Brushless hpi baja rc-monster

[jpoprock]

Question... My goal is to one day in the next year or so to BUY a used/hopped up 5T. But for me, the allure was the idea it runs on gas. I wouldn't have to worry about it getting wet, and could drive it anywhere, anytime.

If you go with Brushless... now suddenly you have to worry about sand, water, mud, etc getting on the ESC and in the motor. So... what's so great about going BL in something like this, other than lack of noise!?

Thanks!

[snellemin]

ESC can be waterproof and the motor and batteries can be sealed. No biggie really. Lack of noise is a big plus for me, as I currently only get to play with my stuff in the middle of the night. My neighbors would be pretty pissed if they heard a lawnmower go off at that time of night.

[mohanjude]

Originally Posted by RC-Monster Mike

Looking good, Mohan. Don't forget to install a screw on the non-spur side top brace(mising in the pictures). I actually cut the middle of the cross brace off on my baja and kept the "ends" for spacing. Threadlock is your friend on the metal to metal attachments, too(the top brace, motor mount and brace plate, and lower plate connections specifically). That is a quite aggressive setup you have there, too(10s, 30 series motor, big pinion) - I hope you have a lot of space!

mike

I didnt fasten the left plate securely as I had to take it off to solder the wires. I have now firmly thread locked all the screws. On the left top plate there is an empty counter sunk hole where the screw would have gone into the rubber plastic / damper fixed to the engine. it is an awkard piece - do you think I need this?

[thomatrix]

mohanjude,
excellent video. Would really like to see a video of that beast running at max throttle...

What is your experience with the Lehners - are they worth buying for this kit? I am thinking of trying a 438kv 3060 with a 12S setup. I have 17-20 pinions that would fit this setup. Let me know your thoughts.

I already have on kit ready with a 750kv 2215 Neu motor that is going to run 10S config but I have been quite keen on trying a Lehner for some time and now it seems doable :)

[mohanjude]

thomatrix

My first ever brushless motor was a Lehner way back in 2002 for a emaxx. My jaw fell off when the e-maxx screamed on a simple 16.8v nicad setup. No Lipos those days. It gave my t-maxx 1.5 a roasting.

I love the Lehners but find them very pricey compared to say Castle. Hard to get hold off one unless you go to the factory website. But these motors are really efficient and spool up quickly.

I would always recommend Lehners if you can afford them. I think Castle / Neu are brilliant motors too now that they are making different can sizes. If you go with your setup you will have plenty of run time but compromise on speed. I am a speed junkie and that is why half the time I convert everything to brushless.

The Lehner fits perfectly on Mikes motor mount. the biggest motor will be 3060 - I have a 3080 and it is too long to fit.


mohan

[RC-Monster Mike]

Yes, I think it is wise to use the left countersunk screw - the wierd angled molded plastic piece can simply be trimmed with a dremel for clearance. IIRC, the screw is an M5 or M6 with a lock-nut on the bottom side - this will add significant support to the top plate, as the next closest screw holding the top plate own is all the way at the rear of the bulk.

Lehner motors are excellent, though expensive and poorly backed in the service department in my opinion. 4 pole is better in the Baja specifically IMO as well(more torque at startup/smoother startup in sensorless operation and the Baja ha a fairly high rollout).

In electrics bigger motors are for bigger constant loadings these cars have relative light duty cycles.

I am wondering if any of the talk about the bigger motors has taken into account the efficiency spread and torque output on those motors are; how they stack up in terms of power to weight and how efficient they are at the loads the car runs at most of the time?

There seems to be a lot of assumptions made that relate to fossil fuel ie bigger is better. Bigger electric motors arent better, they are heavier, they are more expensive and they may deliver ordinary results with more wear on other components.

