Pittman 9000 Series Motors

It’s basically thread sealer, not a thread locker, although with an aluminum screw, it might as well be loctite,…..they use it on both the aluminum screw, & the stainless non-magnetic type. …….next time you have to take one apart, stand it up with the thread holes up, and put a drop of something petroleum distillate on the through holes. ( WD, PB, or your favorite ) and walk away for a while,…..it’ll wick down and that’ll  aid in removal. If you need replacement screws, gimme the part number, and. I’ll hook ya up,…

Pat

The removal of the “nub” was fun.

Not.

Thanks for the offer Pat. I was actually switching the front (mounting side) from one to another because i wanted different size mounting threads. So, the motor I need is back together.

Looks like I just need some 6-32 60mm flathead screws for the other one.

Pat, thank you.  Informative as usual.  Is there anything in particular you do to keep the penetrant out of the shaft bearings?

Ryan, I enjoy a good broken screw removal story.  Which method(s) did you use?

@SteveH posted:

Pat, thank you.  Informative as usual.  Is there anything in particular you do to keep the penetrant out of the shaft bearings?

Ryan, I enjoy a good broken screw removal story.  Which method(s) did you use?

When you stand the motor up on it’s back, you’re just putting a drop in the through hole. The other end of the fastener is visible in the hole. Any penetrant won’t wick over to the shaft bearing,…..If it does, no big deal,….re-oil and carry on as usual,….

Pat

@rplst8 posted:

The removal of the “nub” was fun.

Not.

Thanks for the offer Pat. I was actually switching the front (mounting side) from one to another because i wanted different size mounting threads. So, the motor I need is back together.

Looks like I just need some 6-32 60mm flathead screws for the other one.

Looks like I just need some 6-32 60mm flathead screws for the other one

close, it’s 6-32 X 2.25” or 57mm & change for the large 60 mm motor ….

Pat

@SteveH posted:

Pat, thank you.  Informative as usual.  Is there anything in particular you do to keep the penetrant out of the shaft bearings?

Ryan, I enjoy a good broken screw removal story.  Which method(s) did you use?

Steve, here’s a pic of what I mean,……I don’t spray it all over the front of the motor, I keep WD in a can, so I can dispense it as I see fit,…..usually I’ll dip a toothpick in the WD and let the fat drop fall in the hole …..

Pat

Pat, thanks for the pic and further detail.  That makes perfect sense to only use a drop per #6 screw.  Typically when I'm using PB, it's right out of the spray nozzle on 20 to 60 year old rusted tractor bolts.  Good to know that for a small screw with thread sealer, a more nuanced approach will work just fine.

@SteveH posted:

Pat, thank you.  Informative as usual.  Is there anything in particular you do to keep the penetrant out of the shaft bearings?

Ryan, I enjoy a good broken screw removal story.  Which method(s) did you use?

Well, I panicked and made a mess of it honestly.

Both case screws on the 56mm motor with 6-32 threaded mounting holes broke off. I didn’t realize the first one broke because it just sort of felt like it was loosening. The thought hadn’t really even crossed my mind because all of the 8xxx series motors I have messed with had steel screws and they just backed right out. Anyway, it wasn’t until I did the second screw and noticed it was shorter that the other (and broke off much easier) that I realized what I’d done.

The one broken piece came out pretty easily. It had about 7-8mm sticking out. After a little WD-40 a pair of vice grips made quick work of it.

The other one however, snapped off right at the plate where it screws in to the receiving threads. In my haste I forgot to put WD-40 on that one. I started with a screw removal tool I had. I got a small hole center drilled (mostly) but the tool just kept chewing away the aluminum remnants and wouldn’t catch. I should have then realized my error but you know, I thought swearing at it was the proper course of action.

After that, I drilled a pilot hole all the way through. Then I tried using a reamer to grab it and twist it out. Again I was just mining for aluminum. So then I used set of metric taps to cut new threads in it. Then I put in a new STEEL screw, and just tightened it until it striped those. Repeated with the next size up.

Then using some spare long 6-32 steel screws that I ground into a point, I went in from the other side and just turned that through to push all the remaining bits out.

It’s not perfect, but it’ll do.

All of this to move the mounting plate with smaller threads from a 56mm Pittman to a 61mm Pittman.

Removed a chunk of my finger in the process too. Nothing serious. But, ouchie.

@rplst8 posted:

Well, I panicked and made a mess of it honestly.

Both case screws on the 56mm motor with 6-32 threaded mounting holes broke off. I didn’t realize the first one broke because it just sort of felt like it was loosening. The thought hadn’t really even crossed my mind because all of the 8xxx series motors I have messed with had steel screws and they just backed right out. Anyway, it wasn’t until I did the second screw and noticed it was shorter that the other (and broke off much easier) that I realized what I’d done.

The one broken piece came out pretty easily. It had about 7-8mm sticking out. After a little WD-40 a pair of vice grips made quick work of it.

The other one however, snapped off right at the plate where it screws in to the receiving threads. In my haste I forgot to put WD-40 on that one. I started with a screw removal tool I had. I got a small hole center drilled (mostly) but the tool just kept chewing away the aluminum remnants and wouldn’t catch. I should have then realized my error but you know, I thought swearing at it was the proper course of action.

After that, I drilled a pilot hole all the way through. Then I tried using a reamer to grab it and twist it out. Again I was just mining for aluminum. So then I used set of metric taps to cut new threads in it. Then I put in a new STEEL screw, and just tightened it until it striped those. Repeated with the next size up.

Then using some spare long 6-32 steel screws that I ground into a point, I went in from the other side and just turned that through to push all the remaining bits out.

It’s not perfect, but it’ll do.

All of this to move the mounting plate with smaller threads from a 56mm Pittman to a 61mm Pittman.

Removed a chunk of my finger in the process too. Nothing serious. But, ouchie.

The steel screws will mess with the permanent magnets that create the field that the motor runs in. Depending on the application, say, like a locomotive with 16:1 to 20:1 with some sort of cruise, you may experience minor cog, or even some noise as the live poles pass by the now energized ( magnetic ) screws,……there’s a reason why they use aluminum, or 100% pure stainless ( low magnetic properties) ……Pittmans are designed specifically for nearly zero cog, …..hence the term “Lo Cog” ……run your repaired motor as you fixed it, if you experience low rpm issues, stutters, stalls, etc,….you know what to do,…..be careful of off shore stainless hardware, most I’ve encountered are just as magnetic as plain steel.

Pat

@harmonyards posted:

The steel screws will mess with the permanent magnets that create the field that the motor runs in.

Pat,

I’m still using the aluminum case screws. I only used the steel ones to clean out the threads.

@rplst8 posted:

Pat,

I’m still using the aluminum case screws. I only used the steel ones to clean out the threads.

Ahh, cool,…copy that …

Pat