Read this if you made an A+ in geometry class

[Ed Blough]

Bill
In your first post you said two things that caught my eye.
First the trunion rods are solidly in the same plane. How do you know and did you change them at all?

Secondly I used PALS to adjust. Don't PALS require you to completely remove the trunion bolts? Is there any possibility that some crude got under one?

There was also something you didn't say, you clearly stated that when the blade was up it was 90 degrees to the table. What angle is it when it is lowered? I'm guessing it is off.

The fact that the ZCP is cut in a bow tells you the blade is moving in an arc rather than perfectly vertical up and down. If the slot simply got wider then you would know the blade was moving laterally. The arc, or bow as you called it, tells us the blade is moving in an arc right to left as it is being raised. This would happen if the height piviot part 205 was not parallel to the table. I suspect the side opposite the bevel crank side is slightly (read very slightly) lower than the end closest to the bevel crank side.

Going back to the trunion rods. Have you measured them to insure they are exactly the same distance from the table top (bottom)? If one of these are torqued it would do exactly what your describing.

Play detective. Insure part 207 is exactly 90 degrees to the table and see if it changes as you crank the blade up and down. I will wager it is also moving in an arc.

If so check part 250 if it isn't exactly 90 or changes then check the two rods and see if they move. If they don't move and are exactly even then check parts 267 and 214.

My guess is one of these parts is not square to the table and/or one of the trunions rods are torqued.

I'm guessing the side of 214 or 267 (most likely 214) that points away from the bevel crank is higher off the table than the other end.

In any case I would think a shim placed on the bevel crank side of one or both of these parts will solve your problem.
Hope this helps
Ed

[Ed Blough]

Bill
One last question why are you even messing with Delta at this point? Why aren't you talking to the dealer you bought the saw from?
I would think any reliable dealer would make this right in an instant. They should be the mediator between you and the Delta. In fact I would expect them to be your advocate!

Ed

[Bill Bryant]

I set the trunnion rods exactly planar, and exactly parallel to the table top.

I set the blade at 3", exactly 90 degrees to the table top and exactly parallel to a miter slot.

But this is irrelevant. I could set the blade in any other plane and I would still get the same problem, and it has nothing to do with problem of setting a blade parallel to the miter slot at both 90 degrees and 45 degrees. I know all about that now and can set that up easily.

Please understand that the problem has NOTHING TO DO WITH TILTING THE BLADE AND GOING OUT OF PARALLEL WITH THE MITER SLOT.

You can have your trunnion rods twisted like a pretzel. You can have them totally out of parallel with the table top. But none of that affects what makes a blade change planes when lowered or raised.

I know that the guys at Delta have said otherwise, some in a rather patronizing tone.

But they need to examine their design a bit better. Nothing, but nothing affects a blade staying in the same plane when being raised or lowered (not tilted!) except for whether the blade arbor pivot and the height adjustment pivot are parallel.

[Chris Parks]

Bill, is the table perfectly flat? It has been a while since I looked at a contractor saw but the one I had the table was not flat and maybe that could be an issue in alignment.

[Bill Bryant]

Bill, is the table perfectly flat? It has been a while since I looked at a contractor saw but the one I had the table was not flat and maybe that could be an issue in alignment.

The part of the table I'm measuring from is flat enough for it not to matter.

[Ed Blough]

I set the trunnion rods exactly planar, and exactly parallel to the table top.

I set the blade at 3", exactly 90 degrees to the table top and exactly parallel to a miter slot.

But this is irrelevant. I could set the blade in any other plane and I would still get the same problem, and it has nothing to do with problem of setting a blade parallel to the miter slot at both 90 degrees and 45 degrees. I know all about that now and can set that up easily.

Please understand that the problem has NOTHING TO DO WITH TILTING THE BLADE AND GOING OUT OF PARALLEL WITH THE MITER SLOT.

You can have your trunnion rods twisted like a pretzel. You can have them totally out of parallel with the table top. But none of that affects what makes a blade change planes when lowered or raised.

I know that the guys at Delta have said otherwise, some in a rather patronizing tone.

