# Using lathe to sand square blank ends



## TX_Planes (Aug 1, 2009)

Someone asked about how I sanded (squared) blanks on the lathe. I built a box that sits on the ways of the lathe with a runner that fits between the ways. This box sits at about the center line of a sanding disk. I attached MDF to a face plate and turned it round. I attached an adhesive backed hook pad to the MDF which allows easy removal and replacement of sand paper. I move my dust collection stand from my Powermatic to the Jet when I am sanding. 

I first use a barrel trimmer then sand the ends flat and square on the lathe. I think I will add a square piece of plywood to serve as a register to help ensure square ends. I am doing it by eye based on a square center line I have drawn in pencil on the top of the platform. When actually sanding I attach a clamp in the hollow end of the box to the lathe to prevent movement.


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## Marc Phillips (Aug 1, 2009)

I will throw my 2 cents in... This is meant to be helpful OK... but if that works for you, great!

What needs to happen is the end of the blank needs to be squared up with the brass barrel inside the blank... what you are registering the blank to the sanding disc with your set up is the side of the blank, not the brass barrel.

One way to do this with a sanding-disc-on-the-lathe set up is to put a chuck in the tailstock and put a rod (one of those transfer bits from Harbor Freight works great) in the chuck the slide the tailstock up to the sanding disc and just slide the blank along the rod and square it up that way... now it will be square with the brass tube, not the side of the blank.

There are other ways too... like a miter gauge set up for a disc sander... 

Hope this helps...


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## KenV (Aug 1, 2009)

Marc -- while the tail stock will be more rigid, it may or may not be more accurate.  Some of the drill chucks have huge runout - especially the cheap ones.  I have one that is off about  1/16th (0.05 inch) in the headstock.  The scribed line extended from the face of the abrasive wheel will be pretty close guide, and if it is aligned with the center of the pen with any of several holding jigs, it will be acceptably close.


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## Marc Phillips (Aug 1, 2009)

KenV said:


> Marc -- while the tail stock will be more rigid, it may or may not be more accurate.  Some of the drill chucks have huge runout - especially the cheap ones.  I have one that is off about  1/16th (0.05 inch) in the headstock.  The scribed line extended from the face of the abrasive wheel will be pretty close guide, and if it is aligned with the center of the pen with any of several holding jigs, it will be acceptably close.



I use a different set up... mounts to my miter gauge on the disc sander... was trying to figure out a way for him to use the disc sander he made for his lathe... guess he could route a miter slot?


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## Fred (Aug 1, 2009)

Nice idea, but I have a question and a suggestion.

Why is your 'box' so long? Maybe you are using it for other items than pen blanks??

Suggestion ... 
Shorten the box. Make as sure as possible that the top plate and the right end of the box is SQUARE and vertical to the front edge of the sanding disk.

Make a plate to fit against the right hand edge and attach a SQUARED guide rail to the plate to act as a brace for the long edge of any wood you intend to sand square on the ends. Kinda like taking a miter guide from the table saw and using the guide rail to square the wood to the sandpaper while the miter part extends above AND below the far right hand edge of your box. Think of a T-square shape with a deep lower lip on the T end.

Simply slide the device back and forth while holding the blank against the sandpaper. Flip the blank around and repeat the procedure for the other end.

A strip of 200 grit sandpaper attached with spray adhesive down the length of the edge of the guide against the blanks edge will help control movement of the blank.

Make sure the 'brace' is strong enough to not flex at all. A piece of 3/4" hardwood/plywood about three inches wide by appropriate length should do the trick.

BTW, congratulations on using your vacuum to catch the fine dust AT THE SOURCE. Your future health definitely depends on very adequate vacuuming of all particulate matter as early on as is possible.

Heck, with a quite a few smaller holes in the top plate of your box and a hole at the back for the vacuum hose you could make a kind of downdraft table. Of course you would have to make the inside of the box closed to create the vacuum.

See your idea just expands and makes things even better for all that will follow your lead.


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## TX_Planes (Aug 2, 2009)

Marc,

Great suggestion.  I just started using this setup last week.  Works so far but I can see the weakness in the current set up.

The pencil line on the box serves as a guide but no where near as accurate as your setup Marc.  I'll try to adapt your suggestion to my set up.

Yes, Fred, I used this sanding setup before I started making pens.  The longer box helped support larger items.

Thanks for the tips.


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## JimB (Aug 2, 2009)

Here's mine. Works great and was easy to make.


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## its_virgil (Aug 2, 2009)

It looks as though the metal rod is smaller than the tube. Wouldn't a squaring jig work best if the rod/mandrel were a really close fit to the tube? I think so. I use an old mandrel and have shims from waste  wood for each size of tube. Then there is no way for the blank to move. The end of the blank will be square to the tube if the rod/mandrel is perpendicular to the sanding disk.
Do a good turn dailoy!
Don



JimB said:


> Here's mine. Works great and was easy to make.


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## KenV (Aug 2, 2009)

Don -  

I have been learning about accuracy - precisions- repeatability - and rigid as I work to learn machinist tricks and trade secrets.   It gets me to looking at things in a different process sense.  

Jim B is using a considerably thicker rod and is using the parallel nature of the tube and rod to create the square end.  The rod is much thicker than the 0.246 mandrel rod, and provides good control to the extent that the tube is kept in contact with what appears to be a transfer punch.  The larger radius of the transfer punch make the alignment more sure.   There is an inherent inaccuracy in use of drill chuck in the tailstock, but for this process, it is probably within acceptable tolerances.  

A check of seeing how square the rig is to the paper (and there is another discussion about accuracy and precision in use of different attachment schemes for sand paper) is to turn the blank 90 degrees and very very lightly touch the end to the abrasive and then look at the end.  Visually, the marks from the most recent touch are also 90 degrees from any marks remaining from the earlier ones.


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## Marc Phillips (Aug 2, 2009)

TX_Planes said:


> Marc,
> 
> Great suggestion.  I just started using this setup last week.  Works so far but I can see the weakness in the current set up.
> 
> ...



My jig is super-simple really... just some metal conduit drilled and tapped for the thumb screws... and I use the Transfer Punches from Harbor Freight for the guide rod... the rod fits so tight inside the tube that it will literally remove and CA residue that happens to get inside the tube. I think that is one of the keys to it's accuracy.... no slop at all.... plus since it is one round object inside another it self=centers when you tighten the thumb screws down.

Once you have the metal tube drilled and tapped and mounted to some scrap wood, just screw it onto a miter gauge... I used machinist squares to get it all squared up and it has worked ever since with no problems at all... sometimes even *I* get lucky!


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## Wheaties (Aug 2, 2009)

TX,

Thanks for posting this. I asked about it a few days ago. I am doing a similar setup on my belt/disc sander, but have gotten ALOT of get ideas out of this thread. Thanks!


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## JimB (Aug 2, 2009)

KenV said:


> Don -
> 
> I have been learning about accuracy - precisions- repeatability - and rigid as I work to learn machinist tricks and trade secrets. It gets me to looking at things in a different process sense.
> 
> ...


 
Ken - you are correct. It is a transfer punch and does not flex so the tube is always parallel to the punch and with a light hand the tube is held against the punch. The punch does not need to be a tight fit to the tube. I trued the face of the wood block to make that square to the transfer punch. I use turners tape to attach the sandpaper and it sits very flat where I need it flat. I did post a thread about 2 weeks ago about how I made this. http://www.penturners.org/forum/showthread.php?t=48603

I will say that the pens i have made using this to square the blanks have a better fit than my previously squared blanks. It is also great for just cleaning up any finish that accumulated on the ends of the blank.


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