That's the way it works for all of us. Two steps forward and one step back. It takes a lot to shake out the jim jams especially in a brand new first build boat. You're doing great. Rinse and repeat as they say.
Well, the second sea trial was better. She was going VERY slow. Probably close to a 100sec to a 100ft. Still had some leaks, but not as many as before. After getting tired of going slow I adjusted the pitch on the propeller hoping she would go faster. Turned out that one of the prop blades stuck out too far and got caught on one of the rudders. After getting locked up, the the nut on the propeller striped out, ending any further boating. So, after that is fixed, might actually get to drive her around in a timely fashion. Photos and video tomorrow, sorry.
I've made props and bought props. Store bought works better (for me). Props are something you should have a spare of because stuff is always happening to them.
Working on uploading some video right now. Here are some photos of her on the water. Sorry about the poor image quality, the photos were taken from the video. I forgot to tell my mom to take some photos as well as video.
Looks Good! Slap some guns on it. Carve out a mock superstructure from pink foam insulation and bring that puppy to battle. At our Spring Regionals Chris K forgot to bring his superstructure and spent the whole weekend with a flat piece of styrafoam to cover the inards. He was as dangerous as ever. As a last resort don't enable the guns or pump then slow it down and run the boat as the convoy ship FN Suffering. Endless possibilities
Thanks! FN Suffering, sounds cool. If I were to run her as a convoy though, I think I might need to speed her up. Video is here. In the beginning of the video, she wasn't responding at all. You can hear me moving the throttle stick up and down trying to get a response. Ended up I had to pull her back to shore with a stick. What do you think her speed is, other than SLOW? https://www.youtube.com/watch?v=MCYh4qCwl2M&feature=youtu.be
The second part where the deck is on looks pretty close to Convoy speed (34sec per 100'). The big surprise was how well that long boat turns! I think you got something there.
I see, it is a brushless. I think you just need to change the pinion gear (more teeth I think) to get your speed up
Really, I didn't even think I was going that fast. You think she turns well too? I thought the turning was a little lazy. Maybe when she gets going to speed she'll turn even better. Plus if I build rudders to the allotted size who knows how well she could turn. Yeah, the motor is a brushless motor. 2500kv running on 7.4v with a 4 to 1 gear reduction. I added a little more pitch to the prop the other day when I was running her. That's why it bound up and stripped out the nut on the prop. So I haven't been able to try Suffren out with more pitch. I think I might have also been getting some slippage in the set screw on the drive gear, so that might account for some of the slowness.
Well it is pretty hard to tell the speed since you are the only one out there but convoy is mighty slow. Turning looked good on the video, although max rudder area is always desirable. Right now I would just concentrate on getting it running. The tweaking is a never ending process and if you get hung up in that you will never get on the water.
Set screw slipping can absolutely kill your speed. Make sure you've got that good and tight. I agree that you look to be around 30-34 seconds, its hard to tell exactly though since you don't have much space to gather speed in. Your turning could be better for that ship, but it might improve if you get more thrust back there (more flow over the rudders). Make sure at no point can your prop shaft move enough to allow the prop to contact your hull or rudders - if it can, it will, and that will either bind you up in some unpleasant way or slow you way down.
Your prop was 1.5" across? Do you have a tachometer or some way to measure shaft RPM? if your prop was spinning anywhere near 4500 RPM and you had a 1.5" prop, you should definitely be moving more water than what we're seeing here. Seems to me you're slipping somewhere or the motor isn't running at 100%. I wouldn't fiddle with gear ratios though until you are absolutely sure you have solid linkage at every point (prop to shaft, shaft to coupler, coupler to motor), no bindings and were reasonably certain of the ESC and radio's settings.
The prop is 1.75" across. I don't have a tachometer or any way to measure the RPM's. Should be somewhere around 4600 rpms though because 2500kv* 7.4v/4 = 4625rpm. The set screw was slipping because I pulled the shaft out and it had grooves where the set screw was spinning. So I'm going to file a flat spot on the shaft to fix that. So, hopefully I'll have her back and running at a much faster speed in the near future.
"should be" and reality dont always line up, that is why I asked if you had a way to measure actual shaft speed. File that flat on though and recheck your speed, would not be a surprise if that largely resolves the issue. Another thought is a 1.75" prop is pretty sizable, and may be too much for your motor to keep at speed. I'd be a little surprised if that is the case though, with that 4:1 reduction.
Went up to the pond today with Suffren to see if the improvements helped bring up the speed. I must say, she was running much faster. I'll have to upload some video of her running when I get high speed Internet back. Using Dial Up right now, SO slow. Things were going great up at the pond, running around and such, and then I hit a stick. Such a sickening noise. Got that cleaned out and started running again went the motor slid up just enough to make the gears miss. I didn't have the right Allen wrench to fix it, so I called it a day and went home. I'm not sure of the speed. Probably close to 23 seconds, but I might be totally off.
Hey, Steve, Thanks, working steadily on getting her driving nicely by NATS. New video of yesterday's run. Running much faster. What do you think her speed is now? https://www.youtube.com/watch?v=DQ8Wt6JaXv8 Thanks,
