Shopsmith Forums

Bought used bandsaw for my mark 5, blade keeps coming off after turning on, how do I keep it from coming off? Has anyone else have this problem?

It is a common problem that could be caused by a number of different causes.
1. Speed too high
2. Bent or damaged blade
3. Tension set wrong
4. Misaligned guides
5. Bent or damaged parts on the saw.

And, probably a lot more things can cause it. The manual is useful in giving you tips on how to align it and set it up properly. I started there when mine was throwing the blade.

Have you been through the manual and the set-up procedure? What width blade are you using?

Here is the manual on-line: https://www.shopsmith.com/ownersite/manuals/845539.pdf

garys wrote: Tue Feb 02, 2021 7:30 am It is a common problem that could be caused by a number of different causes.
1. Speed too high
2. Bent or damaged blade
3. Tension set wrong
4. Misaligned guides
5. Bent or damaged parts on the saw.

And, probably a lot more things can cause it. The manual is useful in giving you tips on how to align it and set it up properly. I started there when mine was throwing the blade.

Upper Wheel Cant not right!!!!

You can verify proper cant by 1) unplug power, 2) remove cover, 3) mount a blade, 4) manually spin the wheels and watch the blade. The band should seek a position toward the back of the wheel UNTIL the blade comes in contact with the guide bearings.

If the blade tracks forward toward the front edge of the wheel it is likely that the cant is wrong.

viewtopic.php?f=10&t=22798&p=261831&hil ... nt#p261831

Also, check that the tires on the bandsaw wheels have not come loose from the wheel. You can see that by running the saw with the cover off. If you see a tire separate from the wheel when it gets up to speed, the tire needs to be replaced as that will throw the blade.

First let me say Welcome to the Shopsmith Forum.

The "cant" Dusty is talking about is not on all Shopsmith/Magna Line Band Saws. In 1984 the 2° Bevel was added to the upper wheel. Before that the wheels were in line. That Bevel/cant was added to make them track better but earlier Band Saws will track fine without it. That bevel is in the upper arm assembly P/N 517640 and could be replaced on an older Band Saw to add the bevel. My 1956 Band Saw without the bevel, that I restored, tracks just as well as my 1998 Band Saw. In any case follow the setup and alignment instructions. As others have said release the blade tension when not in use. Not doing that could lead to tracking and other problems.

If replacement parts are needed the current parts will work on the older Band Saws. Because of small changes some may require more than an individual part. Replacing older cast iron table parts with new parts from the newer Aluminum Table will require an upgrade to the Aluminum Table. The table is the biggest single change made to the Band Saw over the years.

One more thought. In the link Dusty provided.
beeg said,

You can check the cant by laying a metal yard stick vertically across the upper wheel and measure the gap between the yardstick and the lower wheel. It should be about 1/6".

That gap would only be in Bandsaws made after April 1984 or earlier ones with the upper arm assembly replaced. This is also a good way to check the wheel alignment to see if the upper wheel is canted wrong. Placing a long metal straight edge across both wheels check that the upper wheel is not canted down instead of up or no cant. Also check the lower wheel to see if it is running true, no wobble.

chapmanruss wrote: Tue Feb 02, 2021 12:31 pm First let me say Welcome to the Shopsmith Forum.

The "cant" Dusty is talking about is not on all Shopsmith/Magna Line Band Saws. In 1984 the 2° Bevel was added to the upper wheel. Before that the wheels were in line. . . .

I do not understand that. The patent drawings clearly show both wheels with a 2 degree bevel and a corresponding upper wheel cant.

JPG wrote: Tue Feb 02, 2021 7:01 pm

chapmanruss wrote: Tue Feb 02, 2021 12:31 pm First let me say Welcome to the Shopsmith Forum.

The "cant" Dusty is talking about is not on all Shopsmith/Magna Line Band Saws. In 1984 the 2° Bevel was added to the upper wheel. Before that the wheels were in line. . . .

I do not understand that. The patent drawings clearly show both wheels with a 2 degree bevel and a corresponding upper wheel cant.

That is what I thought when Russ said that. Everett Davis posted an article about the original Magna patent for the band saw.

I don't recall ever seeing patent drawings for the Bandsaw.

From Everett January 15 2016 in a forum post.

I just got off the phone with Shopsmith Customer Service and was told that the 2° Bevel was added in April 1984 to the upper wheel. Prior to that, they said they were flat like the lower wheel. That may answer some of the questions since many of us have Bandsaws from early and later production.

I just checked my 1956 and 1998 Bandsaws and here is what I found. Using a 3' metal ruler across the upper and lower wheels the 1956 Bandsaw is not flat across both wheels but appears to have a cant downward on the lower wheel. This must be cast into the Main Frame (back) part. The upper wheel appears to be at 0° to the Main Frame. The 1998 Bandsaw has the 2° bevel on the upper wheel and the lower wheel appears to be at 0° to the Main Frame casting.

I do know there was a change in the Main Frame Assembly. The early casting had pressed in Bushings. The later/current casting has slip in Bushings. I believe this change occurred with the Aluminum Table upgrade but I am not sure. So now my questions from what I learned today.

Did the early Main Frame castings actually have a 2° bevel or any cant on the lower wheel? My 1956 appears canted downward but Everett's information from Shopsmith has both wheels as originally flat.

If the lower wheel was originally canted was the Main Frame casting changed at the same time as the 2° bevel being added on the Upper Arm Assembly in April 1984?

When was the Main Frame casting changed from pressed in bushings to slip in bushings?

Does that coincide with the change to the Aluminum Table? I had a December 1985 Bandsaw with the cast iron table that I refurbished and sold. That Bandsaw was made after the 2° bevel was added on the Upper Arm Assembly in April 1984 according to Shopsmith. I didn't check for any bevel or cant in the wheels. I don't recall if it had pressed in or slip in bushings.