Lead screw question.

Spacer- OD: 1 1/16" +0.000"
-0.020"
ID : 3/4" +0.010"
-0.000"
Length: 1/2"+0.010"
-0.010"
That's what I mean when I say dimensions aren't that critical, for example, my spacer is 0.520" long, haven't had any problems.
The gear box is by no means close alignment wise, but it is a LOT better than it was. Zamac is not very ductile, and low melt point. Easy on the heat, light on force. It took me nearly a week, to do mine. A bit here and a bit there. The half journal was bent nearly .125" from where it should have been, within .020" now.IMG_20200317_080449.jpgIMG_20200317_080622.jpg
 

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Here's the set up you're looking at; 64t on the leadscrew, 20t/64t with the 64t adjacent to the spacer. Well worn zamac gears are meshed closer than they should be, 3d printed 64t has .012" clearance on the spacer.
If you get the bore of the spacer close(within .005), you could even go + .020" on the OD.
If you don't have a spacer at all, that will get you going. I would hesitate to try filing a double keyway spacer, doable but difficult.IMG_20200317_102802.jpgIMG_20200317_103124.jpgIMG_20200317_103056.jpgIMG_20200317_111557.jpg
 
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A bit of bad news, I finally removed the gearbox and aside from the hailine crack in the top left hand corner of the reversing gearbox (the inclination of the stub was indeed off, even noticeable by eye) the lower support for the right hand reverse gear has a cracked finger support. My only choice now is to get a reverse gearbox casting made. I could make a half moon support and bracket it from inside the casing as a stop gap but it’ll need repairing.

Does anyone have a dimensional drawing for this box so I can get one made?
I have contacted Clausing but am waiting for a reply. Obviously if they supply one I’ll post it in here.

Looking at the break there is evidence of discolouration on the break which I would assume happen some time ago. Irrespective of when it happened I am going to try and get one manufactured!

I was also surprised by the wear in the stub gear collar as the brass bearing doesn’t look too bad!


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That's strange, though. The center of the 24T and 12T gears are the same. And there would be roughly four times as much material in a 24T as in a 12T. ???
 
On the gear case, we don't have any sort of drawing. I would first call Clausing and see whether or not they still have it, and if so, price. If they do, then buy it or don't. If not, ask them for a copy of the drawing. And send me a copy.
 
I may not need to go down that route Robert. I posted pics of my original spares on the welding forum I frequent when I purchased it, including a homemade gearbox......I was pointed back in their direction today......

can you spot it?? I didn’t!!! :D

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@timmeh, could I ask you a favour? Any chance you can measure that collar OD and I’ll turn down my 24 to fit.
 
1 1/16" or 27mm.
Unless you have extra 24t gears or that one is damaged, as the "set" only has one.
If you make a spacer, the keyway doesn't have to be close, its not under load.
 
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