My Blackjack Dual

[tiqueman]

Man that looks good.

Looks really good.

[blackcat26]

Thanks guys! I'm still sweating it's top speed. Got more props on the way and am gonna try dropping down in diameter since these motors can't wind the 42's out. Think I'll try a x438 then trim the 442r down to match. I have a feeling this will help alot!

[Fluid]

Justin, what is the current setup, motor/prop/voltage? The BJ motors will swing larger props than x442s with ease in a single drive....what am I missing?




.

[tiqueman]

Justin, what is the current setup, motor/prop/voltage? The BJ motors will swing larger props than x442s with ease in a single drive....what am I missing?




.

I think hes talking about the Turnigy motors now.

[blackcat26]

Running Ammo 36-50-3300's on 3s each with 442's counter-rotating using turnigy aquastar. Smoked a blackjack motor so ditched the blackjack setup.(was running bj's on 6s) So far I have smoked 2 aquastars and one BJ motor. I think my underhull pickups have not been picking up that great. 2nd to last run esc was about 150f and the next time out it caught on fire. This boat smells like crap AGAIN.

[tiqueman]

Running Ammo 36-50-3300's on 3s each with 442's counter-rotating using turnigy aquastar. Smoked a blackjack motor so ditched the blackjack setup.(was running bj's on 6s) So far I have smoked 2 aquastars and one BJ motor. I think my underhull pickups have not been picking up that great. 2nd to last run esc was about 150f and the next time out it caught on fire. This boat smells like crap AGAIN.

What kind of pick ups are you using?

Wait.. It caught fire again????

[blackcat26]

I made a pickup with some copper tube. Its epoxied into the hull the sweeps up for easier access up transom wall. Yes this is fire number 2.......I need an onboard extinguisher! I really think that 42k rpm's on this size prop/motor is loading it way too much, you can hear that it's just not whinning like my Elam does.

[tiqueman]

For your pick ups, if I can explain this... when you bent the tube, before it was cut flush w/ the bottom of the hull, as soon as the tube exited the hull, was it always touching the bottom of the boat and running along it? I ask this because the first set I did in one of my cats didnt work that well. BUT, I found it was because it did not exit and do as explained above Instead, it was maybe 1/8" off from touching the bottom. I re-did one to see if it made a difference and it was quite a bit better. I then re-did the other and have efficient cooling now.

[blackcat26]

Mine is flush with the bottom of the boat. When I sanded the bottom i was sanding copper tubing with it.....The trailing edge of the tube (closest to the transom was perfectly flush with the bottom of the hull. Here is a few pics of what I'm testing to see if the temps drop. (a smaller brass section lower in the flow of water) This method cools better but lifts the bow like crazy. I think chamfering the inside of the brass section made it drag worse. (prolly should have chamfered the outside)

[tiqueman]

Yeah I used gundert pick ups first, that OSE sells. They stuck down a bit, like an inverted fighter jet canopy and caused all kinds of wierd handling characteristics. But it doesnt make sense yours is lifting the bow, it should be gluing it to the water and casue it to ride really wet???

[blackcat26]

When I took it out yesterday it blew over under hard throttle, no wind, nothing. Riding extremely dry. Pushed her back in and taped a 3/8 ratchet (all i had that was heavy) and re-ran. Ran better but still not the same. Temps were about 120f or so esc and motors. Did not open it up totally to see if the new drag was bringing my top speed down any. Max mph was 55 but I think it still had more. I didn't feel like recovering it again so I didn't push it.

[tiqueman]

Wierd

Whats your angle on the stingers?

[blackcat26]

Not 100% percent sure. Same as my maiden, have not changed. I set the hull on a pc. of mdf then placed the stingers flush with the board then bolted em up. Kinda rinky dink method but it looked pretty good in the water.....

[tiqueman]

Not 100% percent sure. Same as my maiden, have not changed. I set the hull on a pc. of mdf then placed the stingers flush with the board then bolted em up. Kinda rinky dink method but it looked pretty good in the water.....

I used a similar method w/ the end of a 12" shelf. I was going to say set them neutral, but it sounds like thats done.....

Wheres your cog (without the ratchet)

[blackcat26]

Ha! Ratchetless, it's about 220mm forward of the transom. Normally running both batteries, runs just a little dry and slightly bouncy. Before I could peg full throttle and not sweat it....just accelerated. Running one battery, the bow lift was more pronounced but still driveable. No flips and wild jumps like that Blackjack run.