Thank you! I took it down to 1.5"; which brings the waterline under the bulge as you guys are describing.
Progress on propulsion! Those motors are internally geared to about what the Big Gun guys are using. It “should be” more than enough. If it turns out it’s not fast or reliable enough; than I swap-in a fast-gun tranny. The rudder is a direct copy of what the plans showed. I’m planning on differential drive, although I may update it so the rudder is a little larger for the outside screw.
OK... I'd love some recommendations... I increased the rudder to the maximum that NTXBG rules will allow. I still don't have full barn doors. I'm thinking to take a little off of the height of the rudder and use it in front of the outside rudder. Other recommendations?
Rudder height has more effect on turning than increased rudder length. I'd actually make it a hair shorter and add the extra to the height. If big gun allows top and bottom plates I'd add those as well.
Onboard gearing approximately what big gun guys are using. After wiring it up yesterday, my mk1 eyeball says the RPM looks ‘bout right. No idea on durability yet…. View: https://www.amazon.com/Greartisan-Electric-Reduction-Centric-Diameter/dp/B0B611141L
It appears you made it longer? Once again I would make it shorter and deeper. You could certainly try that design but try a deeper design too. I think you'll find it more satisfactory.
got it. Yeah. I did make it longer. I guess i didnt quite understand you. I don’t quite understand your concept though.. I would have thought unless I have something in front of the second prop, the water pressure will just push the ship forward while you are trying to turn?? I figured the best bet was to get as much water moving side ways as I can??
It might not make sense but it works. I've told many people in this hobby the same thing. Most don't believe it till they try it. Make a couple different shapes to try. I'll bet the deeper ones perform better.
I tweaked the screw positions as you recommended. I'll probably tweak the rudder a bit more; but I like where this is going.
Update - I’m going section by section finishing all loose ends. AFT - After reprinting this section I’m quite happy with it and the way the rudder is working now. The rudder is not getting stuck on anything and the servo holds at 90 degrees in both directions with pressure. Once it’s on the water I’ll play with different rudder shapes. But I’m calling that section “ready for water”. Motor Hull - I printed what I thought was going to be my final motor hull section too. Unfortunately, there is far too much tension between the motors & the new inward facing prop shafts. To compensate, I believe all I need is to drop the motors mount so the shafts line up. I am using a flex-shaft to fix any slop. If this doesn’t work, the. I will return to the more classic style everyone else is using. The other thing I added was a small shelf above the motors for the ESCs. In NTXBG, I can use variable drive, so I added two shelves for future upgradablity. This section is currently reprinting, and will be ready for bench testing tomorrow. Pump & Battery hull After fitting the co2 & battery into my previous prints, I found everything is just too tight. So I moved the motors, and the pumps aft to gain more than an inch more clearance. It all fits; but the real question is how be removable it’ll be. I also completely reworked the pump, having its output tube line up perfectly with the outlet port on the hull; all with a slight angle so the water goes overboard. I’m quite happy with it, I’m assuming it’ll be easier to install and will be able to argue a mythical reduction to water flow resistance. ;( I added imprints in the hull for both the batteries & the co2 bottle. The bottle has a built in magnate to hold it in position. I also went through all the screw holes & added imprints for me to glue nuts in place too. Lastly, I reworked the center smoke stack to act as my float. Anyway, I should add some photos.. I know this thread is useless with just words…
