Delta 40-694 Table Moves When Locked

[silentsoundguy]

I just bough a Delta 40-694 scroll saw and I am having an issue with the table staying still. I have done quite a bit of searching, but haven't found anything on the topic. The issue is that when it is tightened the whole table pivots on the tension knob. In other words, there is no movement at the knob. The trunnion isn't actually sliding.

I loosened the two bolts that attach the trunnion to the bottom of the table so that I could adjust trunnion to hit flush with the pad behind the tension knob and the table is all the way back on the rear table mount. Still no good. The table moves side to side a couple of millimeters.

I also tried putting a piece of paper as a gasket between the trunnion and the plate where the movement occurs to give it something to grab. It didn't help at all.

I also tried removing the zero indicator assembly thinking everything was resting on that point. It didn't help either.

Running out of ideas.

[new2woodwrk]

If this is a new unit, I would contact Delta - they are very good at replacing/repairing units - at least I have not had any issue with their support on any of my Delta tools

If it's used,  i have little input - it sounds more like the tension knob is stripped

[silentsoundguy]

18 minutes ago, new2woodwrk said:

It sounds more like the tension knob is stripped

It is a refurb - everything looks new. Definitely not stripped. I can really crank the knob.

[Woodmaster1]

Try adding a washer or make the washer that should be there is there.

[silentsoundguy]

5 minutes ago, Woodmaster1 said:

Try adding a washer or make the washer that should be there is there.

The washer is installed. It's more of a bushing/spacer that fits into the groove in the trunnion. I checked the parts diagram and I can't see that anything is missing.

[Roberta Moreton]

Time to contact Delta

[silentsoundguy]

23 minutes ago, Roberta Moreton said:

Time to contact Delta

I know, I just want to fix it myself. I'll call tonight.

[OCtoolguy]

7 hours ago, silentsoundguy said:

I just bough a Delta 40-694 scroll saw and I am having an issue with the table staying still. I have done quite a bit of searching, but haven't found anything on the topic. The issue is that when it is tightened the whole table pivots on the tension knob. In other words, there is no movement at the knob. The trunnion isn't actually sliding.

I loosened the two bolts that attach the trunnion to the bottom of the table so that I could adjust trunnion to hit flush with the pad behind the tension knob and the table is all the way back on the rear table mount. Still no good. The table moves side to side a couple of millimeters.

I also tried putting a piece of paper as a gasket between the trunnion and the plate where the movement occurs to give it something to grab. It didn't help at all.

I also tried removing the zero indicator assembly thinking everything was resting on that point. It didn't help either.

Running out of ideas.

Can you post a pic or two of what you are talking about? I have a Dewalt but it should be the same.

 

[OCtoolguy]

When you "crank" down on the lock knob, does it lock the trunnion tight? Is there a possibility that the lock know screw is bottoming out and not truly locking the trunnion. I'm trying to envision what it is that you are experiencing. It's such a simple design that it should be fool proof.

 

[silentsoundguy]

14 hours ago, octoolguy said:

When you "crank" down on the lock knob, does it lock the trunnion tight? Is there a possibility that the lock know screw is bottoming out and not truly locking the trunnion. I'm trying to envision what it is that you are experiencing. It's such a simple design that it should be fool proof.

 

That is a good idea, maybe I'll try a washer or two. not sure if the knob is bottoming out.

I will see if I can get a video of what's going on.

Didn't get a chance to call Delta and probably won't for a couple of days.

[jerry1939]

Is there a chance that the bolt is turning?  The back side, that you can't see without lifting the saw, is a carriage bolt.  It fits into a square hole.  When I have mine apart for greasing, I duct tape the bolt in place.  Makes it a heck of a lot easier to slide the trunnion onto it.

You indicated that you don't know if the knob is bottoming out.  For whatever reason, maybe someone installed the wrong bolt.  i.e. Not a carriage bolt or a bolt that is too long.

jerry

[OCtoolguy]

5 minutes ago, jerry1939 said:

Is there a chance that the bolt is turning?  The back side, that you can't see without lifting the saw, is a carriage bolt.  It fits into a square hole.  When I have mine apart for greasing, I duct tape the bolt in place.  Makes it a heck of a lot easier to slide the trunnion onto it.

You indicated that you don't know if the knob is bottoming out.  For whatever reason, maybe someone installed the wrong bolt.  i.e. Not a carriage bolt or a bolt that is too long.

jerry

My thoughts too Jerry.

