BBY's 1/8 Pro Boat build

[RandyatBBY]

There may be come confusion on the amp draw it is the spikes on launching that may be high, once on plane the motors are very efficient and draw little current.

[photohoward1]

That littlescreamers outrunner should have fairly low amp draw being that it's only 650kv I believe.

KV has nothing to do with it. I run a Big lehner 3060/13 turn 550KV@150 amps to 200amps.

60mph Open Mono.

The Motor Randy Picked is perfectly capable of 150amps or more. I think it's good for burst to 8000watts.

[Brushless55]

KV has nothing to do with it. I run a Big lehner 3060/13 turn 550KV@150 amps to 200amps.

60mph Open Mono.

The Motor Randy Picked is perfectly capable of 150amps or more. I think it's good for burst to 8000watts.

Holy cow, 200amps!

[RandyatBBY]

KV has nothing to do with it. I run a Big lehner 3060/13 turn 550KV@150 amps to 200amps.

60mph Open Mono.

The Motor Randy Picked is perfectly capable of 150amps or more. I think it's good for burst to 8000watts.

Yes but do not confuse the big amp draw with a mono and a hydro, that same setup in a Hydro will draw a lot less amps. 1/3rd less or so.....

[Rumdog]

Of course it CAN pull a lot of amps. Overpropped, or a wet running boat, and sure. KV, however, does have something to do with it.

[photohoward1]

Yes but do not confuse the big amp draw with a mono and a hydro, that same setup in a Hydro will draw a lot less amps. 1/3rd less or so.....

Don't take it the wrong way. I am just stating that the Motor Randy is using is very capable of pulling giant amps and gobs of power once he figures it out. I talked to the guy from Little screamers and he feels if the motor isn't getting hot then your not pushing it hard enough. I think Randy could get the right hull well into the 80's with that motor. But he will need to pull over 100 amps. ( I know you now all this Randy)

Keep us updated and get some speed readings on that hull.

HT

[RandyatBBY]

Don't take it the wrong way. I am just stating that the Motor Randy is using is very capable of pulling giant amps and gobs of power once he figures it out. I talked to the guy from Little screamers and he feels if the motor isn't getting hot then your not pushing it hard enough. I think Randy could get the right hull well into the 80's with that motor. But he will need to pull over 100 amps. ( I know you now all this Randy)

Keep us updated and get some speed readings on that hull.

HT

If it is not proped right yes it can pull lots of amps, And yes I will be pulling in the 100 + range to get the speeds we all want. But at 56MPH it is real easy on the amp draw.

[CircusCircus]

Sweet job Randy, As far as painting the boat, the hull is modeled after the Bud
T-5, that hull can make just about any boat on the circut today, So your options are open.

[rchippie]

Hi Randy

How strong of a servo do i need for the rudder on my 1/8 hydro ?. Thank's

[RandyatBBY]

Hi Randy

How strong of a servo do i need for the rudder on my 1/8 hydro ?. Thank's

I am running a HS-645-MG in mine on 5 cell Nimh 1400mah receiver pack

[cybercrxt]

Randy, I have been watching your thread for a while, as I am building an 1/8th scale U-31 Miller High Life with Newton plans. Well, I am to the point of trying to figure out my rudder and strut. I would love to know what brand strut and rudder you are using. I also saw you mentioned using a 1/4" strut, but then you said something to the effect that you steped the cable down to 3/16". Does this mean your propshaft is a 1/4" propshaft with 3/16" cable soldered in? Any help would be great. I will be powering mine with the same motor, and probably that hifec 240a HV that will soon be available. Thanks for any help, Mike Luszcz (252) 717-6282

[j.m.]

Randy makes his own hardware from SS, and he would probably sell you a set. A lot of his stuff is on his website. (Blew By You racing)

Don't know about the cable setup though.

Jon

[RandyatBBY]

Randy, I have been watching your thread for a while, as I am building an 1/8th scale U-31 Miller High Life with Newton plans. Well, I am to the point of trying to figure out my rudder and strut. I would love to know what brand strut and rudder you are using. I also saw you mentioned using a 1/4" strut, but then you said something to the effect that you steped the cable down to 3/16". Does this mean your propshaft is a 1/4" propshaft with 3/16" cable soldered in? Any help would be great. I will be powering mine with the same motor, and probably that hifec 240a HV that will soon be available. Thanks for any help, Mike Luszcz (252) 717-6282

I make kits for the boats. The cable is 1/4 inch and has a stub shaft that is stepped down from 14 to 3/16.
I will give you a call.

[cybercrxt]

Thanks for the call Randy. People, this is a top notch guy! Its nice to get much needed answers when you are building a complex boat! Talk soon, Mike

[crabstick]

Nice work Randy, Any video available to watch of the new beast?

in order to do that you would have to have 10c 5,000 lipos- for 20c 10,00 2p

2 10c pack in parallel = 20c

40c packs in parallel would make 80 c , do you get it?

You are wrong. Unless anyone wants to puff packs I would not follow this chaps advice.

C rating stays the same no matter how many MAH.

if a cell is 20c 4000mah you can draw 20 x 4 amp hour (4000 mah) = 80 amps
if a cell is 40c 4000mah you can draw 40 x 4 amp hour (4000 mah) = 160 amps

To get the 160 amp draw with 20c cells you would need to double the available Milli Amp Hours (MAH) for the calculation I drop MAH into Amp Hour.

if a cell is 20c 8000mah you can draw 20 x 8amps = 160

Hope this clears this up and no one has taken the previous bad advice.

Formula is C rating X Amp Hour = Safe Amp draw.