Question on squaring blank ends..

[Gary]

I was wondering what others here are using as a jig on their disc sander for squaring the tubes to the pen blank end. I'm aware of the PSI jig, but it looks kind of flimsy to me. This photo is one I found at the penturners Y

ahoo group. I guess you could just make some sleeves to be used with the larger tubes. I don't like using a pen mill on some burls and would like to do them on the disc sander. Any other suggestions would be appreciated.

 

[Fred in NC]

Gary, the jig in your pic will cost little to make and try. Then you can decide if you really like it. By the way, I have found that most 1/4" bolts are actually a little smaller in diameter and are a snug fit in a 7mm tube. If you don't have a mandrel that you want to cut up, that is an option.

 

[Gary]

I'm not that concernd about the Slimlines, Fred. I was wondering what people are using for the larger pens with the big tubes in them.

 

[Fred in NC]

I see... I think I need to work on this one. There are several tube sizes we have to deal with. Sooner or later we will figure it out.

 

[Gary]

I realized today while making a Ligero, that my technique is bad. On previous occasions, I've just clamped a board to my disc sander table, squared it to the disc and used it as a guide as I pushed the blank into the sanding disc. Then I realized that isn't all that accurate because the blanks aren't always square and the tube isn't always perfectly centered in the blank. I was wondering how others are handling the problem.

 

[Fred in NC]

Gary, most of the time I square to the tube by eye. When I get very close to the brass, I quit using the sander, and use my jig, which is like the pen mill, but with sandpaper instead of the metal cutters. A truly accurate squaring can only happen with the tube and the cutter or sander are on the same axis.

ADDED:

Look at the bottom of this page for PIN CHUCK:
http://www.fholder.com/Woodturning/tips.htm

The blank, with tube glued in, can be mounted to the spindle with a pin chuck of the proper diameter. Sandpaper can be mounted on a disk on the tail stock. Thus the barrel will rotate on the same axis as the tailstock, squaring the barrel to the tube.

This will need a pin chuck for each size tube. I think a very hard wood can be used for it. Aluminum also turns well in a wood lathe. <b>Be sure to use a mask if you sand aluminum.</b> The pin is a piece of nail or rod.

Just an idea ....

 

[btboone]

It's also easy to make expanding mandrels from aluminum. I hold my rings for a side 2 cut this way. The aluminum is turned a few thousandths of an inch below the inner diameter of the tube. The end is tapped for a capscrew. The end is drilled with a centerdrill or other drill with a shallow angle so that it makes a V shaped hole at the end of the tapped hole. The rod is sliced about halfway with a bandsaw along the axis twice so that 4 prongs are left standing. The underside of the capscrew is turned so that it matches the V shaped hole. When the capscrew is threaded into the hole, the V shaped head expands the 4 prongs away from the center. It is very accurate and solid.

 

[its_virgil]

Gary,
I use the disk sander and a jig similar to the one you posted from yahoo. I found when I started making larger pens, the pen mill was of no use. I just turned a sleeve from scrap to fit the ID of the different size tube I use on the larger kits. I drill the sleeve 1/4...no use to waste a brass tube. I find the disk sander and jig a much better tool for squaring pens than the pen mill.
Do a good turn daily!
Don

Originally posted by Gary
<br />I was wondering what others here are using as a jig on their disc sander for squaring the tubes to the pen blank end. I'm aware of the PSI jig, but it looks kind of flimsy to me. This photo is one I found at the penturners Y

<br />ahoo group. I guess you could just make some sleeves to be used with the larger tubes. I don't like using a pen mill on some burls and would like to do them on the disc sander. Any other suggestions would be appreciated.

 

[jwoodwright]

When I square the cigar pen blanks I use my 7mm barrel trimmer with a Corian Adaptor. I had a Corian piece mounted and it chipped and the next thing I knew it was too small in diameter. Fits the 10mm tube like it was designed for it...[8D]

 

[bajacrazy]

Originally posted by jwoodwright
<br />When I square the cigar pen blanks I use my 7mm barrel trimmer with a Corian Adaptor. I had a Corian piece mounted and it chipped and the next thing I knew it was too small in diameter. Fits the 10mm tube like it was designed for it...[8D]

I was just going to suggest making a sleave or adapter for the 7mm barrel trimer as I just went through the same thing with larger tube sizes.
I've used the disk sander as well with extended board attached to miter gauge to bring work closer to sander.

 

[Fred in NC]

Bruce, for the larger diameter pens, your idea will work also with wood, and some plastics. I think both the pin chuck and the expanding mandrel will be difficult to understand for some people without pics and drawings. We have both used this type of devices for metal work. Unfortunately, I don't have a good drawing or CAD program.

 

[RockyHa]

I understand how the pin chuck or expanding mandrel work, but don't really understand why that would be the way to go. It would seem that without a carriage on the lathe using either would add even more time. It would seem easier and even a bit faster to mount a sanding disk on a faceplate in the powered end of the lathe and just a steel rod in the tail stock. That way one could just slide the tubed blank onto the rod, slide the tail stock up close, turn on the lathe and then just slide the blank gently up to the spinning sanding disk on the faceplate.
Rocky
PS I'm not criticizing, just trying to understand the reason for or advantage of the pin chuck or expansion mandrel.

 

[Fred in NC]

Clifford, I have to admit you have a good point! That will be easier, requiring just a plain mandrel for each size tube. Thanks for the idea!

 

[Guest]

Variaton on a theme.
I don't think it will work on my Ryobi sander for reasons I posted on another thread( too much vibration),but...
Why go through all the bother of drilling a hole for a mandreshaft?
Using the same concept of the jig in the picture take a block of hardwood that has been squared on a table saw and turn a tenon the same diameter as the inside of the tube?The tenon would be parallel to the sides of the stock,would it not?( assuming the the blank of the jig was sqaure before turning)
It might be a little weak for slimlines but should work fine for the larger diameter tubes.( it would require a different jig for each size tube,but it would be easy to turn them once and have them on hand.)

 

[wayneis]

Gary the PSI jig is not flimsy at all, it's all that I use any more. I've made bushings for it so that I can square up all of my blanks with it. You could also make one by getting a couple pieces of al. angle and a piect of drill rod or something like that in 1/4".

Wayne

 

[Gary]

Originally posted by wayneis
<br />Gary the PSI jig is not flimsy at all, it's all that I use any more. I've made bushings for it so that I can square up all of my blanks with it. You could also make one by getting a couple pieces of al. angle and a piect of drill rod or something like that in 1/4".

Wayne

Thanks Wayne, I had hoped to find someone that had actually used it. What material did you use for the bushings you made? Did you just drill some stock and then turn them to fit the various tube sizes?