Craftsman table saw blade alignment

[Mark Mrsa]

I have a 1965 Sears Craftsman 10" contractors table saw that I've brought back to life, so to speak. I've made several upgrades to acessory components on the saw including a PALS alignment kit on the back truninon.
I've not been able to achieve consistent blade to miter slot alignment equal to, or less then, 0.003".
Aftermaking a cross-cut sled and attempting to align the front fence, I discovered the blade was not acceptably parallel to the slot. I used a metal ruler with 1/32" graduations for measuring front and back of blade measurements. When raising the blade to its highest vertical postion, there was a 1/32" difference between the front and back of blade measurement. The difference decreased when the blade was lowered to several positions so that when it was approximately 2" above table surface level there was a difference of 1/64". When I took the link belt off the blade and motor arbor pulleys, I had no difference in front and back blade measurements, but when reinstalling the belt the difference was approximately 1/64" at a 2" blade height.
Can the alignment of the blade and motor arbor pulleys and/or tension of the link belt throw off the blade to miter slot alignment? Does the measurement difference with the link belt on and then off indicate a problem with the blade arbor flang or bearing?
Your thoughts and answers will be appreciated!!!
Mark Mrsa

[David Buchhauser]

It sounds like you may have some play in your arbor resulting in some lateral movement when the force of the drive belt is applied. Perhaps mount a dial indicator on your table with the tip on the side of the blade and manually (with the drive belt removed) move the arbor side-to-side to see what sort of play it may have.
David

[Thomas McCurnin]

I had two of these saws, and had nothing but problems with trunion alignment after the saw was well worn. I, too, used the PALS system and found that while it did make adjustments easier, the table top and saw blade required almost weekly adjustment. It wasn't a super big deal, about 30 minutes every month or when I needed a precise cut, but I honestly got sick of it and bought a Unisaw. I never found a reason for the mis-alignment or found a fix, I just constantly re-aligned the table.

[Lee Schierer]

On my craftsman TS there are bolts holding the trunnions to underside of the table. The machined holes do not have a lot of clearance. I found on mine that the toothed locking washers would pull the trunnion back into the original position. If I rotated the locking washer teeth out of the indentations they had made into the aluminum trunnion castings, then they wouldn't draw the trunnion back to it's original location.

You can purchase a dial indicator from Harbor Freight for about $20. I mount mine on a block of wood clamped to my miter gauge. I raise my blade to full height for checking set up. Make sure your link belt is long enough so that the motor doesn't run out of room to tilt on it's mounting bracket. Also the hinged motor mount should be free to pivot. The weight of the motor provides the needed belt tension.

[Pat Germain]

I have a Craftsman contractor saw from the early 1990s. Likely it's no different than the 1965 saw. Over the years I have hot-rodded that saw to the max. It's functional, but nothing more.

I also have problems keeping the blade aligned. Just last weekend I spent about an hour trying align the blade to the miter slot using a dial indicator. I also have the PALS system, but over the years the threads stripped out from constantly trying to get the arbor to move.

What I've discovered is you have use some "Kentucky Windage" to get it aligned. As described above, even with the PALS system, the arbor/blade will move as you tighten the bolts. Therefore, you must over-adjust the arbor to compensate for the movement. After you do it a few times, you can get an idea for how much the arbor is moving as you tighten the bolts. Then move the arbor that much further so when you the tighten the bolts, it's as close to parallel as you can get it.

Also, be aware a Craftsman contractor saw is far from a precision machine. Even after all the hot-rodding, my saw isn't like a cabinet saw. I'm ready to buy a new Sawstop Cabinet saw. Just waiting for the 220V outlets to be installed.

Good luck.

[glenn bradley]

A contractor saw from the 60s may have actually been used as a job site saw. It is possible it took a few knocks being loaded and unloaded from the pick up truck. If this is the cause of your deviation at different blade heights I'm not sure how far I would go toward fixing that on a 1960s C-man. JME. I've had a few. I recently rebuilt an old Craftsman in this thread. The alignment is spot on although the method with table mounted trunnions can be time consuming, a bit of luck, and frustrating or all three .

Many Emerson Craftsman machines (model number prefixed with 113.) use 5 trunnion bolts. I loosen all of them, shift the trunnion to the extreme left side to give me a starting point (and the maximum room to put blades on and off), snug the front or rear center bolt, pinky-tight the others and begin.