But they need to examine their design a bit better. Nothing, but nothing affects a blade staying in the same plane when being raised or lowered (not tilted!) except for whether the blade arbor pivot and the height adjustment pivot are parallel.

Bill
I think you dismissed my answer without fully reading what I said. I never said a thing about tilting the blade or setting it as 90 and 45 degrees. Please reconsider what I said.

If the slot in your ZCP just got wider it would mean the blade is moving in a laterally plane as well as up or down plane. But the bow in the ZCP says it is moving in an arc.

here is how it is happening. As you raise the blade the top of the blade passes through the zcp the blade is closer (but parallel to the mitre slot) to the right, then as the blade comes up the sides of the blade in the arc are moving way from the mitre slot as the blade reaches the top of height adjustment the sides are further to the left (but still perfectly parallel and set at 90 degrees). The result is a bow in zcp.

Since the piviot point is left to right that means the lateral axis of the piviot is either tilted or is moving. We can discuss this all day but there is no other way for a flat blade to cut an arc just adjusting the height.

You hit on it when you said "Nothing, but nothing affects a blade staying in the same plane when being raised or lowered (not tilted!) except for whether the blade arbor pivot and the height adjustment pivot are parallel." You are nearly one hundred percent correct. The height adjustment pivot (the pivot where the blade arbor piviots as the blade moves up and down) has to be parallel to the table. If not the blade when moved up and down will move in such a manner that it will in effect cut an arc in the ZCP. Is the piviot parallel? We both know it is not.
Whether it was bored wrong or the tubes and trunion that attach it to the table are not holding it parallel, it is easily fixed by making it parallel. Either by shiming the trunions or if there is crud under them removing it.

I'm not patronizing you, nor am I trying to be stupid. Before you dismiss me as being another idiot think about your symptoms. The arc is key. Reset your focus (trees and forest) Stop thinking about what you have proved can't be wrong and think of the only way a bow would be cut in the ZCP.

Sorry if I offended you in any way.

[Bill Bryant]

If I may be so bold to say, stop thinking what you have proved can't be wrong and start thinking about how a flat blade could cut an arc.
Sorry if I offended you in any way.

Relax, I'm not offended at all. We're big boys here.

I've been thinking about how a flat blade could cut an arc for quite some time, Ed.

Trunnion rods out of plane with each other won't do it unless you tilt.

Table not parallel to trunnions won't do it unless you tilt.

The thing that WILL do it is for part #207 to be warped so that #202 isn't parallel with #205. It's that simple.

If 202 and 205 are parallel, you can have the rest of the mechanism they are attached to twisted into a pretzel, and the blade will stay in the same plane when raised and lowered.

If 202 and 205 are NOT parallel, you can have the rest of the mechanism they are attached to lined up to .0000001 and the blade will cut an arc when raised and lowered.

[Ed Blough]

Relax, I'm not offended at all. We're big boys here.

I've been thinking about how a flat blade could cut an arc for quite some time, Ed.

Trunnion rods out of plane with each other won't do it unless you tilt.

Table not parallel to trunnions won't do it unless you tilt.

The thing that WILL do it is for part #207 to be warped so that #202 isn't parallel with #205. It's that simple.

If 202 and 205 are parallel, you can have the rest of the mechanism they are attached to twisted into a pretzel, and the blade will stay in the same plane when raised and lowered.

If 202 and 205 are NOT parallel, you can have the rest of the mechanism they are attached to lined up to .0000001 and the blade will cut an arc when raised and lowered.

Bill
I will concede if 202 and 205 are not in the same plane the blade will cut an arc when raised. However if just 205 is not parallel to the table this will also happen. The thing you need to find out is which is not parallel to the table 202 or 205. If 202 is not parallel but 205 is parallel then you do have a problem the casting is bad.

However it is my guess you will find 205 is not parallel. Check it both at the highest and lowest blade position. I think your going find when the blade at it's lowest point 205 is not parallel to the table.

I really believe you closing in on the problem. Do this and prove me wrong.
Check the blade at the highest setting is it exactly 90 degrees to the table? Now check it at the lowest is it still 90 degrees? Hard to measure and only a fraction of a degree will cause a fairly large .001 arc in the blade. If you say yes then I'm totally wrong and I have misunderstood what you telling me is happening. I understood you to say your cutting a bow like this looking down on the ZCP ")".

