Need a 376-0144-00


Eric
 

Does anyone have or know how to duplication a 376-0144-00 This is a mechanical shaft coupler used in the 177 fixture. It needs to be insulated up to 1600 Vdc from the collector supply. This is one of the last pieces I need to get a 577 up and running again. I currently do not have a 3d printer so this is not an option for me at the moment.


Michael W. Lynch
 

On Wed, Dec 2, 2020 at 02:28 PM, Eric wrote:


Does anyone have or know how to duplication a 376-0144-00 This is a mechanical
shaft coupler used in the 177 fixture. It needs to be insulated up to 1600 Vdc
from the collector supply. This is one of the last pieces I need to get a 577
up and running again. I currently do not have a 3d printer so this is not an
option for me at the moment.
Eric,

I went to my 177 (JAN/1983) Fixture Mechanical parts manual and I do not see a part listed by that number. Is that extension a part of the switch? Are you sure about that Part #? I see "384-1305-00 EXTENSION SHAFT: 0.494" x 1.2" LONG. W/SHLDR". Perhaps I am overlooking this in the list?

Do you have a dimensional drawing, 3D model, STL File, etc.? One would need to make sure that the 3D printing materials used had the Dielectric strength to insulate 1600V. I can print it if we can determine that the materials that I use have the proper insulation properties.

.
Michael Lynch
Dardanelle, AR


Eric
 

In the mechanical of the 177 service manual I have it is part # 70 it is under the extension shaft it sits between the switch and the shaft that goes to the current per div knob. Apparently collector voltage is on this switch so that is why the need for the insulated coupler.

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Michael W. Lynch via groups.io
Sent: Wednesday, December 2, 2020 4:46 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Need a 376-0144-00

On Wed, Dec 2, 2020 at 02:28 PM, Eric wrote:


Does anyone have or know how to duplication a 376-0144-00 This is a
mechanical shaft coupler used in the 177 fixture. It needs to be
insulated up to 1600 Vdc from the collector supply. This is one of the
last pieces I need to get a 577 up and running again. I currently do
not have a 3d printer so this is not an option for me at the moment.
Eric,

I went to my 177 (JAN/1983) Fixture Mechanical parts manual and I do not see a part listed by that number. Is that extension a part of the switch? Are you sure about that Part #? I see "384-1305-00 EXTENSION SHAFT: 0.494" x 1.2" LONG. W/SHLDR". Perhaps I am overlooking this in the list?

Do you have a dimensional drawing, 3D model, STL File, etc.? One would need to make sure that the 3D printing materials used had the Dielectric strength to insulate 1600V. I can print it if we can determine that the materials that I use have the proper insulation properties.

.
Michael Lynch
Dardanelle, AR


 

On Wed, Dec 2, 2020 at 11:21 PM, Eric wrote:


In the mechanical of the 177 service manual I have it is part # 70
In an older manual it is as you say #70 however this part and #71 were both replaced with
384-1305-00 which is the coupler and shaft in one piece. In a newer manual only the newer
part is shown and then as #72.

/Håkan


Michael W. Lynch
 

/Håkan,

I knew that there was some discrepancy somewhere. I was not seeing anything that looked like a coupler or that part number in my manual. #72 the 384-1305-00 shaft assy. was as close as I could get. I do not have a copy of the older version of the service manual. Thanks for shedding light on this.

--
Michael Lynch
Dardanelle, AR


Michael W. Lynch
 

Eric,

BTW, the Dielectric Strength of my preferred printing material (PETG, See Below) is 45kV/mm so I can print the parts if you can give me some accurate dimensions to work from.
Materials Dielectric Strength (kV/mm) Min Max
PET - Polyethylene Terephthalate 60.00 60.00
PET, 30% Glass Fiber-reinforced 16.80 22.50
PETG - Polyethylene Terephthalate Glycol 45.00 45.00

I'll print it free of charge just cover the cost of shipping.

Should cost next to nothing to ship as it will weigh almost nothing.

Let me know.

