Aeromarine Sprint Cat .80/.90 twin 1717's

[urbs00007]

oh, my god!!!

After far too long, the cats ready to play. I finished things off today by soldering a couple of sets of parallel cables, making up the flex drives (thanks steve :)) and a few other small things like hatch nuts ect. After I shut the office it was almost dark so I took the boat over to the lake fully loaded and taped to see how it'll sit in the water and I'm very happy with the angle and height it sits, it looks like its ready to launch. I found the boat a little heavy to carry so back in the workshop I put it on the scales and they read 10.7kg or 23.6lb, it'll be interesting to see how the 447's go pushing the weight. I'll get some footage when I get the time to take it for a spin.

why didnt anyone question those brass tubings hanging off the transom. that killed your esc's its like dragging bricks behind your boat. why did you do that? rudder pickups are fine.

[srislash]

Just saw this catastrophe Danny, man that bites. I think for tossing her in and ripping may be better with one big power plant . I also have a twin 1717 in the works now. So that smoke is a little disturbing to me. Got a pair of PropShop 5518/2's sitting for it but not sure now. Just have to be careful I guess,and start smaller.

[drwayne]

Tag me into the new thread mate.
DocW

[millzee]

I finally got around to ordering a motor mount for the 2028 along with a 1/4" driveline and a inline strut/rudder to get this boat back on the water. I'll marry the motor up with a sf300 and run 8s-10s with a x457 and see what happens. I'll start a rebuild thread when the goodies come in.

[millzee]

It's been a while and the cats still sitting up on the shelf (all cleaned up). I Killed my speedo in my losi 5ive on the weekend and have ordered a gas engine to put back in it so I should have a spare castle 2028. I'd love to know if it'll be worth me doing a little work on this hull to drop the 2028 in it and run a 300amp speedo (I have one to use). I think a single cat would better suit my "basher" style of boat driving as it's 1/2 the work, lol. 8s, 10s or 12s, would it be worth the while do you think???

[kendt]

I disagree with the the theory that split lines dont work. I have used that set up on several boats without issue. The pressure feeding the lines is more than enough to fill all the lines.The short ones my fill first but water will always flow through both lines. Much harder to keep water out than to get it in.

[millzee]

The hull has 4x water pick ups with a cooling line going to each motor and to each esc, that shouldn't be a problem.

[millzee]

The motors, batteries and right side speedo where cool, just the one speedo took to amp hit. The hull only needs a clean up as no damage has been done, no re-build needed here, just a clean up and a new esc.

[D&D]

Just wanted to jump in on this one - I love 90 Sprint Cats.

[Chrisg81983]

I have 4 cc 1717 same as danny in same hull as him well had the same hull but still have the motors. That setup will hit 80 miles per hour no problem. I also found cooling the motors first saved me 10-15 degrees on them but yeilded the same on esc's no matter what way I cooled them first or second. I also spun 55mm props with ease. Motors never went over 110 degrees f

[Brushless55]

Turnigy 240 amp speedo's.

running that wet killed the esc due to excessive amp load

would have been interesting seeing how it would have run with good CG and strut adjustments

[drwayne]

....cheap motors will demagnetize if not cooled adequately.

However, the 1717's in Danny's boat were built for high yield with passive air cooling . any encapsulated water passage across this motor will extract more heat than design due the higher surface area of the finned can.... more heat extracted than if still air cooled.....

Highest possible cooling efficiency pathways and flow rates are well discussed on this forum and others, documented by well learned and experienced people.

If you also need help with esc, just ask... I aided design a few the recent ones, and repair under factory license many the Eu types .. money for jam, mate .... ( means 'easy work' )

[Chrisg81983]

Its actually best to cool motors first a motor will start to demagnetize themselves at the temp a esc can run at if need be but you will have people tell u differently. This is something I tested myself and researched

[drwayne]

Hey Danny
I read somewhere previously.. you have 2 pickups and four outlets....
Split water will take path of least resistance.. when you rebuild this.. 2 pickups 2 outlets... run water to esc then motors then out.
The fusion here looks like packs dropped voltage under load, esc increased amp draw to feed what your finger demanded.. and low speed low cooling high draw quite simply overloaded the system and flamo..
I suggest 5017/3 is a too large jump up from x447s in a new still trialing system.

Always avail for a chinwag, mate.

I wont say my favorite motto here, although it is most applicable.

[Chrisg81983]

bahahahaaha you Americans spell funny...

Thats why I dont have a Dr. In front of my name