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Jonny042 Jonny042 is online now
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Join Date: Aug 2010
Location: Thunder Bay, ON/Grand Portage, MN
Posts: 1,986
I ordered standard guides last night - I'll measure all the 1st oversize ones and see if there's much variance, maybe keep a few (or all) to machine down if required.

I also ordered a dial bore gauge that will fit in the bore holes (.4--.7 range) - no huge rush on this and I'd feel better about my ability to measure the bore diameter with that over the telescoping gauge and the split ball thing I've tried so far. I don't find I'm getting very repeatable results and I'd feel better being able to slip the bore gauge up and down the bore and read the interference directly over the entire bore.

My concern withe machining the OD of the guide is if I somehow chucked the guide and the runout on the lathe is, say, .0003, I'm already going to be fighting tolerances. It occurred to me I could chuck some bar stock in the lathe and machine it to a slight taper but leave it chucked in position to "grab" one end, and use the live center to support the other end.

Not to mention it's not my lathe and I don't even know if it's set up to cut a parallel OD or if i'd end up with taper, etc. so I'd have to check all that and tune it up if required. Come to think of it I don't even know if the live center is actually centered to the chuck. I bought a test indicator though and have been slowly teaching myself about machining. Most of what I've been making so far have been lower tolerance stuff like drifts to remove the guides etc.

Probably a moot discussion though assuming the new guides are the right size.

Trackrash - a couple thou different? That's a massive size difference, maybe some first oversize guides got mixed in the standard bin?
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Old 02-23-2019, 05:13 AM
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