# Turning Between Centers?



## Troy Cole (Dec 10, 2008)

Hi Guys,
            This has probably been answered before but I have been unable to find it. I know that there has been threads on turning between centers. My question: Is it possible to turn slimlines between centers? Thanks for any info.


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## Texatdurango (Dec 10, 2008)

A 60 degree center goes down to a sharp point so any tube or cylinder will fit between centers.  I would say turn away and give it a try.


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## Russianwolf (Dec 10, 2008)

yes, yes and no.

Yes, you can turn slims between centers without bushings

Yes, you can turn slims between centers with custom bushings

No, you can't turn slims between centers with standard bushings


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## leehljp (Dec 10, 2008)

To build on what Mike said, I did try it once to see if I could turn without a bushing. I did, but I used considerable care in rounding the blank. There is a strong tendency to "catch" and stop the blank, which will flair the ends. 

Some people turn their own bushings. You may not want to try making bushings out of steel (unless you have experience in turning steel) but with a chuck you can make your own bushings from aluminum or brass. It takes patience, a steady hand, sharp chisel and calipers.


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## rherrell (Dec 11, 2008)

Absolutely Troy, use calipers for sizing and don't over tighten. Make the blank round by whatever method you choose before mounting between centers, this enables you to put a looser "grip" on things and helps prevent screwing up the ends of the tubes.:wink:


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## monkeynutz (Dec 11, 2008)

rherrell said:


> Absolutely Troy, use calipers for sizing and don't over tighten. Make the blank round by whatever method you choose before mounting between centers, this enables you to put a looser "grip" on things and helps prevent screwing up the ends of the tubes.:wink:


You can round the blank on a standard mandrel, and then lose the mandrel for shaping and finishing.


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## leehljp (Dec 11, 2008)

monkeynutz said:


> You can round the blank on a standard mandrel, and then lose the mandrel for shaping and finishing.



Yes, this can be done, but if there are mandrel related problems, they still will be there. I used to find more slippage on mandrels than I do now on the mandrel-less method (Turning between centers).


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## monkeynutz (Dec 11, 2008)

leehljp said:


> Yes, this can be done, but if there are mandrel related problems, they still will be there. I used to find more slippage on mandrels than I do now on the mandrel-less method (Turning between centers).


What I meant was basically knocking the corners off while on the mandrel.  Any eccentricity at this point will be worked out as the piece is sized down and shaped between centers.


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## PaulDoug (Dec 11, 2008)

Russianwolf said:


> yes, yes and no.
> 
> Yes, you can turn slims between centers without bushings
> 
> ...



Mike, I've heard talk (actually read) about bushings for turning slimlines between centers, but I cannot picture what they would look like.  Is there a picture available or can you describe?

Thanks


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## jkeithrussell (Dec 11, 2008)

PaulDoug said:


> Mike, I've heard talk (actually read) about bushings for turning slimlines between centers, but I cannot picture what they would look like. Is there a picture available or can you describe?
> 
> Thanks


 
It would look like a step bushing.  The small end would fit snugly inside the standard 7mm tube.  The larger end would match the standard slim bushing diameter with (hopefully) a flared end to meet the dead/live center.  The size of the hole would not matter as long as the center could properly seat.


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## Chasper (Dec 11, 2008)

It looks like this.  The small end goes into the 7mm tube and the large end is the outer diameter of the standard bushing.  There is a 60 degree tapered hole in the end of the large end for the live or drive center.  We used to buy them from JohnnyCNC but he had some flooding problems and is not able to make them at this time. Paul in OKC might be able to help you http://www.penturners.org/forum/showthread.php?t=37433


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## jack barnes (Dec 11, 2008)

I turn all my slimlines between centers, just don't over tighten and take light cuts with sharp tools.

jack


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## GaryMadore (Dec 21, 2008)

Please believe that I am not being flippant here, but I need to ask "why?" (as in, "why would anyone bother forgoing a mandrel and turning a pen between centers?")

Thanks,

Gary


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## ed4copies (Dec 21, 2008)

Gary,

When you find yourself making "out-of-round" pens and you cannot figure out why, you try LOTS of things.  "Mandrel-less" is one "solution" that has worked for some turners.

Personally, I tried it, I went back to "adjustable" length mandrels.  But several excellent pen-makers here use mandrel-less.

To each his own.


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## GaryMadore (Dec 21, 2008)

It's another good day because I learned something.

Thanks Ed,

Cheers!

Gary


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## leehljp (Dec 21, 2008)

GaryMadore said:


> Please believe that I am not being flippant here, but I need to ask "why?" (as in, "why would anyone bother forgoing a mandrel and turning a pen between centers?")
> 
> Thanks,
> 
> Gary



Gary Below is a long compilation of reasons for mandrel-less as it relates to your question:

Posted from a previous post:
http://www.penturners.org/forum/showthread.php?t=7319&page=2


*People hate change.* The learning curve of overcoming all the little problems associated with a mandrel is a little high. (OK, quite high for a beginner.) However, once you become proficient enough to recognize just where a problem might be, you don't want to let go (and therefore) learn a new method. Call it the Stockholm syndrome.  

