Between Centers Advice?

[NittanyLion]

Hi everyone....Just turned pen #100, so still new.....I just started turning between centers and love it.....I only use my mandrel for Slimlines. Right now, I'm using standard mandrel bushings to help strengthen the blank at the headstock and tail stock. I don't necessarily use the right bushings,( as long as they fit the tube)because I'm using a caliper for accuracy. I do not want to purchase between center bushings(I'm cheap!) Couple of questions:

Is this overkill?

Can I use my dead center in the headstock and live center in the tail stock pressed into the pen tube without damage?

How do you finish with CA between centers?(right now I'm using bushings but would like to get away from them)

I just ordered derlin bushings, can I use just them between centers to finish?

Any advice is appreciated!

 

[longbeard]

If your gonna use your drive and live center for turning, be careful you do not flair your tube or crack your blank from the tail stock pressure.
CA finish, between the drive and live center with no bushings on the slowest speed.
The delrin bushings, i dont use them but im sure some does and will chime in with thier experience.
Hope this helps. Just my. 02 cents before taxes.
I have BTC bushings for all my pens i turn except maybe 1 or 2, i only use my mandrel to paint my tubes for acrylic blanks. I use the standards bushings, put the brass tubes on them and then on the mandrel and paint.

 

[Texatdurango]

Hi everyone....Just turned pen #100, so still new.....I just started turning between centers and love it.....I only use my mandrel for Slimlines. Right now, I'm using standard mandrel bushings to help strengthen the blank at the headstock and tail stock. I don't necessarily use the right bushings,( as long as they fit the tube)because I'm using a caliper for accuracy. I do not want to purchase between center bushings(I'm cheap!) Couple of questions:

Is this overkill?

Can I use my dead center in the headstock and live center in the tail stock pressed into the pen tube without damage?

How do you finish with CA between centers?(right now I'm using bushings but would like to get away from them)

I just ordered derlin bushings, can I use just them between centers to finish?

Any advice is appreciated!

This is just my opinion so take it for what it's worth, you'll likely get some contradictory answers.

I have turned literally hundreds of pens between dead and live centers without ruining one single blank so the answer is YES, you can turn down blanks without using any bushings whatsoever! Some will say you are taking a chance on "stretching" the brass or cracking blanks, to those folks I would say like Harry mentions above, "learn to properly tighten the blanks without over tightening"

I applied ALL my CA finishes between centers with no bushings and loved the results. If you don't slop on the CA, you won't have any problems with getting the blank stuck on the centers. I would stop every few coats of CA and break loose the blank and clean the CA off the centers with a razor knife then check the CA thickness and either continue or stop and start sanding... between centers as well.

And as far as the "special stick free" delrin bushings......... save your money, CA sticks to acetal and delrin as well as it does steel dead and live centers! I have always seen these as a gimmick but there are some who probably swear by them.

As with anything else, turning blanks without bushings requires more frequent stopping for measuring with calipers but is very doable so keep going, you're on the right track!

The little Elegant Beauty kit is one of the few kits I still make and I have made over a hundred and there isn't a bushing that will fit these tubes in my shop!

 

[Russknan]

I do not want to purchase between center bushings(I'm cheap!)

Buy ONE set of TBC bushings from John Goodin (Johnny CNC) for the pen kit you turn most. Try them out between a dead center and live center. Then come back and tell us you won't spend the money for others. Not trying to be snarky - really! I bet you'll have an epiphany and pester him for more. DAMHIK.

How do you finish with CA between centers?(right now I'm using bushings but would like to get away from them)

I just ordered derlin bushings, can I use just them between centers to finish?

Put the delrin bushings on your old mandrel (wipe some wax on the mandrel first) and have at it with the CA. If you have turned between centers, your blanks are already round. Just do your CA thing, and even some light sanding in between some coats if you wish. I even have an extra mandrel that I put Delrin bushings on on either side of a single blank to make it easier to hold while buffing with Tripoli and White Diamond.

Russ

 

[longbeard]

Might not be how i worded it, but what i meant by "be careful not to flair your tubes or crack your blank".

 

[ssajn]

I also turn most of my pens between centers with no bushings and never had a problem. I've even been known to turn a few slims that way.:biggrin:
Sure you have to measure often and it could be real easy to take off too much but this is my preferred way. If your concerned about sticking your blank to the centers put a little wax on them first.

