Gruber
HobbyMasters
M.L. Toys
KidsWheels
Gruber
HobbyMasters
M.L. Toys
KidsWheels
HobbyMasters M.L. Toys
Gruber
KidsWheels
Anything that doesn't fit somewhere else & general forum updates
User avatar
By Shambosley
#146779
Ive recently just upgraded a PW Dune Racer to a Full 24v ESC setup and its definitely slower and has less torque than when i just had ran 18v through the stock setup. Im assuming if i was to run 24v though the stock setup it would be faster but also dangerous for the gears and motors? So.. My question to you is, Does the watt of the esc effect the speed or torque? because i am using a 24v 250w esc and i wondering if thats slowing it down and what would you recommend?
By Rob222
#146784
250w is small ESC and is limiting the performance . At the very least go to a 500w ESC.
Straight 24v would destroy the gear boxes quickly with the quick starts.

If each motor draws lets say 175w on 12v then at 24v it will draw 2x that or 350w.
So both motors would draw around 700w total (max) on 24v but they are not built to run on 24v so limiting
the total to 500w helps to save the motors. That's the idea with using a 24v 500w esc on the stock 12v motors.

You can use a larger ESC (800-1000w) and limit the throttle with a physical stop or a potentiometer (limit the output
to the motors at about 18v). I did this and it worked well until I got greedy and removed the throttle stop to "test" the speed at full 24v. I got lot of smoke from the motors quickly. We went back to the 18v limit.

https://www.electricscooterparts.com/sp ... llers.html
Last edited by Rob222 on Mon Aug 14, 2017 2:13 pm, edited 3 times in total.
User avatar
By Shambosley
#146786
I had and extra 24v 500w esc that I put in it but I wAnt more. Anyone know where to get just the 1000w controller they sell in the kit at eastcoastpowerup,Or a good 1000e ESC in general? thanks in advance!
Last edited by Shambosley on Mon Aug 14, 2017 5:30 pm, edited 1 time in total.
User avatar
By Hammer-fm
#146787
The torque game all comes down to how much current the motor gets.

A stock 550 motor stall current is 60A each. At 18V this is going to be 50% higher (90A). That's 180A if you're running two motors. Even considering switch & wiring resistance, when you hit the gas pedal on an otherwise-stock Dune Racer it's going to try to pull >100A. This current draw will rapidly decrease as the motor starts spinning due to back-EMF in the motor windings.

Most of the "500W" ESC components have a 25-35A limit. This means that when you push the pedal, only 15-20A can go to each motor (instead of 50+), so your off-the-line torque (and acceleration) ~40% of what you had in stock 'unlimited' form. The plus side is that also means your motors and gearboxes will never have full torque applied to them, but it means it's going to be much slower off the line (assuming you weren't just spinning the wheels in both cases).

A 1000W ESC should have a slightly higher current limit, but they usually get the 1000W by increasing voltage (to 40+) instead of current. That doesn't help you here.

Example 500W unit from Ebay (peak = 24V * 28A = 672 watts):
Rated Voltage: 24Volts
Rated power: 500 watts
Under Voltage Protection: 20V±0.5V
Current Limit:28±1A
Usable Motor: 24V500 Watts


Example 1000W (peak = 36V * 32A = 1152W):
Feature:
36V motor brushed controller
matching motor: dc brushed motor
motor brush controller for Electric bicycle & scooter
rated voltage: dc 36 v
Current limit : 32A
rated power: 1000 w
Under Voltage Protection: 31.5V

The EastCoast Powerup website does say their 1000W ESC has a 50% higher current limit than the common 500W one -- a larger differential than the two ebay units I pasted above.

If you still want the features of ESC -- variable throttle, gearbox protection, etc., then I'd recommend getting 7-series motors instead of spending money on a bigger (but only slightly faster) 1000W controller. A Mabuchi 8016 (ebay) will give you about 40-45% more torque than the stock motor and at 24V will be slightly faster than your current setup at 18V. And it will handle higher speeds better (better dissipates the heat). You can also get the Banebots motor (Mabuchi 8514), or you can get the cheapo option (Nichibo 7013F - $3/ea -- see the Motor sticky thread).

If you don't care about any of the ESC features then the simplest is just to go back to straight 18V w/o limiters.

