Tweet
I was having trouble finding correct gearboxes to fit in my U-boat and getting them to connect with my single motor. All this was solved when I found a suitable gearbox in one of my model cars, well there is a catch... by drilling a hole in the gearbox wall and trying to fit the motor shaft, I discovered that once the the motor will be installed, the gear coupling will allow the propeller shafts and propellers to rotate all in the same direction and I know that both props should rotate in opposite directions (e.g.]http://www.subcommittee.com/forum/icon_question.gif[/img]
-
-
Hi Captain Nemo 12,
Your aircraft
Hi Captain Nemo 12,
Your aircraft must have the props with the same pitch direction... My OTW U-boat has props that have opposite pitch angles. Therefore, the motors must turn in opposite driections. I don't have a WTC completed as of yet, but the props are set on the drive shaft to turn top to the outside when running forward. I went by photos and drawings to set the props on the drive shafts. I hope I got it right??? I can always change it because the drive shafts screw into the brass props...
Regards,
Don_
Edited By Don Prince on 1115336635A man's gotta know his limitations...
Harry Callahan, SFPD -
Hi Captain Nemo 12,
Your aircraft
Thanks for that Don,Hi Captain Nemo 12,
Your aircraft must have the props with the same pitch direction... My OTW U-boat has props that have opposite pitch angles. Therefore, the motors must turn in opposite driections. I don't have a WTC completed as of yet, but the props are set on the drive shaft to turn top to the outside when running forward. I went by photos and drawings to set the props on the drive shafts. I hope I got it right??? I can always change it because the drive shafts screw into the brass props...
Regards,
Don_
Yep, the prop pitch angles are the same on the plane, I forgot to mention that in the previous post. Since I haven't really started to make the props for the boat yet, I can always decide on the pitch angles later. Will this mod work as well as making the props spinning in opposite directions?Comment
-
with the props rotating in
[color=#000000]It shouldn't. The U.S. PT Boats of WWII had 3 right hand pitch props, all turning the same direction.with the props rotating in the same direction, will this affect the boat's run
You need an even (2 or 4) number of gears for counter rotating props. One gear is connected to the motor and a prop shaft. The second gear is connected to the other prop shaft.
In my 1]Comment
-
Beg to differ, Chips. Pinion
Beg to differ, Chips. Pinion drives one spur which drives the other spur. Counter rotation direction determined by which spur is driven by the pinion.
All the twin shaft/ single motor boats in our club are set up this way, works great.
Dan
ONT Sub ClubComment
-
I have seen it done
I have seen it done with two gears in the gear box. Both gears were attached to shafts. One gear (spur) had a short shaft with a Dumas brass u-joint coupler attached to it. The second gear (pinion) had a longer shaft, with 2 Dumas couplers on it (coupler-gear-coupler); one coupler went to the motor, the second went to the prop shaft. Both gears were the same size.
Yellowdog - I have also seen quite a few set ups like you describe, with three gears for counter rotation - but they required a little more room than the 2 gear setup I described. I have seen more counter rotation set ups done with 1 motor and an even number of gears. The important thing is for the two spur gears that drive the props to be the same size - diameter & tooth count - for the props to turn at the same speed. The pinion and any intermediate spur gears can be any size.Comment
-
Chips on your system you
Chips on your system you are direct drive. That takes a big motor to turn both shafts in the direct drive mode.
I'm using Team Losi RC car spur and pinion gears, 35 pitch. From side to side I only need 3.25" or 83mm of room, which I have in my 1/48 scale Type 9.
If I need to I can go from 2.5 to 4.0 ratios without changing spur gear sizes. Very flexable system where you can use many different motors.
Dan
ONT Sub ClubComment
Comment