Help! Stupid mistake has put table saw seriously out of alignment

[Arthur Wood]

'll try to briefly provide background on what I did and seek your help on getting things right again.

I own a Delta Contractor Table Saw. I (had) a hardboard cover that I used for the back of the saw to help keep dust from shooting out the back. This cover was supposed to be removed before making angled cuts. . . .
. . . but, i was cranking the blade angle on the side of the cabinet and it started to get really bogged down. I *thought* it was because I had so much dust gunked up in the gearing so I *cranked* harder (I had obviously completely forgotten about the hardboard cover on the back of the saw that was interfering with the raised/angled trunnion) and. . . .

BAM! I hear a loud pop. I realize my stupid mistake and now was worried that I'd cracked something somewhere. Good news is that it appears no permanent damage was done. But what did happen was that the rear trunnion popped out of its sem-circular "groove".

I loosened the front and rear trunnion bolts to the point that the whole saw mechanism was barely attached to the table and got the blade square to the fence again. The problem now is that my blade is about 1/8" closer to the fence than it was before.

I could (and have) cut a new zero clearance insert because of the new blade position - but I realize that the blade now no longer works with the "stock" insert that came with the saw. The blade is just about 1/16 to the right of the stock opening. This is telling me that something isn't right. . .and that while I could just go ahead with a new zero clearance, there's more adjustment to be made.

I should also mention that I've tried re-loosening all the trunnions once again - but, standing at the back of the saw, there is no more "play" to get the blade mechanism moving to my right (away from the fence).

I've attached a few photos to help illustrate the problem. Really appreciate your help.

1st pic: illustrates how, with athe old zero-clearance instert, the blade is about 1/8 inch off (too close to the fence, preventing the insert from seating properly
http://lh5.google.com/art.wood/R3a-vWWZsLI/AAAAAAAAAMU/z57vbLD7Des/DSC_0145.JPG?imgmax=800

2nd Pic: Same idea, from above
http://lh6.google.com/art.wood/R3a-vmWZsMI/AAAAAAAAAMc/Mdm6XkP6Dos/DSC_0146.JPG?imgmax=800

3rd Pic: from under the saw, the front trunnion (and the blade angle gear that caused the problem in the first place)
http://lh4.google.com/art.wood/R3a-wGWZsNI/AAAAAAAAAMk/PTFmHMahyxg/DSC_0148.JPG?imgmax=800

4th Pic: under the saw, upward toward the blade. You can see here how close the blade is to the "tabs" of the table saw top (which support the insert). I realize that the blade should not be centered in the opening, but it's still too close to one side).
http://lh6.google.com/art.wood/R3a-wmWZsOI/AAAAAAAAAMs/1vsSwEf5TMc/DSC_0150.JPG?imgmax=800

[Mike Marcade]

Is the blade in your pictures square to the tabletop? It looks to me like it is set at an angle.

Have you been able to ascertain if there are any bent/cracked parts?

[Arthur Wood]

Is the blade in your pictures square to the tabletop? It looks to me like it is set at an angle.

Have you been able to ascertain if there are any bent/cracked parts?

The blade is square. . . it's just a bad angle of the photo that's suggesting otherwise.

As far as I can tell, no parts are bent/cracked.

[Mike Marcade]

Are the trunnion rods still both in the same plane?

[Doug Shepard]

You mention loosening the trunion bolts but did you actually remove those to see if they got bent?

[Chuck Lenz]

Hello Arthur, while I may not be able to solve your alignment problem, I do however wonder if a set of PALs would help you to get things right if there isn't anything broke or twisted. Also I'd like to add that when I designed the dust collection for my Delta 34-445X Contractors tablesaw I did not fully block off the back of the cabinet for fear of doing what you and others have done. Dust collection can be done on these types of saws efficiently without fully blocking the back off.

[Dale Johnson]

you should still have some lateral adjustment in where the trunnion blocks attach to the table. check the manual or go on-line to look for a diagram.

