About these motor prop nuts...

[Monte.C]

I have a couple pairs of real small motors - these happen to be from Xnova - and the prop nuts are giving me a great big headache. They work perfectly well, but they're the kind with plastic built in to tighten on the threads of the prop shaft. The plastic is way too tight. Anybody have this problem?

I can use a wrench on the nut, but to get the job done I've resorted to using channel-lock pliers to hold the motor housing, with a piece of T-shirt to try not to bite into the housing with the pliers. This is the LAST way I would want to treat this motor. Every part of me says this is wrong!

I used my hobby blade to remove as much of the plastic from inside the nut as I could. I was able to remove only a few tiny slivers. Then I've used a drop of oil on the shaft. These things helped a tiny bit but I still need two tools to do the job. And I won't want to change a prop at the field if I break one - I'm afraid I might break the plane if I try.
This is ridiculous. I'm almost ready to try to burn out most of the plastic with a lighter...

Anybody?

 

[leaded50]

self-locking, thats reasonfor the plastic to be there...

 

[Monte.C]

self-locking, thats reasonfor the plastic to be there...

Yes that's the term I couldn't think of. Well these ones are brutal. I might have to buy a terribly overpriced package of prop nuts that work better. Using heavy pliers on the motor housing is not my idea of a good time.

 

[shadeyB]

Yes that's the term I couldn't think of. Well these ones are brutal. I might have to buy a terribly overpriced package of prop nuts that work better. Using heavy pliers on the motor housing is not my idea of a good time.

Get regular sized nuts to fit the shaft and use some ‘ thread lock ‘ blue colour not the red stuff

 

[Monte.C]

Get regular sized nuts to fit the shaft and use some ‘ thread lock ‘ blue colour not the red stuff

Yeah - Duh - Thanks. You're right. I needed somebody to tell me that.
With the blue threadlock, how hard is it to crack it free?
On that note, what about a little bit of that Teflon plumbers tape?

 

[chrisvdv]

Or:
https://store.flitetest.com/flite-test-motor-grip-pliers-flt-4009/p1144510

 

[shadeyB]

Yeah - Duh - Thanks. You're right. I needed somebody to tell me that.
With the blue threadlock, how hard is it to crack it free?
On that note, what about a little bit of that Teflon plumbers tape?

Never tried the plumbers tape ?
The blue will sit tight , only use small amount 1 drop 2 at most , it will crack open fine with grips or spanner , whatever you’d use

 

[Bricks]

Take your nylock nut and heat it up and melt the plastic out of it, simple fix.

 

[Monte.C]

Take your nylock nut and heat it up and melt the plastic out of it, simple fix.

Thanks that's what I was considering. Will do.

 

[Piotrsko]

The proper way is to get a tap of the correct size and partially run it through the plastic retaining, or fully run it through and use threadlocker compounds. Sometimes metric stuff can be tapped the next millimeter smaller. My local Ace hardware has them for maybe $5.

 

[Monte.C]

Love that. Exactly. Thank you @Piotrsko.

 

[Monte.C]

The proper way is to get a tap of the correct size and partially run it through the plastic retaining, or fully run it through and use threadlocker compounds. Sometimes metric stuff can be tapped the next millimeter smaller. My local Ace hardware has them for maybe $5.

@Piotrsko I'm not a machinist or mechanic and I've never figured out drill & tap sizes or the M designations for bolts. The dimension diagrams for these little motors shows a threaded prop mounting shaft at 1.5mm diameter. Would you know what tap size I'm looking for?
Thanks in advance.
EDIT:
Sorry Piotrsko I'm being a knucklehead. The question was about a little bit larger motors that have a threaded prop shaft. What I'm using lately are a smooth shaft with screws for prop mount. My mistake!
I'd still love to be able to figure this out though. Is it as simple as M1, M2...? Is that in millimeters?

 

[Piotrsko]

Not sure what the M in M3-.07 screw means, I just thought it was a Metric identifier. Caveat: I prefer american size and pitches, but the system works in both metric and B&S tap specifications. I believe the 1st number to be the major diameter, so a m8 would be 8 mm through hole. If you drill a hole this size the tap just falls through so the tap drilled hole has to be smaller or minor diameter. Look up somewhere what the starter hole should be. There tend to be Common Thread pitches .07, .08, 1.0 and I think 1.2 or 1.5. 1 This kinda corresponds to the American threads of coarse, fine, extra fine and means one thread revolution will take up that much length in mm. The american equivalent is like 10-32 which uses a #9 drill bit major pitch and 32 threads to the inch and it's not the same as a M10-1.0

