Cutting keyways in Myford changewheels

I have a couple of changewheels from a Myford ML4 that need keyways cut in them to make useful on my ML7 . Could someone suggest a simple (and accurate) way of cutting them - without investing too heavily.

Steve

---------------------------------------------------------- Steve Randall G8KHW snipped-for-privacy@btinternet.com UKRA #1072 Level 2

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steve randall
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Classic way is to rack a suitable cutter back and forth mounting the gear in the chuck and taking very small increments per traverse (power off please when doing this !)

Andrew Mawson

Reply to
Andrew Mawson

Hi Steve,

Make a single tooth broach from a stout round bar and fit a hss toolbit in the end. Then grind a single cutting tooth with lots of top rake and virtually no front or side rake. The width of the cutter should be the final keyway width (1/8" from memory). Mount this in the tool post on axis with the lathe bed and with the centre of the tooth exactly on the lathe centre. Clock the gear spot on in the four jaw and lock the mandrel. Wind the saddle back and forth taking a thou or so off each time. Even the stoutest of tool bars will flex and you should hear a slight click as you wind the tool out after a cut. Pass the cutter through repeatedly until the click in minimal and then wind the crosslide out and make another cut. It is a bit tedious but it does work.

HTH

Bob

Reply to
Bob Minchin

make the tool holder as strong as possible with minimal overhang, I would suggest checking all you jib strips are adjusted correctly before starting as well.

HTH

Reply to
Tim Bird

Probably not aesthetically appealing to model engineers but your local engineering shop, or merchant that sells pulleys, may well have a simple broach press that will cut keyways to a precision not attainable with toolbar in lathe. Small broached keyways are so accurate and take a minute or two to do so costs shuld be little.

ChrisR

Reply to
Chris

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