(and yes, 24V without an ESC or some other limiter setup will just break stuff)
User avatar
By Shambosley
#146788
Well put my friend. I dont care about all the ESC stuff but man did I put a lot of work into making a variable speed setup work for my limited knowledge on eletrical wiring. I would like to upgrade the motors indeed, so above listed is what you would reccomend? Only reason I havnt touched the motors is becuase I know nothing about pinion gears or gearboxes in general.
User avatar
By Shambosley
#146790
So I went ahead and ordered some 755 banebot motors, i think the shaft diameteris 5mm, my stock motor pinion wont fit on there will it? And how do I go about getting one. It should be more clear the ESC will not make it go faster even though you can up the volts hahaha. Would i have more speed or torque(mainly torque) if I went back to 18v unlimited form with banebot 775 motors?
User avatar
By Hammer-fm
#146791
What you're looking for is a 16T 5mm 32DP pinion -- that's 16 teeth, for a 5mm shaft, 32 diametrical pitch. The stock motors have a 3.125mm shaft. I got a few of these and they seem to be fine:

http://www.ebay.com/itm/HobbyStar-32DP-Pinion-Gear-16T-Hardened-Steel-5-0mm-Bore-5mm-32-Pitch-16-32P-/171955600929?epid=525168309&hash=item28095a3e21:g:-0cAAOSw8GhZhNDf

When you get the motors you'll need to grind a small flat in the shaft (so the set screw has something to set against). You'll need to fit it into the gearbox with the top removed and set the gear in the right height on the shaft.

The stock motors have a plastic ring around the motor collar (where it goes into the gearbox). You want the same thing for this -- it turns out the outside diameter of a 1/2" PVC pipe is exactly the right size for the gearbox shim (0.84"). You have to drill a 11/16" hole in it, then cut it to the right length. This ensures the motor stays centered (and thus, the gear meshes correctly).

This has more information, though I found I didn't need a spacer for 7R gearboxes (which you likely have):
http://forum.modifiedpowerwheels.com/viewtopic.php?f=30&t=1201

i don't have any pictures of the PVC-pipe shim.
User avatar
By wesleyb82
#146884
I believe the factory plastic ring around the motor shaft prevents the motor to be mounted to the wrong gearbox and serves no other purpose
User avatar
By Shambosley
#146885
So I dont need a bushing to keep the motor and pinion gear centered, the screws holding the motor on will suffice? I dont need a spacer to align the pinion and the first gear either, its seems to line right up.
User avatar
By Hammer-fm
#146933
I believe the centering collar is absolutely required for reliable operation. I wouldn't expect the friction along the motor-to-gearbox interface to be sufficeint to prevent the motor from moving laterally and changing the pinion-to-first-gear spacing, and the screws aren't a tight enough fit in the gearbox to prevent this either. If the motor shifts and that spacing opens up it can result in stripped teeth. That said, maybe it's sufficient under normal (limited current, no sudden impacts from ruts/etc) conditions.

None of that explains the 'smoked a Banebots in ten minutes" though. You should not need cooling fins/heatsinks with a 7-series motor with an ESC (unless the ESC has a > 80A limit and you're doing a lot of offroading). Any chance it was in one-wheel drive (eg. perhaps one of the pinion set screws worked loose) -- this would send all the current to one side. Does the motor turn at all? Unusual coloration, etc?

(BTW, when I say "I believe it's important", that's based on my limited mechanical engineering -- I'm an EE and my ME education is limited to a few statics classes and real-life experience with race cars and other fastener applications. Wesley has probably run this stuff on 10x as many power wheels as I have, so if it's worked for him it may be fine. But it doesn't seem right..)
User avatar
By Shambosley
#147056
The PW is completely ran off road, on grass. I dont beleive the pinion set screw worked its way loose, it dremeled a flat spot on the shaft and put lock tight on screw. No discoloration of motor, motor will turn but the really rough, the copper wires broke to peices as did the motor fan. Ive been running 2 titans 775s with no change to anything else without any problems so far. Not sure of the ESC amp limit.
Where to find batteries

I like to take computer UPS's and use the batterie[…]

I’m trying to find headlights for this Jeep. They[…]

Most of the ESCs should have current limiting buil[…]

Lightning McQueen wiring help

Collage_Fotor.jpg

HobbyMasters Udemy Course