--
Michael Lynch
Dardanelle, AR


Ed Breya
 

If you can print fiber reinforced plastics, I'd recommend that. Those couplings need to be pretty strong. Also, the dielectric strength rating is for through the insulating material - that's usually the easy part. What matters is what can go around the insulator, so the dimensions and clearances have to be big enough, and the surfaces as smooth as possible. If the surface is rough, it can break down at lower voltage, especially after a long time collecting dirt and moisture. This shouldn't be too critical for only 1600V, well below corona voltage, so many plastic types should be just fine in this respect. I think it's safe to assume the original part design handled it with plenty of margin, voltage-wise, and the mechanical size is mostly for strength.

Ed


 

On Wed, Dec 2, 2020 at 10:45 PM, Michael W. Lynch wrote:


Do you have a dimensional drawing, 3D model, STL File, etc.?
www.hakanh.com/dl/temp/384-1305-00.pdf

/Håkan


Michael W. Lynch
 

On Thu, Dec 3, 2020 at 07:52 AM, zenith5106 wrote:


On Wed, Dec 2, 2020 at 10:45 PM, Michael W. Lynch wrote:



Do you have a dimensional drawing, 3D model, STL File, etc.?
www.hakanh.com/dl/temp/384-1305-00.pdf


/Håkan
Håkan, Thanks for the PDF, saved me the trouble looking for that information.

Looking at the dimensions in the PDF and other information, so graciously provided, this appears to be a simple straight, stepped shaft with a aluminum insert in the larger end. if this is the case, this could easily be turned on a lathe. No need to 3D print this at all. I would think that nylon rod might be suitable? Nylon is easy to machine and durable.

One piece of information that is missing is dimension "C", which is probably a critical dimension. Strange that in this entire list, this part is the only one that omits Dimension "C"?

If we had dimension "C", the rest of the project would be straightforward. It would take time to build, but completely doable. If someone can provide the original Aluminum insert, then that would make the process less time consuming.

--
Michael Lynch
Dardanelle, AR


SCMenasian
 

I agree. Delrin (acetyl) might be even better than nylon. Nylon and delrin are difficult to bond;
however adhesive systems do exist which would work to bond either to aluminum. It should be easy
to turn the plastic part for a couple of dollars (under a dollar in quantity).


Michael W. Lynch
 

Yes, I agree. DELRIN is my material of choice for such things. I have done several knobs and shafts combining DELRIN with Aluminum inserts. I do not use adhesives, DELRIN has a slight bit of elasticity, with careful fitting, and heating the DELRIN, the aluminum insert can actually be a press fit into the DELRIN. These assemblies typically hold very well without adhesives. I believe that this part could be produced in a similar manner. I am willing to give it a shot. Nothing ventured, nothing gained.

--
Michael Lynch
Dardanelle, AR


Jack2015
 

Hi Eric,

This is my solution,I bought a plastic knob with a metal shaft receptacle,took out the receptacle and locked it
with the shaft of selector(with screw),fixed the plastic shaft with screw glue.it works well.

https://groups.io/g/TekScopes/photo/255563/5?p=Created,,,100,2,0,0
https://groups.io/g/TekScopes/photo/255563/4?p=Created,,,100,2,0,0
https://groups.io/g/TekScopes/photo/255563/3?p=Created,,,100,2,0,0
https://groups.io/g/TekScopes/photo/255563/2?p=Created,,,100,2,0,0
https://groups.io/g/TekScopes/photo/255563/1?p=Created,,,100,2,0,0
https://groups.io/g/TekScopes/photo/255563/0?p=Created,,,100,2,0,0


 

On Thu, Dec 3, 2020 at 03:52 PM, Michael W. Lynch wrote:


If we had dimension "C", the rest of the project would be straightforward.
Oops, should have added that to the text.
C is 0.5"

/Håkan


Eric
 

Yes this part was 2 al inserts with 2 set screws each. There is then a short al shaft that goes up in to the knob and the knob tightens down directly on the shaft. In a later revision of the 177 this was a 1 piece plastic shaft with only one insert. I had the plastic on one of these crumble right at the dimensional transition. It just broke apart in to about 4 pieces. I do think the spacer with 2 inserts and al shaft is the more robust option but I am sure it was more expensive to manufacture. I can provide photos if need when I get back to the lab tonight.

