About 12” should be the length of the drive shafts. Motors should be farther forward. Check these sites out. http://www.portpolarbear.com/reports/Derfflinger 2.html http://www.portpolarbear.com/reports/Derfflinger Build.html
Believe me, Ive looked through his build plenty. They are 12” how it is modeled and the motors are in similar placement (under the D turret) on the wood hull build. On his fiberglass hull build it looks closer to 18” since the motors are under the superstructure.
you may have already checked out my Idaho Stem-to-stern, but just in case, if you're needing ideas on how to get that D turret to work with the motors there, it might help. I do minimal clearance stuff with my wood boats and pull it off pretty okay. hey so, stupid question maybe, but you mocked up your rudder turning and such with the props situated like that? also, another really dumb thing maybe, did you Toe-in the motors and shafts? the build looks great, dude. with how well you're meeting the various challenges, I think it's gonna be an awesome boat. I'm really stoked to watch how this goes. gives me the urge to get my Derf out of the box and start working
Hey thanks! The props are at a 3.5* down angle, but no toe. They are straight back. The rear rudder should just clear the props (props shown arent in the exact right spot. I didnt add the space for a locking nut so they need to slide back a bit) I may need to clearance the hull JUST a touch to make sure there is no issues with any prop vibration, but they do clear. The prop blank is a ridiculous chonky 12mm so in reality I will have more wiggle room. I have 4 used 50rd coil guns that I need to model to see if they will fit and where they will fit. I may go with a 3D printed gun if they dont fit because why not at this point.
I did have luck modifying my 550 mount for the 775 i out in the konig. I set the end point at 75% when we had it on our pond last time
Would a single 775 perform better than dual 550’s? I’m going to mock up a hot-swap mount to see once the boat is in the water. Not much to lose with trying.
You would be powering 2 shafts on a Derf rather than just 1 on a Konig though. It would be way easier to run the 2 550s instead of trying to gear the 2 shafts together for a single 775. As for performance of a 775 vs dual 550s on a single shaft, it's back to gearing where it is easier to set up a single 775 compared to dual 550s. I know from having a bunch of the Traxxas E Maxx trucks, the single 775 and dual 550 setup was a very negligible difference in performance there. I doubt there would be any difference when it comes to boats as well.
All I can say for sure is the konig danced on the pond. Wish I had a chance to get some video. But if you will be in Hagerstown I hope to bring it depending on space
The shafts are going to be geared either way. The tube materials -should- be here today and my local hobby shop will most definitely have gear sets so I can start mocking stuff up. They only do planes and cars so picking up some traxxas gears shouldnt be an issue. Was also thinking of running them via a belt drive, too but that is for after the boat is in the water. Ive changed from built in mounts to a mount plate. That way upgrades and design changes to the “engineering space” can be done with minimal effort.
I live 45min from Hagerstown and even is Derf is not ready to fight, I am hoping to make an appearance with her at the very least on Friday and or Saturday.
Konig only is a 3 shaft ship, with dual rudders so a single 775 is good for that ship. its gives the power of 2 550s in one single motor, is easier to install and deal with. the only gearing is between the motor and shaft, a total of 2 gears. Derf is a 4 shaft ship with a single (or inline) rudder. They are 2 entirely different beasts. going with 1 775 to power both shafts is just extra work when a 550 on each will do the same much easier. you would also have some theoretical power loss from the extra gearing required to do so, as well as make the shafts counter rotate. Dual 550s also allows counter rotating shafts much easier too, just run the motors the opposite way. you could run a 775 on each shaft. if that is what you are thinking. not sure if you really need that much power though.
(Grunts in Tim Allen…) yeah no, scratch it. I was having a complete derp moment and forgot how gears work I had it in my head that I could put the 775 in the middle and run a gear off each side. Totally forgot that whole ‘counter rotate’ thing
You would need one extra gear to accomplish the counter rotation with a single motor. It's possible, but just unneeded and not the norm in the hobby. I am kind of thinking about it for my Deutschland though. Right now the props hit since I went up in size from what the ship came with. If I time them together it wouldn't be a problem. I'll probably just go back down to a smaller prop, but make it a 4 or 5 blade and less pitch than the 2 it came with.
Imma stick to the dual 550’s. Just need to gear them. Since that section of the boat is 2nd to last to print, it will be late next week by the time I’m ready to put that on the printer. Poor thing needs a glass of water and a good nap. Shes been printing nearly nonstop since Sunday, only pausing to put the next file on the card and remove the finished pieces. She is on hour 44 of 49 on this section. One more section to hit half way!
I’m trying to solve an infill issue (nothing critical, just skips occasionally when doing infill lines) so I slowed the print speed down. This has been my longest single print so far, though Ive printed bigger things.
