house circuit, which includes a Synchronome (with 4 slaves) and a Gent (with 4 slaves and a programme unit) everything runs from a 50 v.d.c. supply.  I use physics lab type rheostats to control the current in each circuit to the relevant required values.

The current is not that critical and can be lower than the specified value, but ideally should not be too high otherwise the reset becomes a bit violent (and noisy!).  As Andrew pointed out, the adjustment of the air gaps in the master clock (and the slave dial mechanisms) should all be correct for reliable operation.  Should the current be too low, there is a "warning" given by the master clock in that the gravity arm will not reset promptly, but be helped by being nudged by the returning impulse pallet.  This is clearly audible both at the master clock and at any slaves in the circuit as, instead of a prompt "click" each half minute, there will be a prolonged click as the reset current starts and then ends about 1/2 second later.  Synchronome and Gent both produced a device called a "battery warning indicator" which sounded a bell or gong if the reset duration was too long.

Don't know if any of that helps, but I hope so.

Cheers,

Ian R

Somewhere in France

-----Original Message-----
From: Andrew Nahum <andrew.nahum@...>
To: synchronome1@groups.io
Sent: Tue, 2 Mar 2021 18:00
Subject: Re: [synchronomeelectricclock] DC Power sources for a 1920's Synchronome master & Current Regulation?

I use 2 Duracells in series and the clock works well but it has to be in good adjustment on all the contact arm gaps etc. They last about a year. My impression is that more volts give more noise.

Andrew

On Tue, Mar 2, 2021 at 3:54 PM John Hubert <jfphubert@...> wrote:

The master draws 300 - 350 mA …….. but the duty cycle is low; approximately 100 - 150 mS every 30 seconds, so the average is low.

J

On 2 Mar 2021, at 15:31, Thomas D. Erb <tde@...> wrote:

I'm not familiar with this type of master - but if it is really voltage-sensitive you can also use a diode - each diode will subtract .7 volts from the power supply.

alkaline batteries nominal voltage is 1.5VDC so 3 in series would give you 4.5VDC.

If the master really draws 350ma - you would'nt get a lot of life -

A D cell battery will give you 12000-18000 mAh

12000/350=34.2857 to 18000/350=51.4286

so between 34 and 50 hours of run time.

Re: DC Power sources for a 1920's Synchronome master & Current Regulation?

Ian Richardson

I may be preaching to the converted, but clock systems such as the Synchronome are current controlled, and the recommended current through the system is 330mA.  The voltage applied will be dependent upon the number (and type) of slave dials in the series circuit. There is something to be said for using a voltage higher than the minimum required, and controlling the current with an appropriate series resistor.  In my house circuit, which includes a Synchronome (with 4 slaves) and a Gent (with 4 slaves and a programme unit) everything runs from a 50 v.d.c. supply.  I use physics lab type rheostats to control the current in each circuit to the relevant required values.

The current is not that critical and can be lower than the specified value, but ideally should not be too high otherwise the reset becomes a bit violent (and noisy!).  As Andrew pointed out, the adjustment of the air gaps in the master clock (and the slave dial mechanisms) should all be correct for reliable operation.  Should the current be too low, there is a "warning" given by the master clock in that the gravity arm will not reset promptly, but be helped by being nudged by the returning impulse pallet.  This is clearly audible both at the master clock and at any slaves in the circuit as, instead of a prompt "click" each half minute, there will be a prolonged click as the reset current starts and then ends about 1/2 second later.  Synchronome and Gent both produced a device called a "battery warning indicator" which sounded a bell or gong if the reset duration was too long.

Don't know if any of that helps, but I hope so.

Cheers,
Ian R
Somewhere in France

-----Original Message-----
From: Andrew Nahum <andrew.nahum@...>
To: synchronome1@groups.io
Sent: Tue, 2 Mar 2021 18:00
Subject: Re: [synchronomeelectricclock] DC Power sources for a 1920's Synchronome master & Current Regulation?

I use 2 Duracells in series and the clock works well but it has to be in good adjustment on all the contact arm gaps etc. They last about a year. My impression is that more volts give more noise.
Andrew

On Tue, Mar 2, 2021 at 3:54 PM John Hubert <jfphubert@...> wrote:
The master draws 300 - 350 mA …….. but the duty cycle is low; approximately 100 - 150 mS every 30 seconds, so the average is low.

