Worn out pinion

[bpd]

This pinion is on the center wheel of an Ingraham desk clock from 1937. Is there any hope for this pinion other than replacing it? The clock runs but lacks power and stops frequently. I tried to see if I could move the pinion or great wheel to an undamaged area but don’t see a way to do that.

 

[Keith Doster]

Time for a sacrificial movement from eBay. Unless someone here has that movement in their bone yard.

 

[R. Croswell]

This pinion is on the center wheel of an Ingraham desk clock from 1937. Is there any hope for this pinion other than replacing it? The clock runs but lacks power and stops frequently. I tried to see if I could move the pinion or great wheel to an undamaged area but don’t see a way to do that.

View attachment 737873

That pinion is pretty used up. Any chance that you can remove the pinion and turn it bottom side up and put it back in placed? It certainly is a contributing factor to the stopping problem, but I expect this is not the only point of wear in this old movement.

RC

 

[Bernhard J.]

I never saw a pinion like that

 

[gmorse]

Hi Bernhard,

This is a perfect illustration of a soft brass wheel cutting a steel pinion to pieces; counterintuitive but that's what happens.

Regards,

Graham

 

[Thomas Sanguigni]

This is a perfect illustration of a soft brass wheel cutting a steel pinion to pieces; counterintuitive but that's what happens.

Over the years, the brass becomes charged with the steel particles and it becomes an abrasive to the steel. It is hard to believe, but true. You can really see this on recoil escapement anchors.

 

[bpd]

Thank you all for the comments. Below is a picture of the other end of the pinion. I did replace six bushings and worked on polishing the balance wheel cups but the cups did have bad wear damage inside. I think I will try to turn the pinion over if I can get it apart.

 

[Willie X]

Main wheels can often be moved a bit.

If you have a lathe, the back pivot's shoulder can be necked down about 1mm (to match the pivot) and the other end washered a bit. And, you would probably need a bushing on the end, where you machined the pivot's shoulder. This is a sound repair, if (big if) the move won't cause further problems. You've got to do a lot of 'figuring' when you move something in a clock movement. Willie X

 

[bpd]

Thank you Willie. I had not thought about moving the main wheel but I can see where it could be moved. I think it is going to take a lot of staring and thinking to figure out what will work. A lot of work for a cheap desk clock but it’s fun when the solution works and disappointing when it doesn't.

 

[Dells]

What’s wrong with replacing it with the correct size pinion wire if it’s part of the arbor just turn it down and drill pinion wire for a friction fit, I did a Westminster chime that had a broken leaf like it and it worked a treat.
Dell

 

[bpd]

Dell, I’m not sure I understand what you did. This pinion is a separate gear attached to the brass wheel and they slip on the minute arbor to be able to set the time.

 

[R. Croswell]

Other options may (or may not) become clearer if we could see pictures of this part out of the clock.

RC

 

[bpd]

Ok if the fix I tried does not work I will take it apart and get more pictures. I put a brass spacer between the center wheel and the brass collet next to it. That moved the contact point of the great wheel down a little ( I hope its enough) on the pinion. I was able to compress the spring and slide the spacer in place without pulling the tight friction pieces off. I could not use a thicker spacer because of the mesh between the center wheel and the next wheel lantern pinion. I also looked at willie's idea of working on the great wheel arbor but I can’t go towards the back because the mainspring is close to the plate and to go the other way would bring the threads of the winding key into the back plate. I still may try it with a longer bushing if this first fix does not work.

 

[Dells]

Pinion wire comes in all sorts of sizes and leaf count , in my case I had to press fit to arbor but it could also be made to be a snug slip fit.

 

[bpd]

Thank you Dell. Now I understand and that gives me another option to try.

 

[Uhralt]

Pinion wire comes in all sorts of sizes and leaf count , in my case I had to press fit to arbor but it could also be made to be a snug slip fit.

View attachment 738149

Where do you source the pinion wire? I didn't have luck so far to find what I needed.

Uhralt

 

[Willie X]

It has poped up from time to time in the US but I think it is more available on the other side of th pond. A lot of the clocks they deal with are 200 to 300 years old.
My 2, Willie X

 

[Dells]

Where do you source the pinion wire? I didn't have luck so far to find what I needed.

Uhralt

I think this company is in USA

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

And this

Pinion Wire and Pinion Rod Manufacturers in MA | UtilityMFG

Utility MFG is a pioneer in manufacturing cold drawn Pinion Rods and wires in Massachusetts. Cold drawn process makes them much stronger. Call us for a quick quote.

utilitymfg.com

 

[Uhralt]

I think this company is in USA

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

And this

Pinion Wire and Pinion Rod Manufacturers in MA | UtilityMFG

Utility MFG is a pioneer in manufacturing cold drawn Pinion Rods and wires in Massachusetts. Cold drawn process makes them much stronger. Call us for a quick quote.

utilitymfg.com

Thank you so much!

Uhralt

 

[Jim DuBois]

Much of the pinion rod/wire is of an involute tooth profile than the more desirable cycloid form generally found in clocks. I acquired a number of pieces of pinion wire many years ago and have never used any of it. It is either a bit too large or too small or doesn't mesh well with the mating wheel due to the profile incompatibility between the two forms. Sometimes the two wheel/pinion forms can be used together but getting them to work together would require changing the center distances between the two parts, and that opens up an entirely new set of issues. If I were engineering a less precision clock from a blank sheet of paper I suspect pinion wire and involute wheels could work well.

