Band saw blade change problem

[dgreen810]

I purchased a Timberwolf 1/2 x 72" blade to do some extensive re-saw work. Removed the 1/2 blade that was on the machine. I am almost positive is an original SS blade. In spite of all my efforts, the Timberwolf blade works it's self off the front of the upper wheel almost immediately . I re-installed the SS blade an no problems. I ran the blade guides back so there is no tension on the blade no tension from the support rollers either. The blade came yesterday via Priority mail in a package pretty well damaged. I am wondering if the blade it's self may be damaged. Looking for experiences from others before I contact SUffolk Machinery.

I also installed a 1/4" blade, no problems then installed an additional 1/2" blade (Maker unknown), and it runs with no problem.

Suggestions please??

Don G

[JPG]

I would claim shipping damage, get a replacement and go from there.

It would be interesting to place it on a known flat surface to see how straight the back edge is.

[charlese]

Turn your Timberwolf blade inside out so the teeth point down.

[dgreen810]

I did some checking this morning and found the following: I took a 30" straight edge touching the upper wheel rims extending down past the rims of the lower wheel and found the wheels are within 1/16" of being co-planer. It appears the previous owner or someone may have tried to make them parallel, or maybe over tightened a blade bending the upper wheel arm. What I don't understand is three different SS blades running true with no problems.

Before I do something I may regret, someone tell me what the gap should be if I lay the straight edge touching both rims of the upper wheel extending down over the both rims of the lower wheel???

By the way, I guess I am stubborn, but I don't quite get the "In side-out" statement. It seems to me, there is only one way a blade will work. Teeth down!!

Don G

[charlese]

The distance should be 1/4" or a little more.

If a new blade gets twisted when un-packaging, the teeth of the blade will point upwards when mounted on the saw.
The way to fix this is to grasp the blade in both hands about a foot or so from each other with thumbs down. Then rotate your hands so both thumbs are up. The blade will turn inside out. (Really right side out)

I had assumed your blade got twisted (flipped) when un-packaging. (or packaging)

[dgreen810]

Charlese

Thanks so much! The blade did not get flipped it had 3 wire ties on it so I know it was correct. I did hold it as suggested and managed to get it so the gap is about 3/16 but don't have enough strength to go any further without taking the wheel off and using a "Cheater" on the shaft. I did re-install the Timberwolf and will run for several revs. and start working its way off the front. Did notice that you can turn it backwards until the cow comes home and it tracks perfectly. This is telling me the teeth are probably digging in somewhat at certain places causing it work its way off.

By the way the Timberwolf lays perfectly flat on a flat table.

next step is use the "Cheater"

Don G

[reible]

Before you do any strong arm changes be sure to do as Charles said and look at the blade. The teeth must look like this:

IMG_3996scm.jpg (308.94 KiB) Viewed 5976 times

blade direction as shown with the red arrow.

Ed

[dgreen810]

ED

I have the blade installed correctly. I removed the upper wheel and used a break-over and a 1/2" deep well socket to get the required 1/4" gap. It took a pretty good effort to achieve this. I would like to meet the gentleman that can do the same pulling on the bottom and pushing on the top to get the 1/4" gap. I re-installed the Timberwolf and now it is tracking perfectly.

Thanks to all

Don G

[JPG]

The 1/4" gap Charlese mentioned is our long standing understanding of what is correct. That served us well for a long time. We have recently acquired a different measurement courtesy of CS that the back of the blade should ride 1/4" out from the back rim of the upper wheel. That is determined by the upper rear guide bearing and the upper wheel cant.(all else being correct)

Now the same 'situation' exists with the lower front guide bearing positioning the blade on the lower wheel. I believe it should also be 1/4" from the back rim.

The lower wheel runs true to the input shaft. The blade surface of the wheel/tire is very slightly beveled(back side larger od than the front side).

The upper wheel has identical geometry and the purpose of the cant(twice the bevel angle) is to provide a straight path for the back edge of the blade to travel in a flat plane.

I believe the blade will tend to force the blade back edge to be in a flat plane and that forces the blade towards the back of the upper wheel because of the lower wheel bevel.

So why does your new blade want to slide off the upper wheel in forward, but not in reverse. A clue is that in reverse the guide bearings(both upper and lower) are no longer guiding the blade ONTO the wheel, but positioning the blade as to traverses between the wheels. GEE blade 'wants' to track correctly with the guide bearings being ineffective.

I am curious where on the upper and lower wheels the back of the blade tracks(distance from the back rim) when running in reverse. I be guessing it is closer to the back rim of the upper wheel.

If so the cant needs to be increased(top of wheel in, bottom of wheel out). Adjusting it is best done with a cheater(pipe inserted onto the shaft).

Before doing that, I would measure one more thing first. Lay that flat edge on the LOWER wheel and determine the distance the top and bottom of the upper wheel clears the straight edge. Based on looking at a sample of ONE, the bottom should just touch the straight edge and the top should be 1/4" away from the straight edge.

If only cant angle is incorrect, the deviation from those observations will be equal and opposite. If not equal, the arm is also bent either towards the front or the back.

I have proposed a drastic measure here so I request you share the results of the straight edge against the lower wheel measurement before engaging the gorilla.

Your effort here may help another member having a similar issue.

As for why only the new blade has this problem, is it possible the new blade is thicker(stiffer)?
.....................................................................

Well I see you fixed it as I was creating this post. Because much torque is required to bend the arm, Bill Mayo long ago warned against pulling/pushing the upper wheel as that could warp the wheel.

All is well that ends well!!!!

[dgreen810]

James

I will try to take some pictures tomorrow.

Good Night all. Time for this old fart to hit the hay.

Don G