To compound the inelegant method of alignment in the contractor design the trunnion will pull out of alignment when tightening the bolts to test. Do not let this frustrate you. Remain diligent and loosen, tap or PALs tweak the position and re-tighten/test. You will get to the best you can get within a half a dozen tries IME. It is normal to have the blade well aligned at 90 degrees but fairly useless at other angles on a contractor saw. Just find other ways to make bevel cuts.

The blade to slot alignment should do nothing about the deviation while raising the blade. Maybe it will . . . fingers crossed. If not you will just need to make a decision on how to move forward. I would not start buying parts for a 1960's contractor saw when another one could be picked up for not too much money. I have a spare. Where are you located?

[Mark Mrsa]

Lee,
Thanks for the tip regarding the trunnion bolt. My back trunnion has three bolts. I removed the bolt and was able to align the blade within 0.0001-0.0002" and when I tight the middle bolt there was some slight movement, but not beyond 0.0002". More significantly, when I placed my link belt back on and achieved the belt tension that I that appropriate I noticed the motor bracket had come out of alignment. I adjusted the nuts securing the bracket and re-established belt tension, but alignment was still off. Using a metal rule with 1/32' graduation, the back of blade measurement is 1/64" more then the front of blade measurement from the miter slot. Is there any way to prevent the motor mount placement and belt tension from throwing off the blade arbor alignment (I think this is the root cause of my alignment problem as I was able to achieve parallelism with my PALS kit and a dial indicator of less then 0.0002")?
Given the age of my craftsman saw-1965- and the fact that it is not a quality machine, even for 1960's standards, do you think this the best I can achieve and live with it or seriously consider a saw upgrade.
I make boxes, and to date the boxes store small jigs. My goal is to make boxes with a variety of joinery and wood species that require precision cutting.
Your further thoughts and recommendations would be greatly appreciated.
Mark Mrsa

[Lee Schierer]

Lee,
Thanks for the tip regarding the trunnion bolt. My back trunnion has three bolts. I removed the bolt and was able to align the blade within 0.0001-0.0002" and when I tight the middle bolt there was some slight movement, but not beyond 0.0002". More significantly, when I placed my link belt back on and achieved the belt tension that I that appropriate I noticed the motor bracket had come out of alignment. I adjusted the nuts securing the bracket and re-established belt tension, but alignment was still off. Using a metal rule with 1/32' graduation, the back of blade measurement is 1/64" more then the front of blade measurement from the miter slot. Is there any way to prevent the motor mount placement and belt tension from throwing off the blade arbor alignment (I think this is the root cause of my alignment problem as I was able to achieve parallelism with my PALS kit and a dial indicator of less then 0.0002")?
Given the age of my craftsman saw-1965- and the fact that it is not a quality machine, even for 1960's standards, do you think this the best I can achieve and live with it or seriously consider a saw upgrade.
I make boxes, and to date the boxes store small jigs. My goal is to make boxes with a variety of joinery and wood species that require precision cutting.
Your further thoughts and recommendations would be greatly appreciated.
Mark Mrsa

I align my saw with the drive belt in place and tensioned by the motor. I've never tried doing it with the belt off. I don't understand why you align it with a dial indicator and then measure misalignment with a scale.

[glenn bradley]

I make boxes, and to date the boxes store small jigs. My goal is to make boxes with a variety of joinery and wood species that require precision cutting.
Your further thoughts and recommendations would be greatly appreciated.
Mark Mrsa

Over half of my use of the tablesaw is as a joinery machine such as you describe. Before you throw money at something else I would make a few boxes using mitered corners, box joints, and drawer-lock type joinery made at the tablesaw. If things fit well I would say you've got a workable machine.

swap-2 (43).jpg . Pic-boxes-done-1.jpg

If you are having to force things together then a poor joinery result could be your culprit. This assumes the parts have all been milled flat and true before adding the joinery.

If you will work primarily with mitered corners you could make a shooting board fixture to true op the failed joinery.

Shooting Board miter acc (6).jpg

This adds some extra effort but puts off the large expenditure of an alternate saw. I would work myself through a few projects to see what the machine's strength and weaknesses are before I walked away. You may find it to be a very workable machine at best. At worst you will learn the things that are important to you and what to look for on your next.

