Blade Alignment on Delta Contractor Unisaw

[Scott Kies]

Hi,

I have a contractor Delta Unisaw that developed blade alignment issues. I align the saw using a dial caliper and it will do a nice job cutting. When I tilt the arbor the blade falls out of alignment. I realign the blade and repeat and it is out of alignment. So much so you cannot get the blade insert back in. I have had the saw for roughly 15 years and it just started doing this recently.

Anyone have a thought on what is causing this? I really would like to resolve this vs purchasing a new saw. I lied-- I would love to purchase a new saw but they are expensive!

[Bill Geibe]

Out of curiosity, what so you mean by a Delta 'Contractor' Unisaw? A Unisaw is a cabinet saw. A contractor type saw is one with the motor hanging out in back. Delta made them, too.

Bill

[Cary Falk]

I agree that a contractor saw and a Unisaw are 2 different things. If it is a contractor saw then the 2 trunnion rods have probably come loose allowing the trunnion to get tweeked when you tilt the blade.

[Vince Shriver]

Maybe he means a hybrid cabinet saw.

[Scott Kies]

Sorry for the confusion. It is a 10" Contracter's Saw (Model 34-444) with a Unifence Saw Guide. I know how to align it and do it regularly but the issue is it now comes out of alignment when tilting the arbor. I mean 1/8" out. So much you cannot run board through it without stopping the saw. As long as I don't tilt the arbor it appears to not be to big an issue. I cleaned a lubricated the various mechanisms to insure there was build up that was causing gears to ride off track.

Scott

[Cary Falk]

Make sure the 2 parallel rods that connect the front and rear trunnion together are tight.

[Scott Kies]

I will give that a shot. You think there is any possibility I could rack the front and back trunnions? I don't think much but just thought I would ask?

[Cary Falk]

You should be able to loosen up the nuts and tweek the blade back to where it was before you tighten it back up.

[Dave Kirby]

Out of curiosity, what so you mean by a Delta 'Contractor' Unisaw? A Unisaw is a cabinet saw. A contractor type saw is one with the motor hanging out in back. Delta made them, too.

Bill
Delta also made a contractor saw with a direct drive motor (where the motor shaft IS the arbor).

[glenn bradley]

I know how to align it and do it regularly but the issue is it now comes out of alignment when tilting the arbor

No offense but, it does not sound like you know how to align it 'completely' :) Alignment at 90* is one set of adjustments and alignment at angles is another. Alignment at angles is handled by shimming the table to trunnion relationship. Although I wonder why you have to align your saw frequently, let's pass on that for now. My steps (which probably differ from someone else's steps) go in this order:



Set blade at 90* to the table and align it to the left miter slot.
Align the fence to the left miter slot.
Set blade at 45* to the table and align it to the left miter slot.
Reconfirm alignment at 90* and repeat the sequence as required (generally 2 or 3 times on an unaligned saw).


To align the blade when angled the relationship between the plane that the trunnion mounts occupy and the table top plane needs to adjust. This is a bit more painfiul on a contractor's saw than a cabinet mounted trunnion format saw but, is still achieved through shims between the trunnion mount and the table. The pain factor is greatly reduced is PALs are employed but, now the PALs can get in the way of your working opening :(. Once aligned, your saw should stay in alignment. Things that would take a saw out of alignment might include a mobile base and relocating to an uneven floor location and not leveling said base, loading the saw into and out of a truck, hauling it up and down stairs on the job site and so forth. Almost any saw will require re-alignment after those kinds of moves. If the saw is staying in your gara . . . er . . . shop, it should not require realignment.

276086

This diagram chooses the miter slot that would make using your dial indicator (or whatever) more easily. I tend to always adjust (or at least final check) from the miter slot I use the most.