If you're really into this I suggest either a library copy of the Machinery's handbook isbn(0-8311-1129-1)or Thomas Glovers Pocket reference (ISBN 1-885071-00-0), both of which will give you a headache or a lifelong passion for this stuff. I have both so I really should have looked up the data, but that would take forever. Oh and BTW m 1.5 will be .35 pitch but they called out a m5.5-4

 

[Monte.C]

Not sure what the M in M3-.07 screw means, I just thought it was a Metric identifier. Caveat: I prefer american size and pitches, but the system works in both metric and B&S tap specifications. I believe the 1st number to be the major diameter, so a m8 would be 8 mm through hole. If you drill a hole this size the tap just falls through so the tap drilled hole has to be smaller or minor diameter. Look up somewhere what the starter hole should be. There tend to be Common Thread pitches .07, .08, 1.0 and I think 1.2 or 1.5. 1 This kinda corresponds to the American threads of coarse, fine, extra fine and means one thread revolution will take up that much length in mm. The american equivalent is like 10-32 which uses a #9 drill bit major pitch and 32 threads to the inch and it's not the same as a M10-1.0

If you're really into this I suggest either a library copy of the Machinery's handbook isbn(0-8311-1129-1)or Thomas Glovers Pocket reference (ISBN 1-885071-00-0), both of which will give you a headache or a lifelong passion for this stuff. I have both so I really should have looked up the data, but that would take forever. Oh and BTW m 1.5 will be .35 pitch but they called out a m5.5-4

That's SO not the answer I was hoping for!
How about I carry the motor into Home Depot and compare by eye?

 

[Hondo76251]

I hate those tight nylocks on my motors. I have a few bolts that match the motors and i use my impact gun to run them up and down a few times to loosen them up. I also run basic hardware store nuts too. Only advantage of the nylock is that if it loosens the you generally dont lose the prop and the nut. Although, in my experience, they very rarely come loose if tightened securely, even without thread lockers.

Good idea to puck up a few spares while at the store regardless!

 

[Piotrsko]

That's SO not the answer I was hoping for!
How about I carry the motor into Home Depot and compare by eye?

Oh well heck you dinnt ask that. No you wont go anywhere close by and get a die that you can use to tap your motor shaft. Amazon perhaps but it will be $$$$$ and the nut assembly will be pricey, too. You can buy the drill bit undersize to the motor shaft diameter, get some aluminum, find a lathe and center drill a hole then thread that (adapter) to whatever you want or use a stud in the proper size once again center drilled on a lathe. Key word is lathe.

 

[Piotrsko]

Thinking about it more....... Just go buy quad props for a 1.5 mm shaft. Maybe 1/16" american ? They will press on and a drop of slow CA glue will keep them there.

 

[Monte.C]

Oh well heck you dinnt ask that. No you wont go anywhere close by and get a die that you can use to tap your motor shaft. Amazon perhaps but it will be $$$$$ and the nut assembly will be pricey, too. You can buy the drill bit undersize to the motor shaft diameter, get some aluminum, find a lathe and center drill a hole then thread that (adapter) to whatever you want or use a stud in the proper size once again center drilled on a lathe. Key word is lathe.

No no no, back to the original question.

The proper way is to get a tap of the correct size and partially run it through the plastic retaining, or fully run it through and use threadlocker compounds. Sometimes metric stuff can be tapped the next millimeter smaller. My local Ace hardware has them for maybe $5.

You would try to tap the plastic insert to fit the prop shaft threads, right? So I either need a number to describe what those threads are on the prop shaft, or be able to match the existing threads to the same size tap in the store.
Seriously I could email Emax and if they're professional enough they'll forward my question to someone who can answer it. They'll just say "Oh yeah that's M2 30-24" or whatever the code is.

 

[Tench745]

I'm having a hard time focusing enough tonight to read through this thread, but I wanted to throw in my two cents to see if I can help a little anyway.

M-whatever is the outer diameter of the bolt/thread in millimeters. If you have a 5mm threaded shaft, for instance, it will take an M-5 nut. You just need to figure out whether it is a coarse thread or a fine thread. I'm pretty sure the ones I have are fine thread; yours may vary.

If you put the nut on the prop shaft or a bolt of the same size, you can heat the shaft up with something like a soldering iron and relax the nylon around the threads so it doesn't grip so hard. Ny-loc nuts will wear out over time with use. The general rule of thumb is, if you can screw it on with your fingers, it's dead (won't hold strong enough to actually "lock") and should be replaced.

 

[Piotrsko]

Jeez Louise it's probably a M5-.8