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View Full Version : Wood Lathe Runout (AKA - The Wobbles)



Big A
17th January 2013, 04:48 PM
I have searched using "Run out" and "Lathe run out". Got nuthin' with the first string and plenty with the second, most of which was from the Metalies.

I found out that with bowl work it is just about impossible to avoid run out, especially with rechucking. There is a stack of reasons for this and I have accepted that I will have to put up with a certain amount of the wobbles (and I will probably be the only one to notice.)

I have an idea that my faceplates are giving me grief and it may not be the plates. With a 6" faceplate, I measured .010 runout at the rim, on the face. For the metric guys, that would be 150mm and 0.25 (maybe.) This was measured with a feeler gauge, old tech I know, but it is what I have.

So, how much is too much runout with a faceplate?

The photo shows the kind of pattern I get, although the formply might be out a bit too.

Thanks,
"A".

ian thorn
17th January 2013, 08:09 PM
Turn the face on the ply to true then us that as the face plte base it may help

RETIRED
17th January 2013, 08:42 PM
Turn the face on the ply to true then us that as the face plte base it may helpDefinitely.

Paul39
18th January 2013, 04:34 AM
Big A,

Clean the threads and the flat behind the threads on your spindle nose. Look for any nicks with raised places on the flat. If present, remove with a stone or file. Clean and lightly oil using 3 in 1, sewing machine, automatic transmission fluid, or 20 weight motor oil.

Clean the threads and flat on the back of the face plate, check for nicks with raised places on the flat. If present, remove with stone or file. Clean and lightly oil.

Put face plate on spindle and snug up by hand. Put tool rest barely touching faceplate on outer edge. Rotate faceplate by hand to see if the gap changes, if less than .060, ignore. A bowl or platter will move more than that overnight.

If the above tolerance really bothers you. Screw a piece of plywood or medium density fiberboard to the face plate and true the face to your taste, as suggested above. Mount your faceplate work to that.

If you need to work at less than + - .010 you need to be doing metal work with a metal lathe.

A wood piece on a lathe will move .010 or more while you are having a cuppa & biscuit break.

Mobyturns
18th January 2013, 07:15 AM
Checking the registration of the chuck insert or faceplate helps. What registers on what. Is it the spindle nose to inside of thread on the faceplate / insert; or is it the spindle boss to the rear face of the face plate / insert? Shouldn't be anything weird like tapered threads in your case. ( but their are things like the Oneway Taperlock adaptors out there)

Maybe a case of a poorly cast / manufactured face plate or poor registration. Trueing up the face should help heaps, but also knowing if the registration / wobbles are different each time you mount it to the lathe may help figure out what is happening. Timber or ply faceplates will move as timber naturally moves in different environmental conditions even during the day.

Tim the Timber Turner
18th January 2013, 11:39 AM
A faceplate can be fine tuned to a lathe spindle by the carefull use of a file on the back of the faceplate. File the surface that locks onto the spindle.

Make sure every thing is clean before checking.

A dial indicator makes this job easy.

Go easy with the file.

Plenty of checking as you go.

This method won't fix a warped faceplate.

Cheers

Tim:)

Big A
18th January 2013, 12:20 PM
Thanks for the help, guys. No easy fix in sight.

"Turn the face on the ply to true then us that as the face plte base it may help" - true, but fixes the symptoms, not cures the problem?

"Clean the threads and the flat behind the threads on your spindle nose. Look for any nicks with raised places on the flat. If present, remove with a stone or file. Clean and lightly oil using 3 in 1, sewing machine, automatic transmission fluid, or 20 weight motor oil.

Clean the threads and flat on the back of the face plate, check for nicks with raised places on the flat. If present, remove with stone or file. Clean and lightly oil.

Put face plate on spindle and snug up by hand. Put tool rest barely touching faceplate on outer edge. Rotate faceplate by hand to see if the gap changes, if less than .060, ignore"

"Checking the registration of the chuck insert or faceplate helps. What registers on what. Is it the spindle nose to inside of thread on the faceplate / insert; or is it the spindle boss to the rear face of the face plate / insert?"

Checked the threads, shoulder on the spindle and the back of the chucks and face plates. All appears to be OK and the runout on the 6" face plate is still .010. A big 3 jaw chuck (over 6") also has runout .012 on the circumference and .010 on the face.

I marked the spindle and the runout on both these items is in the same place.

"If you need to work at less than + - .010 you need to be doing metal work with a metal lathe."

Maybe so, but the wobble is more real than apparent to me and I don't like it!

"A wood piece on a lathe will move .010 or more while you are having a cuppa & biscuit break."

