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Guyproc
11th Nov 2020, 10:28 PM
Hi people, I have another bodge, (I mean fix), which I'd like to share with you and may help somebody else out.

My Colchester Chipmaster had dials on the cross-feed handle which didn't really achieve anything apart from spinning around independently. Upon stripping the assembly down it was apparent that the small, nylon (?) gear in there was badly worn on one side and had no teeth to engage on the inside of the micrometer dial.

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After trying unsuccessfully to locate a new one I set about finding a solution to fix the one I had!

First off, I secured the gear on a small nut and bolt to hold everything in place. Next up I clamped this in the vice and then, with a Dremel, carefully cut through the gear along the middle of the good teeth.

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This left me with the nylon gear in two pieces which, if I flipped the piece with the worn teeth over, gave me good teeth on the outsides of the gear and the worn part now sitting in the centre.

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With the two gear parts in place on their spigot, I drilled a 2mm hole through both parts and pegged them together with a press fit shaft, (in between the two pieces I put a thin washer, with a notch cut out to accommodate the hole and shaft. This was to build the depth of the gear back up to its original height after losing material when they were cut with the Dremel).

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The finished repair now has a nylon gear which has teeth which engage in both micrometer dials on the handwheel.

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Another job done!

Zsteve
19th Nov 2020, 09:55 PM
interesting post.

looks like you have a metric Chippy?

Are the imperial cross feed handles likely to be the same?

Hopefully I don't need to do mine anytime soon, but now have some idea of what I am in for.

Cheers