[Mike Marcade]

you should still have some lateral adjustment in where the trunnion blocks attach to the table. check the manual or go on-line to look for a diagram.

I belive Art said in his post that he is as far as he can go to the right with his trunnion adjustment.

[glenn bradley]

Before you knock yourself out, verify that the trunnion assembly did not get tweaked. Flip the saw on it's head (remove your motor first), pull the trunnion/arbor assembly and set it on something flat (not your TS top as it may be in question). If it sets reasonably flat you're OK there. Check your motor bracket support rods as long as it's now convenient (they won't cause what you're showing but can cause other problems so you might as well check 'em as long as the guts are out of the base.

If you have teeter-totter-city while the trunnions are setting on something flat, breath deep . . . breath . . . . OK now try to decide if it is bad enough to replace or if you think you can tweak it back to the proper plane. Let's try to get that far and see how it goes. Then we can proceed.

[Brian Weick]

Whole assembly mounted underneath to the Cast iron table- ? If so I think you can fix this problem relatively easy!
Brian

[M. A. Espinoza]

I think you should verify that your trunnion rods are in the same plane. Essentially you remove the blade and place a flat surface across the trunnion rods. It should not rock; if it does you must readjust to get the trunnions back in the same plane.

I usually just use a piece of mdf that I've checked for flatness on my jointer bed. A flat piece of steel or some thick float glass would work. Doesn't have to be dead flat within .001 but flatter the better.

The ability for rod connected trunnions to get tweaked is why I want to retire my Grizzly contractor and don't want that design in anything that replaces it. It gets out of adjustment far too easily.

After you get the trunnions adjusted you should be able to get your carriage assembly back where it was before, or at least very close.

Luckily table saws are pretty simple machines. I would also remove the motor and flip it on its top if possible. Will make this the process a little less painful. Get things back where you want and then replace the motor and recheck to see if anything moves due to the weight. It might but should only need minor adjustment at that point.

Good luck.

[John Bartley]

In the last picture, on the side of the blade mandrel closest to the pulley there appears to be a threaded plug - maybe for setting the lateral position of the mandrel and bearings in the mandrel housing? It "looks" as if it's threaded out or has jumped out of its housing, almost the same distance that your blade is out of position. ... or am I seeing things...?

cheers

[M. A. Espinoza]

In the last picture, on the side of the blade mandrel closest to the pulley there appears to be a threaded plug - maybe for setting the lateral position of the mandrel and bearings in the mandrel housing? It "looks" as if it's threaded out or has jumped out of its housing, almost the same distance that your blade is out of position. ... or am I seeing things...?

cheers

Good catch. I missed that.

Just because something is unlikely doesn't mean it didn't happen. Although I don't see how overcranking a binding carriage would shift the arbor, doesn't mean it couldn't have happened. If there was enough force built up to pop the trunnion out; weird things could have happened.

[Bruce Wrenn]

Good eyes John. The spanner nut has backed out. Unfortunately, the spanner nut only holds the bearing next to pulley in place. The "special nut" hold arbor assembly together. I expect that the trunion rods are the problem. Don't ask how I know, but I do. Every time I forget to slide my contractor's saw forward, the motor hits the out feed table and upsets the trunion rods, when I try to do a 45. Seems like I would remember! It is a good idea to RECORD the measurement from one of the miter slots to the face of the arbor. It something moves, it can be returned to where it was by duplicating measurement. Then all your ZCI's and sliding jigs will fit.

[Arthur Wood]

Are the trunnion rods still both in the same plane?

By visual inspection they are, but I'll take a measurement tomorrow when I'm back in the shop.

[Arthur Wood]

You mention loosening the trunion bolts but did you actually remove those to see if they got bent?


No, I didn't .. .. I'd be surpised that the bolts would get bend (rather than shear or break) but will check that out.

