The Best Sander Drum

[ChristopherO]

As an official member of the Tightwads of America and after seeing the thread on Home Made tools I've decided to put together a spindle sander from a motor I have on hand and a box I will soon make with veneer ply, on hand as well, and a slick formica top.  
My question is which 3"x3" drum sander will be most ROUND and stable?  I know that some of the expanding rubber drums can be wobbly (I have one of those in a smaller size) whilst others are said to be smooth spinning.  This is going to be used for many purposes but the pressing task for this spindle sander right off is to create clean, even fades on risers.  Does anyone have an opinion on the performance of the various drums on the market?
I appreciate all your feedback.
Christopher

[BenBow]

Christopher you might think about making your own out of mdf. Here are 2 pics of a drum I'm making for a lam sander. Once you get it glued up you set up a guide that is squared up with the sander base the run a board with sandpaper glued on it so it sands the drum square with the table. You have to glue sandpaper to the drum to use it.
   
   

[Robertfishes]

I just bought a Tunco tungsten carbide 3" x 3" 36 grit sanding sleeve for my 3" robo sander. haven't used it yet, but the sleeve is metal not cloth or paper..I hope to use this combination next week to shape a couple of risers, but I have to build the jigs first..

[ChristopherO]

Thanks for the replies, gentlemen, they both have much to consider.  
Benbow, I imagine you use contact cement to glue the sandpaper on with?
Robert, is the Robo Sander body solid for an even surface?  Those Tunco sleeves look impressive, how much do they cost?

[Robertfishes]

the robo sander has a 1/2" thick rubber drum,not solid rubber, I bought a 1 1/4" PVC coupling to insert into the rubber drum to stiffen it up if needed.
The Tunco 3 x 3 sleeve is a nearly 1/8" thick metal tube/pipe with the abrasive tungsten carbide on the outside. I got the Tunco from McMaster Carr Item # 427A43, It is expensive($48.61) but is advertised to last 50 times longer than the standard sanding sleeves..but I wanted it since it is metal and should remain straight, even if the rubber drum is not perfect ..I will try it out in a couple of days. If it doesn't work I have some zirconium sanding sleeves..

[Robertfishes]

I was expecting the Tunco to run larger than the wheel on the robosander...but its even with it    

[IdahoCurt]

On a 3"x3" sanding drum I found if you over tighten the drum nut it can cause it to become out of round.

[Robertfishes]

made some longbow riser jigs this week. Used the robo sander and tunco sleeve combo, it worked great but finished riser was rougher than the 50 grit sanding sleeve that I was using. Maybe I should have ordered the 50 grit instead of the 36?..

[ChristopherO]

Robert, I was wondering if 36 grit was awfully aggressive.  You've answered that question!  Post a picture, Robert, and let me see how it came out.

I did what BenBow suggested and went ahead and used my 3 1/4" hole saw and the MDF scraps on hand this week.  I spooled it up with an 1/2" handle bolt that has a good solid portion on the end to couple with the motor shaft.  After gluing the MDF rounds together then it was fastening to the bolt via an 1/2" hole drilled in the center of the drum.  A good friend with a metal lathe chucked it up by the bolt and trued up the spindle good and clean for me on Tuesday evening.  After that I glued a strip of white paper to the drum to protect MDF fibers from being torn out in use.
Now I need to pick up a rigid 1/2"x1/2" coupler and finish building the stand and I will be ready to go.
The next step is to see if a 3" sleeve will fit.  It has come out just undersized of 3" diameter.  My thought is to slip a bike tire innertube over the spindle/drum to thicken it and give it surface for gripping the sleeve.  Or I could try gluing sandpaper to the drum but how difficult is it to peel off when I want to replace it?  Some of those self adhesive disc sanding pads are a pain to clean off.  
I am really looking forward to contouring some risers with this set up as soon as it is finished.

[Robertfishes]

sounds like you will have a good one. I'm glueing up tonight right after I eat a little supper..I lightly went over the riser with a 50 grit sleeve it feels about like the rough side of a piece of fiberglass.