running 6s question.

[ozzie-crawl]

I will try the 6s setup if it fails i have a couple of nue 1515 1y motors sitting here and some 4s packs.

[champion221elite]

As a BJ 29 owner, I can testify the factory equipped 1800 kv is too hot for running 6s. It lacks torque, and is prone to excessive heat build-up after even a short 90 second run. The wires however are a major choke point. A 90 second run heats my motor to 130-135 degrees and the wires were literally smoking at 270 degrees. Horizon Hobby actually replaced my original motor after I called and told them what it was doing.

[hydro_pyro]

I think prop balancing is a big factor. Grease choice may also play a role. I run a stock balanced prop and AliSyn TriboLube-12 grease, and I run back-to-back wide open passes on 6s until my packs are at 3.85 per cell. It gets plenty hot, but not hot enough to cook anything.

Take a stock boat on 6s with the propeller too deep and out of balance, with pig-snot-thick shaft grease, and one bad connector... Then you'll have problems.

[angrycat]

As a BJ 29 owner, I can testify the factory equipped 1800 kv is too hot for running 6s. It lacks torque, and is prone to excessive heat build-up after even a short 90 second run. The wires however are a major choke point. A 90 second run heats my motor to 130-135 degrees and the wires were literally smoking at 270 degrees. Horizon Hobby actually replaced my original motor after I called and told them what it was doing.

i have done nothing but run 6s on this boat (i only have 3s packs) and i also ran into the same issue, nothing i changed besides drastic prop sizes would bring temps down on the stock motor. the 6 pole is perfect for 4s and will run on 6s but usually not without any issues. typical motor temps with upgraded cooling/5.5 motor bullet connectors and ec5 batt connectors after 2-5 mins was 130-150 and that was with an m440 prop which has less pitch than the stock prop. my esc went first after about 3 weeks of just about every day use and pushing it hard while trying different props and trying to get the boat dialed in. the motor just recently went on me and it was a wire that frayed broke off inside the motor can. i am now running a seaking 130a hv esc and a turnigy sk3 1900kv with an m440 prop and i can run the batts all the way through without motor temps exceeding 135-140 and keeping everything els at just about 90-100 deg. also these hulls scrub alot of speed in turns without blueprinting the bottom so staying on plane in the turns to help keep heavy load and amp draw down is also a major key in keeping the boat running cool. i was honestly surprised how well the stock parts held up after lots of trial and error and re-learning FE boats since im used to building rc cars

[champion221elite]

I have already upgraded the esc discharge leads to 5.5 mm bullets since that how my 3s inventory is setup anyways. The 80 amp esc has so far stayed nice and cool. Temps have yet to exceed 95 degrees. The 1800 kv, 6 pole motor however runs far too hot for my liking.

I took Diesels advice and ordered a 1500 kv motor and will be turning a thinned/ sharpened/ balanced X442 prop. I'm hoping the lower kv motor and better prop will reduce my amp draw and solve the heat issues for good.

[angrycat]

my esc also never saw any temps over 95 but it did see a lot of abuse. i was going to buy the pb 1500kv motor but i had found a deal on sk3 motors at the time and went 4 pole instead which imo is better for 6s boats since they see high rpms and rarely need the grunt of the 6 pole which is inefficient at high rpm comparatively. looking forward to see how you like the 1500 motor on 6s compared to the 1800

[champion221elite]

It should arrive early next week. Just waiting to install the motor and prop. I have thinned and sharpened the factory stainless prop, but don't have a balancer yet. I'll post an update after I get a chance to run it.

[angrycat]

thinning a stainless prop?? that must have taken some time haha

[hydro_pyro]

It takes some effort, but I thinned down my stock prop too, and thinned some more to help get it balanced. If I remember right, it's a couple grams lighter than a stock casting, smooth and sharp.

[champion221elite]

It took a few hours and a good portion of my bottle of Jamesons, but I got it done. I will try the stock prop with the new motor and see how it runs compared with the X442. I also have an X448 and Y547, but I think those may be a bit too much prop.

[angrycat]

yeah i would believe that anything more than a x442 is going to really heat that stock motor up. maybe a s&b/t&p and DE-tongued x642 but the magic number on 6s seems to be 40mm or 42mm highly modified. i am currently running an m440 which has the same dia. as stock but the m440 has 2.1 mm pitch while the stock one has 2.5 mm

[angrycat]

and did you guys just wet sand to thin it out or file it down then wet sand smooth?

[hydro_pyro]

Working mostly on the back side, not the thrust face...

220 sanding disc on a Dremel, followed by an abrasive-impregnated soft gray tripoli wheel on a Dremel, followed by wax compound on a small felt buff wheel.

Thrust face work was limited to smoothing out the rough-cast surface and polishing it. It's very important to stay off the squared-off trailing edge in particular while sanding and polishing. I mounted my prop in a home-made jig and ran a diamond-grit file over the flat trailing edge to square it clean and sharp, as a final step.

[angrycat]

very nice, lots of elbow grease applied there

[champion221elite]

Hydro_Pyro wins. Mine is nowhere near that shiny... yet.