Thread: Wood Lathe Runout (AKA - The Wobbles)

Paul39,

All being well, your quotes should be in red and my replies in black.

This reply was written in Word before I saw the last few posts - a chunk of wood that size should have whizzed as it went past!

Somehow I get a feeling that if I was to approach a local club, they could have helped me with this. I said in my introductory post that I thought there were a couple of clubs in Rocky – can’t find them on Google. However it is very nice of the forum to help out.

The register is on the flat behind the threads on the spindle and on the back of the faceplate.

The threads only hold the faceplate or chuck on. If you put the faceplate on and screw it on snug, then back off 1/4 turn, you can make the plate flop back and forth on the threads.

The register on my spindle appears to be OK but is hard to check. It is probably only 3/16 of an inch, and is less than this where the flats for the spanner are. It could be worn a poofteenth and without any experience with a dial indicator, I don’t know if it could be checked. (Not enough register to run the indicator on all the way around.)

FWIW, the spindle is 1 1/8 inch, UNF, 12 TPI and the faceplates and chucks are loose until they butt up against the register.

Back to your first post, too much run out for me would be 1/2 inch - .500 inch.

Gee, that sounds like a lot of run out, but I suppose experience tells you what you can get away with, rather than strive for <strike>perfection</strike> near enough.

I could make bowls on a faceplate that was 1/4 inch out - .250, then sand the wedge off the bottom.

I will take my camera and dial gauge to my daily driver lathe today and see how much run out I have and show the register surfaces on my lathe, or lathes if I get ambitious.

Have you made a bowl on the lathe using the faceplate in question? If not, you might want to do that before replacing bearings.
I have not used the big faceplate for a bowl, but have used a couple of 3 inch ones to turn the bottom and a tenon. When I remount the bowl in a dovetail chuck, I have to true it up, right back as close to the dovetail as I can.

If the bearings do not get hot in 15 to 30 minutes of running, they are not too tight. Warm like putting your hand on a cat in the sun is good.

The bearings have not been getting hot. I can’t get the damn things out without a fight, so they can stay a while.

Put the faceplate on the spindle and run the edge of the tool rest even with the top of the faceplate. Put a piece of timber under the faceplate and try to lift the faceplate. If it moves the thickness of a business card or less it is fine. If it bounces around while turning it is too loose or the bearings are bad.

Haven’t done this yet. Can’t for the next 5 days as I am at work away from home. Can’t feel any play by hand.


When disassembling the spindle, only press, do not hammer the spindle, as that will put dents in the bearing races and cause them to fail.

This will be a problem for another day. Because they take end loading from both ends, I can’t use the spindle to bump then out.

I am assuming you have not had experience with disassembling machinery. I am not trying to insult your intelligence.

I have had experience with disassembling machinery, both non-destructive and the hard way! No offense taken.

Set up for checking for loose bearing. Lift to see if there is any movement.

Not yet.

Turn Spindle by hand to see if distance between front of chuck jaws and tool rest changes.

Tried this but the jaws were loose. Didn’t think to wind them right in!

Turn Spindle by hand to see if distance between edge of chuck jaws changes. Jaws do not make a perfect circle in this position, slight change in and out, equal on all 4 jaws.

Have not tried this yet.

Check for wobble on faceplate. About the thickness of a business card - .011 inch. This is used to friction drive a bowl blank so that I can rough the outside and turn a spigot to grab in the chuck. It is also used to put a rim of the bowl into a fresh cut groove to finish the bottom.

.010 is where I came in. So it appears that this is acceptable and one just works with it.


My usual bowl blank, I do cut off the stub of limb before turning.

I am definitely not going to try that with the wood that I have been using lately. It is dry Ironbark and harder than woodpecker lips. I even it up as much as I can, screw it to a faceplate and still run the tailstock up.

I make all sorts of plates for sanding and cup chucks that are grabbed in the chuck. A spigot is cut, grabbed in the chuck, the side turned round and the front turned flat. I then mark on the plate the location of the #1 jaw and always put it back in the same position.

When that is done, the chuck or faceplate can be quite off but the surface will run true.

I will persevere with what I’ve got for a while, but will put a wood face on my steel faceplates and true it up and see how I go.

Thanks again those who posted with help.

"A". (Alister.)

A,

I am definitely not going to try that with the wood that I have been using lately. It is dry Ironbark and harder than woodpecker lips. I even it up as much as I can, screw it to a faceplate and still run the tailstock up.

Very good proceedure. I also run the tailstock up when I hollow the inside and leave a long spigot sticking up from the bottom of the bowl until the last. I then slide the tailstock back and carefully take the spigot down to the bottom of the bowl.

The red oak piece above was dry and hard with the harder knot running through. I had several catches using a tungsten carbide Easy Finisher for hollowing that were hard enough to either make the belt slip or stall the motor.

Sometimes I get carried away hogging out bowls.

The bottom that went into the chuck was rather soft, and I had soaked the spigot with CA glue and left it overnight before chucking.

Without the tailstock the bowl would have come out on the first catch.