[Ed Blough]

Okay I have played this over in my head a hundred times.

I concede if the blade is exactly 90 degrees to the table then part #202 by default would also have to be perfectly parallel to the table.

For the blade to cut an arc in the ZCP would then require part 205 to be out of parallel which could only happen if casting 207 was bored wrong or warped.

However if the blade was anything less than perfectly 90 degrees to the table what is happening would happen. If the blade was 89.5 degrees the blade moving raising or lowering approx 3.25 would produce a bow in the zcp of about the amount your seeing.

So the question becomes is the blade exactly 90 degrees to the zcp?
If so then yes part 207 is bad or at least the culprit causing the problem.

I feel rather bad now accusing you of not being able to see the forest for all the trees when if fact it was me being blinded by the trees. I was totally certain the arbor support tubes were racked.

I guess we all know how well I did in geometry now.
Sorry

[Bill Bryant]

That was big of you, Ed. There was really no need for an apology, but thanks all the same. I appreciate it.

Now do you think you can help me firgure out how to get the guys at Delta to get it?

[Don Squire]

Hi

Step 1

Go to the dealer that you purchased the saw from and nicely tell them what the trouble is and what you and others have figured the problem to be and ask them what they can do about it. If they remedy the problem satisfactory them things are OK. If not proceed to step 2.

Step 2

Report your findings on this forum and we can all send an email or make a phone call to Delta and let them know that if this is the way they treat a customer after making a purchase that we will make a point of not making any purchases from Delta, Porter Cable etc. and will be sure to tell everyone that we can about how they only want peoples money and after they get it, tough.

I find that asking in a nice polite manner first, then as necessary becoming more vocal usually gets their attention. If you are standing there complaining about bad service and other potential customers can hear that you are getting the runaround, it makes them think twice before they make a purchase.

My 2 cents worth

Don

[julie Graf]

is the actual frame for the saw square?

i returned a rigid contractor saw because the frame bent, which in turn messed everything up. so all the trunions & inside parts were fine, but the frame was pulling things out of whack - the blade would not stay square and you could not get a 45 when trying to tilt.

[Ed Blough]

That was big of you, Ed. There was really no need for an apology, but thanks all the same. I appreciate it.

Now do you think you can help me firgure out how to get the guys at Delta to get it?

Bill
I think to convince Delta will be a huge problem.

First I will guess that part #207 is probably a casting that is has a final machining done by a precision boring machine setup to make perfectly parallel holes for part 202 and 205. So they can/will not think beyond that.

Secondly if the blade is even .2 of a degree out of 90 in reference to the zcp this problem would be seen. The angle the blade is moving is calculated, tangent = Opposite side/adjactent side. As I calculate .01"/3" (tan-1) = aprrox a .19 degree off of 90 degree angle and would cause the error your actually seeing. The numbers I used are, .01" is the amount you said you measured the blade tooth moved toward the fence and I used three inches as the amount of you lowered the blade figuring you have to leave a little above the table to measure. If your lowering the blade less than 3 inches this angle of error would slighly increase. That all said you will have to prove to Delta your are capable of that kind of exactness. First that you set the blade to exactly 90 degree with less than a .2 degree error and that you measured the movement of .01 again without any error.

Thirdly we have no idea what Delta's specs are for part #207 is. This could well be within their range. I will wager many many table saws exhibit this same problem but it has never been discovered by the owners. Further the chance of this really messing up a project is slim to none. That is no excuse, but I think it will effect Delta's view of the severity of the problem.

Fourthly I think your going to have to involve the dealer you bought the saw from. If you can get him on your side I think you have a chance with Delta.
Ed

[Phil Thien]

I think we're all going to have to call Delta Customer Service on his behalf and tell 'em we aren't buying any more Delta products until this fix this for him. Maybe if 100 of call we can get their attention.

[Bill Bryant]

Please, nobody call until I've given them another chance. I'll go back over the problem with them again, and if they are still telling me it's a trunnion alignment issue, I'll hop back on here and let y'all know where we stand.