Table saw runout on 45 degree

[Scott Davis]

Hoping for some wisdom.

I have a PM 66 which was set up a while ago. It is tuned very well at 90 degrees but I was checking the alignment today with a dial indicator and at 45 degrees I have about 18-20 thousandth's runout. So I guess it needs to be shimmed in front or back somehow. I vaguely remember something that looked like washers coming out when I took it apart last time.

This thing is a pain to take apart, especially by yourself.

Should this be a conern? It this a meaningful amount? (I don't put it at 45 degrees very often)

How exactly do you shim it? Was that a special shim of some sort or just a washer? Are there varying thicknesses?

Thanks

[glenn bradley]

Are we talking about runout (which would be present regardless of setting) or alignment? Sounds like we are talking about alignment between blade surface and miter slot, yes? The good news is that cabinet mounted trunnions are a breeze to setup when compared to something like a contractor format saw. Misalignment at angles other than 90 degrees is due to table tilt (generally front to rear).

FIRST A WARNING . . . If you remove the top, the "washers" at any bolt positions are not just washers, they are shims that were used at the factory to align the saw to Powermatics standards. Although it sounds like this has already been changed, keep track of which ones go where and your life will be easier.

Now on to the game . . . Loosen the top's retaining bolts at the front and re-check without doing anything else. If your number change, you've found the problem. Adjust the height of front or rear of the table as required by shimming (I use cut up slices of aluminum can but, brass shim stock is preferred by some). Figure out which way to go to head toward the "better" reading and then continue is small steps until you go too far. Tighten the top securely and re-check; if it is still "too far", remove some shim material and repeat.

I pull my fence and wings when I do this as the time gained in misalignment due to their presence has proven greater than that required to take them off an on. The downside is that you may need to do some final tweaking once the fence and wings are back in play depending on the table top's ability to resist the weight.

This process can be quite tedious and I generally plan on about 4 hours so that I am mentally prepared should it take that long. This keeps me from doing 90% of the work, getting frustrated and calling it good enough (which is a waste of time). It takes a lot less time unless things are really screwed up.

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[David Kumm]

Yes the top needs to be shimmed. If you get into setting up machines, a box of slotted shims is a must have. I have a box of 5/8" ID but you might not need that large. You can also cut some yourself from brass shim stock available at a hardware store. Dave

[Bill Space]

Google "table saw alignment" and you will find everything you need to know.

Here is a link to a Grizzly video...

https://www.youtube.com/watch?v=bpg39Lbwpu0

Bill

[Scott Davis]

Thanks all,
I did watch some videos when I first did this, there is one by wood whiperer:
https://www.youtube.com/watch?v=lxRSarTJLMU

and this pdf from wood mag:
http://www.woodmagazine.com/wood/pdf/delta/ds-038free.pdf

I remember reviewing both but unfortunately neither speaks of the shims. I do remember losing them and not knowing what they were. Oh well.

Maybe I should change the belts while I am down in there, I know mine have a "memory" because the saw was unused for about 10 years at one point. It works fine but I have wondered if they should be replaced as they are nearly 30 years old.

Thanks for the tip on how to do it, i would not have thought to just take the bolts out and check alignment first. Good idea.

Scott

[Scott Davis]

Looked up shim stock...wow!. I don't know which thickness I need and that stuff is not cheap! Cheapest slotted ones I can see are 25$

Will try the tin can idea first I think

[glenn bradley]

My previous saw was done with aluminum can stock. Worked for years, went to my dad and is still working fine. Just used it the other day.

[David Utterback]

This is all new information for me and it is the reason that this forum is so valuable. Gotta go check mine out! Thanks

[John Schweikert]

$30 this will give you all the shim material you could ever need: http://www.amazon.com/Unpolished-Finish-Temper-0-001-0-015-Thickness/dp/B002BYTCL6/ref=sr_1_1?ie=UTF8&qid=1456090936&sr=8-1&keywords=brass+shim+stock