Best Mandrel for Pen Turning?

[JWS Penworks]

What is the best mandrel for pen turning. I am getting deflection out of mine when I turn cigar pens and I can't seem to get rid of the deflection no matter what I do. I have an A/B Mandrel.

Thanks!
John

 

[toolcrazy]

None, Turn between centers. One half at a time.

 

[johnnycnc]

You might check to see if your live center has a 60° point.
Most live center tips that come with the lathes are not.
this lets the tip of the mandrel wallow around after wear has it's merry way with things.
Mandrels in theory are suppose to have a 60° seat for a live center of mating angle to seat in. The factory live center tip never fits right,and wears a big ugly groove.
Wobbles and flopples follow.
Also, sharp tools and lght cuts will diminish deflection within the capabilities of
a mandrel setup.
You could also try a collet chuck mandrel holder,and shorten up to turn one barrel at a time.
Shorter is stiffer. I had some improvement in results doing this before
going to no mandrel; (turning between centers).

 

[stevers]

I agree with Steve. I have been turning between centers for a while and it is sooooooo much more accurate.
Do a search on "between center turning" and you'll get a bunch of results.

 

[Nick]

You could possibly be tightening the nut to tight. finger tight is enough. Try putting the bushings and blank on the mandrel, then engage the tailstock live center to the end of the mandrel and lock the tailstock and advance the handwheel no more than a 1/4 turn then tighten the brass nut on the mandrel, finger tight.
If that does not work, put a spur center in your headstock and a live center in the tailstock, advance the tailstock to the headstock, the points should line up exactly. If they do not, either the headstock is out of alignment or the tailstock. some lathes have the headstock mounted with bolts, that can be loosened up to adj. As a last resort, take your mandrel shaft only, and roll it on a known flat surface to see if it is bent.
Good luck

 

[JWS Penworks]

You could possibly be tightening the nut to tight. finger tight is enough. Try putting the bushings and blank on the mandrel, then engage the tailstock live center to the end of the mandrel and lock the tailstock and advance the handwheel no more than a 1/4 turn then tighten the brass nut on the mandrel, finger tight.
If that does not work, put a spur center in your headstock and a live center in the tailstock, advance the tailstock to the headstock, the points should line up exactly. If they do not, either the headstock is out of alignment or the tailstock. some lathes have the headstock mounted with bolts, that can be loosened up to adj. As a last resort, take your mandrel shaft only, and roll it on a known flat surface to see if it is bent.
Good luck

I checked the alignment of the tailstock and headstock and they were good. And when I put the mandrel on and slide the tailstock into place, it hits perfectly, so I will try to not tighten the nut as much and see how that does.

Thanks to all for your suggestions. I will do some research on turning between the centers.

John

 

[leehljp]

Thanks to all for your suggestions. I will do some research on turning between the centers.
John

Below is a link to Mandrel-less (Turning between centers); about half way down the page in the link - some answers to questions about why and why not. I will say that some people who have problems like you are, yet do not want to go to the mandrel-less route - they end up using adjustable (shortened) mandrels and seem to be liking it.

http://www.penturners.org/forum/showthread.php?t=40005&page=2

Other help read both pages:
http://www.penturners.org/forum/showthread.php?t=7319

Picts with bushings and without bushings (but no-mandrel)

http://www.penturners.org/forum/showthread.php?t=38361&highlight=skogger

http://www.penturners.org/photos/images/940/1_Dead_drive_1.jpg


FYI, I have 3 "A" mandrels and 2 "B" mandrels. I also have the Beall which is great. However, The ability to take the bushings off at the "finishing sanding" and "CA application" stage was what pushed me into mandrel-less. No more sanding dust and not more CA lifting from oily woods upon removing the bushings.

 

[toolcrazy]

Thanks to all for your suggestions. I will do some research on turning between the centers.
John

And just FYI, you don't need to buy special bushings to turn between centers. With the exception of slims. You will need to buy or make those.

 

[JWS Penworks]

Thanks again for the encouragement guys. I'll give turning between the centers a try.

John

 

[mywoodshopca]

I am doing the mandrel thing and noticed a bit of out of round, but followed a trick I saw on here (cant remember the name to give proper credit) but when near the sanding stage, loosen the nut and turn the blank 1/2 turn and round that side down as well. works pretty good I must say.

 

[bitshird]

What is the best mandrel for pen turning. I am getting deflection out of mine when I turn cigar pens and I can't seem to get rid of the deflection no matter what I do. I have an A/B Mandrel.

Thanks!
John

there is no such creature !! Turn between Centers, like people have said get a good MT1/MT2 live center for your tail stock and a dead center for your head stock, No wobble, No out of round turnings.
If you have a beal er collet set up, or know someone with a metal lathe, most of your current bushings Except for slimlines and most 7mm pens, But there was a fellow who used to make them, and another that was going to start, and since I got nothin better to do I might start too.
But your bushings can be chucked up on the end that goes into the tube and counter drilled with a # 5 or 6 center drill,
This may not be as good as custom machined bushings, but a lot better than turning using mandrels.

 

[BeeAMaker]

I turned my first 2 pens with a Mandrel, had the second pen bushing seize onto the mandrel shaft and almost lost the pen getting it off - but I did loose the mandrel. I got a set of these,
https://www.pennstateind.com/store/PKMBCM2.html
and haven't used a Mandrel since, these also let you use 7mm bushings.

 

[jcgolov]

I got better results using a mandrel saver. Seemed (for me) to give better results than the normal live center.