New to rc boats, Prop question

[Leesome]

G'day everyone, RC has been a hobby of mine for some time now and now that I have a lake near my house I thought I'd get into boating. I bought a boat off ebay ( http://www.ebay.com.au/itm/400172259...ht_7005wt_1053 ) and have been tinkering around with little things until I get the batteries I need. After reading a fair few of the posts and looking at products available on
here I have noticed something with my boat that I am a little worried about.... The prop I have screws onto the end of the flex shaft and all the ones I have seen on here seem to be held by some sort of key way. I understand The motor will tighten the prop on acceleration but I reckon the prop might un-screw itself and be lost forever when the boat comes off power. I thought maybe thread lock might do the trick but then I thought that would be permanent i.e never be able to remove prop again, lol. Does anyone have any experience with props of this sort? Do they come loose often?

Cheers.

[sanyijr]

Leesome,

I have no experience with that model or prop type. But if you visit the hardware and prop sections of the OSE site, you will see how 100% of the props are secured on the flex drive that I have seen. Yours, if the pricures on Ebay are correct, is fastened with a allen/set screw? Is that the case? Is there a dog drive in the front? Seems hokey to me, but who knows. I would assume that if it secure, It should be good. Also, make sure that when the flex drive compresses (durring load/acceleration), you have enough of a gap in the line to prevent friction. So you should have about the same size gap as the diameter of the flex cable between the strut end and the front of the prop attachment, dog drive or whatever type mechanism you have.

You have a blow-up of that from the front side of the prop and the rear view? That would help.

Sean


And oh, and

[Leesome]

The prop shaft is one of the 4mm metric deals with a metric thread on it, and the prop has a thread on it as well (it screws onto the prop shaft) but there is no fixing grub screw on the prop. My thinking is that it relies on rotation to keep the prop tight hence why it might just well fall off on deceleration. The prop shaft doesn't seem to twist up much at all, I put a fair bit of torque on it to see if it would lose any length on load and it looked okay. I'll leave a small gap though and maybe put a spring in there to keep the plastic bush tight against the bearing in an effort to keep water out. Attached are pics of the transom with and without prop.transom 1.jpgtransom 2.jpg

[highflyerbill]

Just use some loctite blue #242 . If you have to remove the prop just use a soldering iron to heat up the prop and it will come right off. I run two small boats useing 4mm props with that stuff and it works great .

[sanyijr]

Leesome,

I see. i missread the "prop screws on" part. Got it! Loctite would surely secure it as Bill mentioned.

How does that thing run?

[785boats]

The usual way to retain those props is with a lock nut. Just the same as with the drive dog set up. But you need more threaded shaft hanging out past the strut for that.

[Leesome]

Cheers guys, I'll just use some medium strength thread lock then. I'm still yet to run it actually, I have all the gear I ordered but I thought I could use a 4s lipo on it and then after reading the forums decided 3s would be much better for a 3450kv motor. Now I'm just prepping everything to make sure I don't lose anything or sink the boat on my first outing, lol.

[larryrose11]

I run a prop like this in a Grapuner Eco Manta, with a Tacon 1500KV motor, 60A SeaKing, on 6s lipo. It is my first season with this setup, but I have yet to loose a prop due to it unscrewing. No need for loctite, just a set screw on tight is fine, assuming you don't have reverse!!