esc help needed

[Propeler]

hello,

i have bought one of Mike's awesome T-6 Framekits and now it's time to buy and install all of the the electrical parts.

i'am completly new to fe so here are some of my questions. I'am planning to use a Scorpion HK 4035/800 on a 10s1P 5000mAh 30C Lipos and now i need a matching esc for this setup. What kind of esc brand do you prefer? is there any formula to calculate the amps i need for this setup?

many thanks

Juergen

 

[Jim Caldwell]

240 amp, 12 s ESC. Castle, Swordfish are the popular brands.

 

[sailr]

I would NOT buy a Castle Hydra 240HV. They notoriously have problems. HOWEVER, Castle's new ICE Hydra 200HV is getting really good reviews. You also need to run TWO 10S packs in parallel (10S2P) or you won't have enough amp capacity to carry the setup. Talk to Mike. He's using the same controller I believe.

 

[Paul Traufler]

The Scorpion HK 4035/800 motor is rated for 4200 watts (100 amps continous) so as long as the ESC are rated over this you will be ok. 10S is not a low cost solution! A 5000 mhA pack with a 30C rating will supply 150 amps (if they are good packs they will do more) but you may want more run time also.

 

[SeanKewley]

You might consider a Schulze 40.161wk for that type of power system. Pricey, but the guys with the BIG toys use them http://www.schulze-elektronik-gmbh.de/index_uk.htm

 

[Propeler]

a 10s 2p parallel setup?

that means in my case 4 Packs with 5s1p and an overall capacity of 10 000 mhA and 37 volts, right?

oh boy thats a huge heavy batterie load of weight (4.4lbs) in the boat . whats the approx running time with this high capacity?

Juergen

 

[MarkTanski]

Probably 3-5 minutes before heat starts becoming an issue, all this depends on prop choice and hull setup. But probably not to much more if you expect the electronics to survive. Most guys are setting up their boats to basically finish the race.

Think about it you are using about a 200 amp esc . Your house electrical service probably isn't a 200 amp service more likely 100 amp.

Your boat will draw more amperage than you home breaker panel can supply!

 

[hugh hargett]

HK's Turnigy aquastar 240 is the same as the swordfish and cheaper. Id stay away from the castle period

the shulze is nice but 160 amps isnt enough esp for a mono. Alot of companies boats max current but you need one that will do what you want rms power. Take there peak ratings and divide by the square root of two that will give you rms power. Id aim for double the current draw I expect my average to be.We should always aim for rms ratings

 

[hugh hargett]

Probably 3-5 minutes before heat starts becoming an issue, all this depends on prop choice and hull setup. But probably not to much more if you expect the electronics to survive. Most guys are setting up their boats to basically finish the race.

Think about it you are using about a 200 amp esc . Your house electrical service probably isn't a 200 amp service more likely 100 amp.

Your boat will draw more amperage than you home breaker panel can supply!

Yeah if you were running at 120 volts you wouldnt need to draw 200 amps.Thats the key to that my friend. Let us hope you never need to draw 200 amps continuous coz you will likely have issue unless you have an etti spin 300 a 700 dollar shulze or a 63250 mgm comp pro $$$$$$$. Just imagine what it must feel like to burn a 700 dollar esc up lord forbid a shorted motor lead. I wouldnt trust a cheap motor on such an esc. Unless you can hang with the $$$$$$$ the swordfish or turnigy will be your best bet.the main thing with your esc is to make sure your batteries can supply what you want to pull, and that is doesnt get wet, waterproof or not. DATALOG def.By the way is this a mono cat or hydro? It makes a big difference. The monos are the amp hogs of the industry. If you got 40c 5000mah batteries you "MAY" be able to get a way with a 1 p setup, as that would support 200 amps.Ive heard that the scorpions can run hot. Keeping it below 100 amps draw if thats your goal might be a real challenge in a high speed mono!

 

[MarkTanski]

What on earth is that miss-spelled, un-punctuated mess of a reply! It makes absolutely no sense what so ever, I've read it repeatedly and still can't figure it out!

 

[Propeler]

So again from the beginning. I've bought one of Mike's kits. a t-6 Miss Budweiser 1 / 8 Hydroplane. I plan to use a scorpion 4035 800 Motor with two 5S1P 5000 mAh 30C packs installed serially in order to get 37 volts at 5000mAh (10s1P).

Now my question: are 5000 mAh enough to get a honest drivetime or do I need actually 10 000 mAh (10s2P) for 3 - 4 minutes running time?

Juergen

 

[hugh hargett]

So again from the beginning. I've bought one of Mike's kits. a t-6 Miss Budweiser 1 / 8 Hydroplane. I plan to use a scorpion 4035 800 Motor with two 5S1P 5000 mAh 30C packs installed serially in order to get 37 volts at 5000mAh (10s1P).