. . . Because the mandrel has been around for a good while - if we were to just come out and say - Don't go the mandrel route, it is too complicated - then we would probably be in for a fight and Jeff would throw all of us off!  And besides, when you as a beginner see all the catalogs, online store set ups and videos that show "mandrels" - would you believe a few others who said "Don't go this way, Go mandrel-less"? People generally follow the larger crowd or commercial entities as Frank pointed out.

Most people that ask about it on this forum - think that it is complicated! Why? Because mandrels are complicated with their own inherent problems. Why believe that more precision can be more simple? Most people equate higher precision with more complication! 

In this case, less IS more!



Another post on *problems related to mandrels*:

1. Bent mandrel for one reason on another.
2. Mandrel flex from being too tight against the tail stock.
3. Mandrel flex from too much pressure of the chisel on hard wood, especially for beginners.
4. Mandrel / bushing fittings being slightly loose fitting will cause OOR.

Bushings with the hole drilled off center will cause the same problem on the mandrel-less method as it will for the mandrel, however it will be amplified a bit more on the mandrel.

Tail stock out of alignment will still cause problems.

However, when you eliminate 1, 2, 3 & 4 above, the difficulty in finding an OOR problem is GREATLY reduced.

ADDED BENEFIT: after bringing the blank to size or near size, take the bushings off and finish sanding to size, as measured by calipers. NO Sanding dust! Finish in this set up (no bushings) and no problem with CA/bushings sticking.



*Mandrel setup versus Mandrel-less:*

Steps for Mandrel:

1. put bushings on the blank
2. put spacer bushing on mandrel, 
3. place bushing/blank on mandrel
4. add another spacer
5. place and add nut and tighten
6. pull up tail stock and check as to just right tightening.
Turn

Remove to check and see if it is OOR anywhere, replace and go through the 6 steps again.


For no mandrel/mandrel-less/Turn Between Centers:
1. add bushings to blank
2. put bushing/blank on lathe and hold
3. pull up tailstock and lock
Turn

Remove to see if it is OK
repeat with three steps OR leave bushings OFF and:
1. place on lathe
2. finish sanding to size without bushings and check with calipers
3. Apply finish and sand, wax, buff

Much less steps on single blank pens. DOUBLE for two part pens which makes it come out about the same, but with less chances of OOR from mandrel related issues.

Where this REALLY speeds things up is the quickness with which you can remove and check a blank for size or for how it will look against the pen kit parts, and then replacing. On some pens, I take the blank off two or three times to check something. It takes less than 10 seconds to do this with mandrel-less but 30 - 45 seconds or more (take off and put back) with mandrel set up, and more if you drop a spacer!
__________________


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## ed4copies (Dec 21, 2008)

Hank,

Everything you said makes sense.

With one exception.  The Law of Critical Droppage clearly states, "You WILL drop the MOST IMPORTANT component".  So, clearly I will NEVER drop a spacer (Of which I have dozens), I will ALWAYS drop the bushing that I have the fewest of.  Usually, the SAME size bushing I dropped last time and never found, so I am NOW down to my LAST one.

But, this pertains to both mandrel and mandrel-less turning, for me.

(My tailstock travels --loosens ---a little as I turn, making mandrel-less a bit dicey.  If your lathe is not 15 years old, you probably won't share my difficulties.)


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## leehljp (Dec 21, 2008)

ed4copies said:


> Hank,
> Everything you said makes sense.
> 
> But, this pertains to both mandrel and mandrel-less turning, for me.
> ...



_"Everything you said makes sense."_ A first, A FIRST for me! Been preaching for 30 years and something finally made sense! :biggrin: You made my day!

I noticed that the tailstock on my lathe has started to travel also. At a snails pace. I think I will make me a new lock.


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## GaryMadore (Dec 22, 2008)

Wow Hank: Thanks for an extremely informative (and detailed) lesson.... You took some time, methinks, to put that together.

I like the idea of being able to test-fit center bands without disassembling all of the mandrel-borne bits and pieces.

Cheers!

Gary


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## GaryMadore (Dec 22, 2008)

leehljp said:


> I noticed that the tailstock on my lathe has started to travel also. At a snails pace. I think I will make me a new lock.



My tailstock used to travel a tiny bit, but then I stopped cleaning the ways so much... A bunch o' rust and a buildup of flung finishing gunk does wonders for keeping the tailstock fixed.

... well, not so much "fixed" as "stuck"

heh heh

Cheers!

Gary


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## TellicoTurning (Dec 22, 2008)

I haven't gone to the mandrel-less turning yet, main reason is I've not released the funds from captivity to purchase the 60 deg dead center, but I have cut a mandrel down to half length.  It's less likely to flex - not unlikely - but less likely and I seem to get better and more concentric tubes.  I mount the cut mandrel in a Jacobs chuck and turn that way.  Much like Ed's adjustable I think.


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## ed4copies (Dec 22, 2008)

Hey Chuck,

If your pens are round, your method works.

Merry Christmas, my friend.


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