Adjusting Table Saw Trunion

I have a Delta 10" Contractor Saw. I checked the blade with a dial gauge as described in the January issue of American Woodworker and discovered that the blade isn't parallel to the miter slot across it's length. The article said check your owner's manual for trunion adjustment. Well I looked in the manual and didn't see it. So how do you adjust the trunion?

Reply to
Thomas
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As posted by Bob S. many, many moons ago...

..............................Alignment Procedure..............................

Just thought I'd pass this along to those that have been having difficulty in aligning the blade parallel to the miter slot on these particular contractor saws. They may also apply to other Delta series saws as long as they have two tie-bars as part of the undercarriage.

I installed a new blade the other night and checked alignment using my TS Aligner Jr. and found that it was off by nearly 5 thousandths (front to rear - using same tooth on blade as ref). Decided to align and while doing so, managed to snap a trunnion bolt !

Well, the saw was due for a good cleaning and lube anyway, so I pulled out the whole undercarriage mechanism. It was a fairly simple process actually and not nearly as difficult as I was anticipating. Luckily, the bolt I snapped was left with a few threads exposed and was easily removed. There is no printed spec for these bolts in their literature so I called Delta tech support and finally got connected with a very knowledgeable and helpful individual (Ron as I recall).

He said a grade 5 bolt (same size) will do - but add lock washers to each of the four trunnion bolts as long as I have it apart. These will help maintain the alignment. There also is no spec for how tight these bolts should be but "good 'n snug and not over-tightened" is all that's needed he said. The trunnion bolts are not marked with a grade number and using a grade 5 means that I probably will never be able to snap the bolt again, it will most likely strip out the threads in the base before it breaks. So a word of caution - tight enough is one turn before it strips or snaps - wherever that is !

Considering that I was using a 6" long 1/2" box wrench and was not leaning on it when it snapped, the original bolts are definitely not grade 5.

Now for the interesting part. Delta faxed me a two sheet procedure that describes how to do this alignment. It's called "Blade Alignment Instructions for Original Contractors-Type Saws (when the saw has two Tie-Bars)". Pages are marked CS07 and CS07a and are not in the manual. I've included the instructions below but since binaries are not appreciated in this ng, I didn't scan the diagram.

Here's the procedure (minus diagram) as faxed to me: (unplug the saw first)

I've added a note or two to help which are denoted by (My note....).

.......................................Delta Procedures......................................

Initial Measurement:

  1. Raise the sawblade to it's maximum height and mark one tooth, at the front of the blade as a reference.
  2. Using a combination square, measure from the left edge of the right-hand miter gauge slot to the sawblade tooth that was marked in step 1 (Note this measurement). Then rotate the blade to the rear and measure from the same marked tooth to the miter slot. (Note this measurement).

IF the two measurements are NOT the same, proceed with step

  1. Note: refer to parts diagram on the following page for part locations.

(My note...this is the step I never knew had to be done, nor have I ever heard anyone mention it before.)

  1. Remove the sawblade. (Remember, it is still at it's maximum 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). 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.

To make the Tie-Bars parallel:

  1. Loosen the tie-bar locknuts (2ea. ref #245) located at the rear of the saw.
  2. Grasp the motor bracket (ref #244) 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.

Aligning the saw undercarriage:

  1. Remove the flat plate and re-install the sawblade.
  2. Loosen the front trunnion bolts (2ea. ref #207) and the rear trunnion bolts (2ea. ref #243).
  3. Move the entire undercarriage around while measuring as in step 2.
  4. When the two measurements are the same, re-tighten the front two trunnion bolts (ref #207).
  5. Before tightening the rear trunnion bolts, push forward on the rear trunnion bracket to allow the undercarriage to snugly fit between the two trunnions.
  6. Re-check the blade to miter slot measurement and if they are still equal, re-tighten the rear trunnion bolts (ref #243).
  7. If the blade to miter slot measurements have changed, repeat steps 8 thru 12.

.........................................End of Delta Procedures..........................

Without a diagram to look at this may be confusing but I suspect most of us never thought about the tie-bar alignment steps 5 & 6. If these are not parallel to each other then you can tap / hammer / move / and swear at it until the cows come home and it will never align correctly. Move the blade (up / down) then recheck alignment and you will find that you're out of alignment again ! You must keep the trunnion brackets tight to the rest of the mechanism.

