Jam Nut and Bullet vs Nylock Style Prop Nuts

[mitchesx]

I bought the OSE shaft upgrade for my Revolt 30. They come with the jam/bullet combination. I've never been a fan of the jam/bullet nut for props, especially after losing a $100 gas prop due to one coming loose. I have an M445 for the boat from Chris (Dasboata) and I went to install the prop, and realized that after the jam nut I may have 6 -8 threads available for the bullet. Even after tightening and using blue loctite I'm still a little "iffy" on it. What is everyone's thoughts over here?

[martin]

You will find most experienced members on this forum don't use bullet nuts but use lock nuts. bullet nuts offer no advantage apart from potentially lost props.

[NativePaul]

Fresh Nylock every time for me, but lots want to use bullets for some reason, and if you must then make sure you use a jam nut with it.

[785boats]

I ALWAYS use Nylock nuts. I've seen too many props lost to the Pond Gods with those bullets. Even with a jam nut.
On my twin cat I do have bullet nuts for Bling, but there is a Nylock nut on first.

[properchopper]

I use Zuber jam nuts + ALWAYS Blue Loctite. Never lost a prop from nut coming loose. Nylocks wear out. Once in a while I'll get a shaft where the threads are cut a few 'thou too deep and then I'll use a Zuber jam + second small nut but again ALWAYS Blue Loctite regardless. I'm OK with any disagreement with this - it's just my opinion

[TheShaughnessy]

Funny this came up. I have a bullet but I never really use it cause I'm always worried it will come off. For some reason I decided I liked the way it looked so I put it on with a jam nut. Ran it today with no issues but I'm not sure ill leave it on.

[tlandauer]

The Zuber jam nut is nice but sometimes I come across a batch that doesn't jam as well, I remember reading here about giving them a crimp----good luck, at least my weak hands can't do that! Blue Loctite is a must.
Touble with the Nylock is that unless you spend the money and time to find the hobby grade stuff, your garden variety ones from the hardware store is really to big. Unless you have a huge prop hub.

[NativePaul]

Zubers wear out just like Nylocks, as above I always use fresh locknuts of whatever type and Nylocks are cheaper and much easier to source locally so I use them. PropperChopper has a good point about threadlock though, you can't threadlock a Nylock but you can threadlock a Zuber, so there useful life may be longer.

I live in a metric country and my 1/8th inch flex stubs have 3mm threads not 1/8" and a 3mm Nylock is the perfect size tip to tip for an Octura 1/8" prop, anything bigger than that I now use a wire drive with stub machined to prop hub diameter and use a threadlocked screw instead of a nut, but I have used and 3/16 flexes in the past, both American made with 3/16 threads and locally made with M4 threads, and indeed the American one came with locknuts that were bigger than the prop hub, I used it for a while then replaced it with one with M4 threads and the locknuts for those are the same size as the smallest Octura 3/16prop hubs. I didn't know you had 2 different sizes of imperial nuts, I think all metric nuts are the same size for a given thread unless flanged, and then still the same spanner size.

[tlandauer]

The O.D. of a 10-32 thread locknut is quite big, I think a 10-32 locknut that is meant for the axle of a rc car would have an ideal O.D. for prop hub. But I don't stock them so in a hurry I will go to a local hardware store and pick the above mentioned variety.
It still gets me how people live in the U.K. use metric and the U.S. was never able to convert , now that I have been in this country for 34 years I am finally getting the hang of the Imperial system .

[gsbuickman]

I dont run anything less than good nylocks. I've lost way too many parts due to jamnuts, bullets and unlock-tited hardware viberating loose to lose props to Poseidon......

[kfxguy]

How come I never see anyone mention a bullet with a set screw in it? That's what I run. I keep two different sizes to match the prop I'm using. Ill use blue loctite on it. Not that ive been doing this a long but but I've never had one come off yet. I make a flat in the shaft pretty deep so the set screw doesn't stick out also. Just wondering..... Everyone here has a drive dog with a set screw in it and I never hear issues with them coming loose. Same thing with the motor coupler. So why not go this route?

[tlandauer]

You mean you tap a hole and add a set screw on the bullet? Won't the set screw bite/damage the thread and interfere with the lock nut for the prop?

[gsbuickman]

I assume he taps a hole in a bullet, then flatspots the propshaft where the hole lines up at when tightened with a dremel . Being a mechanic I naturally steer clear of tampering with a clean thread set. Nothing ruins a day faster than realizing you marred up a vital thread set.

Good idea bro, are the bjullets pretapped & is there an out of balance issue ?...

[Fluid]

How come I never see anyone mention a bullet with a set screw?

Because it is more trouble than it is worth. The long-standing solution, which has been successfully used for at least four decades is the crimped lock nut. Cheap, no need to modify the shaft, no fragile threads like a set screw, reusable many times, and a vast history of success. Use what you want, but why try to reinvent the wheel?


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[properchopper]

After obsessively balancing a prop to eliminate shaft vibration, adding a bullet nut with a set screw which could (possibly) be out of balance in the worst possible place seems counter-intuitive to me