out of round when turning between centers??

[darcisowers]

How do I check for out of round when turning between centers? I thought this was one of the main reasons we chose TBC, to avoid out of round!!

I initially thought that the problem was because one of my sierra tubes fit a little "big" on the bushings, but now we've encountered the same problem on another pen style (triton, if anyone is interested in commenting specifically)... and it was TWO triton pens that just were ruined.

So what do I need to do to check everything out before we ruin ANOTHER blank....I think it is something that just changed - up until now, we've never had a problem, and now three in a row are wrong.

Thanks,
Darci

 

[Monty]

Make sure your head and tail stock are perfectly aligned.
To do this, place your dead center in the head and the live center in the tail, bring them together and the two points should touch. Rotate the dead center by hand and see if there is any variation in the position of the points. Is so, you may need to adjust the head or clean out the MT in the head and tail stock.

 

[Atherton Pens]

Two things I would suggest.
1. Be sure the ends of the tubes are square.
2. Be sure there is NO CA build up on the bushings.
CA buildup between the blank and the bushing was recently a culprit for me. Cleaned the bushing and aggressive sanding fixed the problem.

 

[Johnny westbrook]

Put dead center in head stock shaft and turn on your lathe and check for run out, if your head stock shaft is out you will see it

 

[zig613]

Darci...

Check out this article from the library http://content.penturners.org/library/general_reference/Why-are-my-pens-not-round.pdf

Also, check out John's video "Run out on lathe and how to check it" https://secure82.elinuxservers.com/...e&id=6&zenid=72050086322c151c84c6d8c0b68ff7c1

Wade

 

[tim self]

Two things I would suggest.
1. Be sure the ends of the tubes are square.
2. Be sure there is NO CA build up on the bushings.
CA buildup between the blank and the bushing was recently a culprit for me. Cleaned the bushing and aggressive sanding fixed the problem.

In my opinion, this is the main cause of OOR regardless of manner of turning. Especially if someone has attempted to sharpen the squaring tool. I place my bushings and tubes on a loose mandrel and hand turn them checking for any gaps. The bushing should rock slightly if blank is not square.

Also, I've began turning everything down to close to size and square with a sanding jig on my disc sander.

 

[Wood Butcher]

I bought one of those green urethane morse taper cleaners from CSUSA and the amount of goop in the taper was surprising. The tool is somewhat pricy for what it is but hey, this is a hobby for me, it's supposed to cost money right?
WB

 

[darcisowers]

Thanks everybody!!

We definitely have square tubes, so I knew that wasn't a problem.

I still don't know why it suddenly started goofing up for just those two pen types (Sedonas came out fine!). There was a miniscule amount of out of alignment in the head and tail stock; but what we found was some "gunk" in the ends of the triton steel bushings. I bet that was the problem!! So now we're checking something else everytime we start a new pen. :biggrin:

but that MT cleaner thing looks like something interesting to have on hand.