My bandsaw makes me nervous

Roger Tulk

Member
Messages
3,018
Location
St. Catharines, Ontario, Canada
The blade popped off my bandsaw today while I was using it. At first I thought I had broken the blade, but when I opened up the saw it was simply come off the wheels. I am pretty sure the problem was that I had too much tension on the blade. I find it hard to determine which way is looser and which is tighter on the adjustment screw on this Rockwell/Beaver saw, manufactured in 1981. Before the blade popped off, I had tried to reduce the tension on the blade, and probably turned it the wrong way. Anyhow, it is now, after a few minutes fussing with it, at a good tension and running fine.

The wheels on this saw are not coplanar, and I know that the know wazos say that doesn't matter, but the blade runs at the front of the lower wheel to such an extent that when using wider blades the teeth are over the edge of the blade. I would like to know how to adjust this, just for my peace of mind. On the upper wheel the blade runs at the centre of the crown, and it cuts perfectly straight.

Also, the lower blade guide sometimes does not engage the blade. I took a photo, but it was hard to focus and I didn't get a good shot, and I'm not going to take the damn thing apart again just to photograph it. So, at present the guides engage the back half of the blade, but I cannot move the guide any farther forward, and the blade is sitting about 3/16" from the circular guide thingy. Sometimes it has not engaged the blade at all. I have considered taking a round file and elongating the bolt hole for the guide in order to move it farther forward. Does this sound like a bad idea, or am I missing some fundamental point about installing a blade in a Rockwell/Beaver (now Delta) 10" bandsaw?
 
An attempt strictly from memory to provide a generic overview. Your BS should probably be similar regarding adjustments:
1. Kill power to the saw.
2. Remove the blade
3. Loosen the blade guides.
4. Open the top & bottom doors & get a good straight edge.
5. Lay the straight edge against the face & near the hub of both wheels.
6. Use a flash light to see how well the top & bottom wheels bear against the straight edge. Also check out the near the OD of the wheels for reference.
7. This will give you a good idea of how well the wheels are aligned in terms of parallelism & planarity.
8. Using the lower wheel as the reference to adjust from, adjust the upper wheel, if necessary, for parallelism using the tilt adjustment.
9. When the wheels are parallel to each other, then you can adjust for co-planarity
10. For co-planarity, add or remove shim(s) from behind the top wheel hub to get both wheels on plane.
11. Install the blade, spin the wheel & adjust the tilt mechanisn to center the blade.
12. Once the wheels are co-planar, & the the blade is centered, you can install the blade guides.
 
...I have considered taking a round file and elongating the bolt hole for the guide in order to move it farther forward. Does this sound like a bad idea, or am I missing some fundamental point about installing a blade in a Rockwell/Beaver (now Delta) 10" bandsaw?

Yes, it sounds like a bad idea to me. If you fix the co-planar problem, the blade guide problem will probably go away too. ;)
 
OK, I checked the alignment of the wheels, and find they both tilt towards the back. The upper wheel can obviously be adjusted by the mechanism for this purpose, but that would cause the blade to not ride on the crown of the tire. According to material I have seen, that is the gold standard for the upper wheel, and when I adjust the wheel to put the blade in that position, it cuts straight as a die, with no drift whatsoever.

Now, to the bottom wheel. I cannot see how to adjust it at all. I took the nut off the front of the wheel once, but couldn't figure out what tool I needed or how to remove the next fastener. So, I will have to find a mechanic to help if I am going to do anything with that wheel.

Come to think of it, the two wheels tilt from the vertical by the same amount, If could move the upper wheel back, or the lower wheel forward,That could achieve coplanarity. This could possibly change the position of the blade on the lower wheel, but I'm a poet, not a mechanic, so I don't know. Even if I got the wheels coplanar by this method, wouldn't it be thrown out of coplanarity as soon as I adjust the position of the blade on the upper wheel?

Or am I just overthinking this, and should shut up and just use the bandsaw?