I'm off to find some grade 5 bolts, lockwashers and a flat plate (glass maybe if I can't find a steel plate of some sort). I'll be reassembling and aligning tonight. If I find a better or easier way, I'll make a follow-up post and let you know what I did.

If you try to contact Delta tech support, (800) 438-2486 you'll most likely get a busy signal like I did for two days. Finally contacted HQ at (901)

668-8600 and they paged tech support for me and he was on the line in less than a minute. Course I was nice to the sweet young thing that answered the call, told her I'd been trying for two days and could she help - sure 'nuff !

I'll ding Delta for not including these procedures in the manual or at least posting them on their web site but tech support (Ron) was very helpful and friendly. He also gave me a few tips on how to adjust the blade height (worm-gear) mechanism since mine is a bit to tight when raising/lowering the blade.

The worm-gear is pinned to a shaft that goes thru another guide-shaft that has an off-center hole bored thru it. By loosening the nut near the worm-gear end, the shaft (with the off-center bore) can be rotated which adjusts the gear meshing clearance between the worm-gear and the gear-height mechanism. Confusing explanation but when you look at the mechanism, it will be clear to you.

Hope all the above is useful to someone and provides a better explanation on why we're having problems when making the blade to miter slot adjustment.

Bob S.

.....................Follow-Up.............................................. ....................

Said I would follow-up if I had anything more to add to my original post.

Just finished aligning the saw - the Delta procedures work as advertised - follow them exactly.

I know I'm being a bit anal over 5 thousandths but it was more of a curiosity of "why" it couldn't be adjusted out. No matter what I had done previously, it would come out close but never dead-on. Was it me, or just the machining tolerance ?

The problem was the adjustment of the tie-bars not being parallel. I used an 8" sanding disk (minus the sanding paper of course) as the flat plate they want you to use in the alignment procedure - see original post above. The lock nuts on the tie-bars are 15/16th's and they sure are on there tight. Had to use an 18" strong-arm bar to break them loose. Did exactly as the procedure called for and the alignment came out dead-on. Surprised the hell out of me too !

Now when you do the alignment (blade parallel to miter slot), you truly can loosen all 4 trunnion bolts (leave just slightly snug) and move the undercarriage around to make the adjustment. No more 2x4's as levers and whacking the hell out of the undercarriage to coax it into alignment. Simply tap (rubber mallet or use your fist if you like pain) the undercarriage and when front and back measurements are equal, snug 'em up good but don't over do it (as I did which has lead to this whole diatribe).

Ran the blade up and down, changed blade angle, made some saw dust and remeasured - still dead-on ! Never even came close to getting repeatable measurements before this, so I'm a real happy camper.

May as well align the fence to the miter slot while you're at it too. I have the TS Aligner so it's easy and accurate but the procedure in the manual works well also.

Will it improve my cuts any - Yes ! Ripped a piece of maple and no burn marks at the end anymore. Could be the new Freud blade but I tend to think it was the alignment that made the difference.

Only addition to the procedure I would make is to be sure the blade is at 90 deg to the table when doing the alignment which isn't stated in their procedures.

I did make a slight modification to the front trunnion bolts that you may be interested in doing to make life easier. If you ever tried loosening / tightening the front trunnion bolts then you know how difficult it can be to get to them - not to mention the skinned knuckles.

While I was at the nut's and bolts place looking for a replacement bolt for the one I snapped, I came across a bin of couplers, 2" long which accept

5/16" thread.

Idea came to mind. Why not get a short section of threaded rod (5/16th's) and two couplers and make "extended stud bolts" for the front trunnion ? Bought a section of threaded rod, some inside star-washers and some flat washers.

I cut two sections of the threaded rod 2 5/8" long to for the studs. I wanted the threaded rod to go into the table as far as possible (5/8") and

2" into the coupler to help stiffen the whole thing.

If you have the entire undercarriage out as I did, you need to put the undercarriage in-place first, then insert the stud bolts (threaded rod sections). If not, then simply replace the front bolts one at a time with the "extended studs". Put a flat washer and a star washer on the stud and run the couplers on up till they're good 'n snug.

Now it's a simple matter to use an open-end 1/2" wrench to get at those front trunnion bolts. No more fiddling with a socket and an extension and finding the bolt heads. You can now see them and get to them easily. Delta - ya listening ?

I was initially worried that the right front coupler would interfere with the blade tilt mechanism by using a 2" long coupler, there is still plenty of clearance and clears the trunnion by a good 1/2" or so when the blade is tilted the full 45 deg. The left coupler - no problems on clearance.

