[PSUBS-MAILIST] Brushless thruster test

[T Novak via Personal_Submersibles]

Thanks for the update, Alan.

It looks like your research is coming along quite well.

Tim

 

From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org] On Behalf Of Alan James via Personal_Submersibles
Sent: Saturday, January 30, 2016 1:47 AM
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Subject: [PSUBS-MAILIST] Brushless thruster test

 

I had an initial pool test of my brushless thruster yesterday.

Thruster is on projects page http://www.psubs.org/projects/1235435392/brushlessthruster/

A bit of a mixed bag. Firstly I was testing it on 36-37 V & not 44 that it was designed for,

due to size restrictions on import of Lithium polymer batteries. I will buy the additional voltage.

   I was getting 5kg (11lb) thrust off 150W & 10kg (22lb) off 515W, which is comparable &

better than some commercial direct drive BLDC thrusters that I have specs on.

However I got to 13kg thrust & the propeller seemed to slip at that point & even though 

it was running at 2,200W I wasn't getting any more thrust. I was only a couple of feet out 

from the pool edge when testing, so that could be contributing.

Another factor could have been that the seal leaked badly & the motor was short circuiting 

through the water. Why did the seal leak? Possibly I damaged it hammering it in to it's housing

or because I didn't polish up the propeller shaft. 

I have other motors I will be testing, so a lot more work & learning to do on this one.

I did notice I had the same problem as  Cliff, with the motor wiring starting to wear through

where it comes out of the housing.

Cheers Alan

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20160130/9783a884/attachment.html>