Member postings for s d

Chester have a deal on their VS30 mill atm so I took the plunge. I've been looking at so many different models and manufacturers I didn't notice the Chester is MT3 not R8. I have no experience with either as I've never had a mill.

Will I regret it?

Yes, I didn't understand that a dti was much more imprecise than a micrometer. I've been watching many videos on YouTube and ubiquity of their use especially for measuring machine set up made me trust mine perhaps more than I should have. All good learning experience.

I think I saw a clickspring video about 'sneaking up', and the way I understood what he meant was not taking ever smaller cuts, but dividing what you want removed into decent sized regular chunks, that way you can more easily keep track of errors and deflection as you go and then be able to make the final adjustment adding or subtracting a small amount from that final cut which is still of near optimal depth before spring and finishing passes. This makes a lot of sense to me as you're reducing variables as much as possible. It's still all theoretical as I've yet to make any super precise parts, but interesting. Good to hear the same thing from a 2nd source, thanks for the insight 👍🏻

These are good points, thanks. I figured I would need to be measuring and sneaking up for fine work so it makes sense that in practice it wouldn't matter much. I think its still useful for understanding where exactly I am in the measurement landscape as it were, what tools I can trust, what not etc and in which circumstances. And just to know how (im)precise my lathe is. As a beginner there's a lot to take in and reducing variables helps.

Yes. Thanks!

Yes good point. I did consider this, the markings are for both 0.001" and 0.025mm. But 0.001" is 0.0254mm, so it should reach a whole unit slightly before a full turn, and accumulate, if the threads were imperial. My more accurate test suggests they are metric so all is good.

Great tip re setting the compound parallel to the cross slide, I'm curious to try it just because...

Edited By s d on 09/06/2023 06:33:25

Morning all...

I repeated the measurement with a much more precise setup. I think an out of parallel error is one of the main things I was seeing. The indicator has a very short collar, not much to judge by. That and I've learned that indicator dials are sensitive but not necessarily that accurate.

I clamped a digital vernier guage under the toolpost (a cheap one!) which allowed me to get it as absolutely parallel to the compound as I could visually (sighting a hair-width gap between the straight edge and the compound over about 15cm, assuming the latter is parallel to its dovetail) and rigid and measured off the tailstock.

I got essentially no error. 10.01mm over 10mm of travel.

This taught me a lot about these tools and methods. Thanks for all the responses helping to figure this out.

Edited By s d on 09/06/2023 06:39:10

OK that's good to know in terms of expectation. I did also check at multiple regions of the indicators travel and it was consistent at least. I don't have any other guages unfortunately.

No, but I did cross check with a digital vernier guage and got the same result. That could still be inaccurate, but it is the same degree of error.

Hi, first post, hello all.

I've bought a mini lathe and have a question about accuracy of the dials on the cross slide and compound. These seem to be consistently out by 0.025-0.05mm, 1-2 markings when making a full rotation. I'm checking them against an indicator and it seems pretty consistent on both dials, requiring a bit more than indicated to get to a full 1mm travel. Is this normal?