 

[jerry1939]

From the "knob" side of Part # 91, I have 1/2" of bolt showing.       jerry

[OCtoolguy]

I checked mine today and I agree with Jerry. Now, if the bolt is not a carriage bolt, it may not be tightening completely.

 

[silentsoundguy]

It definitely isn't bottoming out. I can take the table and trunnion off and the knob can still thread all the way into the base. I can make it VERY TIGHT. the bolt is not moving. Talked to Delta this morning. Didn't get very far with the technician and he suggested I take it to the nearest repair facility. It's over an hour from my house. Two round trips there is not an option when I could just return the saw. I would rather fix it, but I have my limits. (I didn't tell him any of this)

He called back a few minutes later and said he had talked to a few people and they are unaware of the problem, but it is either an issue with the trunnion, or the cast base. They are sending out a trunnion to see if that solves the issue.

Here's a short video of the issue that I made.

 

[OCtoolguy]

Just for the heck of it, try taking the trunnion bolts out of their holes in the table so the table is eliminated from the equation. Tighten up the trunnion and see if it still moves. If it doesn't move, then see if the trunnion bolt holes are aligned with the holes in the underside of the table. From what I could see in you video, the table is really only moving at the rear. I'm wondering if the hole in the back of the table is oversized or if the o-ring on the locator pin is the wrong size. I don't see much movement at the front of the table at all. I'm thinking that if the rear of the table was stabilized, it would be pretty solid.

 

[silentsoundguy]

Well, unfortunately that is not the case. I know it's hard to see in the video, but there is definitely movement at the front of the table. You can see it at the end of the video when comparing the trunnion to the cast base (above the right 20 degree marker) I know it is almost imperceptible, but it doesn't take much.

 

I'll try removing the table and see what happens. I don't know if I will be able to get enough leverage to movie it though.

[silentsoundguy]

And by the way, thank you for throwing ideas my way. I really do appreciate it.

[OCtoolguy]

By the way, that zero pointer should be installed as it has a detent ball that centers the trunnion and believe it or not, it does keep the table from small movements when at the zero point. That ball should locate in a hole on the underside of the trunnion. If that is back in play, I feel that the movement you are experiencing is all at the back of the table. You maybe have a defective table, a defective rear swivel point or??????? I watched the way you "cranked" down on the locking knob and you should never have to apply that much pressure. It won't be long before the threads in that brass bushing are going to be worn out. The only other thing that I can come up with is if the table is possibly over-length and it is contacting the rear pivot point and not allowing the front trunnion to mate with the base. It wouldn't take much for that to happen. There are a lot of things that can still be checked but if none of these are the case, I'm out of ideas.

 

[silentsoundguy]

I think the problem is that the curve of the trunnion doesn't match the curve of the base. You say that the movement is in the back, bit I can see it in the front. That 1mm movement at the blade translates to an even smaller movement at the base and it's hard for the camera to pick it up.

[OCtoolguy]

1 minute ago, silentsoundguy said:

I think the problem is that the curve of the trunnion doesn't match the curve of the base. You say that the movement is in the back, bit I can see it in the front. That 1mm movement at the blade translates to an even smaller movement at the base and it's hard for the camera to pick it up.

If you can stop the movement at the rear, there will be no movement at the front. Try a clamp of something.

 

[silentsoundguy]

Since the table just pivots on the back pin, I'm not sure what you're suggesting.

[OCtoolguy]

33 minutes ago, silentsoundguy said:

Since the table just pivots on the back pin, I'm not sure what you're suggesting.

Check to see if the table has any up-down or side to side movement at the pivot pin. It shouldn't. If it does, try a wrap or two of masking tape and tighten it up.

 

[JackM]

I had the same problem with my DeWalt 788 and finally resolved the problem by

replacing the small "o" ring where the rear of table fits into the frame.  I hope this

is your answer also.

Jack

 

 

[OCtoolguy]

13 minutes ago, JackM said:

I had the same problem with my DeWalt 788 and finally resolved the problem by

replacing the small "o" ring where the rear of table fits into the frame.  I hope this

is your answer also.

Jack

 

 

I think that will be the answer Jack. I watched his video a few times. The front was locked down very tight and I could see the movement coming from the rear because of the leverage factor. And also, he has the detent ball/zero pointer completely off the saw. That in itself serves to hold the front of the table in place.

R