Arbor/Arbor Nut Issue

[BuzzDog]

I just pulled my BT3000 out after sitting in a corner of my garage for a few years, and I'm "tuning it up" before I put it to use.

I had a heck of a time getting the arbor nut off (yes, I knew from the start it was left-hand threaded), and I have no idea what happened other than humidity. But here's the deal: I've tried hand-threading the arbor nut, and it's not going on easily.

Thanks to this forum, I've learned that the arbor and threads are 5/8" x 18. I'm ordering TWO new arbor nuts (I have a repair center near me that doesn't charge for shipping).

Now here's the big question: The threads on the arbor look intact, but a bit flat. Would it be a good idea to "chase" the threads on the arbor with a die?

And big question number two: I've used a tap to prepare an aluminum engine head for a heli-coil, but I've never used a die...how foolproof is it if you're using it to re-thread?

Thanks in advance for any and all help.

[dbhost]

A lot of expansion and contraction, topped off with various dust, grime, and nasty stuff tends to build up on machines and threads that sit unused for years. You may not need to chase those threads (then again you might, your description is a little vague...) I would probably start off by cleaning the threads up with rubbing alcohol (no residue left behind...)

[LCHIEN]

because of the two flats on the arbor, its always a bit tricky to start the arbor nut on the arbor without cross threading it, given its also a reverse L-H thread which its also an unnatural action.

Another warning is that you don't have to put the arbor nut on with a "death grip" as some have called it. The turning action of the saw tends to tighten the nut rather than loosen it (because of the L-H thread) so its not necessary to torque it very highly.

My method of putting on the nut:
Use three fingers to hold it so that you don't drop it - that's always a pain to fish it out.
Put it on nearly parallel with the blade as you can, rotate with two fingers using the third to hold it against the end of the arbor. There should be an easy turn, it it doesn't spin easily its cross threaded so try again. Don't force it. after starting it you can go back to two fingers and run it down until its just finger tight against the blade washer.
Then lock the shaft and use the 1/2" wrench to turn it about 1/8-1/4 turn more to snug it up with what I consider to be a moderate force. Doesn't have to be real hard.

I'd say if its not cross threaded and its hard to turn, try some wd-40 and a toothbrush to clean off the nut threads and the arbor threads. Its not real greasy or anything to attract and hold dirt. As i said, it should spin real easy.

[BuzzDog]

Thanks for the replies. I'll hold off on the die (the least expensive one I've found is $15 plus shipping, as others have noted) and give the threads a good cleaning.

And thanks, Lchien, for the reminder not to tighten the nut as much as one would normally expect. I've read that in some other posts, and I can't say for certain that I didn't indeed overtighten it when I installed the blade several years ago.

Now, to start building boxes for that cabinet project I've been putting off...

[LCHIEN]

yeah i meant to add that I wouldn't take a die to it right away... aside from the difficulty in locating a L-H die, it will be hard to start correctly because it also has some gaps for chip removal....

Unless you Cross threaded it before, that' might have bunged up the threads, although I suspect the arbor is much harder material than the nut which some have complained is kind of pot-metal-ish.... brittle.

[capncarl]

A thread file is a handy tool to have in the shop to touch up threads that get mashed or rounded, rather than have to buy a die just to clean up threads. They can be picked up at better hardware and mill supply stores. FYI, Thread files are square 4 sided files with a different cut on each side for a specific thread per inch. Mine are double ended giving me 8 different threads I can use it on. Great to have around.
capncarl

[L. D. Jeffries]

Just another 2cents on the arbor nut thread. I've found on my BT3 that the arbor nut starts on very nicely only if started from one side. That is if you take it off and try to put it back on with the same side that was towards the blade it goes on OK. Turn it around and the stupid thing doesn't want to ever start! I've scratched my head about this lots of times, but finally gave up and accepted the nuts little "joke".