Larry,
You ask "could the bushings be out of round?",
the direct short answer is a positive YES.
But,if I may,could I suggest you consider some other areas first?
There are several other issues that can cause out of round.
I'll presume you have the correct A or B mandrel for your bushings.
I won't address head and tailstock wobble,as you say they are good.
If you eliminate some other things,it's easier to say bad bushings.
I'll ask the same questions I had to work thru,
on some not-so-obvious issues that seem small,but can cause trouble.
A.)are your lathe tools truly sharp?
>even if so,they don't stay that way for long.
this can cause a
lot more trouble than imagined.
>A dull tool has to be pushed,which can bow a mandrel
under tool pressure;can cause out of round.
>dull tools don't often cut evenly,and tend to chatter
and bounce on a small scale;can lead to out of round.
Sharpening can be a steep learning curve,at least it was for me.
B.)Are the ends of your blanks square,to the
inside</u> of tube?
note:square to the outside of blank doesn't necessarily count.
>if not,it can push the bushings out of alignment and
you could see the wobble you describe,and out of round issues.
(out-of-square also causes a poor fit to your kit parts !!)
C.)What live center are you using?
>does it have a groove worn in it from mandrel?
>mandrel ends are supposed to have</u> a 60 degree hole to mate
with the live center tip.(no guarantees,some look good,others awful)
>If you are running the factory center tip,odds are it is not</u>
60 degrees.
If it's not,it never seats properly in mandrel end and soon chews a groove;
that groove is mechanical damage,and alignment and trueness only get worse with time.
Many here recommend this one,it's fine for the price: http://www.littlemachineshop.com/products/product_view.php?ProductID=1189&category=1
D.)Is your mandrel nut overtightening while you are roughing down?
>Stop after you get roughed at least to round,and check.
Mine always over-tightened theirselves during roughing,
and an overtight mandrel nut will bow a mandrel,which in turn
will cause wobbles and out of round.
>Loosen and re-snug after roughing,then carry on.
I hope there is something here to help,as I know it's
frustrating to have a poor,out-of-round fit spoil your work.
This exact</u> issue is what almost turned me away from turning pens.[:0]
Have a nice evening!
Originally posted by Hayseedboy
Hey All,
Another newbie question. I have turned 3 cigar pens one I was actually kinda proud of and two of the three have turned out to be out-of-round on the cap side. Watching this last night as I started to turned another I finally saw that the bushings seem to be wobbling. Enough that the cap is out of round by probably almost a finger-nails difference on one side.
Tried another mandrel thinking maybe I bowed this one and found the same thing on a brand new mandrel. Don't think I have applied to much pressure to the mandrel's or tighted them to tight as I always have to stop and tighten a little more after I start.
Could the bushings themselves be out of round? The headstock and live centers neither seem to have the wobble....
Thanks in advance for your help!
lr