Tube Sanding

[Mark18969]

I am trying to find a quick way to sand the outside of 1-1/8" Aluminum Tubing to put on a grain finish and remove the line marking from the mill. I saw at another shop a machine they had said they built from a baseball pitching machine. It had 2 wheels spinning with a sanding belt wrapped around and the bar or tube being sanded would feed right thru in a few seconds.

Anyone have any ideas? I don`t want to tie up a lathe with someone going over a large volume of these by hand.

[keebler303]

do you want the grain of the sanding to be down the length of the tube or around the tube?

Matt

[Mark18969]

The parts in the past the grain was around the tube. Sort of like feeding thru a centerless grinder. The part is getting powder coated. There is a casting being welded to one end. We want the sanding to blend in the machine marks from when we turn the weld off, and to remove the lettering on the tube from the mill.

[keebler303]

Something like this should work. You will need a drive roller on top of the tube. It would be mounted on the same angle as the roller blade wheels. As the tube spins, it advances through the belt sander. The pitch of the wheels and speed of the drive roller would determine the angle of the sanding marks on the tube.

Good luck
Matt

[mxtras]

That would do it. The only issue is after the end of the tube exits the first set of rollers - the tube would drop away. You have the same problem getting it started.

Good idea!

Scott

[keebler303]

You would have to have infeed and outfeed rollers to alleviate that problem. It might also require a second drive wheel on the outfeed as it would mess up the continuous surface finish when the tube passed the drive roller and there was nothing pushing it through.

Matt

[mxtras]

It's a nice solution you offered up, Matt.

...wonder what Marko thinks of it??

Scott

[Geof]

Originally Posted by keebler303 ..... It might also require a second drive wheel on the outfeed as it would mess up the continuous surface finish when the tube passed the drive roller and there was nothing pushing it through. Matt

With a tube I would be tempted to devise some kind of pusher rod that had an extension to fit inside the tube and an OD the same as the tube. This way you could carry the tube through the sander without any wobbling or pausing.

[mxtras]

What about some kind of hand held gizmo? Got any ideas about something like that?

I can see a handheld belt arrangement with three rollers - the middle one is spring loaded to allow you to engage it around the tube and the outer two wheels would wrap around - kind of like a clamshell. Might be tough to get a consistant finish. Might also be tough to get an angled finish on the tube.

Just thinking out loud..

Scott

[keebler303]

The pusher rod is a good idea. Would make it simpler to build the machine. It would be a bit of a pain though because it would need to be an expanding mandrel. The drive wheel has to spin the tube against the pull of the belt sander (or at least thats how I envisioned it). The pusher would have to withstand this torque. Something handheld would work for certain circumstances but I would think it would be a pain to do a 20' section of tube or something. You would still need to keep it off the ground and fixed from rotating. Unless there is not enough volume to justify it, I would think a machine where you just feed the tube right through would be most productive.

Matt

[Geof]

Originally Posted by mxtras What about some kind of hand held gizmo? Got any ideas about something like that? I can see a handheld belt arrangement with three rollers - the middle one is spring loaded to allow you to engage it around the tube and the outer two wheels would wrap around - kind of like a clamshell. Might be tough to get a consistant finish. Might also be tough to get an angled finish on the tube. Just thinking out loud.. Scott

Regarding your second question: My idea is that this might be a bit dangerous.

Perhaps if you had fixed In-Feed and Out-Feed tubes concentric with the center of the centerless sanding wheels. You push the part into the tube until it is grabbed by the sander which spins it through and spits it out into the other tube.

[Nono]

use an expandable drum sander and expand it inside to tube chuck it in a drill and go
http://www.rockler.com/product.cfm?p...=drum%20sander