shallow depth waterproof thrusters

[scubersteve]

I finally got started on the thruster project I mentioned a while ago.
As I said then, this is likely useless for real-world applications, but may be just the thing for pool-based competitions that require "waterproofed" thrusters.
I used a Turnigy dst-700, some 3/16 u-cup seals, a thickwall 3/16 aluminum tube, and a 1.25" pvc pipe pluc and cap.

[olegodo]

Really nice and simple scubersteve!

Will be interesting to see how this works out and to witch depths it holds up!

[Erik102696]

It looks great! I have been wanting waterproof a brushless motor using a u cup seal like you. the one that I bought where labeled as rc sub shaft seals. they are basically just u cup seals. if you have tested it do you get a noticeable power drop with the seal on the shaft? also how do you mount the seal so that the whole seal wont spin when the motor spins or is that something that even happens?

thanks-
erik

[scubersteve]

I haven't finished it yet, I have to pick up some locktite for the shaft threads.
I have two motors only one of which is being enclosed, so I suppose I could test both of them and see how much power is being consumed by the drag of the shaft seal.
As far as retaining the seal, I cut a 9/16" recess in the front cover so the seal can set down into it and I intend to glue the seal in place with GOOP or something similar.

[scubersteve]

I got the thruster assembled and tested minus the green shroud in the picture.
I also tested an exposed version with the same prop.
The results are posted in the "draw, thrust, and components" thread.
The short version is that they put out the same numbers so apparently the drag of the seal is negligible.
I did make sure to lube the shaft before I installed the seal.

[Erik102696]

That is awesome to hear! keep up the good work.

[scubersteve]

BTW the u-cup seals came from www.theoringstore.com and cost 50 cents each.

[Erik102696]

Which u cup seal? They have so many different kinds. And also do you know the difference between the u cup seals and the oil seals.

[scubersteve]

This u cup seal...
http://www.theoringstore.com/index.php? ... ts_id=7435

An oil seal generally has a metal outer shell and a spring around the center portion.
Oil seals would probably be better for deeper depths but I'm lookkng for cheap and easy for pool based competitions.