J

On 2 Mar 2021, at 15:31, Thomas D. Erb <tde@...> wrote:

I'm not familiar with this type of master - but if it is really voltage-sensitive you can also use a diode - each diode will subtract .7 volts from the power supply.

alkaline batteries nominal voltage is 1.5VDC so 3 in series would give you 4.5VDC.

If the master really draws 350ma - you would'nt get a lot of life -
A D cell battery will give you 12000-18000 mAh
12000/350=34.2857 to 18000/350=51.4286

so between 34 and 50 hours of run time.

Re: DC Power sources for a 1920's Synchronome master & Current Regulation?

Andrew Nahum

I use 2 Duracells in series and the clock works well but it has to be in good adjustment on all the contact arm gaps etc. They last about a year. My impression is that more volts give more noise.
Andrew

On Tue, Mar 2, 2021 at 3:54 PM John Hubert <jfphubert@...> wrote:
The master draws 300 - 350 mA …….. but the duty cycle is low; approximately 100 - 150 mS every 30 seconds, so the average is low.

J

On 2 Mar 2021, at 15:31, Thomas D. Erb <tde@...> wrote:

I'm not familiar with this type of master - but if it is really voltage-sensitive you can also use a diode - each diode will subtract .7 volts from the power supply.

alkaline batteries nominal voltage is 1.5VDC so 3 in series would give you 4.5VDC.

If the master really draws 350ma - you would'nt get a lot of life -
A D cell battery will give you 12000-18000 mAh
12000/350=34.2857 to 18000/350=51.4286

so between 34 and 50 hours of run time.

Re: DC Power sources for a 1920's Synchronome master & Current Regulation?

John Hubert

The master draws 300 - 350 mA …….. but the duty cycle is low; approximately 100 - 150 mS every 30 seconds, so the average is low.

J

On 2 Mar 2021, at 15:31, Thomas D. Erb <tde@...> wrote:

I'm not familiar with this type of master - but if it is really voltage-sensitive you can also use a diode - each diode will subtract .7 volts from the power supply.

alkaline batteries nominal voltage is 1.5VDC so 3 in series would give you 4.5VDC.

If the master really draws 350ma - you would'nt get a lot of life -
A D cell battery will give you 12000-18000 mAh
12000/350=34.2857 to 18000/350=51.4286

so between 34 and 50 hours of run time.

Re: DC Power sources for a 1920's Synchronome master & Current Regulation?

Thomas D. Erb

I'm not familiar with this type of master - but if it is really voltage-sensitive you can also use a diode - each diode will subtract .7 volts from the power supply.

alkaline batteries nominal voltage is 1.5VDC so 3 in series would give you 4.5VDC.

If the master really draws 350ma - you would'nt get a lot of life -

A D cell battery will give you 12000-18000 mAh

12000/350=34.2857 to 18000/350=51.4286

so between 34 and 50 hours of run time.

Re: DC Power sources for a 1920's Synchronome master & Current Regulation?

John Hubert

OK, what I actually do is quite different as I have a large system with a distribution board etc.

If you have no risk/worry over power cuts, then a ‘wall wart’ type adaptor is fine.  If you get power cuts and with to run through then, then there must be a battery involved.  What I would (probably, and actually do for a single Silent Electric master running one salve dial) do for one clock is this;

Use a battery made up of AA cells (NiMh) - probably 4 cells if I was using no external slaves.  Use a 6 Volt (or slightly more if you have an old one to hand - I often use old redundant mobile phone chargers) ‘wall wart’ in series with a resistor to trickle charge the battery (charge at about 50 mA or less).  Run the clock from the battery, limiting the current to 300 - 330 mA with a suitable resistor. It is important that you think about getting the correct CURRENT - and use whatever Voltage needed to do that (typically about 4.5 Volts).   It will run for some days, even weeks on AA cells in the event of a power outage, but they are the most plentiful variety of rechargeable cell.

D cells are fine, and I do run a Bentley clock on a single D cell, where it runs happily for over a year.

Synchronome didn’t usually have a variable resistor fitted (though some late ones do.  Gents generally do have a variable resistor.

