Thanks! The tape did work good. It does compress alil bit, just add a extra layer to compensate. Been out of state for little while on work, ended up on the flight deck of the CV-12 (pictures soon). Now im back home, and have some time to work on my Chicago. Need some input on these dog bone direct drive setups. Tolerances. For the prop to the shaft collar, i have it snug, just enough to have the prop shaft turn freely by hand. What about the actual dog bone? From coupler to coupler, how much slop should i have in there?
Enough slop that it doesn't rub when it turns. Also, they do really well when they aren't doing any crazy angles. The stranger the angle, the more likely that they'll fly off in combat.
Alright, sounds good. Yes, the rudder does clear the props. I had laid out everything BEFORE i fiberglassed the rudder, oops. So there is a smaller gap then i had planned, but it does work alright. I also did hook up a low voltage battery to the shafts, no contact with rudder.
As long as the rudder doesn't hit the props, the smallest gap you can get is best So sounds like you're golden.
Then again if the props hit the rudders after a little bit you'll end up with the smallest gap you can have. Laugh if you want but it actually works pretty well.....
My old rudder on Lil Scharnie did that when it overtravelled and locked there. Had a nice little prop-shaped cutout on the back end
So Ahead flank and hard over?? Sounds like a plan While i was away, i had some time to research brushless motors, KV, thrust and batteries, thanks to alot of info on this site. I am going to keep the brushed setup i made as a backup. However it really seems brushless is the way to go. What i came up with: The Two drive motors; 750KV, max of 14amps, www.hobbyking.com/hobbyking/store/_...ouse_.html Using three of this Car ESC rated 25AMP. Sink them into epoxy to water proof them. www.hobbyking.com/hobbyking/store/_...r_ESC.html, I Checked out those marine hobbyking/turnigy ESC's, and they "NEED" to be watercooled. Not sure if i wanna go for that hassle. Also checked out the G2 hydra 30. Looks great accept for the $100 a pop. Im leaning towards running two 6V or7.2V 5000Mah "stick/AK" type Nimh packs in parallel for 10Ah. So, 7.2v Battery, 750KV drive motors, 1.25'' 25pitch prop 4blade. Direct drive. Using Mike's chart Gets me 5400RPM/ about 12oz of thrust. OR 4500RPM/7-8oz of thrust on 6V. Does this setup sound about right? Also, does the 1500-2000KV 28mm motor sound good for a small bc pump?
He said direct drive. Just so your aware, that motor you showed the link for, mounts at the back of the can (the opposite end from where the shaft outputs).
Aw, well that's no good. Thanks for the heads up! And yes, direct drive. The only modification I'd have to make to go brushless, would be to drill out the coupler to accept the larger 4mm motor shaft
It is possible to reverse the shaft, but you have to feel comfortable disassembling the motor to do so. Not highly recommended. But that kV range is fine for direct drive on a cruiser.
That's the brushless setup that I use in my 20 pound Alaska cruiser on 6.6 volts. I run 1.5" 25 pitch props and need about 90% throttle to run 25 seconds. If you are running smaller props or a lower voltage, a slightly higher kv motor may be better. I did switch the shafts on the motors, it's not hard with a little care and the right tools. Of course I bent the endbell on first time I tried to remove a shaft many years ago, so YMMV. You could also go with these motors http://www.hobbyking.com/hobbyking/..._140w.html which have the shaft on the right side.
Alright, i do have a hydraulic press at the shop, no problem there. I'll go with the Turnigy, it looks like a lower voltage motor compared to the NTM. Plus that orange color is cool! I'm gonna pick a 2200kv to try out for my pump aswell. I'll be using 7.2V instead of the 6V. Hopefully that will bring me to speed. If no can always start a "parts bin" . Now when you say you switched shafts, you mean that you had a brand new shaft? Or that you pushed it through to the other side? Thank you!
I pushed the existing shaft through the motor so that it stuck out the other side. 7.2 volts should be good for the cruiser. And the great thing about brushless motors is that if that doesn't work, you can try 8.4 and even 9.6 volts. No need to throw it in the parts bin.
Alright, i got the motors in the mail, and reversed all the shafts. I had to pop off the E-clips on the shafts to reverse them, without them, i can pull off the outter shell. Question, do i have to make a new slot in the shaft for the E-clip to prevent the shell from flying off from use?
I've run motors like that successfully without making a new slot for the e-clip. If you are running dog bones there should be no thrust on the motor, so the magnets will keep it aligned.
Chicago Update New brushless setup. I have discovered a nifty little feature with these outrunner motors. I am useing Direct drive with dog bones. Since i removed the retaining E-clip on the shaft, the outrunner case can be pulled off the armature slightly. It is enough to slide the dogbone in without removeing the Motor mount. Score! I had to change the bolt hole layout on the port motor, to get the wires out of the way. The allen M3 bolts can use the same wrench i use for the 6-32 bolts. The pump. Bought a old Large BC pump off a forum member, epoxied in the old bolt holes, epoxied/fiberglassed/Drilled the large 540 motor hole. And then redrilled and counterbored for the 380 sized motor. For the Mount i took aluminum bar stock, swiss chessed the inside of it, and drilled and tapped for 6-32. Using brass shim stock and the pump bolts, it is very solid. Possibly overkill . Plus i will be able to shim the pump up or down depending. Its a hair higher then 1/4". It may need a diet plan, so i will trim the bolts, drill holes and sand the brass to shape.
