EXTREME band saw blade drift

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Forum topic by MuseumGuy posted 08-31-2015 03:08 AM 1298 views 0 times favorited 18 replies Add to Favorites Watch
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8 posts in 424 days

08-31-2015 03:08 AM

Topic tags/keywords: band saw blade drift shopsmith question

Hi everyone. I have a (used) Shopsmith band saw where the drift is so extreme that no matter how much I angle the infeed it still just keeps drifting. Eventually I am feeding the stock at such an extreme angle (about 30 degrees from centerline) that the blade binds and the saw trips a circuit breaker.

I have checked and double-checked everything I can think of: I adjusted the upper and lower guide blocks and rollers, checked the squareness of table to blade, and increased blade tension. [I kept cranking up the tension on the blade—a 1/2” 3 TPI re-saw blade—and it didn’t solve the problem. Eventually I cranked it up all the way and all it did was throw the blade off the wheels.] I have tried three different blade widths/types. I have tried raising and lowering the blade guard height. I checked the wheels and both rotate true without wobble.

There are two things I haven’t tried: replacing the tires and putting in new guide blocks. Could worn tires or guide blocks be causing this kind of problem?

Thanks for any ideas or suggestions you might have.

18 replies so far

View MrUnix's profile (online now)


4049 posts in 1623 days

#1 posted 08-31-2015 03:15 AM

You didn’t mention anything about how you set the tracking?


PS: Obligatory video: Band Saw Clinic with Alex Snodgrass

-- Brad in FL - To be old and wise, you must first be young and stupid

View Logan Windram's profile

Logan Windram

289 posts in 1886 days

#2 posted 08-31-2015 04:17 AM

A sharp well made blade will still cut stock easily with the blocks completely removed. I don’t know, I have set a fence at pretty decent angles to account for drift, 35 degrees does sound like a lot.

Are you feeding to fast? Is your blade upside down, when unwinding that rolled blade was it turned inside out? Are the blades resharpened and done incorrectly? Are you cutting wood, not ply or Mdf?

View ForestGrl's profile


445 posts in 510 days

#3 posted 08-31-2015 04:29 AM

Second the motion to ensure proper tracking of blade on wheel. Another thought was whether the blade-tensioning spring might be worn out, but obviously it was tensioning (having come off the wheel). Although….the fact that it came off wheel may hint at improper tracking?

-- My mother said that anyone learning to cook needed a large dog to eat the mistakes. As a sculptor of wood I have always tried to keep a fireplace. (Norman Ridenour)

View MuseumGuy's profile


8 posts in 424 days

#4 posted 09-01-2015 01:26 AM

Hi Mr. Unix, Logan, and Forest Grl:

Thanks for your helpful questions and comments. I’ll try to address these below.

1. Blade tracking
The Shopsmith bandsaw is unusual because it does not have a blade tracking adjustment. There is an “auto-track roller bearing” mounted just below the spot where the blade contacts the idler wheel—but it has no front-back adjustability. You can only move it side to side—so that it is centered behind the blade. You can’t use it to adjust where the blade rides on the wheels/tires.

2. infeed speed
Very slow: cutting 4” thick hardwood stock, I am moving at a pace of about 30 seconds per inch.

3. blade quality and sharpness
Have tried three different blades, one (used) 1/4 general purpose, one 3/8” 4 tpi (new), and one 1/2” 3 tpi (new). Blades were sharp enough that I needed band aids after blade installation. All 3 mistrack.

4. blade orientation
It’s a valid question—especially for a beginner like myself—but the blade is correctly oriented with the munchy-munchy teeth point downward.

5. material being cut
Blade drifts on both hardwoods and softwoods of all types I have tried (maple, oak, crab-apple, pine).

6. Worn blade tensioning spring
Not sure how to tell if it is worn, but I did follow the procedures in the manual for re-aligning the blade tension scale.

At this point the guide blocks are looking more and more like the culprit: they are very worn down and don’t seat themselves perfectly parallel to the blade (bottom edges of the blocks are nearly touching the blade, but upper edges ride about 1/32 away from blade).

I’ll probably get new blocks soon. May be I should order new tires at the same time, but I don’t know how to tell a worn band saw tire from a non-worn one…

Thanks again for your help. I’ll re-post if I make any progress.

View Jim Finn's profile

Jim Finn

2391 posts in 2346 days

#5 posted 09-01-2015 02:38 AM

I had similar problems until I went to carbide blades. Fixed the issue. No more drift until I finally dulled that blade. I get 105” carbide blades 1/2” for re-sawing for $25 from “Supercut”

-- "You may have your PHD but I have my GED and my DD 214"

View Nicky's profile


695 posts in 3516 days

#6 posted 09-01-2015 02:48 AM

The blade should be riding the crown of the tires. The tires should fit tightly, with no play. Insure that your tracking is true. Do this by hand for a few revolutions.