Art

[Arthur Wood]

Hello Arthur, while I may not be able to solve your alignment problem, I do however wonder if a set of PALs would help you to get things right if there isn't anything broke or twisted. Also I'd like to add that when I designed the dust collection for my Delta 34-445X Contractors tablesaw I did not fully block off the back of the cabinet for fear of doing what you and others have done. Dust collection can be done on these types of saws efficiently without fully blocking the back off.

Thanks Chuck. . .. I have since bought a PALS kit and will install it once I get this bigger problem solved. My problem (for the moment) isn't getting the blade sqaure to the fence (which the PALS system solves) but rather getting the whole blade structure further from the fence.

Good to know that block the back of the saw may not be necessary. I don't yet have "suction" dust collection.. . .but a dust bin that my sawdust falls into. I've notice that when I don't have the back in place (and no suction via vacuum). . there's dust all over the place.

[Arthur Wood]

Before you knock yourself out, verify that the trunnion assembly did not get tweaked. Flip the saw on it's head (remove your motor first), pull the trunnion/arbor assembly and set it on something flat (not your TS top as it may be in question). If it sets reasonably flat you're OK there. Check your motor bracket support rods as long as it's now convenient (they won't cause what you're showing but can cause other problems so you might as well check 'em as long as the guts are out of the base.

If you have teeter-totter-city while the trunnions are setting on something flat, breath deep . . . breath . . . . OK now try to decide if it is bad enough to replace or if you think you can tweak it back to the proper plane. Let's try to get that far and see how it goes. Then we can proceed.

I haven't yet turned the whole assembly upside down because the whole saw is part of a custom cart/table I built and damn. . .i'm reluctant to disamantle the whole thing. But I guess that's where I'm headed.

I'll turn it upside down and see what I learn. I'll be sure to report back here.

Art

[Arthur Wood]

I think you should verify that your trunnion rods are in the same plane. Essentially you remove the blade and place a flat surface across the trunnion rods. It should not rock; if it does you must readjust to get the trunnions back in the same plane.

I usually just use a piece of mdf that I've checked for flatness on my jointer bed. A flat piece of steel or some thick float glass would work. Doesn't have to be dead flat within .001 but flatter the better.

The ability for rod connected trunnions to get tweaked is why I want to retire my Grizzly contractor and don't want that design in anything that replaces it. It gets out of adjustment far too easily.

After you get the trunnions adjusted you should be able to get your carriage assembly back where it was before, or at least very close.

Luckily table saws are pretty simple machines. I would also remove the motor and flip it on its top if possible. Will make this the process a little less painful. Get things back where you want and then replace the motor and recheck to see if anything moves due to the weight. It might but should only need minor adjustment at that point.

Good luck.

Great post.. .while I've already stated that I'm reluctant to turn the saw upside down because of the table/cart it's installed in. . . I think that will be the most productive next step.

Thanks,

Art

[John Bartley]

Good eyes John. The spanner nut has backed out. Unfortunately, the spanner nut only holds the bearing next to pulley in place. The "special nut" hold arbor assembly together.


Gotcha !! The spanner nut holds the pulley side bearing and shim(s) in place in the cast housing. The mandrel slides thru' the "bearing(s), spacer, shim" assembly in the housing and is held by the nut on the pulley side and the arbour flange on the blade side.

It would be interesting to know the model number of this saw so we could see the correct parts breakdown. For anyone who's following along and would like to see an illustration, here's a link to the parts picture for a Delta 36-980 contractors saw, which should be "similar" and possibly backwards (left tilt). The principals of assembly and operation should be the same.

This picture also shows the trunnions and rods.

http://oldradio.ca/woodworking/partspics/Delta36-980TableSaw.gif

cheers

[Arthur Wood]

I'm re-posting a reply (from Dan Boschen) at another forum (hope that's not against the rules) that explores this idea. I'm going to give it a test in the shop today.