As I mentioned in the original post, my blade height adjustment was a bit to tight compared to other saws I've tried. Adusted the "off-center" shaft about 1/8th of a turn and that blade now goes up and down real nice and smoothe. You'll know when the adjustment is right cause it "just feels right". You don't want it to loose or there will be to much slack in the gear mesh - just play with it a bit and you'll know what I mean about feeling right.

So ends the story... and on a happy note too. Now I can get back to making sawdust and stop playing mechanic. Have to make 3 double-hung windows for my shed (the place where my lathe is going to be....8>)

G'night all,

Bob S.

Reply to
Unisaw A100

Shopnotes #25, January 1996 is the best article I've seen. Pictures, even.

In addition, Preston Andreas contributed his experience on February 12, 2001 to this forum.

Just remember - don't smack cast iron with anything tougher'n wood!

Reply to
George

Thanks,

Bob S.

Reply to
BobS

It's been posted a number of times but the very procedure Bob S. references, is available at the Delta web site:

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a follow up, I would strongly suggest another valuable addition to anything else you get... Look at a In-line Industries "PALS" system that is an addition to the saw...

Here is an excellent write up of "how to do it" and it includes a good desciption of the PALS system...

http://thewoodsh> I have a Delta 10" Contractor Saw. I checked the blade with a dial gauge as

Reply to
Pat Barber

The PALS do not fix the problem - the allow you to force an adjustment. There's a reason you can't align it - fix that first.

Bob S.

Reply to
BobS

You lost me there Bob...

If you follow Delta's instructions AND use the PALS, which makes the final adjustment MUCH easier.

I have used the Delta instructions and they will "work" eventually, but it's much more difficult by NOT using the PALS "doo-hickey"...

What is the "fix" for "can't align it" ????

BobS wrote:

Reply to
Pat Barber

Reply to
tiredofspam

Those two bars that tie the motor mount to trunnion.

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Number 143

Reply to
George

Pat,

The reason the PALS were born is to "hold" one side of a trunnion in-place while the other side is being adjusted. Yes - they do help make things easier but they also allow the undercarriage to be slightly warped when forcing the adjustments. The tie-bars need to be parallel. I have yet to see an alignment done with PALS that did not force the tie-bars out of alignment. The blade may be parallel with the miter slot (assuming it was aligned while at 90°) but most likely will not be when at some bevel setting other than 90°. A good test is to make about a 15° bevel cut at max depth thru a piece of hardwood and see if you get any burning. A properly aligned saw with a good blade will not burn.

With the tie-bars adjusted for parallel and with the lands and trunnions flat and all at the same height there is no need to "warp, twist, bend or otherwise distort" the undercarriage into alignment. If you have the PALS - go check the tie-bars for being parallel. If a flat plate does not lay flat across them as per the instructions - then something is still out of alignment.

If you can't get an alignment done without the use of force or by using PALS - does it not make sense that something is not right and should be fixed? It is not a big job to flip that saw over and to remove the undercarriage in order to make some measurements and tweak as needed so the saw will align without force.

I'm sure we have all seen the numerous posts about getting a CS aligned and all read the "Get a bigger hammer" or "Get a set of PALS" replies. Why not fix the problem the right way the first time and not have to go thru all the hassle time and again. The tablesaws don't come from Delta in perfect alignment and there's a lot of slop in the way they were built. With a bit of tweaking you can fix what they didn't do at the factory.

Bob S.

Reply to
BobS

NOV'03 Issue of Magazine uses a Delta Contractor saw in their article and gives photo of adjusting to get balde and miter slot parallel. Under photo it gives this procedure:

"In most cases, each of the two trunnions on a contractor's tablesaw is held in place w/ two bolts. Working thru the back side of the saw, loosen both of the bolts on the rear trunnion, and one bolt on the front trunnion. Leave the fourth bolt snug to serve as a pivot point. Place a piece of scrap (wood) against the rear trunnion, and tap it w/ a mallet. Recheck the blade/table alignment. If it is good, tighten the rear trunnion bolt that's diagonal from the pivot bolt. If the alignment is still good, tighten the remaining bolts."

I used this procedure to align my Delta Contractor's saw and it eliminated a burning problem I was having. Hope this helps.

Joey in Chesapeake

Reply to
Joseph Smith

Read this for a better explanation about tie-bars being parallel. While this is about a Unisaw, it's applicable to the "why" behind the alignment.