That I can put up with, but if you start with a built in deviation, things are not going to get any better, are they?

The bearings are tight and maybe shot, so I will replace them and see where that leads. While it is bits, I will take the shaft/spindle to a machinist and see if he can help. Probably needs to see it on the lathe though.

Thanks again.

"A".

Old Croc
18th January 2013, 01:56 PM
Thanks for the help, guys. No easy fix in sight.

A big 3 jaw chuck (over 6") also has runout .012 on the circumference and .010 on the face.
I will take the shaft/spindle to a machinist and see if he can help. Probably needs to see it on the lathe though.

Thanks again.

"A".

Sound like it is the slop in the threads of the spindle nose and the female thread in the chuck. I found this can be a problem with threads that are cut with a little too much clearance ( or they are worn) and when the chuck is tightened on the spindle nose, it will pull up on the first bit of metal it finds, hence the runout. Not an easy fix I am afraid. I had the same problem with my mini lathe, so I had a professional (and I mean a Professional) Fitter and Turner machine a new headstock spindle to suit the chuck, with zero clearance on the thread. Fixed it. Best $150 I ever spent,:2tsup:
rgds,
Crocy.

Drillit
18th January 2013, 02:28 PM
Big A,
Only other way I can think of is to borrow and try another face plate (& test it) and then test
your face plate on another lathe. If that is the case you could then have your faceplate re-machined.
Hope that makes sense. Drillit.

Paul39
19th January 2013, 06:44 AM
Big A,

Re your post #7:

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.

Using a micrometer; a business card is .011 inch thick, a plastic credit card is .031 inch thick.

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

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.

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.

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.

Depending on the lathe some bearings can be adjusted, some packed with old dried out grease can be soaked in mineral spirits, kerosene, diesel fuel, etc. cleaned, regreased and used for another 25 years.

Some can be replaced inexpensively, The cost of some will make you gasp. $3000 - $6000 for a set of three on a precision metal lathe.

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.

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

Paul39
19th January 2013, 12:46 PM
Big A,

1. Spindle of my Hegner, spindle sticking out of bearing plate, the first flat in front of the hole in the side of the spindle is the register for the chucks and faceplates.

2. Register areas for the Oneway Chuck, the PSI Chinese 33mm X 3.5 female to 1 X 8 male adapter, the PSI Chuck with 1 X 8 thread, & below, the faceplate with 13 1/2 inch plywood circle.

3. Male 1 X 8 side of adapter showing register flat.

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

5. Turn Spindle by hand to see if distance between front of chuck jaws and tool rest changes. None I could detect.

6. 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.

7. 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.

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

I checked the run out of the PSI chuck on the PSI adapter with a dial gauge when I got the adapter. It moved the needle .020 to .040, not enough to concern me. The Oneway chuck came with the lathe and I just used it.

All adapter makers caution that there will be run out when going from big spindle to small hole in chuck. I was pleased it was so little.

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.

powderpost
20th January 2013, 08:36 PM
If the above tolerance really bothers you. Screw a piece of plywood or medium density fiberboard to the face plate and true the face to your taste, as suggested above. Mount your faceplate work to that.

If you need to work at less than + - .010 you need to be doing metal work with a metal lathe.

A wood piece on a lathe will move .010 or more while you are having a cuppa & biscuit break.

Agreed, but I would use timber or thick ply instead of a fiberboard, to big a risk of delaminating.

Jim

Big A
21st January 2013, 03:32 PM
Paul39,

Thanks for your detailed replies. There is a bit to digest there - might take me a while to comment.

"A".

Paul39
22nd January 2013, 12:43 PM
Paul39,

Thanks for your detailed replies. There is a bit to digest there - might take me a while to comment.

"A".

No rush, there will not be a test, nor a grade.

If you have a bit of time, screw a chunk of timber to a faceplate and turn something. You don't have to show it to anyone.

That chunk of timber above turned out to be spalted red oak, hard as concrete. Below are out and in, roughed out. I'll give it a couple of weeks to finish cracking and moving around, then finish.

I'm curious as to where the chunk out of the rim went. I did not hear or see it go.

jimbur
22nd January 2013, 02:55 PM
I'm curious as to where the chunk out of the rim went. I did not hear or see it go.
Shake your head Paul. :D

Mobyturns
23rd January 2013, 07:44 AM
I'm curious as to where the chunk out of the rim went. I did not hear or see it go.

:? :o

Big A
23rd January 2013, 03:53 PM
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.)

Paul39
24th January 2013, 05:43 AM
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.