Now my question: are 5000 mAh enough to get a honest drivetime or do I need actually 10 000 mAh (10s2P) for 3 - 4 minutes running time?

Juergen

Juergen What size prop u thinking of running? With a x455 here is an estimate 101.41amps @ 3286.62 watts runtime 2 min and 54seconds with a setup eff of 95%

62 mph. This is a NUEPOWER 1p 4900 mah setup. your esc will much prefer a 2p setup but you will sacrafice weight and you have to plan out battery placemen for a good cg.

 

[Propeler]

a x455 sounds well.

thanks hugh,

those were my thoughts exactly. 4 packs 5S1P weigh around 4.4lbs that is far too much weight. the center of gravity is not a problem but that many extra weight of the cells is a big one. the finished hull with cowling, rear vertical/wings, motor mounts, driveline, strut, rudder and turnfin, weighs approximately 12lbs - 13lbs.

ready to run so it will weigh approximately 20lbs or more and that's too much.

But now back to the actual problem the esc. Is there any mathematical formula must have the required amps to calculate the esc?

and btw sorry for my bad english but i'am from Germany

Juergen

 

[hugh hargett]

a x455 sounds well.

thanks hugh,

those were my thoughts exactly. 4 packs 5S1P weigh around 4.4lbs that is far too much weight. the center of gravity is not a problem but that many extra weight of the cells is a big one. the finished hull with cowling, rear vertical/wings, motor mounts, driveline, strut, rudder and turnfin, weighs approximately 12lbs - 13lbs.

ready to run so it will weigh approximately 20lbs or more and that's too much.

But now back to the actual problem the esc. Is there any mathematical formula must have the required amps to calculate the esc?

and btw sorry for my bad english but i'am from Germany

Juergen

Your english is better than mine im affraid. Im surprized that mikes hull would finish out at 20 pounds ? That is alot but there are some scales in that area. Its just more work on the gear(flex shaft,motor,etc...). Mikes hulls have all the lightening provisions so I dont know what the deal is(strange it would weigh that much). Maybe its just that particular hull design.On resistance of an esc is the only thing I would think would make a difference between one esc resulting in a longer or shorter run time. Note im not sure if any of the esc's capture the back emf and try to put it back in the batteries,but boats dont coast as compared to a car so I think all that stuff is neglegible to be honest. Lets find someone with real word experience with a 4035 800 in an 1/8th scale heres a video

Cheersall these guys are running scorpion 4035 and 4025's some 800kv and some 600kv on x457 and 8s1p

I think you should just find some 40c 5000mah 1p and that scale will go get it.Note the 1/6th scales im sure are close to 20 pounds.200 amps supply should be more than enough "ballz" to push that scale. The numbers I get back on a 457 10s1p setup are 68 mph @117amps with a 2min 30 second runtime. These guys ran relatively low amp esc's and looks like they survived. I would suspect 120 amps is about where that scorpion will be; somewhere in that area .I wouldnt worry with a scorpion being a little over on amperage because they have high heat magnets and wires . You may consider getting a fan on it some kind of way, or direct the air from the cowl to it through some gortex as not to get the motor wet.Just remember the more amps you can supply the more thump out the hole it will have. With good batteries it appears any boat esc 120 amps continuous or better may work. With more $$$$$$ you get more quality, but I think the turnigy or swordfish will be fine. With the castle the nue site recommends 2p setups on all their motors so I wouldnt do anything less than what the manufacturer says and id only run a castle on a castle or nue motor for warranty reasons.

 

[Propeler]

my main problem are the imperial standart mesurement that you guys use. i live in germany we don't have them over here we are use the metrical system. for example: when the plan says all skins are 1/16" plywood so it became in my case 1.587 milimeters, so i have the choice between 1mm or 2mm birch plywood. 1mm became a little bit sloopy, 2mm are strong but heavy.

but anyway thx a lot for the nice vids

Juergen

 

[hugh hargett]

my main problem are the imperial standart mesurement that you guys use. i live in germany we don't have them over here we are use the metrical system. for example: when the plan says all skins are 1/16" plywood so it became in my case 1.587 milimeters, so i have the choice between 1mm or 2mm birch plywood. 1mm became a little bit sloopy, 2mm are strong but heavy.

but anyway thx a lot for the nice vids

Juergen

thats ok if you need conversion just let me know . Me or any of the others should be able to help you with the conversions.

 

[hugh hargett]

my main problem are the imperial standart mesurement that you guys use. i live in germany we don't have them over here we are use the metrical system. for example: when the plan says all skins are 1/16" plywood so it became in my case 1.587 milimeters, so i have the choice between 1mm or 2mm birch plywood. 1mm became a little bit sloopy, 2mm are strong but heavy.

but anyway thx a lot for the nice vids

Juergen

If you need a source for wood in SI measurement let me know but 17 pounds is doable. I wouldnt sweat it