out of round???

[emtmike]

I have a question. If I don’t drill my blank exactly in the center it should still round out right. I seem to be having a problem with my pens when they are done are just enough off that I notice. The bands are just a hair off. Probably only another pen turner would notice but it there. Could there be a bend in my mandrel? It doesn’t seem to be bent. HELP!!

 

[JimGo]

Mike,
Search the archives, this comes up a LOT here, and there are a LOT of great tips. One of the best is to first check out http://www.woodturnerruss.com

 

[stilgar]

It could be in your mandrel or your ends are not square. I check the fittings to the bushings before turning putting the pen on the mandrel.

 

[Mikey]

Also check the bushing diameters with your calipers. If the bushing is a bit undersized, you will get the out of round as well.

 

[lkorn]

Make sure that your Headstock and Tailstock are in perfect alignment. Then check to make sure that your headstock bearings aren't worn/damaged.

 

[HuskyDriver]

Mine seemed to be slightly out of round untill I changed my live center on the tailstock to a 60 degree to match the mandrel end. Now there nice and round!

Greg

 

[knottyharry]

Mike,
It could even be that you are putting too much pressure on the mandrel from the tailstock. That will cause the mandrel to bow a little. Just run it up till it touches and the live center starts to spin....just till you start to feel a little pressure on it. It doesn't take much at all.
Harry

 

[emtmike]

Harry I think you got it. I have been putting quiet a bit of pressure on the live center. I will try your way (aka the right way)

 

[knottyharry]

Mike,
You are not supporting a lot of weight here so you don't need much pressure on the mandrel. If you keep a lot of presseur on it eventually you will wear out the end of the mandrel also.
Also good sharp tools, and light cuts....don't try to hog the wood off.
Dull tools, and pushing too hard will bow the mandrel also.
Let us know how you make out.
Harry