Art-
Here's a pic:
http://pages.suddenlink.net/dbosch/ebay/contractnut.jpg

See if the arbor has any axial movement. Also look to see if the spanner nut is rubbing against the sheave (pulley). If so, remove the pulley. You can get a better access to it if you tilt the whole blade mechanism to the 45 deg position. The spanner nut has two slots in it. You can tighten it by hand as much as possible and then use a spanner wrench or use a punch that will fit inside one of the slots and walk it around, tapping the punch with a hammer.

Dan

[Brian Weick]

Is it the spanner nut? John's correct- could be the problem.
Brian

[M. A. Espinoza]

Great post.. .while I've already stated that I'm reluctant to turn the saw upside down because of the table/cart it's installed in. . . I think that will be the most productive next step.

Thanks,

Art

Yup, my saw is built into a work table too. And it would be a huge PITA to get it out of there and flip it. So I've gotten good at doing this under the table, bumping my head, etc.

Sounds like you have diagnosed the problem, at least now you will have a much better idea of what it means to have a tool dialed in. Woodworking is much more enjoyable when the tools don't fight you.

[Chuck Lenz]

Good observation on the spanner nut, but when it's loose wouldn't that make the arbor go in the oposite direction than it has gone ? Without being able to be there to actually get a closer look, I still think the problem is where the assembly mounts to the table. Maybe bent mounting bolts ?

[Arthur Wood]

All,

Thank you so much for the really helpful advice. I spent a few hours in the shop and have the following updates:

*as a background for someone who asked, this is a Delta 36-475 10" contractors saw. The "Platinum Edition"

The spanner nut (next to the pulley/sheave) was in fact loose. I've since tightened it but this had absolutely nothing to do with the alignment. The arbor would did not move becuase this nut was loose.

I did lay a flat reference board across the trunnion "tubes" to see if they were in the same plane:
http://lh4.google.com/art.wood/R3g8NmWZsRI/AAAAAAAAANg/174qqLvC-FY/saw-3.jpg?imgmax=512

And as you can see, the tubes are "off" about a 1/16th of an inch.

I decided to disconnect the saw from the base I'd built, turn it upside down, dismantle as much as i could, clean as much as I could (there was a lot of gunk underneath) and put things back together again.

I made two discoveries - good news and bad news.

The good news is - and I'm not entirely sure why - but it appears that the blade is now lining up correctly with the ZCI.
http://lh5.google.com/art.wood/R3g8N2WZsSI/AAAAAAAAANo/2sZ1iPuOJyw/saw-4.jpg?imgmax=512
I say "appears" because I haven't yet turned the saw over, right side up and installed the blade (but a square laid up against the arbor washer is perfectly aligned with the ZCI slot).

The bad news? It's the reason I haven't flipped the saw back over and called it a day. . . .a cracked rear trunnion.
http://lh4.google.com/art.wood/R3g8NmWZsPI/AAAAAAAAANQ/VpxsnZRoOJc/saw-1.jpg?imgmax=512
It's actually a hairline crack. . but I rubbed some white chalk into it so that it would show up better in the photo. From this 2nd photo, you can see that the crack runs through the thickness of the rear trunnion. This is a pic from the other side:
http://lh4.google.com/art.wood/R3g8NmWZsQI/AAAAAAAAANY/JGj1_g9tkS8/saw-2.jpg?imgmax=512

So, http://www.forums.woodnet.net/ubbthreads/images/graemlins/yellowsigh.gif , I've got to order a replacement trunnion from Delta before I re-assemble the thing again. (Unless someone could convince me that this crack isn't a danger to operate). http://www.forums.woodnet.net/ubbthreads/images/graemlins/yellowsmile.gif

I tried to loosen the big nuts on the trunnion tubes but couldn't loosen them with my adjustable wrench. . . .any advice for getting these things loose?

Thanks again all for the wonderful assistance.

Art

[Mike Marcade]

Sorry to hear about your cracked trunnion. One those big nuts I would use a six point socket on a 1/2 drive ratchet or impact wrench if you have one.