 

[Vernon]

Jim brings up a point. perhaps for the occasional part, someone that can cut teeth for a wheel could make a pinion.
Vernon

 

[Dells]

You would need pinion wire the meshes with the wheel so you would need it specifically for clocks, lots of old stock available over here but not sure about USA.

 

[Willie X]

If the steel (damaged gear) slips against the brass gear, just hold everything else as you have it, and put a thin steel washer between the damaged gear and the steel gear. That should get you the distance you need.

That pressed on brass collar, holding the spring in tension, will probably come off easy enough.

I have had the same experience as Jim with the pinion wire.

Willie X

 

[bpd]

The spacer idea did not work. Due to end shake, the Great wheel can still fall into the center wheel pinion notches. Y’all have given me several other options that I am going to try.

 

[JimmyOz]

The spacer idea did not work. Due to end shake, the Great wheel can still fall into the center wheel pinion notches. Y’all have given me several other options that I am going to try.

You can adjust the end shake by bushing both plates, one past the inside of the plate and the other recessed on the inside of the other plate, if the plates are a bit thin you can put a bush in a bush, the outside bush being longer than the inside bush, therefore a recess can be achieved on the inside of one plate and the other can be proud.

 

[bpd]

Thank you JimmyOz. I will add this to my list of possible fixes. I may have to use a combination of ideas so I don’t mess up the mesh of the other wheels.

 

[shutterbug]

I think you have three options. Get a donor movement, reverse the pinion direction (turn it upside down) or move the connecting wheel so it hits in a different place.

 

[bpd]

I was going to turn the pinion over but was not sure how good I would be at staking the pinion back on the center wheel so, I removed one of three brass collets between the center wheel and the front plate. This moved the damaged pinion closer to the front plate. Then added a washer ( since I did not have a bushing big enough ) to the front pivot of the mainspring arbor to move it slightly back from the front plate. There was quite a bit of end shake in this arbor. It looks like there is now plenty of gap between the great wheel and the notches in the center pinion. All the other wheels and pinions look like they are meshing and have end shake. It is running now so I will watch it for awhile and see how it does. If this fixes it, I will go back in later and replace the mainspring arbor washer with a slightly proud bushing.

 

[Jim DuBois]

A person who cuts wheels and pinions could certainly make a new part in a lot less time than has been invested here by several parties. It might not appear cheap, but only unless we count our time as worth nothing. For the want of a horseshoe nail, the kingdom was lost?

 

[JimmyOz]

For the want of a horseshoe nail, the kingdom was lost?

Maybe if the King had asked for the farrier's advice it could have been saved

 

[Jim DuBois]

Cutting pinions is not all that difficult. Here is my overrun/scrap/extra assortment.

 

[JimmyOz]

Cutting pinions is not all that difficult. Here is my overrun/scrap/extra assortment.

It is like any skill, it can be learned, "IF" you have the right equipment, unfortunately I do not, however if I can't find a work around I would have to pass it on to someone who has.

 

[Jim DuBois]

It is like any skill, it can be learned, "IF" you have the right equipment, unfortunately I do not, however if I can't find a work around I would have to pass it on to someone who has.

They can in fact be made with a hack saw and a lot of filing using several small files. I don't choose to do them that way but I did make one that way just to prove to myself I could do it. And it worked and looked pretty good in a late 17th century device. It was pretty rough and so was my work. But it fit right in

 

[Rob Martinez]

Cutting pinions is not all that difficult. Here is my overrun/scrap/extra assortment.

View attachment 738295

NOTE - when first posting this I didn't see the newly posted hand method above. Accordingly, If I was going to mechanize the process, what tooling up would be needed to cut a pinion? Lathe? Mill? I believe Sherline has a wheel cutting attachment for their lathe? Anything else I would need? Not looking to pop anyone's balloons here. I am actually looking to do this and would like opinions on a shopping list!

 

[Rob Martinez]

You would need pinion wire the meshes with the wheel so you would need it specifically for clocks, lots of old stock available over here but not sure about USA.

Looking at the Pinion Wire sources listed above (and the sub-sources the above sources sent me to) it appears the likely issue with pinion wire not working for us is something called "Pitch" (Pitch Inch?). Any idea what "pitch" the stuff in the U.K. is? With the "Pitch" options I have seen here I would think we could match what you have over there....

 

[Jim DuBois]

Pitch is used in involute gearing. Clocks use cycloidal tooth patterns 99.9% of the time. Cycloidal wheels do not have a pitch. And to cut pinions or wheels, one needs a method of indexing the wheel or pinion blanks, some form of a cutter, be it a multi-tooth or a fly cutter, and a device to spin the cutter. I prefer cutting wheels and pinions on a mill, but a lathe is still necessary to bring the work material to the proper diameter, drill a hole in the center when doing wheels etc.

 

[shutterbug]

I think our OP did well. The proper equipment would be overkill unless he's planning on going into business, and having a pinion cut would be costly too. His work around will work for another 50 years, and by then it won't matter

 

[bpd]

Well here it is up and running. Thank you all for the comments. All of this discussion helps me to learn more about clocks and repair. I am a firm believer in learning by repetition . So if I have to take it apart 10 times to try different things that’s ok.

 

[bpd]

I forgot the picture