He's using these: http://battlersconnection.com/coupling-set-1-8-to-1-8/ I personally like the 'Kardan' style couplers, they're a bit pricier though, for example: http://www.harbormodels.com/couplers.html (the red w\ brass inserts)
The coupler would be the point of failure in a typical setup (you hit something really hard). Not using something then puts the stress on the blade or possibly the motor. I guess it is a trade-off.
unless you actually use a long enough motor shaft to mount the prop directly on that, you're going to need some sort of coupler. May as well put a flex one in and let your bearings/bushings live another day rather than test the power of hubris and Murphy.
Even still, Steve, you will need some sort of coupler to connect the shaft to the motor. As far as perfect shaft alignment...I don't think it has anything to do with manliness and I'm no perfectionist so I don't strive for it if I can help it. But I like to think that as long as my driveline holds together I'll show my manliness and courage on the battlefield, where it belongs, whether my motors are perfectly aligned with the shafts or not...
FYI, a single u-joint on a shaft only addresses angular miss-alignment. If you have any parallel offset, you will still get wear. Those plastic prongs on those red u-joints look fairly loosey-goosey (flexible) so that would be hiding offset issues to some degree.
As I'm using direct drive and nylon props, the first mechanical fuse in my no dog-bone setup is the prop. If the prop shears, I'll slap a new $2 prop on. The second is the motor. At stall the 555's are only drawing 6A which my ESC can easily handle. FYI, I went through all the alignment trouble and nixed the dog-bones for reliability but also for better power transmission. Any u-joint or dog-bone setup will lose power if not setup in a straight line. The more angle in the setup, the more the losses. Losses can be 50% or more if drive line angles approach 30 degrees or so.
Hrm, you replied to me but not sure if your comment is intended in general or at the setup pictured. So, responses! They're not very loosey-goosey shaft to motor shaft alignment is actually really close on that particular ship. Here's a better shot: (note for anyone looking to do a similar setup: this ship will need shaft collars to prevent the shaft from sliding back and pulling the couplers apart. The stuffing tubes were 'on hand' and not long enough)
Beaver how did you attach the piece of ss to the collar? Did you weld it or something? What kind of collar is it? How thick is the ss and is it a special type?
The prop is counterbound between two nuts, no collar. My first props I welded a nut onto the prop, but I don't think it's necessarily necessary. The SS is 18 gauge, don't know what alloy, it was salvaged from a remodeling job. Any stainless will work.
Decided to redo all the decks. Also gave them some scribed planking for a more scale look. Printed the barbettes and turrets, but am making the main SS out of blue foam.
Had to rip out the motor mounts. In the process of modifying them for better alignment I didn't realize I had taken too much off the bottoms. So much so that I couldn't get a ziptie underneath to secure the motors. Henceforth, back to the drawing board, or in this case, Fusion. A few minutes of design work and it's ready to print. (no photos of the finished prints on the bed, sorry) All those crack and crevices make for awesome glue adhesion. And glued in. Shaft alignment is 'semi-perfect'. And work continues on the SS. Two more layers added. Enjoy!
Weelll, I ripped out the motor mounts AGAIN! Turns out that 380 motors aren't suitable for a direct drive setup in a ship this large, at least not with 1in props. I'd either overheat the motors, or not be fast enough. So I came up with a new setup that's got both the speed and torque to run this ship. With it I'm bringing a new meaning to the word "drivechain". Motor mount will end up being bolted to the hull.
I realize I loose that, but testing in the pool I see no real difference in turning than with counter rotating props. And the simplicity factor more than makes up for it.
Not sure the X-car 45A ESC's can handle two 550s. In any case, this probably won't be the final driveline for this boat. I just wanted to get it driving and battling without having to order more parts. I was able to assemble this with just stuff I had lying around from other projects.
5 pole RS-550PH motors? If so, stall current on these is usually under 10A. If not PH, can be well above 10A. How much voltage can you install (with stuff you have laying around)?
