HOTR twin build

[Rumdog]

Get as much capacity as you can fit! You're gonna want it with that setup!

[tiqueman]

Thats about all that will fit. But that would give me 6S 6000mah, but then split to each motor. But Im thinking thats beter than two 3S 5000 series then split to each motor.....

[tiqueman]

Just got done reinforcing the seam on the inside as best I could.. man talk about no room!!! Looking at the pics I saw a bit that need to be wetted more on the right side so I took care of that.

[ozzie-crawl]

there a bugger to trying to get up the front properly.
on such occasions i have cheated, take my little scraps of c/f and cut them up like its fibre glass chop, pour a little epoxy down in towards the nose,move the hull around so it spreads out,then sprinkle some c/f chop down,wait till it goes tacky and pour in a little more epoxy,it mite seem rough but rite up the bow were you cant get it is surprising how well it works

[tiqueman]

Oz, I thought about doing it like that as well. I ended up taping a 1" brush to a paint mixing stick. Then brushed the sides somewhat heavy and flipped the boat over so it would run up towards the deck. (The first couple inched from the hatch I couldnt get to w/ a brush) Then I put a little resin on the material, layed it out on the mixing stick, slid the stick down the tunnel (cloth side up), then turned it up and into place. It worked well once I figured out the technique. Then I used another stick to tweak it in there a little bit, and then used the brush to dab it some more w/ resin.

Any more thoughts on the battery situation? Im going to have to start w/ my original plan w/ 2-3S in series, then split to each motor so regardless I will see how that goes. Budget is shot on this and cant make any changes just yet from what I already have.

Whats the most mah you can run and stay safe? I was going to keep it under 6k. But I can fit a bit more mah size wise, I can go to 4k each... I think. But thats 8000mah which Ive not heard of anyone ever doing. All I can think is

Im also considering weight and price of the batteries as well. A 6S to each motor seperately, 1. I cannot get the mah to fit I need,2. If I could, I think they may be a bit heavy for the build, also that weight is sitting on the tunnel as there is no room to put them i the sponsons and 3. One 6S 5000 is just a few bucks less than 2 6S 3000 (both 35C)

[Rumdog]

NO, more mah is good! I run 5s2p at 5000mah each, I get a total of 10,000. The problem I think you might have is not enough amps from the cells. I bet 10 xl's on 6s will pull at least 100 amps continuous. To get the # of amps your batts can supply, take the c rating multiplied by 1 percent of the total mah in your con figuration. IE: 2x3s packs for 6s1p, 5000 mah each. 25c rated packs, 25 x 5= 125 amps continuous that your batts can provide. By sending that power to two different power plants, I'm pretty sure you're cutting that in half.

[BakedMopar]

Yep rumdog is right. With twins your going to be pulling double the amount of power from your batteries. Even though twins put less strain on them you still need to power two of them. I will be running two 4s 5000 40c packs in my twin skunk. They will be run like yours. Parallel then run to both systems together so each system sees the same current. I know builing on a budget is tough. But cutting costs on batteries may lead to burned up equipment. Keep runs to a minimum and check your equipment frequently.

[tiqueman]

So I think possibly the 6S 4000 35C are in my future. Well, as I said, Im going to try it first on the 3S 5000 30Cs and see what happens. So thats 150A outta each batt? And when you say cutting it in half, you mean each batt will only put 75 to each motor (max) ir is it going to try and pull double the Amps outta the batt (300 in theory)?

Who knows... Basing it off of another builders build and what he told me, it should work w/ what I have. Just prolly not as well as seperate systems or bigger batts would.... still pretty sceptical. I will run it for the first time w/ my eagle tree and see what happens. And as stated, check it often.

I have no choice right now about more batts.. Unemployed and shouldnt even be building this one... its batts or house payment and wife.....

[BakedMopar]

When I talked to Clint from Castle Creations he explained it like this to me. If I understood him correctly here it goes. All you are doing by paralleling you batteries AND power systems is they both will see the same voltage. It will keep from one system running hotter than the other. You should be okay but on the edge and run time will be down as 6000mah will be running two systems. Hope that made sense.

[tiqueman]

When I talked to Clint from Castle Creations he explained it like this to me. If I understood him correctly here it goes. All you are doing by paralleling you batteries AND power systems is they both will see the same voltage. It will keep from one system running hotter than the other. You should be okay but on the edge and run time will be down as 6000mah will be running two systems. Hope that made sense.

Makes perfect sense.. just how I thought it would be.

[tiqueman]

For those wanting a bulkhead template

Cut it a smidgen big so you can sand it to fit in nicely. May even want to do it outta balsa first, then cut it outta CF or whatever your using once you get it to fit your hull properly. And remember my boat is layed up w/ 5.7 carbon, so if your not laying yours up etc etc, cut it even a little bit bigger then a smidgen

-Scott

[KillerDave]

Thank you my friend, Very good work!!!!

[KillerDave]

Ok, So I just got back from the lake and I am NOT HAPPY!!!!!
Ok... Twin 380L's running on 3s LiPo's through seaking 70amp ESC's and using PropShop 1435/3 prop's.... It's so slow I think I could walk quicker!!!! The COG is at 220mm behind the transoms and the all up weight is just about 2.5Kg I think...???? the factory kit should do 100Kmh http://www.tflhobby.com/prd/EP/1/1_en.htm

My prop's are nice and low i.e. bottom of the hub is level with the bottom of the hull...

Please help if you can???? I'm getting short on hair now!!!!!

[domwilson]

Did it get on plane?

[KillerDave]

No, Just sat there looking at the sky!