Gear seems to be missing

Hi all,

I just noticed a gap on one of my headstock gear wheels, is it supposed to be like this or have I got a piece broken off.

the lathe still seems to function ok.

it’s a myford ml7

thanks
chris m

Chris,

It shouldn't look like that, a tooth has fractured off. You will not notice it until you try working in backgear.

Brian

Hi,

I’ve had it in back gear from time to time with no difference really, strange.

chris m

I may be wrong but yes it will work but under a heavy load you could break off the next tooth and so on until the gap in the teeth is to big

H

Hi,

any idea how I would renew this back gear cog, is it a bit of a tough job.

thanks

chris m

Many lathe change wheels / headstock gears had broken teeth in the past - Typically back gear teeth were sheared off when used to lock the spindle to remove the chucks. Many repairs were made by drilling and tapping into the gap where the tooth had broken off - Perhaps 3 or 4 x 2BA holes, studding with Loctite screwed into the hole, and when 'set' the studs filed to the shape of the tooth profile. I have seen copper / brass teeth which are better than no tooth.

Leaving yours like that will put extra stress on the adjacent tooth causing an expensive failure for the future.

Professional services can weld up the gap and re-machine the tooth, but that is expensive for the home machinist.

Bob

ME published a fix for this a few years ago, though the machine was a Myford S7. Might give you some ideas. Noel.

Speedy builder wrote:

Professional services can weld up the gap and re-machine the tooth, but that is expensive for the home machinist.

Here is just one video to give you some ideas.

**LINK**

If removed from the machine, I simply ‘pouch’ the area and flood with braze, after drilling some ‘keying holes to ensure it all stays together. I then remove the side plates, by turning, and recut the tooth/teeth profile.

I have/had one change wheel gear, with a single missing tooth, that had been repaired with only by 3 steel screws - and filed to profile. No problem at all.