[Cary Falk]

Glenn,
The Delta contractor saws (and clones) with the dual rods that hold the trunnions together is a poor design if you ask me. The weight of the motor hanging out the back tweeks the trunnion when you tilt the blade. Mine did it but just enough to be annoying. You align the saw at 90 the tilt the blade and the blade would be out of alignment when you return it to 90.
Cary

[Howard Acheson]

As said by many your trunnion rods are out of plane. There is a significant area of alignment that is not detailed in most magazine tune-up articles. It is ensuring that the trunnion bars are exactly in the same plane. Proper adjustment affects bevel cuts and is indicated when there burning when making bevel cuts. Here are the corrective steps that were at one time posted on the Delta website.

First go through the alignment process following the steps in the attachment below.

To check whether the trunnions need to be adjusted, tilt your blade fully to the 45 degree position until you get to the 45 degree stop. Then crank the blade back to the 90 degree upright position. Now again check the parallelism of the blade to the miter slot. If the blade is still parallel to the miter slot, declare victory. If not, follow the process below from Delta to adjust them. The process is the same for all Contractor Saws or Hybrids that have the trunnion assembly hanging from the table.

1. Remove the saw blade being sure it was at it fullest height.

2. Place a flat plate (or similar flat object) on top of the two tie-bars. (The size of the plate should be at least 6" by 8", and the flatter the better. A pane of glass works well.) Depress one corner of the plate and if it rocks, the tie-bars are not parallel. This must be corrected as it will affect the alignment of the blade.

3. Loosen the tie-bar locknuts located at the rear of the saw.

4. Grasp the motor bracket and move it left and/or right. Check the rocking of the flat plate and when it can no longer rock, the tie-bars are parallel...re-tighten the locknuts.

5. Remove the flat plate and re-install the sawblade.

6. Again perform the parallelism alignment process.

7. Before tightening the rear trunnion bolts, push forward on the rear trunnion bracket to allow the undercarriage to snugly fit between the two trunnions.

[Alan Schwabacher]

Are you saying that when you align it with the blade square to the table, it goes out of alignment when tilted but returns to alignment when square? This can be caused by trying to tilt the blade while the motor hits an obstruction like an outfeed table. If so, untwisting the rods to parallel to one another should fix it. Shims can also be used.

Or are you saying that it goes out of alignment when you tilt the blade and does not come back into alignment when you bring the blade to square? That would indicate something loose in the mechanism. A fix for one cause of that is to clamp the trunnions into their mating C-shaped grooves while aligning the blade to the miter slot. Sorry I don't know the proper terminology.

[Scott Kies]

I am saying that it goes out of alignment when you tilt the blade and does not come back into alignment when you bring the blade to square.

[Scott Kies]

I have suspected that there is something a miss with the trunnion rods not being properly aligned. The tip on checking to make sure they are in the proper plane is excellent. I also made sure there is nothing impeding the motor as the arbor is tilted therefore causing the saw to go out alignment.

Thanks for everyones input. I will keep you posted.

[glenn bradley]

Glenn,
The Delta contractor saws (and clones) with the dual rods that hold the trunnions together is a poor design if you ask me. The weight of the motor hanging out the back tweeks the trunnion when you tilt the blade. Mine did it but just enough to be annoying. You align the saw at 90 the tilt the blade and the blade would be out of alignment when you return it to 90.
Cary

I hear you Cary. My old Delta was a pill. My old Craftsman/Emerson would stay aligned quite well but, was built more stout than my 1970's Delta. This is why the Delta got sent down the road. Running out for a new saw is not always an option but, if the saw is failing to re-align after tilting, there's not much help for it. If the saw is losing alignment when you lower and raise the blade (I have had a saw that did this), then adjust your Christmas list because that saw is always going to torture you, it is going to enjoy torturing you, it is evil and must be exorcised! :D Seriously though, a saw that will not maintain alignment is one of the chief contributors to the oft quoted numbers of tablesaw accidents every year. For safety's sake, resolve this one way or the other.

[Scott Kies]

then adjust your Christmas list because that saw is always going to torture you, it is going to enjoy torturing you, it is evil and must be exorcised! :D

Now that you mention it I whacked my head but good on the out feed table when when checking the trunnion rods because I heard maniacal laughter from the saw! It really has been of good service for a long time and why in the name of Christ and all that is holy has it chosen to betray me?