Belt sander info needed

[AGCB97]

Hi
I'm in the process of building a 2" x ??" belt sander and have a few questions for those that have either a commercial or shop-built unit.

1st, On the tracking wheel, how much of a radius should there be on the face. If a straight edge were placed on the face, how much lower would the edges be than the center? This will probably be nominal 3.5" diameter.

2nd, What should be the width of that wheel? I assume something more than 2".

At this time, I just building parts for it but will soon, when all the parts are on hand, begin assembly.

Thanks for taking the time to give me advice!
Aaron

 

[talvare]

I can't tell you what the proper design specifications should be for the crown on the tracking wheel, but can tell you what worked for my 6 x 48 belt sander. The belt on my sander just wouldn't track for more than a few seconds, so I checked the tracking wheel to see how much crown it had. It didn't have any, zero. I mounted the wheel on an arbor in the lathe and turned a 2 degree taper both directions from center and it has tracked perfectly ever since. So, just take that for what it's worth.

Ted

 

[C-Bag]

I don’t mean to horn in on your questions but I have a couple myself. Like why doesn’t anybody else but MultiTool track by just rotating the wheel like they do? Neither of the wheels on my MultiTool have a crown(the one front wheel has ribbed rubber and is also the one that rotates to track). It also has a spring with a catch so you knock in to change the belt and then just pull the latch and it pops out and automatically tensions the belt.

Any comments why most of the 2x72 I see have variable speed?

 

[projectnut]

I picked up a very basic Kalamazoo 1" x 42" belt sander earlier this year. The drive wheel is more like a rubber tire than a drive wheel. The tracking wheel is 2" wide with a 2* taper in each direction from the center. My 6" x 48" Rockwell/Delta has the same taper just like the one talvare described.

The smaller machine is referred to as a sander by Kalamazoo while the larger Rockwell/Delta is referred to as a grinder. The smaller one has a 1/3 hp motor that turns at 1,750 rpm. The larger machine has a 1 1/2 hp motor that turns at 3,600 rpm. I'm not sure where the dividing between sander and grinder is as far as HP is concerned, but all the machines with 1,750 rpm motors I've looked at have been referred to as sanders. Here are a few pictures of the Kalamazoo. Keep in mind it's the most basic machine in their lineup.

 

[7milesup]

The following link shows how to build a bolt together belt sander.

Variable speed... a lot of folks use these for knife sharpening. You want to be able to control the speed depending on the grit and the process that you are using.
Every tracking wheel I have ever seen has a small crown to it. I built a large woodworking sander years ago (still using it to this day) and, at first, could not get the conveyor belt to track straight at all. That was before I knew that a slight crown was needed.

 

[randyjaco]

My drive and tracking wheels are @2.5" wide and the crown radius is probably in excess of a foot. Probably closer to 2 feet. The front wheels are @1.9" wide with no crown.
Presuming that your drive and tracking wheels are of aluminum, the actual radius is not critical. I did mine with a file on the lathe. It just needs some curvature.
Don't overthink it. The system is very forgiving.

 

[AGCB97]

Thanks for all the replies. I think I found out what I needed. I've made a 4 3/4" drive wheel for the motor that I have on hand. It's a 2 HP 1725 RPM Baldor. Calculates to about 2200 FPM belt speed. I'm more interested in cleaning up scaled metal and larger stock removal than finessfull sharpening of small parts so will go with what is on hand to start and see where it gets me. I'll let you know my experiences.

Thanks again.
Aaron

 

[Jspan]

Housemade has a nice set of blueprints for a 2x72 but it doesn't tell on the crown of the tracking wheel but he does have good links to drive wheels, motors and vfd for it. I just got the prints and am starting to get stuff together to build a couple for me and my boys.

 

[ddickey]

I like some of the features on this one.

 

[AGCB97]

I like some of the features on this one.

After watching several (no many) videos on building, I decided to order the plans for that one. Am I glad I did! I'd have spent much time engineering every part of that and it would not have come out near as good. The plans are very thorough and well put together. I saw in one of his videos where he said it took him 100 hours to write the plans. I believe it and together with the video, it's all very clear. A good start has been made.

Aaron