Squaring Blanks

[PTownSubbie]

I was following another thread in another catagory on here and think that it would do better posted in this catagory for some assistance.

I am looking for alternative ways of squaring blanks. I have been using a pen mill but that doesn't work well on the acrylics in my opinion.

Someone posted that they use a skew and square them on the lathe. I am interested in this but am not really certain of the mechanics of it. I have live centers, dead centers, chucks and such to aid in this but am unsure of the easiest way to do this efficienty and accurately.

Can someone that squares their blanks on the lathe take some pictures to help me visualize the easiest way of doing this?

 

[Lenny]

I wonder if your pen mill just needs to be sharpened ... or maybe replaced with a better model. I usually try to keep my tubes close to the end (center of pen) that was cut and then trim the other end close to the tube after glue up to minimize the amount that has to be removed. For me the barrel trimmer works great on acrylics (as long as it's sharp) ! Some will recommend disc sanders ... and with the proper jigs I'm sure they will work equally well. As was suggested in the other thread I'm sure it would be possible to square the end on the lathe with a skew but I would wonder how accurate one could get it to the final tube length. It certainly sounds like an advanced turner's method IMO.
What ever way works for you, good luck!

 

[bitshird]

Fred, you need a lathe chuck to square blanks on your lathe,, after turning the blanks round, put them in a 4 jaw chuck, or a 3 jaw chuck if you have one and use a skew or carbide scraper to turn the end flush, also a sanding disk works well.http://content.penturners.org/articles/2005/blanksquaring.pdf

 

[jleiwig]

I use a collet chuck for all my drilling, and facing of blanks. I mark which way the blank goes in and out of the chuck, so I keep it consistent. I haven't had one problem using the skew doing it this way. I just make sure that the angle of the skew is parallel to the face of the collet chuck and let it do it's thing.

 

[nettech]

I bought i cheap set of forstner bits from Harbor Freight. I use a 4 jaw chuck to hold the blank and use the forstner bit in a MT2 drill chuck in the tail stock. This has worked very well for me.

 

[Blind_Squirrel]

After using the pen mill to get it close, turn the cutter head around. Take a paper-hole punch and punch a hole in some stick-backed sand paper. Attach a small piece of the sand paper to the back of the pen mill. Sand square.

 

[cnirenberg]

I bought i cheap set of forstner bits from Harbor Freight. I use a 4 jaw chuck to hold the blank and use the forstner bit in a MT2 drill chuck in the tail stock. This has worked very well for me.

I agree here as well. Once you have the blank running true a fostner bit works wonders on acrylics.

 

[rherrell]

The idea is to square the end of the blank with the tube. Any method that doesn't use the tube as a center point is, to me, strictly hit or miss.
A SHARP pen mill followed by a sanding mill (shameless plug!) is just about foolproof.:wink::biggrin:

 

[leehljp]

Below are two links that show different ways of squaring the ends:

The first one shows a home made sanding mill. The pipe is the cutter for cutting round pieces of adhesive backed sandpaper for the sanding mill. The Sanding mill avoids the chips and chatter of bladed pen mills. Scroll down about 2/3rds of the way down.

http://www.penturners.org/forum/showthread.php?t=50112&highlight=sanding+mill


This next method shows a round backing block and adhesive backed sandpaper on the block. This setup is on the lathe and uses the lathe to square the blank.

http://www.penturners.org/forum/showthread.php?t=48603

 

[PTownSubbie]

Below are two links that show different ways of squaring the ends:

The first one shows a home made sanding mill. The pipe is the cutter for cutting round pieces of adhesive backed sandpaper for the sanding mill. The Sanding mill avoids the chips and chatter of bladed pen mills. Scroll down about 2/3rds of the way down.

http://www.penturners.org/forum/showthread.php?t=50112&highlight=sanding+mill


This next method shows a round backing block and adhesive backed sandpaper on the block. This setup is on the lathe and uses the lathe to square the blank.

http://www.penturners.org/forum/showthread.php?t=48603

Lee,
Thanks for the links. I have tried the second style. It is not extremely efficient because it only uses the center of the sandpaper.

I guess I need to break down and make a disk sander from the tutorial. It is difficult to get a good square setup though. I was thinking that if someone would show a picture of how they mount between centers and square their blanks that it would be easier to perform that way.

Thanks all for the responses.

 

[JimB]

Fred - The second link from Hank is mine. You are right that it doesn't remove a lot of material. If I have done a poor job cutting my blanks to length I use a mill to remove the bulk of material. I then use the jig on the lathe for final squaring. It does an excellent job at this. I also use it to remove any finish that may have run onto the ends causing them not to be square. Also, you can change the grit sandpaper in just a few seconds if you needed something more efficient at removing material.

My jig may not be the fastest at removing material but on the other hand I never need to wonder if it is square becuase it is as square as my lathe. If you use a disc sander you will need to check how square it is periodically (table hasn't moved even the smallest amount) and if you ever use it for anything else you will need to square it again.

 

[leehljp]

Jim,

The more I look at your set up, the more I like it. Using the HF punches keeps the shaft/tube in perfect size. I really like it. Much more simple than I realized at first glance.

I have three different grits of 2 in wide rolls of adhesive backed sandpaper on hangers by my lathe and snip off a piece when I need for different things. Everything I need to do your setup is already within arm's reach of the lathe.

 

[JimB]

Hank - I'm glad you like it. It really is amazingly simple and in my opinion is extremely accurate for squaring. I didn't have any adhesive backed sandpaper when I made it so that is why I made my own with turners tape. Let me know how you like it once you have tried if a few times.