Delta Tablesaw Alignment

[Russ Hauser]

There is something funny going on with my TS. I'll try to remember the sequence I went thru when I found the problem.

I noticed the blade wasn't parrallel to the table slots, and was pulling work pieces away from the fence. I have a dial indicator attached to a platform with a guide that slides in the table slot and it was showing .025 "runout" at the back of the blade. I lowered the blade all the way down, removed the belt from the arbor pulley, slightly loosened the 4 trunion bolts, ran the blade back up, tapped the trunion to eliminate the .025, retightened the bolts, and the blade was now at .000 "runout." I ran the blade back down and slipped the belt back on the pulley, and , just because it was still in the slot, I rechecked the blade with the indicator. The .025 "runout" returned! Why would the weight of the motor have any influence on the tracking of the blade? I will appreciate any help you guys can give me with this.

Russ

[Tom Veatch]

Remember seeing similar report recently in which the problem was caused by split lockwashers under the trunnion bolts causing the trunnion to move as the bolts were torqued. Fix was to replace the lockwasher with flat washers, do the alignment, torque all bolts. Then, one at a time, remove the bolt, replace the flat washer with lock washer, and retorque the bolt.

[Russ Hauser]

Thanks Tom, but there's something else going on. I just noticed I can easily get the indicator to read .000 "runout" by lifting the motor so as to take all its weight off the arbor pulley. Something is loose or worn. Think I'll get a hold of the nearest Delta service center, and see if they might suggest what to do.

Russ

[Tom Veatch]

The trunnion should not be that flexible if all the attachment bolts are tight. Hate to think it, but I'm wondering if there's not a crack somewhere in the structure.

[Gordon Harner]

I will try to pass on some help I received here. If this model is a contractors saw(it sounds like it) check that the rods between the trunnions are aligned and very tight. What I did was to make sure the entire saw was level front to back and side to side then I checked that the blade was at 90 degrees and then I used a torpedo level to get the rods in the same plane and really tightened them up. I bet that this willo cure your problem.

[Gene Michael]

Russ, I started a thread on this same topic several days ago. My saw is a delta contractors model 36-650. I went through the same process as you. Initially, I thought I'd just adjust the trunions so that the weight of the motor pulled the blade assembly into alignment. This didn't work because there isn't sufficient adjustment range in that direction.

There is (for want of a better term) a yoke that holds the blade assembly. It hangs on a pin from the front trunion assembly. That's where the play is, and as far as I can see, theres no way to fix it short of taking the entire saw apart and either addressing the play in the yoke or the lack of trunion adjustment capacity in the right direction.

Or, if you don't use the saw for crosscutting, you could align the fence with the blade. Or you could sell it and buy something not made by delta. :(

[Fred Belknap]

If it is a contractor type I don't think there is a reliable fix. I fought mine for a couple of years and finally got a cabinet saw and use the contractor saw for square cuts only. The motor weighs to much for the trunnion. I tried to sell it but no takers so guess it will join my RAS in the barn gathering rust and cobwebs.

[Alan Schwabacher]

Since you are getting movement when you let the motor hang off it, something is loose. The first candidate I'd consider is the trunnion position. I'm sorry I may not be using the correct names, but bear with me. Note that the carriage that holds the blade rides in between the trunnions, sliding in a semicircular groove. You want the two trunnions positioned so the blade is aligned properly, can tilt properly, but has no play in the groove. When you loosen and realign the trunnions, it's possible to open up a little space for play between them, and if you do, it will behave as you have described. The solution is to clamp each trunnion to its carriage while you adjust the trunnion alignment. That will prevent any slop being introduced, and of course you remove the clamps after alignment. I was also taught to do the alignment with the weight of the motor in place.

[Russ Hauser]

Since you are getting movement when you let the motor hang off it, something is loose. The first candidate I'd consider is the trunnion position. I'm sorry I may not be using the correct names, but bear with me. Note that the carriage that holds the blade rides in between the trunnions, sliding in a semicircular groove. You want the two trunnions positioned so the blade is aligned properly, can tilt properly, but has no play in the groove. When you loosen and realign the trunnions, it's possible to open up a little space for play between them, and if you do, it will behave as you have described. The solution is to clamp each trunnion to its carriage while you adjust the trunnion alignment. That will prevent any slop being introduced, and of course you remove the clamps after alignment. I was also taught to do the alignment with the weight of the motor in place.

This sounds like good advice Alan, and I will do as you suggest.

Russ

[Russ Hauser]

Well, I tried to realign the blade again, this time I clamped the trunion brackets to the carriage assembly to eliminate play. Still ended up with the same .025 runout. Removed the trunion bracket next to the motor and filed the mounting slots a little. This got the runout down to .017. I am reluctant to file any more because the trunions are die cast. I managed to eliminate the remaining runout by removing most of the motor's weight from the arbor pulley. I did this by wrapping some light nylon line around the motor and bracket, placing a dowel rod between the turns and twisting until the blade was parrallel to the table slot.

Tomorrow morning I'll take a couple of pics. It's a jury rig for sure but it seems to be working. I'll probably get some belt slippage on thick hardwoods. We'll see. Nothing seems to be worn or loose. I think the carriage assembly is being flexed by the weight of the motor, as I think one of the posters suggested. A cabinet saw would be great, but is not an option. I'll live with what I have, unless I hit the Lotto.

Russ

[Russ Hauser]

As promised, here are a couple of pics of the temporary fix for the blade missalignment I came up with. If this works under most or all conditions, I'll come up with a more elegant mechanical solution.