[Dick Strauss]

What a bummer! It looks like Delta wants $125 for a new rear trunnion (PN 422190950004). For that price I might find a local machine shop to weld it (with the appropriate material) and take my chances since it isn't split in two.

Good luck,
Dick

[Arthur Wood]

What a bummer! It looks like Delta wants $125 for a new rear trunnion (PN 422190950004). For that price I might find a local machine shop to weld it (with the appropriate material) and take my chances since it isn't split in two.



Ouch! I'll explore that option . . .I might also see if I can find a "used" one somewhere. . . .

Thanks,

Art

[Luis Oliveira]

I am going to go against the grain here but is it possible that the problem is that you created the ZCI's before your started yo align the saw and now it is the ZCI's that just does not fit. can you put back the original insert and see if the blade actually hits it?

Good luck.

[Richard Dragin]

If you choose to repair the trunnion you want a shop that can braze it. Welding cast is a bad option as the high heat can make it more brittle and possibly warp it. The chalk won't help the brazing process unfortunatly.

I don't think you bent the trunnion, cast doesn't bend but breaks as you have found out. Measuring my ZCI (Delta 34-666 ) the slot is just under 1" from the left edge of the insert, how does your's compare?

I don't think the 1/16" that the bars are out from being co-planar will cause the situation you are worried about. It will cause the ailignment to shift when tilting the arbor.

[Arthur Wood]

I am going to go against the grain here but is it possible that the problem is that you created the ZCI's before your started yo align the saw and now it is the ZCI's that just does not fit. can you put back the original insert and see if the blade actually hits it?

Good luck.

Yeah. . .good thought but that wasn't it. I put the original delta (metal) insert in and the blade wouldn't fit. It appears that I've now fixed that problem (by disassembling front and rear trunnions, giving the whole thing a thorough cleaning, and putting it back together). I also (with the help of readers here) diagnosed a loose spanner nut (though I don't think it was causing any problems) and finally, discovered that I'd cracked the rear trunnion.

I bit the bullet and ordered a new one from Delta. Should be here next week.

THANKS everyone.

[Bruce Wrenn]

[quote=John Bartley;731049]Gotcha !! The spanner nut holds the pulley side bearing and shim(s) in place in the cast housing. The mandrel slides thru' the "bearing(s), spacer, shim" assembly in the housing and is held by the nut on the pulley side and the arbour flange on the blade side. I'm not sure what the "Gotcha" is for. The nut that is referred to as to as on the pulley side is the "special nut", not the spanner nut. The spanner only holds bearing and spacer in place until arbor is pressed through bearing, and "special nut" tightened. On a right tilt, the "special nut" is left hand threads. Just last week, I replaced the arbor bearings on a Model 10 saw.

[Dick Strauss]

Arthur,
Looking back at all of the cracks on the trunnion, I'm sure you made the right move by ordering a new one.

FYI-Welding CI can be done but it isn't an easy process from what I read...
http://www.lincolnelectric.com/knowledge/articles/content/castironpreheat.asp

[John Bartley]

I'm not sure what the "Gotcha" is for.

I always have trouble with expression over the web ... I'm way better face to face where I can smile and make eye contact ..

When I'm chatting with someone and they have explained something to me, "gotcha" (got you) means that the light bulb has come on for me. In other words, "gotcha" means "I understand now" :). I hope it didn't mean something negative to you.

Sorry for the confusion.

cheers eh?

[Bruce Wrenn]

I always have trouble with expression over the web ... I'm way better face to face where I can smile and make eye contact ..

When I'm chatting with someone and they have explained something to me, "gotcha" (got you) means that the light bulb has come on for me. In other words, "gotcha" means "I understand now" :). I hope it didn't mean something negative to you.

Sorry for the confusion.

cheers eh?No problem, we are two nations separated by a common language. Here "gotcha" means that you are wrong, and I gotcha.