Did just that. They first put of epoxy is drying now. The trays had a small leak so here in a couple hours I’ll go out and top them up.
Have you ever had a build with so many problems that you felt like you shouldn't be building it? That's kind of how I'm starting to feel like with this one. Although, when I work all the kinks out, it should be perfect. I was just at the lake trying out the new drive ESC, which works beautifully, AND after cruising around for five minutes my prop spins off and is now sitting somewhere at the bottom of the lake. I took a swim to go find it but it must have been farther out than I went. I've been asking around if I should get another prop, now I am forced to. After the times that I have been able to cruise around, I have been pretty happy with the turning radius and after increasing the speed to closer to the rules, I think the acceleration was pretty good too. Long story, short, I think I was pretty happy with the 5 blade prop I was using after all. On the bright side, that prop was a spare from the first Bismarck and was 11 years old. At least it wasn't brand new. Now, that I am getting a new one. What is the procedure for securing a prop so this doesn't happen to me again?
How were you securing the prop to the shaft? Lots of ways to do it. Flat on the shaft with a set screw through the prop hub, at least blue loctite on the set screw. Probably the least secure but easiest to remove/swap the prop Braze the prop onto the shaft, done right it's not coming off, good or bad. Also don't get the prop too hot or you'll deform it which is bad. Wouldn't recommend trying this with prod that have soldered blades. Doesn't work with plastic props either. "Green" loctite the prop onto the shaft, if you have a good fit between the prop and shaft that makes a very strong joint. Superglue, probably better for plastic props then metal ones. Probably some others, lots of ways to do it. I prefer something more mechanical than adhesive based but everyone has their personal preference or what works for them. Whatever method you use it's nice to have spares or otherwise be able to swap a new prop on if needed. How important this really is depends on the prop and connection method, I've gone through multiple sets of props during a NATS(soldered blades set screwed on) and also had one prop on for multiple years of heavy use and a significant amount of "off-roading" without any issues(cast bronze brazed in). YMMV
It was held on with a set screw. I shaved a flat part on the shaft but didn’t use any lock tight. I also didn’t make a notch in the shaft like I did on my my Lutzow. I like the idea of having the ability to take it off and swap it out if needed. Especially since this boat is going to be “my baby” and take it to NATs and other club battles.
How do you feel about 3d printing a prop? I've been playing around with modeling and printing props for my Mikasa. I'd be happy to share my CAD file and you can edit it to your specifications.
We have found the 3D props to be just a little more durable than expected (until a certain set of sidemounts says hello). It's a great way to test designs and then order that design in metal.
I think the time as come to cut the old prop shaft out and put the correct one in. There’s enough things I did wrong. I’ll also move the motor and do direct drive with the universal joint, take out the classic dog bone.
Re: U Joints This was shared with me and I found it helpful. I did end up with 2 small U joints in a tight configuration. I call it a W Joint. It lasted all Nats no problem and was much quieter than the weed whacker I had in there before. View: https://youtu.be/j1pOGY5vGWY
I make my own. I can share part numbers to build your own from McMaster parts. If you build a 3/8 stuffing tube like I use then you could also install my belt drive system. https://radiocontrolcombat.com/2023/01/29/smithpowerdrive/
Do you build it the same way we used to in the swamp works days? Putting smaller tubes on each end and glue it all together?
Stuffing tube is 3/8. Shaft can be whatever. I prefer 5mm over 3/16. (I used 3/16 back in the day and 5mm is just sooo much easier to find compatible hardware) No smaller tubes, bushings are used. Just cut the length of stuffing tube, insert bushings, grease, add shaft and you're done.
