question re: PM 66 and Freud dado blade

[Brent Esmoil]

Greetings woodworking gurus. I have a Powermatic 66 (circa '96-'97) that I love, save one perceived flaw. I have used it for years and now that I'm about to build a series of cabinets, I decided I should find out if there's a flaw I need to correct. I use a Freud 8" Safety-dado (SD308) and noticed that whenever I have multiple chippers installed (such as for cutting a 3/4" dado) that there are only a few threads left on the arbor. Very little of the nut can be placed on the threads unless I were to go without the "washer" next to the blade. I included two pictures if it might help. One shows the dado blade in place with the washer as well as a second one without it. I bought the SD at an auction so it didn't come with instructions. As such, I was wondering if you could give some advice on the proper blade and chipper mounting so that I'm left with some threads for the nut. I've always been leery of going without the "washer" since there is one on the left side of the blade. I am always careful to ensure none of the teeth are touching. Thanks a million in advance for your help!

[Chuck Lenz]

I don't use the washer. It's not a flaw.

[Lance Norris]

Welcome Brent, Chuck is right. You dont use the washer. I have a Freud 208 dado and the instructions say to not use the washer. The owners manual for my Unisaw says the same, no washer.

[Brent Esmoil]

Thanks for the reply Chuck. I just noticed that I'm not able to place the blades on correctly to take a picture :) Luckily people will get the idea.

[glenn bradley]

Thanks for the reply Chuck. I just noticed that I'm not able to place the blades on correctly to take a picture :) Luckily people will get the idea.

Your kidding(?). Is that why my dados come out a little rough? :D:D:D Good advise here, no washer. I do sometimes sneak a blade stabilizer in there but it is not required, I just don't like marks on my outside blade.

[Steven Wilson]

Not a problem leave the PM washer off. You want the nut to be fully on. If not having a washer bothers you then use a blade stabilizer.

[Brent Esmoil]

Thanks gang! A blade stabilizer appears to be in order. For some reason I'm of the "no marks on the blade" camp. Now a new question came to mind while I was putting my Forrest blade back on. What do you lubricate your arbor threads with? It seemed a little stiff putting on the nut but maybe I'm just getting too picky/lazy.

[Steve Clardy]

Thanks gang! A blade stabilizer appears to be in order. For some reason I'm of the "no marks on the blade" camp. Now a new question came to mind while I was putting my Forrest blade back on. What do you lubricate your arbor threads with? It seemed a little stiff putting on the nut but maybe I'm just getting too picky/lazy.


Small squirt of wd-40 or any penterating oil once in a while.

[Steven Wilson]

I like to take a brush down there and clean the threads. As for a lubricant, pretty much anything you want. I use 3 in 1

[Lance Norris]

Now a new question came to mind while I was putting my Forrest blade back on. What do you lubricate your arbor threads with? It seemed a little stiff putting on the nut

I run my saw with no blade and buff the arbor with a scotch-brite pad. My Freud dado set was tight on the arbor and this worked great.

[Chuck Lenz]

I run my saw with no blade and buff the arbor with a scotch-brite pad. My Freud dado set was tight on the arbor and this worked great.
The blade set is supose to be tight on the arbor.

[Lance Norris]

Chuck ...maybe I should have said it was too tight trying to install it on the arbor. It was so tight, I would have had to beat it on with a hammer. Then it never would have come off. Also I had several turns on the arbor where the nut wouldn't hand thread. This fixed all that. Now the nut is smooth to hand tighten. Since its an acme style thread, I'm sure all I did was smooth the roughness that was there from the manufacturing process. Its a new saw. Well... its a year and a half old now.

[Chuck Lenz]

Chuck ...maybe I should have said it was too tight trying to install it on the arbor. It was so tight, I would have had to beat it on with a hammer. Then it never would have come off. Also I had several turns on the arbor where the nut wouldn't hand thread. This fixed all that. Now the nut is smooth to hand tighten. Since its an acme style thread, I'm sure all I did was smooth the roughness that was there from the manufacturing process. Its a new saw. Well... its a year and a half old now.
Thats pretty tight, obviously too tight. Mine isn't easy to get on or off either, but I think in my case it's just tight tolerances. I will say though that It isn't so tight that I'd have to use a hammer to put it on or get it off. My saw is about 13 years old and the nut spins pretty freely on the arbor. I should also mention that I don't have the PM 66, I have a Delta Contractors saw.