Mini-V w/decoy duck jet drive build

[damfurst]

Maiden run

It warmed up to the low 40's today so to the creek I went to try this boat out on it's maiden voyage. It was both good and bad. It was good that it worked, but it was severly underpowered in the current. It would hold it's own, but just barely. I tried both 2s and 3s lipos and both were about the same. Heres the vid. I also drilled out the cooling tube off the nozzle. This helped alot because it produced a 1 1/2" to 2" stream out the side. Next step to go brushless. Stay tuned.

[wparsons]

Is that WOT just to hold its place? A brushless motor will really help out!

[lucozader]

nice stuff

thanks for posting

[damfurst]

Is that WOT just to hold its place? A brushless motor will really help out!

Yes that was WOT. Will be installing an Esky 3100kv outrunner w/Mystery 30A Esc(waterproofed), Tactic 2.4 receiver, and Corona servo.

[antslake]

Can't wait to see it go. I am wondering about the efficiency of that drive.

[damfurst]

Installed the Esky 3100kv brushless motor w/outrunner cooling plate today. Along with that also a tactic 2.4 rx and Mystery 30A Esc. There was also a new Corona servo that fits right in the servo mount. She's all set now for the creek. Wanted to weigh it to see how much weight came off, but can't find the scale right now. Maybe next post. Will probably be a few days before it's warm enough to try again.

[damfurst]

Just a little update. Due to weather, my wifes broken wrist, and other factors I didn't run this until yesterday, but wasn't able to get any vid of its short run. For reasons I still don't understand, I had to change the motor to a mystery 3000kvas the esky one would not run properly. The mystery wouldn't line up right with the impeller shaft so I installed the motor on a seperate mount and graupner u joint. I tossed it in the water with a 2s battery and it got on plane and went upstream without a problem though it was no speed demon. But I discovered it was listing badly and brought it in. It was half full of water so now I have another leak I've got to figure out. At any rate I think it us safe ti conclue that brushless is the only way to make this work decently in a stream situation as long as you don't have a leak. I just don't think that it will make very much speed because of the small impeller size and if you used in a much larger boat it may take 2-4 of the units to get any speed at all. I still will get some vid of it running on both 2s and 3s lipos.

[wparsons]

I put a thick bead of silicone on the hull around the intake and exit for the pump (inside the hull), then dropped the drive in and tightened it down, smoothed out the silicone and let it dry. It took a couple tries to get it really well sealed, but mine is good now.

[damfurst]

http://www.youtube.com/watch?v=ZmY10_kJL2A

Finally got down the creek today. Winter has us in it's tight grip this year. Anyway, got my leak straightened out and tossed the boat in with a 2s 1800mah 35c battery. Gets up on plane very easily now with the brushless set up. At wot had some serious cavitation with loss of prime in the mild waves. Went upstream well and performed decent at 1/2 throttle though. Wanted to try a 3s battery but my fingers were numb. I'm not sure what to try next=extra weight of the 3s might be enough to help on cavitation problem, or a flat before intake. Maybe a different hull might help as well. At any rate if speed is not what you are after, I give this drive a

[damfurst]

Update on brushed system

I think I had something binding on the original motor coupler I used with the first brushed setup. The set up is the same except that I used a 2.3 X 3mm Graupner u joint. As you can see in the vid the 2s battery did much better against the current even though it was wot. The 3s battery did just as well as the 2s except it was at 1/2 throttle. Bottom line is brushed is also doable on 3s if speed is not a concern.

http://www.youtube.com/watch?v=0bBot1TUctE

[wparsons]

I think creating a flat area in front of the intake would go a long way to helping the cavitation problem, but it's running nice for what's in it! It's not ballistic (no jet boats really are), but it would be tons of fun to play with in a narrow streams fighting the current and driving around rocks.

[damfurst]

I think creating a flat area in front of the intake would go a long way to helping the cavitation problem, but it's running nice for what's in it! It's not ballistic (no jet boats really are), but it would be tons of fun to play with in a narrow streams fighting the current and driving around rocks.

I think you may be right about the flat. I'm first going to put the brushless system back in and then try the screen to see how it affects the cavitation and then a flat in that order. Thanks for your thoughts.