Motors arrived Motor plates to adapt to 25mm bolt holes Covers up the forward bearing two ready to go in tomorrow fingers crossed, the tapping went well this time
Got the motors in and bench tested, ready for sea trials M3 screws felt solid with pumps and speed controls in, pretty cluttered
Made it to the pond today. New drive train worked great. I loved the lack of time delay between fwd and reverse, went from being a slug to a 50 pound rocket ship. Had some issues with one of the rudder gears and didn't bring tools, so I'll have to fix that before more extensive testing can be done View: https://www.youtube.com/watch?v=HL3Yycf_ngc
Looks like she’s way faster than 24sec in reverse. It would be interesting to see if she can go backwards far enough to measure that speed.
Got to the pond today, got a good bit of run time in on this configuration I think 70% on reverse is a bit more realistic, will need to finish turret seals though the stern rides up which is good Took videos of a variety of maneuvers, now going to swap the props to opposite shafts to see how she does. Turning sucks but all else is good. Hopefully back to the pond on Friday
Sinking is over rated Another round of pond testing. No joy on the opposite rotation props. They pulled the stern down in reverse which becomes a deal breaker. Acceleration was essentially the same, turning was worse, so I’ll be going back to top-in forward rotation. Turning still sucks, so decided to move rudder posts and make some other rudders to test. Printed up a guide for multiple posts allows 3 different pivot points 4 styles of rudder to test. Made them taller than previous version as I was losing thrust under the rudders. two styles, two different pivot points epoxied, I think this should work also going to my printed rudder gears. Other mods to aft turret seal and auto pump level probe locations Next pond test will be cycling through the rudders. If turning still sucks I’ll braze up shafts with the 1.9” korts I originally used on this build
Really like that multiple tube setup. Once you find the sweet spot just epoxy up the others. Brilliant.
Cleaned up the rudder posts, also swapped the shafts back to normal a couple different styles to try Things lined up will inside good engagement. Posts and holes are Spaced at 0.2” Decided to also draw up a semi-circle hybrid version, and a short+longer version. My contribution to the grab bag at nats this year will be class 6+ rudders
I decided that I wanted to repeat the last process just for fun, since I didn’t notice how far off center the starboard rudder was Here are the semi-circle rudders I printed up I think I have at least 7 sets of rudders to try, one of the downsides of having a printer is that making iterations of something is really easy 4mm pump impeller showed up from BC, so finally able to swap pump motor. Also added hose clamp and larger diameter sleeve on pump outlet for better hose retention. Turnigy 2350kv I think ripped out the mounting plate I just installed Installed new one with tubes .2” further outboard on stbd side to line up with prop should be set for another round of sea trials no later than Friday. If turning still sucks, will brake up the 4 blade korts
Sea trials today with 7x rudders. Honestly hard to tell the difference between most of them. Took videos of each to compare. In general I think the pivot closer to the prop did better. Next step will be going back to the korts. Turning to starboard is good, which is good for the stern sides. Turning to port is a good deal worse, nothing clearly sticks out for why the difference. About ready to call this boat set for battle
Swapped back to the 1.9” 4 blade korts I first had in the boat a few year ago went to the pond today. It was shocking how much difference the korts made - went from maybe 12ft turn diameter to 4ish feet (6ft boat). I’m guessing the thrust diverges much less for the korts, so the rudders are more effective. Reversal times seem comparable, will need to compare videos with stop watch. Tested out 5 or the rudders running through a standard set of maneuvers. Will need to review video and take down whatever information I can in order to determine which was best. I have an idea but differences were relatively small for the different shapes. Glad to finally be done with propulsion testing.need to test guns and play with the auto switch probes. I’ll try to post a video at some point
I was curious about that. The 5-blade props you installed appear to have slightly cupped or airfoiled blades, and you installed them with the cup/airfoil oriented to run astern. All of the korts I've seen are a very simple profile with symmetric thrust in both directions. I wonder how the ship would handle if you flipped them around.
Kort props are the least directional props that prop shop makes/sells. According to their customer service/product engineer I talked to anyway.
