Brushless Mini-C w/mods

I have already posted the vidhttp://www.youtube.com/watch?v=3i1iNpwUzU4 of the first run with this boat and while this isn't a new project (meaning it's been done before) just thought I would share what I've done to mine so far.

First I took all the electronics out of the inside and stripped off the running gear. I installed a 3800kv Emp Hybrid motor 28mm can so that it fits right where the old motor fits. This motor is fitted with cooling plate bolted on the back side of the motor. It is more of outrunner than an inrunner so cooling coils don't do much on the outside of the motor hull. This alum plate makes a big difference. To power this I used a Quark 33 esc bought off ebay. Esc fitted with 2 1/8" copper tubes to help cool heat sink. Esc also water proofed with Goop. I used a Corona servo bought from my LHS. Perfect replacement for the stock one and with metal gears to boot. Servo dipped in plastidip. RX is a waterproofed (epoxied) Tactic one.

Running gear is from Mini Cat Racing for the Micro Hydro. I did not replace the original prop shaft tube, rather cut some brass tubing to slide over the end of the original one and cut away a minimal amout of hull to accomplish this. Sealed with Goop. Prop for now is 27mm Mini Cat Racing plastic one. Mini Cat Racing flex shaft fits perfectly. I did have to find a couple of alum spacers to the strut away from the transom so that everything would fit however.

For the first run I used an Eflite 2s 20c 1250mah battery. The vid is exactly how it ran and was better that I had hoped. I tried to be somewhat conservative in running since it didn't have any flotation. I added 2 part foam to it today however and reworked the inside some so we'll have to see what it can really do now. Will also try a 30mm prop. I can now add some weight to the left sponson to try to help counteract the torque roll

An interesting setup and pretty much what I am going to shoot for soon.
I plan on replacing my mid size cat (18+") and doing a small one (14") at the same time.

You mention that the motor is a hybrid outrunner/inrunner correct ?
You say it behaves like an outrunner ?
Did you notice any adverse torque roll effects from the motor?

I am considering an outrunner for my 18"ish cat but will deffo do an Inrunner for a mini-micro at 14"

Nice mods and it hauls well. :rockon2:

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Originally Posted by Simon.O.

An interesting setup and pretty much what I am going to shoot for soon.
I plan on replacing my mid size cat (18+") and doing a small one (14") at the same time.

You mention that the motor is a hybrid outrunner/inrunner correct ?
You say it behaves like an outrunner ?
Did you notice any adverse torque roll effects from the motor?

I am considering an outrunner for my 18"ish cat but will deffo do an Inrunner for a mini-micro at 14"

Nice mods and it hauls well. :rockon2:

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Thanks Simon, it's been fun to run and mess with. Some sites call them hybrid, some call them heli motors, but the truely are outrunners in a can. The bell with the magnets turns around the armature. Torque roll is definetly there. My catamarn turns into a mono hull at wot. Read on another thread that sharpened brass props will reduce torque roll, so going to try that especially since I just bought some from Darin Jordan. So we'll see how it goes and I'll try and post a vid of it as well.

Good stuff! Glad to see people still making these things go fast. Mine is coming off the shelf for some changes and will be back on the water soon. Keep up the good work. :buttrock: