I finally fired up the sander now that I made templates / holding fixtures, etc... But as I feared the drum having a hump in it to help belt track makes the riser not square...Im not sure what people are doing about this with similar rigs but this is entirely not acceptable results I got.

QUESTION... If I machine the idle roller Im sanding against flat.... will the belt still track due to hump on drive wheel ?

Id appreciate advice from those who have similar experience.... Im a lil stressed fellas

Thanks guys   

Can you buy a new roller if you mess it up?
If yes you have nothing to loose and much to gain.

Quote from: Mad Max on September 24, 2021, 03:42:31 PM
Can you buy a new roller if you mess it up?
If yes you have nothing to loose and much to gain.

Not available....

 I tried to tell you to stick with Stic...     

My gut tells me that if you flatten that roller you could have problems maintaining your tracking... But I could be wrong and it may not make a difference...   I flattened my drive roller 3" to 4" in the middle of my roller and have no issues...

  Maybe someone will chime in that has flattened that roller...

Hey Stic... what ya think??

You should only need one radiused pulley. If your drive wheel has a belly, that should do the trick. I built a 2X72" belt grinder that has 4 pulleys, plus the drive wheel and only one pulley has a slight radius. It tracks fine. If you are worried about screwing it up, the smart thing to do would be to make a flat one to swap out. Or true it up by hand after using the current set-up. Or maybe sleeve the current one with some thin tubing and set screws.

Quote from: Flem on September 25, 2021, 09:49:18 AM
You should only need one radiused pulley. If your drive wheel has a belly, that should do the trick. I built a 2X72" belt grinder that has 4 pulleys, plus the drive wheel and only one pulley has a slight radius. It tracks fine. If you are worried about screwing it up, the smart thing to do would be to make a flat one to swap out. Or true it up by hand after using the current set-up. Or maybe sleeve the current one with some thin tubing and set screws.

Good idea..... I taped it up to take belly out...it vibrated a lil lol...but belly was gone and it tracked ok and sanded square... Im going to decide to leave on tape or mahine roller flat...... pondering lol   

My 6" x 80" Grizzly  has a 1-1/2" flat roller.
The 4" driver roll is the radius roller.

Quote from: Mad Max on September 25, 2021, 11:28:18 AM
My 6" x 80" Grizzly  has a 1-1/2" flat roller.
The 4" driver roll is the radius roller.

Wow, no kidding ? Its basically same as miy shop fox isn't it ? My idler roller is about 3" though

The top of the roller tilts  this way for tracking

I have a 6x80 Grizzly. I had the middle 4" of the 6" Aluminum drive drum/wheel machined flat..I did buy a new one for a spare in case it did not work..no problems it works fine, still have the spare. Tracks as it should, remember when making jigs to only use the middle 4 inches that was machined flat.

Quote from: Robertfishes on September 25, 2021, 11:57:05 PM
I have a 6x80 Grizzly. I had the middle 4" of the 6" Aluminum drive drum/wheel machined flat..I did buy a new one for a spare in case it did not work..no problems it works fine, still have the spare. Tracks as it should, remember when making jigs to only use the middle 4 inches that was machined flat.

Robert thanks for the tidbit...  I may jneed to come visit you someday soon if ya dont mind n see that

 Maybe all three of us could get together...  I am in Palm Bay FL...  About three hours away...

I have not run sanders or band saws since I was in a car wreck 5 years ago. I'm gonna try to get back in shop next spring.

On the Grizzly 6x80 you flatten the center 4 inches of the large aluminum drum above the electric motor because it dose not move like the adjustable "Idle Wheel".

My idler is hard rubber.
Don't know what yours is.my advice would be use the drive drum because I don't think you will ever get the best results on the idler end.

I made one years ago on the idler end. Its on a grizzly 6x80 . It works but it does have some good and bad.

Bad   --  the roller and table are square. But the table tilts to track the belt.

Good  --  it only cost about $5 to make

If I was to do it again I would put it on the other end.

[attachment=1,msg2977120] I found a shop picture from 6 or 7 years ago and cropped it to show the drum and rub coller. I remember Stic, Jess and a few others having them and I made a similar copy to what they were doing on their sanders. I have a Grizzly 6x80.

Very good Robert.

Thanks CS, You got me thru several bow building issues back in the day... 

Quote from: Robertfishes on September 28, 2021, 10:11:03 AM
[attachment=1,msg2977120] I found a shop picture from 6 or 7 years ago and cropped it to show the drum and rub coller. I remember Stic, Jess and a few others having them and I made a similar copy to what they were doing on their sanders. I have a Grizzly 6x80.

Wow, very nice !