Need help and advice on Electronic's

[niterdr]

I am working on a model of the local fireboat, I have the hull finished (1/24th scale the boat is 40 inches long and 10 inches wide), the bow and stern thrusters built & installed and the running hardware setup to accept 2 - 550 6volt "Johnson" size motors. The battery setup is made to take 2 - 6volt gel cells with the thought that I could use 6 or 12 volts depending on the application. I thought I had the perfect solution for motors when I found single 55 turn "Integy" "Tire truing lathe motors" with adjustable timing so one can be tuned to run clockwise and the other counter-clockwise at approx the same RPM. I gave up on the "Johnson" style motors as they are made to run most of the time in one direction.

Now for the help/advice needed.

1) Are the 3 pole 55 turn motors running on 6 volts going to have the torque needed to turn 55mm 4 bladed scale props? Or should I look at trying to find a couple of Pittman 12 volt 7 pole motors and try to change the mounts?

2) Does anyone sell reasonably priced speed control kits (PC board with parts list and placement diagram) for scale boat use or reasonably priced ESC's? I don't need casings hugh power capability. I have a few projects in the works :-)

Thanks
Alex in Canada

[green-boat]

Since this is a fireboat and not a go fast, I would go with the Pittman motors. The 7 pole feature will give you plenty of run time (low current draw) with plenty of torque. If you can't find them then I would find some 555 or 557 motors. Same can size but 5 and 7 pole respectively. The basic Johnson motors can be run either direction because they are neutrally timed.

As for the ESC's go with the Proboat ones, they are waterproof, compact, reversable and at $40 USD they won't break the bank.

[Roger in France]

Have a look at www.members.aol.com/actionkit this is a one man company in the UK which supplies self assembly kits. His stuff is good and reliable and he gives good, free advice. He has been well known and respected in the UK boating fraternity for many years. He also sells ready to go stuff at a slightly higher price. I have met him and also done business via the net.

Roger in France.

[martin richards]

I'm surprised that your Johnson motors are timed to favour one direction. They are usually neutrally timed.

[k225]

Alex check out this site in my experience they are the best controllers around.
http://www.modelcontrol.com/

Steve

[niterdr]

Oh, but I long for the "Old Days" when the hobby shops catered to the guys that want to go slow, not just the racers!
Thanks for the advice guys, I have placed an order with my LHS for 2 of the pro-boat ESC's but I am having trouble finding Pittman motors, 555's or 557's. Any ideas on locating these would be a great help. I always found that Johnson motors ran better one way than the other not because of the timing but due to the way the brushes are situated, if run against the brush springs sometimes the brushes would break off of the springs (At least that's been the experience of some of my fellow club members).

As I have a few more projects in the closet I am tempted to try one of the kits, and I might try to get MCD (Members of the same model boat club) to give me a quantity discount on a few of their ESC's.

If I can clear the sawdust I will try to get some pic's of the Fireboat hull online

Thanks again,

Alex

[LtDoc]

Alex,
As to the motors, you're on your own, no idea where to tell you to look. As for a speed controler, that depends entirely on the current your motor(s) will draw. Once you know which motor(s) you want, determine their maximum current requirements (stall tests), and find an ESC that will handle that current. Not all, but most ESCs are fairly usable for most motors. Figure on starting around $40 USD and going up from there. Except for really unusaul current requirements, almost any ESC will probably work fine (most max current motor requirements just really aren't that high, usually). Not much help, but not knowing exactly what you need, that's about as close as I can get. Sorry 'bout that...
- 'Doc

PS - Especially for scale type boats, if you can't find an ESC for $100 or less... you just ain't looking.

[martin richards]

Alex, I'm not sure, but the pitman motors frequently turn up in the list of 2nd hand electrical items merchants.

[pompebled]

Alex,

I'm not sure if this applies to your hull, but when I need a low rpm motor for a (releative) large prop I've visited the local scrapyard, or my garage.

The electric motors that drive the fan in front of your radiator are very suitable for the job; lots of torque and low powerconsumption.

They are however quite a bit bigger and heavier than a 550 or 700 motor, hence my reserves. (mail me if you want some pics).

I reduce the weight of these motors, by cutting out as much material as possible without imparing the structure.

Maybe the modern cars have smaller and lighter fan motors.

Regards, Jan.