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Michael W. Lynch via groups.io
Sent: Thursday, December 3, 2020 10:48 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Need a 376-0144-00

Yes, I agree. DELRIN is my material of choice for such things. I have done several knobs and shafts combining DELRIN with Aluminum inserts. I do not use adhesives, DELRIN has a slight bit of elasticity, with careful fitting, and heating the DELRIN, the aluminum insert can actually be a press fit into the DELRIN. These assemblies typically hold very well without adhesives. I believe that this part could be produced in a similar manner. I am willing to give it a shot. Nothing ventured, nothing gained.

--
Michael Lynch
Dardanelle, AR


Michael W. Lynch
 

On Thu, Dec 3, 2020 at 10:44 AM, zenith5106 wrote:


Oops, should have added that to the text.
C is 0.5"

/Håkan
Håkan,

Thanks! My guess would have been about .500, but the confirmation is appreciated.

I can make this part from DELRIN, unless that would not be electrically suitable?

--
Michael Lynch
Dardanelle, AR


Eric
 

From a data sheet http://www.sdplastics.com/delrin/delrin[1].pdf it looks like Delrin is 500 V/mil but I will be honest I am quickly getting out of my depth here.

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Michael W. Lynch via groups.io
Sent: Thursday, December 3, 2020 12:13 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Need a 376-0144-00

On Thu, Dec 3, 2020 at 10:44 AM, zenith5106 wrote:


Oops, should have added that to the text.
C is 0.5"

/Håkan
Håkan,

Thanks! My guess would have been about .500, but the confirmation is appreciated.

I can make this part from DELRIN, unless that would not be electrically suitable?

--
Michael Lynch
Dardanelle, AR


Michael W. Lynch
 

On Thu, Dec 3, 2020 at 11:04 AM, Eric wrote:


Yes this part was 2 al inserts with 2 set screws each.
Eric,

I have a very good idea of what is needed and how it should be constructed.

Do you have the lower aluminum insert? As I said previously, I could use that to construct a DELRIN replacement upper shaft. Having the original lower shaft insert simplifies the project. I have made some other knobs and couplers in this same manner. I will be glad to try to help with this work.

I believe that the one piece plastic shaft will be electrically safer and suitably robust as well. Connecting two pieces of aluminum with a plastic collar is not the best design. DELRIN is more than strong enough to serve as a shaft for that switch. It should not take that much torque to operate that switch. If if does take a lot of force, there is something amiss with the switch.

Let me know.



--
Michael Lynch
Dardanelle, AR


Eric
 

If I remember correctly the lower aluminum shaft is the switch shaft its self the upper one is just a chunk of round stock.

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Michael W. Lynch via groups.io
Sent: Thursday, December 3, 2020 12:22 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Need a 376-0144-00

On Thu, Dec 3, 2020 at 11:04 AM, Eric wrote:


Yes this part was 2 al inserts with 2 set screws each.
Eric,

I have a very good idea of what is needed and how it should be constructed.

Do you have the lower aluminum insert? As I said previously, I could use that to construct a DELRIN replacement upper shaft. Having the original lower shaft insert simplifies the project. I have made some other knobs and couplers in this same manner. I will be glad to try to help with this work.

I believe that the one piece plastic shaft will be electrically safer and suitably robust as well. Connecting two pieces of aluminum with a plastic collar is not the best design. DELRIN is more than strong enough to serve as a shaft for that switch. It should not take that much torque to operate that switch. If if does take a lot of force, there is something amiss with the switch.

Let me know.



--
Michael Lynch
Dardanelle, AR


Michael W. Lynch
 

On Thu, Dec 3, 2020 at 11:19 AM, Eric wrote:


From a data sheet http://www.sdplastics.com/delrin/delrin [1].pdf it looks
like Delrin is 500 V/mil but I will be honest I am quickly getting out of my
depth here.
Eric,

I think that the 1/2+ inch of solid DELRIN for an upper switch shaft will definitely be less conductive than using the upper aluminum shaft of the original design.

Do you still have that lower insert with the two set screws? If I had that part, it would be a simple matter to make the rest work. I have all the other necessary dimensions.

--
Michael Lynch
Dardanelle, AR


 

The vintageTEK Museum has several of what I believe are the 384-1305-00. We ask $10 postpaid. I will post a photo as soon as I figure out how.

--
Bob Haas