This is where the blade rides on the upper and lower wheels. This is a ¼" blade.

bandwheel01.jpg bandwheel03.jpg


This is the lower blade guide. That is as close to the bearing as I can get. Sometimes the blade misses the guides completely.
bandwheel02.jpg


This shows the amount by which the wheels lean from the vertical. On the upper wheel look between 7 and 10 inches, and between 27 and 20 inches on the lower.
bandwheel04.jpgbandwheel05.jpg

All suggestions, opinions, advice and jokes welcome! TIA.
 
Oops, sorry, looks like my last response didn't make it. I frequently hit the back button instead of the Submit Reply button & lose my post response.

To the best of my knowledge the bottom wheel is basically a "fixed" wheel in that the adjustments are made to the top relative to the bottom wheel. However, if the top wheel cannot be inward, towards the rear, to achieve coplanarity then adding shims to the bottom wheel may be in order, "if this can be done". Since both wheels are parallel to each other, as indicated above, then typically what remains to be done is to shift the top wheel using shims so they are coplanar. Some people don't advocate coplanarity, but I believe most do. So, the following comments:

  1. If the lower wheel cannot be adjusted "reasonably" easy, then don't.
  2. Align the upper wheel as close as you can towards coplanarity.
  3. Once this is done, then adjust the tilt to center the blade as best you can.
  4. Typically the blade is centered on the top wheel & the blade falls centered "within reason" on the bottom wheel.
  5. Then adjust the blade guides.

This should get your saw back on "track".
 
Roger, on my BS you don't adjust the back guides to touch the back of the blade when the saw is not running and it doesn't touch when the saw is running until you start sawing a board. My book says to adjust it about the thickness of a dollar bill back from the blade. So there is something you can use that first dollar you made for and still not have to spend it......:rolleyes:
 
What Paul said. The rear of the blade comes into contact with the thrust bearing when pushing against the blade when actually sawing. A slight gap like $1 is good, but I'm not going to go as far as Paul with the "first dollar" advice. :rofl:
 
Thanks, Paul. I knew that!! :doh: I had just forgotten about the screw that holds the thrust bearing in place.Both thrust bearings are neatly placed about 1/32" from the back of the blade now, and the blade is at a perfect 90º to the table, in both directions, so I reckon I will continue to use it until I figure out the wheels. I just had a kiiler idea for a bandsaw box.
Oh, we don't use dollar bills in Canada any more; the $1 and $2 bills have been replaced by coins. The $5 will be next, but the government hasn't said when. The $1 coin is much too thick to use to adjust the thrust bearings. We've also got rid of the penny, so for some reason we end p with a lot of dimes in change. :rofl:
 
Don't think I'd like the coin thing, I hate carrying around a bunch of coins. I hardly carry and cash anymore, that is what debit cards are for. I hate even having to carry the big key things the cars have now days. Makes it awful hard to keep the pants up when you have the old man flat posterior! Going to have to get me some of those "suu-pen-ders" thingies!
 
Yes ad get rid of the 9/10 cent on gas prices! What good is that. You ever notice that people always round gas prices down when they say how much gas is.

Like Al just rounded down instead of the way it is suppose to be done... :D
 
We should have gotten rid of the 5 cent piece as well. That would make the math easier and change simple, although we should revamp the entire coin system so we have a $.1, $.5, $1, $2, and $5. Then change the sizes so everything is workable and we don't have any coins larger than the present 25 cent coin. Other countries have done it, after all. A dollar today buys less than a dime did in 1960, so why hang on to the smaller coins?
 
Boy have I got a deal for you! Just send all your pennies and nickels my way and I'll dispose of them for you for FREE!!! :thumb: :D

If it helps, break down those pesky dollar bills as well and I'll accept those too. ;)
 
Me too .
Look after a penny and get a pound.
I am still remebering buying a loaf of bread for 9cents in SA in my youth and getting 1 cent for bubble gum we called chappies. :)


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