John

On 2 Mar 2021, at 10:07, Chris Wollaston <chris@...> wrote:

I'm still in the process of setting up my first Synchronome master and fortunately have found a supplier of a pukka pendulum & bob to replace the incorrect ones that came with it.  Now I'd welcome advice on what owners use for the DC supply for just the movement & it's integral clock?  I've been using a mains adaptor giving 5.2VDC at max 1A which I believe is too much as Miles mentions the set up voltage is 4.5VDC and 350mA.  My architectural case did not come fitted with a rheostat and again Miles doesn't show that 1920's models with any fitted current regulators inside the case.  Would 3 x D cells in series be adequate and last a decent time span, say a year+ and how do readers regulate their current? Rgds, Chris in E Sussex.

Re: DC Power sources for a 1920's Synchronome master & Current Regulation?

H Hal

Hi Chris,

Just because a power supply states 1A doe not mean it will pump out this much current and burn up a circuit.....assuming your circuit is sound

The circuit will draw the current it requires, providing the voltage is large enough to push it through the circuit.

5.2 is not hugely more than 4.5V

Ideally you would measure the current running through your circuit by feeding the current from the power supply through an ammeter (cheap digital ones are plentiful) then into the circuit.

To control the current ...reduce it...you need some form of resistance. You can use a variable resistor (chunky 2,3 or 4 Watts should do so it does not overheat) to tweak it until the 350mA is obtained, measure the value of the variable resistor (cheap digital multimeter used to measure current) and substitute the variable with a fixed resistor/s if you want, or keep the variable in the circuit to tweak in the future.

hal

On 02/03/2021 10:07, Chris Wollaston wrote:
I'm still in the process of setting up my first Synchronome master and fortunately have found a supplier of a pukka pendulum & bob to replace the incorrect ones that came with it.  Now I'd welcome advice on what owners use for the DC supply for just the movement & it's integral clock?  I've been using a mains adaptor giving 5.2VDC at max 1A which I believe is too much as Miles mentions the set up voltage is 4.5VDC and 350mA.  My architectural case did not come fitted with a rheostat and again Miles doesn't show that 1920's models with any fitted current regulators inside the case.  Would 3 x D cells in series be adequate and last a decent time span, say a year+ and how do readers regulate their current? Rgds, Chris in E Sussex.

Re: DC Power sources for a 1920's Synchronome master & Current Regulation?

Chris Wollaston

I'm still in the process of setting up my first Synchronome master and fortunately have found a supplier of a pukka pendulum & bob to replace the incorrect ones that came with it.  Now I'd welcome advice on what owners use for the DC supply for just the movement & it's integral clock?  I've been using a mains adaptor giving 5.2VDC at max 1A which I believe is too much as Miles mentions the set up voltage is 4.5VDC and 350mA.  My architectural case did not come fitted with a rheostat and again Miles doesn't show that 1920's models with any fitted current regulators inside the case.  Would 3 x D cells in series be adequate and last a decent time span, say a year+ and how do readers regulate their current? Rgds, Chris in E Sussex.

Re: Count wheel & backstop roller & Pendulum length to bob?

Richard Kemp

If you need to make an new bob its not too difficult. I recently restored an ECS master that was missing its bob. I made a replacement quite easily. I purchased a short length of cylindrical steel of the correct diameter from ebay and got a friend with a lathe to center drill it (with an extra long drill bit also purchased cheaply on ebay) and round the corners. The original bob on an ECS is cast iron, but given the density of cast iron and steel are very similar I  just duplicated the dimensions as close as I could. I spray painted the new bob in black crackle finish paint and it looks good and works perfectly. The clock is very stable (dare I say, better than my synchronome!) and is regulated with the nut about half way up the threaded rod - so I guess I got it about right.
Richard

Re: Count wheel & backstop roller & Pendulum length to bob?

John Hubert

You will have to try it.  It is entirely possible the bob is a replacement, but the weight is not ‘critical’.  The rod itself is quite light, so the bob dominates the CoG.  You might have to extend the threaded section at the rating nut end if it has been snapped short, but that is easy.  I believe it is 4 BA threaded rod/stud/bar - widely available in longish lengths quite cheaply.  6 inch and 12 inch lengths of 4 BA threaded bar (note bar or stud is a better search term) are available on eBay for under £10.

