Powermatic 66

Overhaul

The Powermatic 66 is the central focus of the shop. It has a shop built outfeed and downdraft table attached to the rear of the unit. Dust collection and storage have been built into the area to the right side of the saw under the extension table.

This table has been in service for 12 years without an overhaul. The blade elevation and blade angle adjustment mechanisms had gottem very difficult to use.

It was time for an overhaul and tune-up.

Phase 1 was to clean and lubricate the bottom section of the P66.


We had read an excellent article on this phase of Tablesaw Tune-Up in a Fine Woodworking publication...

In particular, the best tip from the article was to use a LPS F104° solvent degreaser
and the LPS Force 842° Dry Moly Lubricant.

First we pulled away the outfeed and downdraft table/cabinet assembly.

 

Then pulled the front and back rails to remove the fence assembly bar.

 

After separating the right cabinet assembly and extension table, we pulled the cast iron side table.
With both side table removed we were ready to take off the main table.
This exposed the heavy build up of old paint, resins, saw dust etc. that was causing our problems.
We began a methodical clean up that involved multiple vacuum passes.

This process really paid some huge dividends.

 

We used the Festool C22 dust collection with the Oneida Dust Deputy cyclonic addon.

We added Stinger miniature dust collection attachments that really got into small places with incredible suction.

We suddenly got to the point where we realized that we had cleaned all the places that the overhaul instructions had said to clean...all that was left were places where they said to spray in a penetrating lubricant.

We said what the hell and decided to cross the Rubicon...we opted to pull everything apart...we would totally break down everything in the unit except the sealed bearing for the saw blade spindle.

So we started by removing the motor. It is a powerful and heavy Baldor unit.

Next came the trunion assembly.
Now we were pretty much down to the cabinet shell.
It was a magnificent day...we pulled the internal assemblies outside so we could used compressed air and wire wheels for the final clean up stage without getting dust in the air in the shop.

Here are the rear and front trunnion pieces.

Wire wheel cleanup got them quite clean.

Hear are the trunnions with the LPS spray on them. We really liked this quick dry lube.

We were able to disassemble and really clean the worm drive raising shaft and tilting shaft.

The biggest mystery of the overhaul was that the two shafts each had a Woodruff key that seemed to serve no purpose at all.

Bobby at Powermatic solved the issue by informing me that the end of the lock down knob pushes one edge of the Woodruff key up and it locks down on the shaft.

The hardest step in the entire process was breaking down the nut on the pivot shaft. This was a "self-locking" nut that was 1 5/8 inches.

We had to dig out my 3/4 inch drive SAE socket set and use the BFH gentle persuader to pound the unit for a bit.

It finally came off and now we had disassembled everything that could be pulled apart.

 

After a major cleaning and thorough lube job we started putting it all back together.

Here is the trunnion unit back in with all turning wheels reinstalled.

Both the blade height system and the blade angle system move smoother than they did the day I bought the unit.

This is a major improvement.

This ends Phase One.

The lower unit is overhauled.

The last tweak before reinstalling the top was put Lock Tite on the large bolt that secures the pivot shaft assembly.

 

 

The first step of Phase Two was to refinish the cast iron table.

We started with a wire wheel to remove bad spots or rust.

Then we moved throught varying grits up to 400 on variable orbit sanders.

Then some manual work with wet sanding up to 2000 grit to really get the center section smooth.

Every nut and bolt was wire wheeled and coated with camelia oil.
Once the table top was waxed we placed the unit back on the saw. Then we began the tweak to make the surface level and square to the saw arbor.

We use the A-Line-It® guage in the mitre groove to get blade run measurement to make the table top square.

We used a MasterPlate® rather than a blade to make sure there was a minimum of deflection.

After many a tap with the dead blow hammer we finally got a runout that was within .001 inch.

Measuring runout at a 45° setting enabled us to determine the front to back leveling of the tabletop.

We again reached a tolerance of .001 inch.
Blade angle at 90° was achieved and the scale was calibrated. We decided to not "stop" the device at 90°.The adjustment will actually carry the arbor to a greater degree. Rather than counting on the accuracy of the stop, we will calibrate it precisely when starting a new series of cuts.
Verification or 45° runout to a blade.

Final verification of 90° runout to blade.

The gauge used here is the Betterly Una-Gauge®.

Placing and leveling of the two cast iron wings was as difficult as any adjustment. The act of the final bolt tightening always changed the level of the wing. After many an attempt we finally got happy with the entire surface.

We replaced the front and back rails for the fence assembly.

The original 2000 install of the extension table had been frustrating because the holes in the table had not matched up well with the holes in the front and rear rail assemblies.

We decided to make this right so we drilled a proper set of holes and replaced all of the hardware.

After the fence was reinstalled we calibrated and adjusted the fence runout.

 

The overhaul is complete. All is clean, lubed, calibrated and adjusted within fairly close margins. Most experts said that error of .002 inches was acceptable and we met .001 in every instance.

The biggest problem now is adjusting to how easy it is to move the trunnion system. I have not had to set the locking features on the elevation or angle shafts for years because they were so difficult to move.

Now that the movement is so facile, the torque of the motor start up will alter the adjustments.

So I am having to retrain myself to get it right and lock it down.


 

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