NO MANDREL TURNING.....AGAIN AGAIN

[doberman]

I have been reading about No Mandrel tuning for a while - I think I get it but have a few questions - what material(s) is the bushing made from - if hard stell won't it do a number on the tools? If soft (brass, aluminum etc) won't sanding chew them up (as bushing's on a mandrel which are replaced often)? The bushings have got to be a lot more expensive?? How do you sand without sanding the diameter of these more expensive bushings away? Also how do you avoud chewing them up with the turning tools? I'm sure there are obviuos and easy answers to these questions - I have been reading quite a bit here and ned some help, please!!


Also how sells the bushings if I decide to get some once I figure it out!!?

 

[johnnycnc]

The bushings I have made are made from tool steel. It is not "hardened"
but will hold up better than cheaper cold rolled steel.It wont hurt your
tools anymore than a factory bushing.
Yes,they are more expensive.Precision comes with a price tag,
and quality does not happen on it's own.
You generally get what you pay for,and this is one of those items.
You can turn close to size,and remove the bushings for final sizing and sanding; just carefully chuck the blank up between your 60° centers
and drive it with these alone.use calipers to finalize the size,and they wont get sanded away.
If you are a bit more careful,you can sand and not do much harm with the bushings in place (my preferred method).
Avoiding chewing up bushings with your turning tools is simply a matter of developing a contolled technique.Remember,if you want nice results,
you can't just cram the tools in and turn like you stole it.
Learn to keep the tools off the bushings just like you keep them away from other lathe parts that don't take well to such things.:biggrin:
Who sells the bushings? I use to,and will be making a comeback shortly.
I the meantime,bug Paul in OKC (IAP username).
Hope this sheds some light for you.

I have been reading about No Mandrel tuning for a while - I think I get it but have a few questions - what material(s) is the bushing made from - if hard stell won't it do a number on the tools? If soft (brass, aluminum etc) won't sanding chew them up (as bushing's on a mandrel which are replaced often)? The bushings have got to be a lot more expensive?? How do you sand without sanding the diameter of these more expensive bushings away? Also how do you avoud chewing them up with the turning tools? I'm sure there are obviuos and easy answers to these questions - I have been reading quite a bit here and ned some help, please!!


Also how sells the bushings if I decide to get some once I figure it out!!?

 

[DozerMite]

I have some of John's (johnnycnc) bushings and he is correct, you get what you pay for. His bushings are GREAT! The cost wasn't bad at all for what you are getting, extreme precision. I only turn between centers now after using John's bushings and I'm sure you will convert after your first pen.
I haven't used any of Paul's bushings but, my guess would be they meet the same standards.
Give them a try, you will never look back!

 

[Paul in OKC]

The bushings I have made are made from tool steel. It is not "hardened"
but will hold up better than cheaper cold rolled steel.It wont hurt your
tools anymore than a factory bushing.
Yes,they are more expensive.Precision comes with a price tag,
and quality does not happen on it's own.
You generally get what you pay for,and this is one of those items.
You can turn close to size,and remove the bushings for final sizing and sanding; just carefully chuck the blank up between your 60° centers
and drive it with these alone.use calipers to finalize the size,and they wont get sanded away.
If you are a bit more careful,you can sand and not do much harm with the bushings in place (my preferred method).
Avoiding chewing up bushings with your turning tools is simply a matter of developing a contolled technique.Remember,if you want nice results,
you can't just cram the tools in and turn like you stole it.
Learn to keep the tools off the bushings just like you keep them away from other lathe parts that don't take well to such things.:biggrin:
Who sells the bushings? I use to,and will be making a comeback shortly.
I the meantime,bug Paul in OKC (IAP username).
Hope this sheds some light for you.

Right on the money! I don't want my tools to touch anything that would dull them, so, keep them away from the bushings. Like John said, they are non hardened tool steel, still tough.....

Johnny, Iwill be glad when you get back into it. They are fun to make, definately fun to use, but I think I will stick to vises for the long run

 

[doberman]

:
Who sells the bushings? I use to,and will be making a comeback shortly.

I think I now have a better grasp of it - thank you. How "shortly" is your comeback and maybe you could send me a price list and what pen kit's you make them for off list dan.boardman at shreditfast.com

Thank you

 

[cowchaser]

Agree with all about except I never turn all the way to the bushing. I measure the parts with calipers and turn the barrels to make the parts. If it happens to be smaller than the bushings I sand down to final size.

 

[johnnycnc]

Dan,message sent.

 

[leehljp]

I didn't see written above - exactly what I do.

The bushings don't wear down for me because:
1. I do not sand with the bushings on;
2. I do not turn the blank down to the bushing size. I turn the blank down to about .02 proud, and take the bushings off for sanding and sizing. (I check size by calipers)

Below is the picture of the blank mounted without bushings. I can take the blank and bushings off of the lathe, remove the bushings and put the blank back on the late in about 10 to 15 seconds without even thinking about it.

 

[jkeithrussell]

Hank -- I've been trying to learn to use your method and I have encountered a problem. When I have the blank set up as in your picture either (1) the blank is not "snug" enough and it doesn't rotate freely, or (2) it is "snug" enough and the pressure flares the ends of my tubes. How do you deal with that?

 

[JimB]

Keith - I've done what Hank shows on my last 10 pens for sanding and CA/BLO finishing. I haven't flared any tubes. It is a delicate tightening process. I place the blank against the headstock. I then slide the tailstock against the blank and lock it in place. I then give the hand wheel just a small, small turn. Probably the equivelent of moving it from 1:00 O'clock to 1:30. Lock it in place. About half the time when I start sanding it is still a bit loose. A very, very very small turn takes care of it. It takes a little trial and error.

I like Hanks method a LOT. My sanding is much much better now that I don't need to worry about sanding dust from the bushings. My CA/BLO finish is also much easier to apply and I never need to worry about bushings getting glued to the blank. It's worth the effort to learn Hank's method.

 

[leehljp]

Keith,

I probably use the strangest method of anyone on here - I listen to the sound. Way way back when, we used to tune engines by the sound! Really!. The sound of something running tells me a lot and I don't know how to explain it.

AS to the lathe, I pull up the tail stock, tighten it by feel, turn the lathe on and then tighten with the back wheel until I recognize the sound. "Too tight" has its own sound. "Too loose" does too, and so does "just right". I don't have good ears for perfect matching of pitch, but I can tell when something is not right mechanically.

There is only about 1/4 to 1/8 of a turn between just right and too tight. That is plenty of space for adjustment. In my opinion, it is worse to to have it too loose - and then apply too much pressure in sanding/rubbing, which cause a differential of speed between the tube and dead drive.
From this - Flaring _will_ be caused by being a smidgen too loose. The fast turning dead drive will spin and wear/flare the tube as it slips. Metal fabrication is often done with this method. Differential speeds between two metals will cause deformity quick and flaring is a controlled deformity. It can be done by pressure alone but it is easier with differential speeds. Don't just assume that your flaring is because it is too tight. It would be my guess that the slippage is what is causing most of the flaring that you are getting.