Problems, problems................HELP!!!!

[bluesy]

:confused:

My second attempt at RC boating was the "White Star" by Billing boats. I took her for her maiden voyage yesterday. She was looking good when I launched her .............BUT.............. as soon as I applied any throttle she torqued over till she was damn near on her beam ends. Scared the **** outta me!!!! I could get her going with a very minor bit of throttle but as soon as I tried to open her up .........over she goes (not completely over but enough to have to back off.)

Any suggestions how I can get this baby under control???? Different motor, outrigger pontoons, training wheels?????

[Umi_Ryuzuki]

Gyro controled stabilizing fins...;)

Well another gorgeous model you have there.
I am glad someone let you outside to play for the Summer. :D
Yes a less torquey motor may be in order. Or a lower pitched prop.
You may be experiencing not just motor torque, but also prop walk.
Where the bottom stroke of the propeller is pulling the bottom of the boat out to one side. Maybe trying lower pitch propeller will allow you to keep the existing motor.

[CG Bob]

Knowing the following info would help in troubleshooting:
Motor type & size (i.e. 380, 500, wheter it's modified, number of wire turns)
Voltage of the battery you're using
Prop size & pitch (if known)
Is there a red gear (reduction gear) & ratio

From the basic info you gave, it sounds like you may have too large a motor; possibly a modified motor with low turns.

How does she sit in the water? On an even keel when looking at the bow or stern.

[bluesy]

Thanks a ton for the comments, guys.

The prop is the one that came with the kit. The motor was recommended by the LHS (mostly plane and train guys).

CG Bob.....

I don't know what the windings are in the motor but it is a pretty basic one. I used to do RC cars and trucks and know that a modded motor has tons too much power for something like this. This motor doesn't even have rebuildable brushes.

The power is supplied by two 7.2 volts stick packs in parallel.

No reduction gear..........straight drive.

From what you guys have said I think I'll be looking for a smaller, less torquey motor.

[MikDee]

Wait!,,, I can see, that prop is too big for a submerged drive!,,, That's your problem. What size is the hull?,,, and what motor do you have?,,, I should be able to help you.

Ok just noticed your captions, a 40mm prop is Way too big, Most boats of this size, 20-26" long submerged drives (inboard stlye) use between a 30-32mm props, this will unload your motor, for more speed & less heat, and stabilize your boat. Nice boat, & nice job by the way.

[MikDee]

http://www.offshoreelectrics.com/images/forsale_props/prop3bld.JPG Go here for good reasonable props, www.offshoreelectrics.com I would go with this 30mm carbon fiber 3blade, if your shaft is 4mm threaded.

[bluesy]

thanx a bunch Mik............

the motor I had in the boat was "apparently" too much motor. When I first went to the LHS they recommended it. But on describing the problem to them and investingating the motor we all decided that the windings were of a larger wire gauge than was orignally thought. Heavier windings=more current=more watts=more horsepower/torque. So I bought another motor of the same construction but with smaller gauge windings. I haven't had it out for a test on the water yet but dry running it, it certainly revs slower and is easier to stop with a finger squeeze.

I think I will be ordering one of the props you mentioned just for experiment's sake. I don't have a lot of spares of anything nautical yet but I'll get there slowly but surely.

Thanx again for your expertise and assistance. Oh!! and thanx for the comments about the boat. With each new build I learn something new eg. bigger batteries for ballast rather that lead shot.

bluesy aka Doug

[MikDee]

I would guess the motor you had previously would probably work fine also, you just need a smaller prop. I found Billings makes a smaller 30mm 3 blade prop, if you have a hard to find shaft size, you just have to pick if its left hand, or right hand drive. Or, to put it simpler, (clockwise, or counter clockwise rotation) at the prop, I would assume left hand or CCWise.

[Ghost 2501]

as regards a motor, try a 385 sized motor or maybe an Mtroniks vision 400, coupled to a 30mm 3-blade, its that combination that I use on my Neptun freighter, running through a 15A Mtroniks esc. not a hint ot torque-roll, and it runs all day