Tool Height Adjustment

grepper

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How is this guy changing his tool height? It almost sounds like he ratchets it up.

 
Never mind. I guess he is just loosening the tool and using the using the screw adjustment.
 
See, you didn't really need us after all. But don't let that stop you from asking questions. This forum is a gold mine when it comes
to knowledge about everything having to do with machines and machining.
Welcome aboard.

CHuck the grumpy old guy
 
Thanks Grumpy old dude. :) I realized it was a rather stupid question shortly after posting it, but didn’t see any way to modify or delete the post.

I saw that video and wondered if there was some sort of QCTP that I had not seen, possibly with an internal worm gear for quick and smooth tool height adjustment. It almost seems like a good idea, but probably over engineering something that already works well.

This is my first lathe, so I’m a lathe noob. I’ve had it for about a week. I bought it (lightly used) from a guy who either didn’t care about or possible understand caring for a machine, so I spent most of that time tearing it down, cleaning, lubricating, adjusting… that sort of thing.

Interesting little machine, this HF 7x10. There is a lot I like about it, but I’m already thinking about ways to improve it. At least lapping the v-ways to smooth its movement, and possibly adding bearings to slider adjustment screws for starters.

I think with a little work, it will become a very cool little lathe.

Thanks for your patience with my noob questions! It’s truly appreciated.
 
Lapping the v-ways? Your machine, but I wouldn't recommend it. Do your other upgrades first.

And, welcome, a person can learn a lot here.
 
Ok, why not lap the v-ways?

The reason I was considering it was because the travel is not evenly smooth, no matter how I adjust the gib. I’ve played with the adjustment a lot trying to get it right. It gets especially tight when it’s fully cranked in.

The other reason is that I have a little bit of vertical play in the compound slider. That little bit of play seems to cause uneven facing on the side of a shaft. It’s very little, but if I polish the metal to a mirror finish, I can see the waver. It’s just enough that I can feel and see the movement of the compound if I apply lateral pressure. Like I mentioned, I can’t seem to get rid of the play by adjusting the gib. The machining on the HF is a little rough, so lapping it seems reasonable.

I got the lapping idea after reading http://www.mini-lathe.com/Lapping/mt_lap.htm where he states, “Now, it slides easier than before, but it has zero slop both side-to-side and up-and-down, as measured on a test indicator.

Would it be better to try to shim it? I’m open to any ideas!
 
Hello,

I'm not an expert on lapping , I think the main reason to be carefull is that some lapping grits can get stuck in the metal and contiue lapping when you don't wan't it too :-0

Their could be a small burr or slight lump in the way that is causing an issue, might be worth wipping the oil off the surface putting some blue (enginearing ink for transfering contact points and also for marking out, a.k.a. Dykum or prussion blue or engenears blue or copius sharpie ink ;-) ) then slide the surfaces together, disasemble and look for very small contact point's

Doing that can help you find very small burrs or raised divits in any mating surfaces.

They can be knocked off with carefull use of a file or some abraisive paper.

Time consuming and all that but can help spot somthing small thats stopping the two surfaces sliding well.

If you havn't got any blue to hand you can run your fingure along the ways and feel for burs and raised bits, I recomend rubbing the oil off a bit first ;-) ha ha

Stuart
 
Sorry, but lapping the ways would be a terrible idea. You need to read up/get more info on the use/ finesse in using of your lathe. Don’t believe everything you read on the net! If you have some mechanical aptitude and safety. I would FIRST just use the lathe as-is and learn as much as I could as to its operandi. Learn its faults and good things and work with it. And don’t forget, it’s a made in China lathe. It will always have its quirks. You will need to learn about them and live with them …Good Luck, Dave
 
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Thanks for the input everybody!

It seems that the general consensus is that lapping would be a bad idea with one possible reason being residual compound. I think a dunk in parts cleaner and a brass brush would remove that. I like the idea of addressing high spots first and going from there. Nothing wrong with going slowly and erring on the side of caution.

Even though the HF is specially imported from the Orient, I do need to address the vertical slop in the compound slide that I am unable to resolve just by gib adjustment. When it’s tightened enough to remove the play, movement of the compound is restricted.

The issue is that when cutting, vertical force applied to the tool causes the tool to tip enough to affect the depth of the cut, further exacerbated by the fact that the tool is hanging off the side of a QCTP thereby a further distance from the post . Not a lot, but enough to be visible on a polished surface. It is especially apparent when reversing the rotation direction causing the tool to tip in the other direction. I haven’t measured it yet, but maybe .001” or .0005”, something I consider a real problem that I doubt I can overcome with a more practiced technique.

I’m sure that every problem I could encounter with the little HF is well known and has been resolved, so I sure appreciate the experienced, friendly help offered here!

Good idea to apply some dye and check for high spots first. I’ll start there. Maybe try a .001” shim and see if that does it. That is easily reversible. While it sure seems the general opinion, I’m still not convinced that at least a light lapping would not be advantageous. As long as it is not lapped out of spec, how could that hurt? Of course in consideration that metal is more easily removed than replaced.

While I am a rank, noob beginner at lathe operation and technique and super appreciative of all the help and advice I can get, I do have mechanical aptitude and experience. I have rebuilt engines, transmissions, etc., hand lapped valves, honed cylinders, turned brake drums… That sort of stuff. And, with 30 years working in the IT world, I can attest that you should absolutely believe everything that you read on the Internet! :)
 
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