need cannon pinion gear

[gregoryjohn]

Hi All,

Well, I've done it this time. Had a cracked pinion gear from a t/s Gilbert movement. I tried soldering it and well..... let's just say the gear is toast. :mysad:
I hate asking but I am hoping someone might have a spare gear in their parts bin.
The gear had 10 teeth, was .338 in diameter (measured across the tips of opposing teeth) and had a bore of .107 - .110 (hard to tell due to the crack). The arbor measures .110 .

Here is a photo of the movement and gear.

If anyone has one for sale please let me know.

Thank you,
Greg

[harold bain]

Good news, Greg. Timesavers part # 20805 was specifically made for Gilbert movements.
Bad news, it has 12 teeth. I guess you will need help with a spare from someone's parts supply. Are you sure yours is toast?

[Doug Osborne]

Hi Greg,
I have repaired these by undercutting the crack with a jewelers saw and then clamping together to close the crack. I then silver or tix solder the area of the crack.

[gregoryjohn]

Hi Harold,

Yes the gear is toast. I heated it way too much and while closing the crack with my needle nose pliers four of the teeth just squished together into one big tooth. It's really embarrassing to even admit I did it. I had been rebuilding this little banjo clock for a while. Had to have the cast iron chime rod mount welded back together. Punched out the broken end of the old chime rod. Then I drilled out the chime rod hole for a 6.5 mm tap and threaded in a new chime rod. Replaced a broken time side spring. The hook on the chime spring arbor was broken off so I built a new one using a SS 4-40 socket head cap screw (worked perfectly). Fixed one pivot that was 'filed' too big for the bushing. Cleaned everything with my trusty tooth brush and while putting it back together discovered the cracked pinion. Never fixed one before (still haven't). :mysad: I don't have much in the way of tools, so making a new gear will be next to impossible. I hate to think this thing finally got the best of me at this stage.

Doug, thanks for input. But as you've read I flunked soldering little gears 101.

My screw up so I guess I have to live with it. At least it's my clock......

Still hoping someone might have one.....
Greg

[shutterbug]

Bummer, Greg! I wish you'd done some searching here first :)
There are some really good ideas for repairing those little devils that work very well. We've all been there with Gilberts :)

[The Tick Doc]

Here is my .02cents worth. contact fendley and cox,wwwfendley-cox.com ,1530 etain street,, irving tx,75060,, he will need the old part and perhaps what it turns on,, I have used this guy several times ,he does good work and turns his work out quickley--- I am not richard cox,, this is not a self advertisement

[gregoryjohn]

Thanks TDoc, I'll check him out!

Anyone care to rummage through their parts bin? Even if you got something close I could file to size.......

You can tease me and heckle me forever. Call me the dumbest bodger yet......

Any help is greatly appreciated!
Greg
(slinking away with his tail between his legs)

[tom427cid]

Hi Greg,
Dont feel bad this is how we all learn. I looked in my Gilbert drawer and while I didn't find the piece you need-I did find (I think its the idler from the motion works) a ten tooth gear.Bad news is that it is .448 dia. Good news it is on a .112 shaft. If you can't find what you need let me know and I will mail it to you-even press out the arbor.
tom

[doc_fields]

Contact David Labounty at http://www.abouttime-clockmaking.com

He has plenty of old movements for parts and may have what you need.............doc

[gregoryjohn]

Thanks for taking the time to look Tom! I may just take you up on your offer.

Doc, I just sent David an email. I know how busy he is.......

In the meantime, between kicking myself I am going to try and fix the gear myself. I filed away two of the worst teeth and filed the one in the middle back to a rough shape. I then filed a V in the space of one of the missing teeth and soldered in a small piece of brass which I will file to match the other teeth if I can get the second tooth replaced. If I manage to get both missing teeth filled with a brass insert, then I can attempt to hand file them to match and maybe come up with a working gear.

A new gear would be better but if I come up short this may be my only hope!

Hears my progress so far.
Thanks for all your replies!
Greg

[shutterbug]

Hey Greg! Your idea of repairing the gear is a good one, but I'm not too comfortable with the method :) Here's a rough drawing of a key-hole type repair that will be much stronger. You can shape it with a file. Looking forward to seeing your progress!

[TonyR]

Hi,

One idea for future reference. I've had good luck drilling these gears on a drill press, which does involve the delicate job of drilling part way through mainshaft, and then pnning the gear in place with a small brass pin. ONce secure, the ger is not under that much strain and, done carefully and filed flush between the gear teeth, the repair is invisible and works real well.

Regards,


TonyR.

[gregoryjohn]

Hey Shut, your idea of dovetailing the new tooth into the gear would definitely result in a much stronger joint. However, the smallest file I have is twice the sized of the dovetail I'd have to make. I am just happy I've gotten one tooth in and it seems pretty strong. Tomorrow I'll work on the others and then see if I can shape them well enough to fool the clock into thinking it has a real gear!

If not I'll buy the gear from Tom and if I mess that up David mentioned in an email he could make me one.

I never thought I would be replacing teeth in a gear and it's .338 in diameter. Can you image what the watch making guys must go through! :o

Tony, thanks for pinning idea! Didn't even think of that one!

I'll send photos, good or bad when I have more to show.

And all this for a $30 dollar Gilbert banjo clock! :rolleyes:

Thanks guys!
Greg

[tom427cid]

Hi Greg,
I did not mention money-if you want the gear pm me your address and usps will do the rest.
tom

[gregoryjohn]

That's true, Tom graciously offered the gear for free. I just thought it didn't seem right to not pay him something. Well, back to work.......

[RobertG]

That's true, Tom graciously offered the gear for free. I just thought it didn't seem right to not pay him something. Well, back to work.......

Greg:

It is very nice indeed of Tom to give you the gear. I have been helped gratis several times on this board with replacement parts, even custom made tools.

I just decided to "pay" them by doing the same gratis type of help to someone else on the board when I can.

This is what makes this board and this group of people so tremendous!

RobertG

[gregoryjohn]

This is what makes this board and this group of people so tremendous!


Robert, you absolutely correct.

.

Hi All,

Well I've completed my gear repair and while it's not perfect it does mesh with it's mating gear as smoothly on my replacement teeth as on the originals. It sure took a lot of trial and error to file the teeth. Lucky for me this gear is on the outside of the plates!

As promised here are some pic's.

Thank you everyone for your support!
Greg

[LaBounty]

Nicely done Greg! We love hearing about successes and especially like the photos.

[tom427cid]

Yes,nicely done-
tom