BMW-Style 1x42 Belt Sander

[exmaxima1]

A few years ago I made a variable speed belt grinder for sharpening my knives, and lately I find that I also like it as a slack belt sander, so I decided to build one for use at work for de-burring and small tasks. I wanted it very simple, similar to my 2x42 Kalamazoo, with a telescoping arm that doubles for tension and tracking.

I bought a hard rubber caster wheel for the drive and after truing it up on the lathe, fitted it to an old Dayton (made by Doerr) bench grinder I no longer used. I then started looking for an idler wheel. Dayco is a large supplier of automotive idlers, and Amazon had alot to choose from.

I came across a complete idler assembly for use on older BMW's which looked very nice and it would eliminate that need to fabricate a telescoping arm. Plus it was really cheap: $8 delivered (retail $135). And did I mention it's from a BMW V12!!

Anyway, the pics pretty much show how I made it. A block of aluminum, a Thompson rod cutoff, a few scraps of angles, and a couple of bolts. If I had a stronger spring in my junk box, there would be no need for the adjuster on top. But still very simple and works great. Those old Dayton grinders are very slim and give lots of working clearance.

 

[pi_guy]

What is a Thompson rod?

 

[exmaxima1]

What is a Thompson rod?

Sorry, I meant Thomson rod. A hardened shaft used for machinery and linear actuators.

 

[pi_guy]

I used to work there. At one time they were the leaders in linear motion products.
That is why I asked, they have moved believe they were bought by a Japanese company.
I see the former owners son all the time he owns a bait store and marina.

 

[the gypsy]

Nice work. Keep it simple works all the time.

 

[BJ42LX]

Impressive.

How do you adjust the belt to keep it in the middle of the wheels?

 

[Mohawk Dave]

I've been using my Burr King and Foley Belsay so much lately, that I want to start building these to keep different belts on and what not.

Great write up. I have several extra grinders, so I guess that is the next project. Good belts are so dang cheap on ebay too.

 

[exmaxima1]

Impressive.

How do you adjust the belt to keep it in the middle of the wheels?

You loosen the lower knob and twist the upright rod slightly. It only takes a little, and so far I haven't had to re-adjust it when I change belts.

 

[Packard V8]

Excellent!

Some automotive idler pulleys have a really strong internal spring tensioner in the mounting boss. Use one of those and no need for the extra spring.

jack vines

 

[exmaxima1]

Excellent!

Some automotive idler pulleys have a really strong internal spring tensioner in the mounting boss. Use one of those and no need for the extra spring.

jack vines

A few years ago I tried that, but the spring was too strong. Plus, it wasn't from a BMW V12

 

[BJ42LX]

A few years ago I tried that, but the spring was too strong. Plus, it wasn't from a BMW V12

True that. First time I put a belt on my Delta 6x48" I screwed down on the tensioner until the belt went "pop". Oops.

 

[404]

Very nice. Since you bought that idler the price on amazon has rocketed up to 18.24
Probably the first one sold in 6 months.
Regards,
404

 

[Provincial]

Very nice. Since you bought that idler the price on amazon has rocketed up to 18.24
Probably the first one sold in 6 months.
Regards,
404

That is because there are only 9 left in the world now!

 

[exmaxima1]

That is because there are only 9 left in the world now!

LOL

But did you know that the BMW "735" used in the first TRANSPORTER movie actually had been retrofitted with a V12 engine? Much better for wheelspin. So that makes 10....

 

[BJ42LX]

LOL

But did you know that the BMW "735" used in the first TRANSPORTER movie actually had been retrofitted with a V12 engine? Much better for wheelspin. So that makes 10....

By retrofitted you mean they changed the trunk badge? [From whatever is used on the V12 car to a 735.]

They would have had better results with a LS1. Ligher, more powerful and cheaper.

 

[404]

That is because there are only 9 left in the world now!

I will buy them all and hoard them and make a killing on resale.
Now I know what to do with my IRA.

 

[exmaxima1]

By retrofitted you mean they changed the trunk badge? [From whatever is used on the V12 car to a 735.]
i

From what I recall, it was a significant ordeal since the V12 models only came with autos. They had to mate a manual to the V12.

From Wiki, " The Transporter (735i) which was a one off manual 750i badged as a 735i"