aligning/adjusting bandwheels

beerguy · October 09, 2004, 12:10:11 PM

I have a tracking problem on my mill. The band (1 1/2 inch) finds a different spot to run on each wheel, about 1/4 inch difference. This results in the blade coming off when it is not in the wood. I have a fairly accurate laser level which I am going to use to check to see if the wheels are lined up. Any tips before I get started? I do not have an actual adjustment to correct any mis-alignment, so I am just checking to see if things are square. It is a 52" Hudson, with 25 inch wheels.

beenthere · October 09, 2004, 12:26:48 PM

Are the wheels ground flat or is there a slight crown ground in?

Will be good to get to the root of the problem.

beerguy · October 09, 2004, 01:13:51 PM

One wheel has the neoprene belt that came 'stock' on the saw, the other has a 'fan belt' replacement belt on it. It has been running fine with this arrangement, until the drive wheel was found to be pushed back less than 1/4", and the blade ran hard against the guide. I put the wheel back in position, and it ran for about 6 more hours, and the same condition came back. The bandwheel is tightened onto a hub with a taper. There is a setscrew that keeps the hub from moving, but it only tightens against a key, (like a woodruff key, but flat). It is the key that is riding back in the channel on the shaft. I am getting a longer key, one that will abut the assembly aft of the hub so it cannot migrate, but I cannot imagine that the wheel would be off enough due to the key being 1/2 inch out from under the hub. Meanwhile, I wish I bought a Woodmizer....

EZ · October 09, 2004, 01:26:58 PM

There should be two set screws in it. One to hold the key in place, the other to hold the wheel in place. Sounds like the wheel is moving back and fourth. The band is holding the wheel in place as you saw.
EZ

Fla._Deadheader · October 09, 2004, 01:27:47 PM

Any chance a spacer would keep the wheel from working back onto the shaft??? A key alone doesn't seem right. Something needs to back-up the wheel so it can't migrate out of alignment ???

beerguy · October 09, 2004, 02:26:21 PM

I agree that something needs to keep the wheel from backing up, I was expecting a round Woodruff style key, but it is just a slotted shaft with a square key. And only 1 hole in the hub for a setscrew. That is why I am adding a very long key to extend back to the bearing behind the hub, for support. It should work fine once I get the bugs out of it, but I havn't had to mess with the alignment before. I put the laser on it and the wheel does seem to be a tad crooked, but I am waiting for some assistance to arrive before I draw any conclusions. I want someone to hold the laser from a few different places on the structure. How often do you guy have to 're-align' the wheels on a quality saw?

MemphisLogger · October 09, 2004, 02:40:51 PM

I had to realign my wheels after I put new bearings on my shaft. I used the edge of a freshly jointed 1x3.

The slot on your shaft runs the entire length? Could you put a stop collar on it behind the wheel? Feed pressure and the band should be plenty to keep it from coming off the front.

Are you sure there's no way to adjust the cant on both wheels? It wouldn't seem prudent to build a bandsaw that didn't.

Fla._Deadheader · October 09, 2004, 04:03:42 PM

We eyeball across the edges of both wheels, in the beginning. Then we stretch a string REAL tight across both faces of both wheels. That way, you don't have to try to "prop" a straight edge or other leveling device, to start adjusting.

I can't seem to figure from your post, which wheel is moving. If it's the drive wheel, It needs to be TIGHT on the shaft. 1 set screw is NOT enough.

beerguy · October 09, 2004, 04:35:26 PM

It is the drive wheel. I like the idea of a locking collar behind the hub for support. The shaft in an inch and a half. Are there two- piece units so I don't have to completely dis-assemble? I have pictures, but I am unable to reduce their size right now. I will try and provide a link to another web-space, my ISP's site seems to be down.

beerguy · October 09, 2004, 05:56:00 PM

Here are pics of the shafts, both sides.
http://mysite.verizon.net/res8f0h7/id12.html

EZ · October 09, 2004, 06:44:58 PM

Looks to me that the only alinement is moving the wheels back or up.
EZ

Fla._Deadheader · October 09, 2004, 07:30:40 PM

  Those look like split taper bushings. They should bite the shaft pretty hard, IF they are tightened enough.