From you description, it sounds like the blade has a lot of play, and that may be under tensioned. Try the tension’ing spring adjustment you mentioned above.

A few degrees either way is acceptable, not 30 deg.

-- Nicky

View DrDirt's profile


4143 posts in 3166 days

#7 posted 09-01-2015 04:15 AM

as many have said – obviously the blade needs to track the center of the upper tire. it is ‘nice’ to be reasonably centered on the bottom – but really the bottom wheel is to complete the blade circuit. The tracking is controlled from the top tire throught the guide blocks… then through your workpiece.
What happens below the table is pretty irrelevant (within reason)

I would look at the specific shopsmith forum that deals with this rollerbearing autotrack ‘feature’

The obligatory video from Mr. Unix is truly the best IMHO… but not applicable to a shopsmith.
I cannot imagine a way to even intentionally make a blade track 30 degrees from true.

-- 'Political correctness is fascism pretending to be manners' ~George Carlin

View MuseumGuy's profile


8 posts in 424 days

#8 posted 09-01-2015 03:23 PM

Thanks Jim, Nicky, and Dr.Dirt for your input.

I took a look at the Shopsmith forum thread a while back before setting up the bandsaw, and thought that I followed all of these procedures, but mabe I got lazy somewhere. Since tires are firmly seated to wheel rims and since blade appears to be tracking correctly as it contacts and exits the idler wheel, I’ll try replacing the guide blocks. When I do, I’ll probably start from square one and recheck all adjustments discussed on the Shopsmith forum thread. I’ll report back this weekend.

View Clarkie's profile


380 posts in 1265 days

#9 posted 09-01-2015 03:54 PM

Hello Museum, do yourself a favor and call ShopSmith, they are more than willing to walk you through a fix. More than likely it is something simple and after awhile you just can’t see it. I’ve had an abundance of really helpful conversations with the help at ShopSmith, they are more than willing to help.

View chrisstef's profile


15486 posts in 2430 days

#10 posted 09-01-2015 04:03 PM

Try setting the blade so that the gullets of the teeth sit in the middle of the wheels. That alone made a world of difference for me with my bandsaw.

-- "there aren’t many hand tools as awe-inspiring as the #8 jointer. I mean, it just reeks of cast iron heft and hubris" - Smitty

View Gene Howe's profile

Gene Howe

8109 posts in 2852 days

#11 posted 09-01-2015 04:05 PM

Hey MG,
My Shopsmith band saw is a 1975 vintage and I’m the original owner.
Drift was always a problem for me, too. Last year I bought the Carter system and haven’t had a problem since. I’ve been running a 5/8 Shopsmith blade through 5 3/4” white oak and have been getting perfect cuts.
I don’t know how old your saw is or if the previous owner abused it, but my experience is that the tension spring doesn’t get weak.

EDIT: Chrisstef’s suggestion is an excellent one, also.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View RobS888's profile


1981 posts in 1269 days

#12 posted 09-01-2015 06:04 PM

Try setting the blade so that the gullets of the teeth sit in the middle of the wheels. That alone made a world of difference for me with my bandsaw.

- chrisstef

+1 gullets in the center! It looks funny with a 1/2 inch blade, but works perfectly.

-- I always suspected many gun nuts were afraid of something, just never thought popcorn was on the list.

View Woodendeavor's profile


276 posts in 2030 days

#13 posted 09-01-2015 07:21 PM

Your blade had no teeth set on the one side making it always wanting to turn. With the saw off run your finger down the side of the blade that it is turning away from and then compare that to the side it is turning towards. Some how there is no set to the one side causing your problem

View Bill White's profile

Bill White

4408 posts in 3384 days

#14 posted 09-01-2015 08:01 PM

I had the MAGNA forerunner to Shopsmith for years. Never had such an issue. Used the phenolic “Cool Blocks” just kissing the blades, tensioned to the indicator.
I did put on new tires considering the age of the saw when I got it.
Try starting over with the set up. Rubber tires? Glued to wheels?
Keep us posted.


View bearkatwood's profile


1175 posts in 435 days

#15 posted 09-01-2015 08:02 PM

It sounds like the wheels are out of plane with each other. use a straight edge set even with the bottom wheel and see where the top wheel is. my guess is it needs to be pushed back on the arbor a bit.

-- Brian Noel

showing 1 through 15 of 18 replies

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