Aquapassion Cat

[785boats]

A bit of holiday time. A cat hull that didn't perform as it should on one motor and a box of spare bits 'n pieces. All I needed to buy was a set of counter rotating shafts & props & a twin pickup rudder, which Madracer donated for me.
So in went a couple of mounts & tubes a pair of Turnigy 2200kv outrunners, a pair of T120A ESC's. Bolted on the rudder & here's the result.
Unfortunately as you can hear one motor goes off song. I thought it might have been the LVC so I switched them both off, but the same thing happened in the next two runs. So I thought it was maybe a slipping collet or shaft.Checked both collets but they weren't slipping. Any ideas?

[srislash]

Try recalibrating the ESC's to the Tx. I have had this issue with the 120's.

[785boats]

I did do that.
But after a few laps & the heat builds up a bit, one motor goes off song, or the other one is slipping somehow & is revving faster than the other. I can't tell which, as they both sound fine on dry land & both rev up at the same speeds & actually both stop together when they spool down. And no matter how much rotational force I apply to the prop by hand, while holding the motor, nothing slips. With either of them.
I'll spend some more time on it this weekend.

[srislash]

Yeah I had two of those motors in my Komodo and found kinda the same thing. One would kick the LVC earlier than I feel it should as well.didn't get to test amp draw on each yet mind you.
Not sure of the quality control on them.

[ray schrauwen]

Check the set screws on the back end of the motors, they could have worked loose. Try to replace them with stainless steel ones. They are short, 4mm set screws.
FighterCat had a Bulletin about them....

[785boats]

Thanks Ray.
Didn't think of that. Sounds like a possibility.

[Mad Racer]

It did look good while it was on song Paul.

Hope you have it sorted by tomorrow as I'm a cat lover!!!!

[785boats]

Well on the Weekend I solved the problem.
I put two new Warhead outrunners in the thing to eliminate a motor problem. Did a water pressure test on the plumbing & found that the Starboard motor had a blockage in the line. So the poor ESC must have been running hot and shutting down last weekend. I didn't notice the lack of water out of the water outlet last weekend. Stoopid me.
When I put it in the water this weekend just gone the Starboard ESC failed completely after about 50 meters. But the BEC still worked.
I have just pulled the ESC out of the boat & both caps are bulged & one is split. So I cut the shrink off to check inside. There is no evidence of a blow up, & no smell either. So hopefully when I replace the caps she will be fine.

[srislash]

Well that'll do it. Hope the ESC lives for you.