John

On 23 Feb 2021, at 16:05, Chris Wollaston <chris@...> wrote:

Hi, well, I may be in a bit of a pickle here with this pendulum and bob. The facts are:
Bob weight = 9.25lbs, dimensions of bob: Ht = 15.4cm,  Dia = 6.2 cm
Invar steel rod length - w/o threaded adjuster, just rod to steel top clamp, not with suspension spring = 102cm
So, is it likely that the CofG is going to be very much different to a 16lb bob on a standard Invar rod of say 108cm that an acquaintance has on a Synchronome master and hence the time period for each swing way out of standardisation?
i.e. Is it likely that this pendulum and bob are for a different clock altogether?
If it isn't going to keep anywhere like correct time then how do I source the correct pendulum and bob?

Re: Count wheel & backstop roller & Pendulum length to bob?

Chris Wollaston

Hi, well, I may be in a bit of a pickle here with this pendulum and bob. The facts are:
Bob weight = 9.25lbs, dimensions of bob: Ht = 15.4cm,  Dia = 6.2 cm
Invar steel rod length - w/o threaded adjuster, just rod to steel top clamp, not with suspension spring = 102cm
So, is it likely that the CofG is going to be very much different to a 16lb bob on a standard Invar rod of say 108cm that an acquaintance has on a Synchronome master and hence the time period for each swing way out of standardisation?
i.e. Is it likely that this pendulum and bob are for a different clock altogether?
If it isn't going to keep anywhere like correct time then how do I source the correct pendulum and bob?

Re: Count wheel & backstop roller & Pendulum length to bob?

John Hubert

I have just had an (approximate) as they are running measure.

Clock No 1 - Lead bob about 16 lbs I believe - fitted with light early type weight tray.  Approx 90 cm from top of lower brass suspension block to top of bob
Clock No 2 -Steel bob - 16 lbs nominal - fitted with heavier pattern weight tray and seconds trip.  Again approx 90 cm from top of lower brass suspension block to top of bob

Both these clocks are running.

I can’t remember what the thread should be - but 8 BA is too small.  Mine is 4BA (about 3.5mm outside diameter) and the threaded section is approx 65mm with about 12mm unthreaded and reduced diameter unthreaded at the bottom.  These thread into the invar rod which has a female thread.  The bob should be nominally about 16 lbs.  On looking at a ’spare’ rod, there is no notch/mark.

John

On 23 Feb 2021, at 14:43, Chris Wollaston <chris@...> wrote:

Hi John, Many tks for the info on various bobs and pendulum lengths. My pendulum doesn't have a weights tray and sadly, someone must have dropped the pendulum and snapped off a length of the 8BA? threaded end on which the brass rating nut travels. Thus, I've 41mm of thread sticking out the bottom of the rod but no record of how long it should be when intact?  The cylindrical brass bob weighs 4.4kg approx 9.25lbs and looks authentic so a very rough measurement guide from the top of the brass block above the suspension spring to the top of the bob would be a useful start? I'm suggesting 92cm, what do you reckon? Chris

Re: Count wheel & backstop roller & Pendulum length to bob?

Chris Wollaston

Correction, the bob weighs 4.2kg

Re: Count wheel & backstop roller & Pendulum length to bob?

Chris Wollaston

Hi John, Many tks for the info on various bobs and pendulum lengths. My pendulum doesn't have a weights tray and sadly, someone must have dropped the pendulum and snapped off a length of the 8BA? threaded end on which the brass rating nut travels. Thus, I've 41mm of thread sticking out the bottom of the rod but no record of how long it should be when intact?  The cylindrical brass bob weighs 4.4kg approx 9.25lbs and looks authentic so a very rough measurement guide from the top of the brass block above the suspension spring to the top of the bob would be a useful start? I'm suggesting 92cm, what do you reckon? Chris

Re: Count wheel & backstop roller & Pendulum length to bob?

John Hubert

The ‘notch’ is really a little file cut - and I don’t think it was always used, but I have seen it on some of my clocks.  It was not very accurate because things varied.  A variety of bob shapes and variations have been used; normal and shell type (at least two versions of shell type), iron/steel, lead, brass, possible other combinations (I have heard suggested brass case, lead fill).  In addition - various other ‘additions’ are occasionally used on the rod; weight trays are common, seconds switch ’trip’ is used on seconds clocks, synchroniser spring assembly is used on a few clocks etc, so it is only a very approximate mark for initial set up.  If you start by putting the rating nut about half way up the available thread, you will soon find you can work from there.  As you get close - you have to take more time, but the initial ‘coarse’ adjustment can be done simply by comparison with a seconds equipped radio controlled clock and typical can be got within a minute a day or so quite easily.  More patience is needed for the fine adjustment!  Very fine ’trimming’ can be achieved by a 4 or 6 BA washer (or two) on the bob top.