Electrics are fast when there is lots of voltage, a light efficient motor and a tough esc. IME the Neu 2215 is a max for a car this size - it easily over powers it and is faster than petrol motor

[RC-Monster Mike]

Light duty cycles relative to what? I do agree with the premise of what you are saying and agree that there can be a tendency for slight overkill, but there is also fairly good reasoning behind this mantra. While average loads throughout the run may be fairly low(30 amps constant with 8s in a Baja is about 1 HP), the peak draws can be significant(5-6HP peaks have been logged on mine with a 1527 Neu motor). The high peaks yield fairly low efficiency for the short burst periods, which can generate some significant heat as they happen constantly(constant intermittent loads). The larger motors can simply dissipate the heat faster due to larger surface area, which can make them "seem" more efficient, but also can allow them to sustain better efficiency with the lower heat. When we are dealing with a couple to a few hundred dollars spent on a motor for the Baja, it means a larger motor, while perhaps not as "ideal" in some respects, is likely to run cooler and therefore less likely to fail. A larger motor is also theoretically less susceptible to thowing a rotor from the shaft when landing a jump or similar shock to the drive train, simply beacause there is more surface area at the magnet/shaft interface(I have thrown one rotor on my 1527 motor already).
I will likely continue to run the 1527 motor in mine, as I like the runtime, power and size, though I have added some heat sinks(2 Losi heat sinks fit perfectly and add a LOT more heat disipating surface area) and will add a fan if I need more cooling. If not for the heat sinking, I could easily overheat this motor and cause failure(and it is very close to a 2215 motor in overall size and power output), which is why people will tend to err on the side of "overkill". Likewise, if I ran back to back to back packs with this or a 2215 motor without cooling consideration, heat would likely win the battle - so a 2230 motor, while technically "overkill" for the task at hand, is likely to handle multiple packs on a hot summer day better than a smaller motor could.
Basically, I agree to a point, but also can respect and understand the reality of the situation and the reasoning behind it. sometimes bigger really is better(to a point). :)

Started my build, finally. Sorry about the terrible pictures, but I suck at photography. The Neu 2220 fit great. The Turtle Racing easy access diff and the GH bulks all fit perfectly. Very good machining on this kit. Usually I have to file and/or grind a bit to get everything lined up. The diff cups are Phatdad 5mm pin Crossovers.

[suicideneil]

*Fap*

Mike

Have you logged your car?

Have a think about this. At the 91% level of efficiency (most Neu 1500s and up will reach this when in the right voltage and load combination) how much change in efficiency will produce a 25% difference in heating?

[Ryu James]

Originally Posted by Electric Eel

Started my build, finally. Sorry about the terrible pictures, but I suck at photography. The Neu 2220 fit great. The Turtle Racing easy access diff and the GH bulks all fit perfectly. Very good machining on this kit. Usually I have to file and/or grind a bit to get everything lined up. The diff cups are Phatdad 5mm pin Crossovers.

is that 2220 the same size can as the 2230? i was looking at buying a 2220 last fall for my rampage and when i called Neu they said it was shorter than the 2230 but just a hair longer than the 2215. but looking at yours i would swear its just the 2230 can but obviously with different windings.

[thomatrix]

Mike - what is the maximum lenght a motor can be and still fit?

Ryu James - I am quite sure this is not a 2230 can. I have tried to measure the space based on measurements in photoshop and from what I calculated there is approximately 114.8mm space for the motor can and the Neu 2230 is around 119.4mm long so it could not fit.

[suicideneil]

AndrewG- trust Mike, and us, in trucks this size you need more motor than you do in something 50% lighter. Big truck = big motor, hence why a little S can motor being used in a maxx sized truck would fry & not be able to achieve a speed in excess of about 20mph. Since full throttle is only used sparingly usually ( due to lack of space ), the motor wont destroy the truck's driveline very easily and overpower the truck- yu just gotta learn how to tame the beast & handle the power

And Mike did state that he logged his runs with an Eagletree too.

The 2220 is 4.3 inches long. There is 5 inches of space for a motor on the kit, so a 2230 might fit. You would have to poke the wires through the chassis brace, but I think it would work.

As far as motor size, my experience is the bigger the better. I went to the 2220 because my 2215 was getting uncomfortably hot when running in grass after multiple packs. This was with a gearing of 58/16. Mike's kit lets me go down to 58/14. With a lower kv motor(and a larger one), I think I'm all set for bashing.

It's all good, watching a huge 1/5 scale leap around like a Savage Flux is one of lifes joys.