  There MAY be a split collar. The only one I am familiar with, is a shaft zinc for marine use. It comes in various sizes and there are 2 or 4 bolts that go through the 2 halves. There is a small ball that is mashed against the shaft for absolute contact. It is for electrolysis purposes, but, I believe it will work. Go to http://www.mscdirect.com and look under collars or something. I HAVE seen 2 piece collars.

  If ya get REALLY stuck, post back and I will see what I can find. I have a very good supply house that can find anything I need. ;) ;D ;D

beerguy · October 09, 2004, 10:30:02 PM

I got some help from my brother, who is familiar with this type of hub. They are called QD bushings, stands for quick disconnect. I had called the Mfr of the mill, and they couldn't tell me the torque spec for these, but I found it elsewhere on the web. Thanks for the input, guys. It really helps! If anyone has some pics of their mills that shows how they have adjustment for the wheels, I would love to see it.
+-

beerguy · October 09, 2004, 11:03:32 PM

Deadheader,
You were right on with the link for the hardware vendors. I have a shaft collar on the way! Maybe I sould send a link to the mfr of this mill, the part was 6 bucks and would have saved me some headaches.

D._Frederick · October 10, 2004, 05:52:46 PM

Beerguy,

You should use a dial indicator when torgueing the QD bushings to keep the rim of the wheel perpendicular to the shaft. Place the indicator so that it touches the rim of the wheel and rotate the wheel as you tighten the bushing bolts, you should get the wheel with in a few thousands of being true. Also, make sure the shaft does not have paint on it where the QD bushing fits. There are shaft collars that are in two halves that bolt to the shaft that can be applyed with out tearing the wheel/bearing apart.

Are you sure that the shaft is not sliding through the pillow box bearings? I would but the collar against the bearings instead of the band wheel. The QD bushing will hold the shaft from moving.

Try McGuire Bearing @ 503 238 1570 in Portland for your collars.

beerguy · October 10, 2004, 05:55:54 PM

Went out today and put the laser across the wheels, loosened the bearings, tapped and pushed, and had the extremely close to perfect, or so we thought. Made 2 cuts, and the band blade came off again. Can the neoprene belt be a problem? The other side has a fan belt style belt, (supplied by the manufacturer after the neoprene one got too hot and degraded) Should I be running two different belts? I called a guy near me that has the same saw, has had the same problem of the drive wheel getting pushed back. I have a few more hours on mine, I have 15! I now am lost as to how to proceed.

Fla._Deadheader · October 10, 2004, 06:04:16 PM

  Is there a way to run the mill, at speed, and watch where the blade DOES ride??? We can see the bottom part of the wheels by looking at the inside of the sawhead, where the log goes through. Maybe you need to adjust the tracking a little to allow for the high speed ???

  Ours will migrate toward the front of the guides at high speed, so, we allow a bit of kentucky windage and it will not throw the blade. You need to see where the blade rides at all times throughout the cut. Then you might have an idea what is happening.

  We don't use belts, but, I would change the poly belt to one that is like the fan type.

  I have read that the poly belts will throw the blade. Some guys like them, other's hate them ???

arj · October 10, 2004, 08:17:40 PM

I had a problem with blades coming off my Hud-Son 36 nad found one wheel not plum to the other. Shimed one side of the pillow block, and had no more problems.
arj

beerguy · October 10, 2004, 10:39:44 PM

I will check the wheels from all angles, but it seems to me that they are as close now as they have been in the past. I am intrigued by the comment about neoprene belts. I saw a thread last year on this forum where someone asked about the Timberwolf Neoprene belts. They are quite different than the belts I have. They start at 25 bucks a side, so I am sure that a fan-belt style would be cheaper. Are these worth the extra $$? Are they the same as any other neoprene belt? I do not know anyone who runs them. Comments?

jgoodhart · October 11, 2004, 07:29:06 PM

Hello Beerguy

When you tighten the QD bushing is the split in the bushing squeeze shut or is it still open? Also the should be a gap between the sheave and the back edge of the flange on the bushing. If the spit is squeezed shut (or) the flange of the bushing is tight against the sheave would mean your sheave is still lose do to a warn shaft or the bushing bore. When I align my band wheels I remove the blade guides and adjust each wheel till the blade tracks in the center of wheel.

coyotebait · May 15, 2017, 11:38:33 AM

I would love to see photos of diy bandwheel adjusting mechanisms. been searching for days now . There are lots of photos of everything else . I want to build soon , but first make my print a good one. I get how to aply tension ,and understand alignment but Photos would help. thanks.