Delta Contractor Saw Runout

[Paul Macias]

A little over-eager I bought an old Delta Contractor saw (34-444) for $150 about a year ago and have had to put considerable money into it. One of the things I paid for were new bearings, professionally installed. The technician said that one of the existing bearings was seized and appeared to have heated up the arbor a little, but according to him these old Delta arbors are tough and he determined that there was no damage to it. So fine, I continued to "refurbish" the saw, and have since been using it and it seems to work just fine. Rececently, however, I've noticed with my eye a wobble (runout) in the blade when it starts up and slows to a stop. I put a piece of stock up against the mitre gauge and blade and slowly rotated the blade with the belt and sure enough the blade pushes the stock away and then rubs at other points. This is runout, I suppose, but here's my question: If my kirf is exactly the width it should be, do I need to worry about this runout?

[Joseph Tarantino]

i think it's a concern. try other blades and measure the kerf with a micrometer. hard to see where a blade that spins on an arbor with runout not producing a cut larger than the blades tooth kerf. sell it and get yourself a nice used emerson built c-man or ridgid contractor saw. they were/are reliable and cheap on CL. they are also left tilt and the older the saw the better as the arbor assemblies were built like tanks.

[Bruce Wrenn]

You want to check the run out of the flange on the bearing side of the arbor, using a dial indicator. Tilt arbor to 45 degrees, and reach in with DI. This will tell you if run out is blade, or arbor. Arbor can be faced on a lathe. The arbor will have to be removed, and bearings removed bearings. I had one that I removed because of run out, and neighbor faced it for me. Or take blade, and mark largest run out with a sharpie. Loosen blade, and rotate 180 on arbor. Tighten nut and check run out again. If it's the same place on blade, then blade is problem.

[Harvey Pascoe]

The centrifugal force of the rotating blade at high speed could be eliminating the run out for you so that you get no teeth marks on your cut even tho you got substantial run out. I experience the same thing on my unisaw yet get perfect cuts most of the time.

[Paul Macias]

You want to check the run out of the flange on the bearing side of the arbor, using a dial indicator. Tilt arbor to 45 degrees, and reach in with DI. This will tell you if run out is blade, or arbor. Arbor can be faced on a lathe. The arbor will have to be removed, and bearings removed bearings. I had one that I removed because of run out, and neighbor faced it for me. Or take blade, and mark largest run out with a sharpie. Loosen blade, and rotate 180 on arbor. Tighten nut and check run out again. If it's the same place on blade, then blade is problem.

Bruce, I just tried the dial indicator, but not with arbor at 45. I did it with arbor at 90 (indicator set up in "cavity" of saw), and the runout is a little under .002, which seems acceptable. ??

[Larry Edgerton]

I have three Delta contractor saws. When I buy one I buy Browning pulleys, link belt, and blade stabilizers. The last one is important for your issue, especially on the saws made in the last 20 years. I have mine machined so I do not lose depth of cut but you can buy a generic set from Freud that will greatly improve your saw. You can have the best bearings in the world and those stamped washers will mess it up. You need them anyway, so try that first.

Larry

[Phil Thien]

.002 translates to at least .01" (1/100, or a bit less than 1/64") at the tip of the blade. Maybe twice that, because when you push one side of the blade out .01", the blade is probably .01" the other direction at 180-degrees. So you may actually see 1/50" of wobble.

Certainly noticeable by the naked eye in either case.

And you should be able to do better.

One thing you want to do is clean everything like crazy with some 409 or something similar. A little pitch in the right spot can cause problems.

There was a thread here about machining the arbor without removing it. Basically, you find the high spot on the flange and you file it down. If you can't find the thread, say something and I'll try to find it for you.

[Joseph Tarantino]

you might find the info in this thread helpful:

http://www.forums.woodnet.net/ubbthreads/showflat.php?Cat=&Number=3395953&page=1&view=collapsed&sb=5&o=