 

[Monty]

the

Hi everyone....Just turned pen #100, so still new.....I just started turning between centers and love it.....I only use my mandrel for Slimlines. Right now, I'm using standard mandrel bushings to help strengthen the blank at the headstock and tail stock. I don't necessarily use the right bushings,( as long as they fit the tube)because I'm using a caliper for accuracy. I do not want to purchase between center bushings(I'm cheap!) Couple of questions:

Is this overkill? Not really

Can I use my dead center in the headstock and live center in the tail stock pressed into the pen tube without damage? If you do not over tighten. Use only enough pressure to drive the blank.

How do you finish with CA between centers?(right now I'm using bushings but would like to get away from them). I finish between centers without bushings

I just ordered derlin bushings, can I use just them between centers to finish? Yes
Any advice is appreciated!

See my response in Blue
I use regular bushing to turn between centers. I modified mine by using a center drill like one of these to make a 60* shoulder to fit the drive and live centers. This gives a larger surface area and helps prevent scoring on the centers. I did spring for a set TBC bushings from Johnnycnc for slims and Euros that use 7mm tubes.

 

[NittanyLion]

Great advice guys.....I bought the derlin bushings for slimlines; I still make these frequently for give aways to friends and family. I made up some wood bushings just on a whim for finishing and loved not having to deal with cutting them off.....plus I ended up with much better finished ends. I've read many opinions on the derlin s, but thought I would give them a try.

Another great thought comes to mind to deal with my cheapness.....take all of my bushing sets and machine them down a little, with just enough to hold the blank taught. Father in law is a machinist with a metal lathe in his garage......he owes me a favor anyway.

I've got some kits arriving tomorrow so I'll give it a try bushing free! Thanks again!

 

[mikespenturningz]

I also modify my existing bushings to turn between centers but, I have also purchased some of johnnyCNC's bushings and they are way superior to the others. I won't purchase any more cheap bushings. I will however use up the ones that I have. I do have johnnyCNC bushings for the bulk of my pens now.

 

[jttheclockman]

To me and this is my opinion. I highly suggest not to turn between centers without bushings. Those that do it are more seasoned and maybe able to get away with it but there will come that time whe that all important blank that they spent hard earned cash and time on will get flaired or bent because of a catch. Finishing is another story.

I would not recomend using standard bushing as the go to bushings between centers, unless you are a machinist to get that cone shaped hole to fit that 60 degree centers. If they are off a slight bit that blank can now be running at an angle. Same goes for if you do not ream those holes and just use the holes that came with the bushings. You can very easily set that blank up between them on an angle. This can produce OOR blanks. This is fact so do not let people tell you otherwise. What has worked for others may not work for you. If you are going to do this get the right equipment. As far as finishing goes you can use any bushings, stick, plastic or whatever you like as long as the blank spins somewhat true.

Again just my opinion

 

[Justturnin]

For kits that I already had mandrel bushings for I just drilled them out w/ a 60* center bit. For kits with no bushings I either go straight between centers or if I am make several I will make a set of bushings out of Corian. I only use the bushing to get close then I take them off and go straight between centers. I also finish between centers. Like others said stop every once in a while to break it free. When I am done I soak my centers in Acetone to clean them off. Careful not to submerge you live centers bushings, just enough to cover the CA.

For Delrin, like was said CA sticks to them to. You can wax them before turning and it will make breaking them off easier but if you slop on the CA it will still bind up and possibly cause your CA to delaminate around the ends if it is still soft and you force it off.

 

[betwisted]

I do like justturnin...I get close with the stepped bushings (haven't bothered with the center drill thing) and then finish cuts between centers w/o bushings. Straight to sanding and finishing from there. I do have a set of the 7mm tbc bushings as the stock ones are not stepped. I've only made maybe 60 pens or so (and have blown up 4 others )
Joe

edit: P.S. This has eliminated the OOR issues I was having with the mandrels (even some of the new ones were having run-out issues)

 

[Jeff Leslie]

My 2 cents worth.

I turn on a mandel with bushes using a mini Sorby roughing gouge sharpened on the Tormek. Once I get down to near the bushings, I remove the blanks and centre on delrin bushings, sand then finish with CA. I get the size right most of the time with measuring, so a win all round.

regards Jeff