John

On 23 Feb 2021, at 13:36, Chris Wollaston <chris@...> wrote:

Hi, I've just fitted my backstop glass roller but it persisted in remaining in front of the Y-bracket thus not held in place and at risk of falling off and disappearing under the furniture (for a second time) so I've bent the backstop wire hopefully sufficiently to tuck one edge of the roller just behind the bracket. The next task is to get the count-wheel vane just a few thou from the latch as per the picture in Bob Miles' tome, p.238, because at the mo it's some way off.
Also, I read somewhere, either tvtesla or the manual that the pendulum's Invar steel rod is supposed to have a 'notch' showing where the top of the bob should be placed. Mine has no notch, just some oxidation roughly in the right place so can anyone give me a measurement from the top of the trunnion's upper brass block to top of bob please? Tks, Chris in E Sussex

Re: Count wheel & backstop roller & Pendulum length to bob?

Chris Wollaston

Hi, I've just fitted my backstop glass roller but it persisted in remaining in front of the Y-bracket thus not held in place and at risk of falling off and disappearing under the furniture (for a second time) so I've bent the backstop wire hopefully sufficiently to tuck one edge of the roller just behind the bracket. The next task is to get the count-wheel vane just a few thou from the latch as per the picture in Bob Miles' tome, p.238, because at the mo it's some way off.
Also, I read somewhere, either tvtesla or the manual that the pendulum's Invar steel rod is supposed to have a 'notch' showing where the top of the bob should be placed. Mine has no notch, just some oxidation roughly in the right place so can anyone give me a measurement from the top of the trunnion's upper brass block to top of bob please? Tks, Chris in E Sussex

Re: Count wheel & backstop roller

Andrew Nahum

In mine there is a c shaped clip or circlip that retains the roller. Is there a groove around the wire you can see under a glass?

On Mon, Feb 22, 2021 at 3:41 PM 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

Re: Synchronome contacts pitted

James Kelly

Hi all

An eBay search for either glass cylinder bead or glass tube bead brings up a vast array of glass beads some of which may be suitable as a roller

Jim

On 22 Feb 2021, at 18:40, Ian Richardson via groups.io <irichar361@...> wrote:

﻿
If you can find some, glass capillary tubing will do the trick.  I made one a few years ago, but I've no idea where the glass tube is now!

Failing that, a piece of silver steel of the correct diameter can easily be drilled.  It could then be made dead hard by heating it red hot and quenching in cold water.  It should then be polished - I made a gathering "jewel" this way a few years ago as a temporary measure, and it's still there doing a good job.

Otherwise, I agree with everything John said about adjustment and running dry.  The effective weight of the glass roller can be varied by winding fine wire around the counterbalancing arm.

Good luck, and welcome to the club!

Ian R
France

-----Original Message-----
From: Andrew Nahum <andrew.nahum@...>
To: synchronome1@groups.io
Sent: Mon, 22 Feb 2021 19:16
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

﻿
﻿ 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: Synchronome contacts pitted

Ian Richardson

If you can find some, glass capillary tubing will do the trick.  I made one a few years ago, but I've no idea where the glass tube is now!

Failing that, a piece of silver steel of the correct diameter can easily be drilled.  It could then be made dead hard by heating it red hot and quenching in cold water.  It should then be polished - I made a gathering "jewel" this way a few years ago as a temporary measure, and it's still there doing a good job.

Otherwise, I agree with everything John said about adjustment and running dry.  The effective weight of the glass roller can be varied by winding fine wire around the counterbalancing arm.

Good luck, and welcome to the club!

Ian R
France

-----Original Message-----
From: Andrew Nahum <andrew.nahum@...>
To: synchronome1@groups.io
Sent: Mon, 22 Feb 2021 19:16
Subject: Re: [synchronomeelectricclock] Synchronome contacts pitted

﻿
﻿ 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: Synchronome contacts pitted

John Hubert

Perspex works well and is easy to work.  It also looks almost indistinguishable from glass.  You can buy a rod of perspex very reasonably and make the rollers in a small lathe.  Glass is more difficult, but can be done.  I have not seen any for sale.

On 22 Feb 2021, at 18:16, Andrew Nahum <andrew.nahum@...> wrote:

﻿
﻿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

 61 - 80 of 1200