Lathe Tune up

[mickey cassiba]

I've started in on my midi lathe, checked spindle run out and have a question.
When I indicated the inside of the taper at the HS I came up with .0005" using an Interapid dial indicator. Assume that is acceptable for woodworking.
Problem is when I mount a chuck or face plate the runout becomes .015-.020" respectively.
Any suggestions?
Mickey

[Steve Schlumpf]

Mickey - you know more about tolerances than I do - but it seems to me that the spindles are usually held to fairly tight specs. Face plates - not even close. Chucks have been known to wobble because they were not fully seated - or - there was a burr holding the chuck from seating fully with the spindle shoulder.

For me - I would want the centers to line up between headstock and tailstock. That would give me a place to start - then I would see if there was a problem using a chuck.

[Peter Lamb]

You may wish to put the DI on the face where chuck and shaft make contact. This face should be dead flat and perpendicular to the axis.
If out which is often the case, reface it.

Peter

[Richard Madison]

Note that a bit of radial runout of a chuck body is irrelevant. However, radial runout of a steel rod gripped in the jaws should be much less than .020" if you have a straight grip on the cylinder. Ditto for the jaws expanded into a steel cylinder. Your test rod or cylinder needs a shoulder to bottom out against the jaws. Similarly, if the faceplate has a bit of radial runout that is not a problem, but would like to have minimum axial runout of the face of the faceplate.

[mickey cassiba]

I can, with a little bumping get the centers to line up, lot of play in the tail stock horizontal, not vertical. That seems good as the tail stock "key" the part that fits between the ways is a little loose. I can live with that, I read a post earlier about fixing up a laser pointer to fit into the tailstock taper to line up the ts to the hs. The shoulder that the scroll chuck( actually two of them) is not square to the bore of the spindle (checked with DI). Any suggestions as to a way to square this surface?
I don't have access to any machine tools at this time.
I thought about clamping a piece of carbide to the tool rest and easing it across the shoulder. Does this sound do-able?
Am I hunting "snipes" here? The primary use of the lathe will be to learn to turn wood, along with pen making to support my habit. I do intend to buy a real lathe "someday" but as the song goes. "someday never comes!"
Mickey

[mickey cassiba]

Note that a bit of radial runout of a chuck body is irrelevant. However, radial runout of a steel rod gripped in the jaws should be much less than .020" if you have a straight grip on the cylinder. Ditto for the jaws expanded into a steel cylinder. Your test rod or cylinder needs a shoulder to bottom out against the jaws. Similarly, if the faceplate has a bit of radial runout that is not a problem, but would like to have minimum axial runout of the face of the faceplate.
Richard I did mount a polished dowel pin in the first croll chuck, and it flopped around like a freshly caught crappie, used the second chuck with the same result.
Steve: I understand about faceplates not being "precision pieces" but how would I compensate/ work around all the wobble. I know that this machine will never produce the high class hollows and bowls that I've seen here at the creek, but I'd really like to dial it in a little better.
As an aside. I ran a DI on the portion of the spindle between the pulley and the bearing at the face of the HS and it is dead nuts(.0000")
Am I just being an*l about the whole thing? I don't want to buy up a bunch of tooling for a machine that is fubar, but I do want to get on with the turnings. At this time a new machine is out of the question.
HELP?!?!

[mickey cassiba]

Put away the indicators yesterday and mounted up a spur center in the HS and a live in the tailstock, mounted a pice of 4/4 ash and started turning a (?) coaster. Actually just tried to make a disk. Started with a cheap set of HF "precision lathe tools"(I didn't know Pittsburgh was in China)They look like they were ground with a chainsaw. Just played with each tool to get a feel for them. The HCS tools were awful with the KD ash, thats some pretty hard stuff! Got out my miniature HSS tools and the cutting was a little easier, but I still couldn't get the nice curly shavings I see in the "how to" videos. Lots of dust, and a few little strings but no curls. Set the tool rest so that the tool was approximately at the center of the work piece, and experimented with angles and managed to get a pretty smooth OD, but when I tried facing the TS side, got all sorts of catches, felt like I was going to break the tools. Tried a parting tool, and a round nosed scraper with equal lack of success, the facing looks like it was dragged behind a truck down fifteen miles of bad road. I figure that it's because of the lack of bulk in the minis, but not sure. I'm going to try to dress up the HCS tools, they are a lot beefier, and see if that's the problem.
Suggestions?
Mickey
PS Thanks for your patience!

[Steve Schlumpf]

Mickey - with regards to the faceplate wobble - have you tried placing a flat washer on the spindle first? Just wondering if the threads on the spindle could be causing any of your problems.

As far as turning - you sure picked a hard piece of wood to start off with! It is going to fight you even when you have lots of experience! All those ribbons of shavings you see in the videos are from turning green wood! Usually cuts like butter and you can make shavings as long as you can keep your gouge to the wood! Lots of fun - a little messy - but lots of fun!

A lot of folks start off just practicing on scrap 2x material as pine/fir is a lot softer.

[mickey cassiba]

Mickey - with regards to the faceplate wobble - have you tried placing a flat washer on the spindle first? Just wondering if the threads on the spindle could be causing any of your problems.

As far as turning - you sure picked a hard piece of wood to start off with! It is going to fight you even when you have lots of experience! All those ribbons of shavings you see in the videos are from turning green wood! Usually cuts like butter and you can make shavings as long as you can keep your gouge to the wood! Lots of fun - a little messy - but lots of fun!

A lot of folks start off just practicing on scrap 2x material as pine/fir is a lot softer.
I used the washer that was included with the lathe, I did have to flatten it as it appeared to be stamped rather than turned(large burrs on one face). I think the problem is the shoulder on the spindle is my problem, but haven't really found a way to face it off yet.
As to the Ash, it was the first thing I came to. At work, the only soft stuff we have is fingerjoint pine, and it really didn't seem to be a wise choice to practice turning on. The other "soft woods that we have are alder, okume and poplar, may try some of that next.

[mickey cassiba]

I mounted the bed extension today...man is that thing long now. Guess I can make some "long range bonkers" now. How would you make a spindle that long without a steady rest of some sort? Seems like the middle would oscillate right out from between the centers. Still trying to figure out how to face the shoulder of the spindle without removing the spindle from the machine(so my chucks will run true). I tried stoning it but the stone just follows the badly turned shoulder(it's real shiny and pretty now) but still not square to the spindle axis.
Any suggestions?

[Ken Fitzgerald]

Mickey,

If you turn a spindle that long without a steady rest, don't worry about runnout. It won't matter!:rolleyes:

[mickey cassiba]

Sorry, all my turning experience is with steel on engine lathes, with all kinds of gee gaws to hold everything in place. I'm still getting used to the concept of my hand as the tool post, if you catch my drift...

[Ken Fitzgerald]

Mickey,

I was funnin' you in my other post.

I just turned a center spindle for candle table. The spindle was probably 25" long and I didn't use a steady rest. Of course, the diameter of the spindle and the type of wood have a lot to do with it too!