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S.

Reply to
BobS

Go here.

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to the third picture.

See the rusted round horizontal thingie (tm Claire, age 10) about two thirds up the picture?

That's one. The other is paired up opposite hand from it (behind it in the picture). That's the back bone of the contractor's saw undercarriage.

UA100, who continues to fight the good fight that the cabinet saw's cabinet hung trunnions are inferior to the contractor's saw's table hung trunnions...

Reply to
Unisaw A100

that's a funny stance for a guy with a name like unisawa100....

so how do you figure? cabinet saw trunnions are generally beefier, easier to adjust and don't rely on gravity to tension the belt, for a few things. what is it that you see in a contractor's saw that looks better?

Reply to
bridger

I don't see any Tie Bars.

I have some questions.

Is there any different procedure for this type of saw? Is it written up anywhere?

Will the PALS add-on be compatible? (I realise there is not uniform agreement on the usefullness).

Reply to
Bruce Barnett

I agree with you up to a point... Following the Delta instructions to the letter(which I do/did) does allow you to "get it straight", but I also think that the ideas behind the PALS is still a good way to make the "final" setting.

You know yourself that when you get the tie bars correct and begin the process of getting everthing back to "tight", that a slight move of the nut and everything is "out of whack" again. I don't quite believe that the PALS screws can exert enough pressure on the trunnion assembly to "distort" it.

Many people a lot smarter than me have stated on a number of occasions in articles that it is "almost" impossible to get and keep a contractor in perfect alignment. The design doesn't lend itself to mechanical perfection in adjustment.

But that's just me...

Reply to
Pat Barber

Pat,

Try adjusting the tie-bars with the trunnion bolts just snugged up to hold things in-place, then after they're tight - now align the undercarriage to make the blade parallel with the miter slot.

Have you checked your tie-bars to see if they are parallel and a flat plate does not wobble when pressure is applied on one side then the other?

Bob S.

Reply to
BobS

I think Bob's point, and one that I endorse is that the PALS mask the problem and don't necessarily offer an elegant solution to the real problem. The underlying problem is that the surfaces that the bolt heads engage on the trunion is not machined and irregularities in it is what causes the slight shift as you tighten down the bolt. It is better to file the trunion down a bit to flatten out that seat than it is to force it in any way. It only takes a very minor amount of work to properly fix the issue instead of working around it. Probably no more work than installing the PALS in the first place.

I'd disagree with this conclusion completely. No one says it's nearly impossible to get and keep a contractor's saw in alignment. We do say that it takes a certain dedication to performing the task properly the first time and not settling for "close enough", but it is typically characterized as a very do-able job. Most here have done it to their saws and encourage others to do it on a regular basis. Likewise, no one says that it is impossible or even nearly impossible to keep a contractor's saw in tune. To the contrary, if done properly the first time it is unlikely you will have to make those adjustments again for a very, very long time. That's more reason to fix the underlying issues with a given saw and not jump to things like PALS. Once you get your trunions lined up and locked down there is no reason to expect them to move under normal use. The design certainly does lend itself to near perfect alignment. Most of us here have our saws - both cabinet saws and contractor saws, aligned to less than .005in. Many of us have them aligned to .001in. This is very achievable.

Don't let what is really a fairly easy task overwhelm you. You can get your saw aligned properly and it really won't take you a lot of work. You'll be hugely rewarded for your efforts the first time you fire it up and cut something and that reward will stay with you for a long time.

Nah - we all felt that way before we dug in and did it on our saws. After we did we miraculously became pinnacles of wisdom and oracles of encouragement.

Reply to
Mike Marlow

That's onna 'count of it's a direct drive. In lieu of the tie bars you've got a motor hung there.

The procedure is the same as long as and up to the part where you loosen four cap screws, adjust and re-tighten the four cap screws. Beyond that what Bob S. has written (tie bars) won't be of much use to you. That is not to say that the twisting could be an issue with your saw, just that the fix isn't the same.

Kinda not sure. Technically you have table hung trunnions and technically the PALS work with table hung trunnions. I suspect a call to PALS would be in order but I would not expect much as I doubt they have gone as far as tracking down a 34-300 to check.

As for the vintage of the saw, I'm guessing something closer to the mid-70's/early 80's otherwise it would say Delta somewheres on it.

UA100

Reply to
Unisaw A100

No folks that is definately not

EL Guapo!!!!

I'm sorry but it's true.

Reply to
royneu

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