Newbie Struggling - Tunnel Supreme F1

[MOTOboat]

OK Guys,

I need some advice. Sorry for the long post.

I have a MRC Supreme F1 Tunnel. I replaced the stock Motor with a Venom Fireball 15T double motor. I’m using a DuraTrax IntelliSpeed Control (12T Modified) I have MegaTech 3300 7.2 Racing Pack for batteries. Its running the stock X431 plastic PROP. A Futaba T2PH AM 2 Chan with S3003 servo. I am using the ESC’s BEC to power the Rcvr and servo. Oh yeah I water cooled the motor and ESC, they both run very cool.

Goes like hell, when it goes.

Some problems
1) Motor brushes wear like heck. I’m getting maybe 10 minutes out of a set of brushes. The ones that come with the motor.
2) The engine sputters like crazy.
3) Turning is erratic.
4) It gets worse as you run it.
5) Today near the end of the end of the run it kept going in circles not responding to the Xmitter. Wife was laughing as I had too wade out in the lake to get it..;)

I first thought it was receiver interference due to the ESC being in the radio box on top of the RCVR. I made a RF shield around the RCVR but it did not help.

I suspect it is the voltage dropping too much and the RCVR not havening adequate voltage.

- Would this cause the symptoms I see above?
- I am going too try the RVCR harness that came with the Futba, but II hate adding the weight. Any suggestions?
- Are their better motor ESC combinations that minimize the weight but give me power comparable to the 15Tdouble?
- I’m an older guy do purchasing a brushless setup is a possibility. Any suggestions.
- Any suggestions why the brushes wear so much.

I am doing this for fun but want it to work. I would really appreciate leveraging your experience.


THX
MOTOboat

[Fluid]

The brushes are wearing fast because they are getting wet. This accelerates their wear a lot. Also, you may be drawing too many amps which will burn the brushes fast. Replacing the brushes with harder ones, and instaliing heavier springs will help, as will shielding the motor from water.

The sputtering is most likely due to the BEC. These work fine for slower boats, but with high-draw motors they cause no end of problems, especially those found on lower end ESCs. Plug a battery into the receiver's battery port - I use a standard 9 volt transistor battery. Weighs a lot less than four AAs, and lasts a surprisingly long time. I prefer to put a switch between the battery and the receiver. :)

You will want to place the receiver as far from the ESC and power wires as possible. Ditto the antenna. Make sure that ALL the antenna wire is outside the hull, don't coil it up inside.

I run a lot of brushelss stuff, and IME brushless motors and outboards usually don't mix well. It can be done, but most of their ESCs are extremely sensitive to water, and it is almost impossible to completely seal them. The motors don't like to get wet either; a brushed motor will run underwater, but I wouldn't want to try it with a brushless motor. :(

[MOTOboat]

Too much current?? With a 7.2 V olt pack and a 15D, what other choice does one have?

The 9 Volt doesn't damage the RCVR, ESC or Servo?

I like your solution!

MOTOboat

[RickE]

Another option might be to try a 700 series 8.4 volt Graupner motor and 12 cells in your hull. I'm not sure if the larger Graupner DC motor will fit the Supreme's lower unit, but you can checkout the motor and an suitable ESC for it at www.offshoreelectrics.com.
RickE

[Fluid]

Too much current?? With a 7.2 V olt pack and a 15D, what other choice does one have?Quite a few actually. By keeping the boat on step and at maximum speed you can reduce the average current draw significantly. It is low speed, full-throttle acceleration which draws the most current.

Make sure the boat is running clean and that the bow is flying. This makes the boat faster and reduces the current draw.

A metal prop can increase efficiency and let the boat run faster, sometimes reducing the current draw.

Increasing the timing advance on the motor to 3/16" will reduce motor wear and improve efficiency, often reducing the average current draw too.

When was the last time the motor armature was cleaned and turned?

Slightly off topic but relavent: Too many beginners try to copy the setups that top racers use in their race boats with disasterous results. Burned up motors, ESCs and cells are the usual result. Why? The beginner's boats do not run clean and free of the water but plow along, increasing amp draw. The drivelines are often nightmares, with no lubrication and lots of binding resulting in huge power drains. Finally and most important, a racer only runs his top performance setup a maximum of 90 seconds then brings the boat in. He knows that if he runs until the cells dump he will have overheated his components and that they will fail.

[69dart]

pitch that motor and get a electrifly 600 size motor for it .. its a great upgrade water cool it and get a x440 prop for it and it should get rid of your problems ... that fireball is crapola