Out of round between centers

[Dvoigt]

So I've gotten away from turning on the manderal and switched to turning between centers. I don't even use the bushings, just calipers. So I have removed alot of the factors that contribute to OOR. The tips of my live and dead center are aligned... I only tighten the tail stock enough on the blank to keep the blank moving through the cutting and finishing process.

Yet I turned a half dozen blanks today and a few of them were out of round. What other factors are I missing?

Oh and there is nothing on the inside of the tube either...

 

[JBCustomPens]

One thing you must check is, are your ends of your blanks PERFECTLY square? That can contribute to having OOR.

Another thing is to make sure that the taper in your headstock and tailstock are clean and free of debris. And also the bearings in your lathe need to be perfoming well too.

Hope you can get this fixed, and hope I helped you some!

 

[JBCustomPens]

One thing you might want to check out is this article. I know a lot of it is about mandrels, but he does talk quite a bit about things that can affect between centers as well. This article has helped me tons.

http://content.penturners.org/articles/2009/Why-are-my-pens-not-round.pdf

 

[PenTurnerfromMaine]

Are you sure that your pen components are round? I have had some issues with that in the past.

 

[toddlajoie]

Another issue I had at one point was too much sanding. If you're relying on sanding to do more than remove tool marks (i.e. significant shaping or sizing) the variations in the density of some woods can cause areas to be sanded away quicker than other areas. This generally doesn't happen with tools, since you're holding them steady, but when sanding, you're usually using your hand, which will give and take with the OOR.

 

[Dvoigt]

One thing you might want to check out is this article. I know a lot of it is about mandrels, but he does talk quite a bit about things that can affect between centers as well. This article has helped me tons.

http://content.penturners.org/articles/2009/Why-are-my-pens-not-round.pdf

Thanks I'll check it out.

One thing you must check is, are your ends of your blanks PERFECTLY square? That can contribute to having OOR.

Another thing is to make sure that the taper in your headstock and tailstock are clean and free of debris. And also the bearings in your lathe need to be perfoming well too.

Hope you can get this fixed, and hope I helped you some!

I clean up the end with the pen mill, end always look good. Tapers look ok, but I do get build up of CA on the on the centers that I clean up on a regular basis.

Are you sure that your pen components are round? I have had some issues with that in the past.

Never thought of that. Is there an easy way to check that?

Another issue I had at one point was too much sanding. If you're relying on sanding to do more than remove tool marks (i.e. significant shaping or sizing) the variations in the density of some woods can cause areas to be sanded away quicker than other areas. This generally doesn't happen with tools, since you're holding them steady, but when sanding, you're usually using your hand, which will give and take with the OOR.

I do sand alot at times, depending on how my day is going. So that is something I'll pay more attention too.

Thanks for all the advice everybody. I'd still be turning plain old oak for my funline kits on a manderal with a dull roughing gouge and wax finish if it wasn't for this forum.....

 

[JBCustomPens]

Never thought of that. Is there an easy way to check that?

If your centers are accurate, you can mount the parts, depending on which ones they are and check them with a dial indicator. You can do the same with your blanks if you want to see if they are OOR.

 

[jocat54]

Derek, I had an out of round problem a while back with turning between centers-it turned out that the morse taper in the head stock was dirty--gave it a good cleaning and all is well now. Needless to say I clean the tapers all the time now.