[Mark Mrsa]

Lee,
In the videos I've watched to align the blade (In-Line Industries comes to mind primarily), it appears the the drive belt is not in place. When using the dial indicator, the blade is moved counterclockwise to get the back of blade measurement. I've used the metal ruler because I have not been able to move the blade counterclockwise the the drive belt in place and tensioned. Am I doing something wrong????
Mark Mrsa

[Mark Mrsa]

Glenn,
Thanks for your advice. I have made a couple of boxes using mitered joinery which were not precisely cut. I was able to hand sand the ends to make a squared fit, but I was dissatisfied that I was unable to maintain a 45 degree along the width the of wood stock. I made a shooting to plane square edges and ends. I'm currently attempting to complete a cross-cut sled for the table saw which prompted my recent posting about blade alignment to the miter slot.
My aim is to mark as precise cuts as possible when using the table saw to minimize the need to plane or sand errors. I know that inpercision is part of the woodworking experience and through this alignment challenge I hoping to find the point that I am comfortable with and proceed from there.
Your advice to make a few more boxes with different joinery techniques is sound and appreciated. How often do you find yourself correcting cutting errors when maing your boxes.
Mark Mrsa

[glenn bradley]

How often do you find yourself correcting cutting errors when making your boxes. Mark Mrsa

Pretty seldom now but I have already marched down the road you are now on. It's a journey. Although there will be frustrating moments, enjoy the ride.

My current saw is a 3HP Saw Stop which, safety feature aside, is a pretty nice home shop level cabinet saw so it is unfair to compare it to your current (or my previous) saw(s). I've had a few Craftsman Emerson contractor saws and I was curious about this statement . . . "I've used the metal ruler because I have not been able to move the blade counterclockwise the the drive belt in place and tensioned.".

I have not encountered an induction motor that doesn't 'free wheel' when power is not applied. I am certainly NOT the end all of motor knowledge . . . I just haven't run into an induction motor that wouldn't spin backwards when de-energized. Not sure how far you want to dig into this but a model number of your saw would let me look into it further.

Be that as it may . One of the things that helped my mitered-corner box making move up a tier was a sled built specific to box making. Maybe more correctly, a sled designed to hold small parts while milling.

2009 bev-sled 002.jpg

Essentially it just has a couple of t-tracks that allow the part being cut to be held firmly close to the cut and secure the off-cut as well. This gives a very solid grip and although the operation takes more time per cut . . . the time saved by not having to tune the miter is all in favor of the sled .

If I had to try to list the things that worked for me in my pursuit of off-the-machine bevel cuts they would be:
- Properly milled blanks.
- Well aligned saw.
- Sled that held small parts VERY securely.
- Full kerf blade (even on my lower horse power saws).

An added benefit to a well aligned saw is that everything else works better on it in my experience. I make air-tight miters for picture frames right off the saw with a miter gauge.

Larry Frame (12).jpg . 5X5 Frame (16).jpg

One cannot attribute this solely to the gauge. The miter slot and blade relationship have to be there. No miter gauge or sled will fix that problem. Likewise, no amount of skill will make an irregular feed path be reliable.

I have managed to wander off a bit and start blathering (it's a curse) so if there is something specific that I can help with that I passed by, let me know. The forums have a wealth of knowledge from a lot of experienced folks. I'm pretty sure we can help.

[Mark Mrsa]

Glenn, thanks for staying with me!!!
During this past week, in trying to achieve precise blade alignment I came to understand better how the blade and motor arbor/pulley alignment and belt tension affect parallelism. Discovered that I was over tensioning the link belt which would not allow the blade to move freely. Still am unsure what blade height should be used to establish belt tension. With the blade at full height, I established proper tension and the blade moved freely. Able to achieve blade alignment to the miter slot less then 0.0001". When I moved the blade down to 2" above the table surface to calibrate my cross-cut sled then belt tension had to be reestablished. Am I doing something incorrect?
I did successfully calibrate the sled achieving spot on diagonal, width and length measurements.
I also discovered my Incra miter guage was not squared properly and did so. All this said, I've not paided close enough attention to how all the table components affect parallelism (mechanical problem solving). I'm becoming more aware of and growing in regard to the machine skill knowledge and set up of woodworking machines!
Thanks for your sharing of what has worked for you. Can I assume that you use full kerf blades with table saw jig construction to allow for interchanging blades or are there other reasons that you would share?
Mark Mrsa