Hey Guys, Having a hard time deciding which way to go for my IRCWCC fast Gun Sodak Direct Drive with Dogbone or BC gears need your 2 cents Monk
I have gears in mine and after seeing how much better the carrier started, stopped and turned with direct drive, I will be removing the gears and going for direct.
I have gears in mine with 3 to 1 ratio with 1 and 3/4 props at about 30 degree pitch, does right on the nose of 26 sec. I have found that I can keep up the rpm in a tight turn and dont lose power. It also seems to extend the run time by letting the motors run at peak rpm. I beleive they dont have to work as hard so they draw lower amps. I have found run times of up to 3 hrs before loseing speed on 6 volt 12 amp hr battery.
I'm with Buddy, you get to run the motors at (or close to) peak torque while being on speed. Using the ESC with direct drive, you are far from peak torque when you are on speed. That said, my I-boat is fine direct drive (because 2 400 size motors make it go 26sec with no tweaking). For most ships, I run a gearbox.
As in a lot of things in life; it is a trade-off. Gears - like the previous guys posted, this lets the motors run at a higher speed which is usually more efficient. tuning for speed can be done without an esc easily by changing gears. But, every time you take the motor out to clean and lube, it must be re-meshed in the gearbox. This is an additional thing to go wrong in combat. When done well and properly maintained, it is a good system. Direct Drive - Simple, smaller amount of room in ship, no gears to adjust, easy to take apart and reinstall at a moments notice, learning curve for setup and handling is small. speed adjustment: major - change prop, change drag discs, adjust esc. minor - tweak angle of props, dremel off a little of prop blade The key is to start with a motor that will give the rpm you need under load at the voltage you want. Our target is 4500 - 6000 rpm. New more efficient motors are becoming available at these speeds in 6 and 12 volts. Gears were the best way to go when all you could get cheaply was 12,000+ rpm. Whereas,The gold standard has been the Dumas at 6 or 12 V in the past for direct drive. It just costs $60. With the availability of the Mabuchi 12V 5000 rpm motor from surplus traders.net, I have switched all our ships from class 3 - 6 to these on direct drive. That is what WeeVee ran on at Nats. Oh yes, and the little VU runs them too. You might remember it.
Hi Nate, welcome! Thanks for the succinct breakdown of plusses/minuses. I looked at the surplus traders site; can you give the item number for those motors?
MD522. They have come down in price and have 160k left. min order is 50. ad reads: MABUCHI RS555PH-3255 HIGH TORQUE 3950 RPM 12VDC MOTOR/GENERATOR - 5 POLE CONSTRUCTION FOR HIGHER TORQUE - LOWER POWER DRAW. no load 5500 rpm. I don't have amp draw-under-load figures. (tested b4 nats but didn't write it down)
Nate Good to see you on the site. Would you happen to have an extra pair of those motors to sell, so that I can run some tests? I am running 12 volts in my ships. Mikey
I'd go with the gear-drive; if your lake is anything like the lakes I've fought on... You'll need the extra torque to mulch through the floating weeds.
Gears or Direct works either way for a Sodak. With Direct drive it's the right motor with the right type of prop. I used direct for PE and it worked very well and lasted a very long time. Smaller motors with more torque are available so the Direct Drive option is becoming more viable in some ships. Direct takes a little more playing around to get the right setup but if you have an ESC it makes it that much easier to set up. Either way Gears or Direct works for a Sodak.
Okay I decided on Direct drive (less moveing parts) BC Dog Bones with a pair of MFA Torpedo 500 Motors from Harbor modelshttp://www.harbormodels.com/site08/motors.htm thanks for your input []
The one thing I have found is that using the BC 1-2 gear box as shipped gets my class 3 ships right on speed no tweaking and i only have to run one motor for drive and get 2 output shafts for that While running 1+1/2 inch props so it means I only have to feed the one motor with power, making my battery management so much better. But hay its a decision on what you like best too.[]
