esk8.news esk8 calc donate now

4WD Heavy Duty Offroad Monster Board - VESC, c6364 sensored, 12S30Ah, 10kW

TIME TO MOVE MY OLD THREAD OVER HERE:

Finally here is the buildlog of my 4WD heavy duty offroad monster board.

As always, all 3D-data is available at Thingiverse: http://www.thingiverse.com/thing:1900477

This is what I’m talking about:

The current setup is:

Next Redux Deck MBS Matrix Trucks MBS F5 Bindings + FX Pro II Heel Straps 4x Mefo Ice Slider 11x4,50-5 on 125mm Gokart rims 4x VESC 4.7 modified with heatsinks, 0,5mOhm shunts, extra TVS diodes and lots of caps 4x c6364 with internal hall sensors 2-stage 8:1 - ISO-04 chain reduction 32W LED headlight 12s30Ah lipo (10Ah+10Ah+10Ah packs) 3D-Printed NRF Hand Controller (VESC NRF Hand Controller)

Just the right toy if you want to have fun when you want to go really offroad:











But let’s go back to 2015 when everything started:

23 Likes

Infected by the eSk8-Virus I wanted to build my own unique board.

When I started this project, the first designs of the VESC were released but not commercially available. So I had to order the PCBs somewhere in Hong Kong and a bunch of electronic parts from mouser and to assemble my VESCs by myself:


I bought a cheap, used MBS Pro90 board of ebay and some MBS Matrix trucks. Unfortunately the board has only 20 degree tip angle so I had to use angled wedges to get good steering capabilities.

As my intend was to go really off road, the ‘normal’ mountainboard tires seemed too small and I decided to use 10" mini quad tires:




Because I tried to build this beast as light as possible I started with quite small Hobbyking NTM-5060 motors. Of the box they have way too high 270kv so i had to reconnect them to WYE resulting in 155kv. To get the desired 40kmh with those big tires I needed a reduction of 8:1 which was easier to archive with a 2-stage chain reduction held together by laser cut aluminium sheets.
image




15 Likes

Have never seen something like this before :slight_smile:

What is the weight of the monster?

1 Like

To connect 6x 4s5Ah lipos to 12s10Ah I made a power distribution board with included lipo alarms and loop key:


That is what you get if you let your friends ride…:joy:


This was the first rideable version in 2015:

Took it to the German eSK8 Championship https://www.esk8b-dtm.de/?language=en but even if the track looks like a desert and the board looks like escaped from Mad Max the smaller boards were better to handle on this course:



Always wear a helmet!!! (at least the guy behind the camera did…)


10 Likes

One of the first improvements was to get rid of those crappy voltage based battery meters. Instead I’m using this coulometer until now without any issues:


It can be programmed to any battery capacity and to different shunt resistors to match almost any setup. It sits together with a bicycle speedometer in a 3d printed case on top of the VESC enclosure:




The next big improvement was to switch to sensored. Therefore I used 3d printed housings for the hall sensors:






The holders sit on the motor holding plate and can be adjusted to the optimal position:






6 Likes

After two sets of tires in maybe 5 months, I had to look for a new type of tires because those mini quad tires are really CRAP:




I tried to find something in a similar size but had no success and had to go for the bigger and heavier Mefo 11-4.5-5 - gocart snow tire:




To fit these tires on my Matrix trucks I had to machine some custom hub adapters out of aluminium:




After this mod the board started looking like a monster:

14 Likes

Love seeing this here. Thanks for bringing this monster over!

9 Likes

Luckily (for you) I had to open my VESC enclosure yesterday, because I had some connection issues with one of my hall sensor plugs.

Cable tension relive:


NRF Transceiver & BT Module and 14 ultra low ESR caps:

6mm bullet connectors for the VESCs:


Microswitches to add the possibility to disconnect every single VESC in case of a fault from the CAN bus:


20µF on GVDD, 0,0005 Ohm shunts for up to 240A current measuring ability, NRF extension and BT directly soldered to the PCB:


VESC with heatspreader soldered to the common positive FET connections, 54V TVS diode on top of of the big ceramic cap. Hard to see under the heatspreader:

With these mods the 4.7 VESC run fine at 120A motor current:

10 Likes

@Duffman
My man
Great to see the awesomeness here :+1:t2:

5 Likes

The first testride with the new big tires was a lot of fun, but they were throwing so much dirt at me that I had to build fenders. Therefore I had the mounting plates cut from 4mm Alu and the fenders from 2mm Alu and bent to shape:


The two parts were riveted together and bolted to the gear housing:


Spray painted and mounted:


Additionally I finally printed the cover pieces for the gear housing:


Completed:

9 Likes

:heart_eyes: The duff monster…

2 Likes

I rode around 500km offroad over the summer 2015, when fall came and the days got shorter and darker I had to build a proper headlight. Before I had done some experiments with flashlights but was never satisfied because there was always too much light directly in front of me and always to less light in the far field and in the corners. I found the perfect solution in a 32W (105 lm/W) high power LED strip in combination with a cylindrical lens.

High Power LED Strip: http://www.leds.de/en/LED-strips-modules-oxid-oxid-oxid-oxid-oxid/High-power-LED-strips/SmartArray-L25-150W-25-LEDs-neutral-white.html

Datasheet: http://www.leds.de/out/media/Datenblatt_SmartArray_2014_V11_ENG(3).pdf

LED Strip Optics: http://www.carclo-optics.com/optic-12750-300mm?opticfamily=strip%20optic

This produces a oval shaped spot, wide in horizontal direction and narrow in vertical direction:


The LED strip and the lens are held by a housing stacked out of laser cut aluminium sheets:

The two different parts in 1mm and 3mm thickness are alternating stacked to produce a housing with heatsink fins:


The stack is held together by M4 threaded rods and Locktite:

The LED strip is sitting in a milled slot:


Completed housing with LED, lens and wires:

The spot has some chromatic aberrations but normally you don’t see them, only when pointing on a wall:


The 32W LED puts out a huge amount of light. It is sold to replace a 150W halogen tube:


The LED housing is mounted on the12mm stabilization rods which connect the front motor holding plates:


To power the LED I’m using a Meanwell LDD-1000HW - a current regulated 1000mA 56V step down regulator which is located in my ‘cockpit’ (black brick in the lower left corner of the last pic):


According to the datasheet the strip produces 3283 Lumen at 32W power and 85°C temperature, which results in 103 lm/W.

9 Likes

Back to my 7 layer burrito ;-):

Because the new tires are gocart winter tires and can officially be equipped with spikes I simply had to try it and bought a 1000pcs set of ‘screw in spikes’:


Each tire can take 132 spikes, at 4 tires this means screwing in 528 spikes and takes about 2 hours:


Ready to ride:


After a short testride:


After a real ride:


In 2015 we had 2 weeks of snow (and 2 weeks of fun!!!), afterwards I simply screwed the spikes out and was ready for spring again. Unfortunately we had no snow in winter 2016 so I couldn’t use them again…:


This was (for reference) a testride without spikes:

And this are some rides with spikes:

9 Likes

I wanted rearrange my VESC and cap wiring because I found out on my other builds that short connections and good ESR can keep your ESC cooler and improve your reliability. To keep wires short, I had to stack the PCBs and the caps and just filled the remaining space with more caps…

No matter how many caps you add, they won’t help you with voltage sag, but can compensate for the inductance of long battery wires, which would induce high voltage spikes when switching at high currents.

This is the best and most detailed description of ESR I read in a long time: VESC FAQ | How Many Capacitors & What uF

I’m running 12s 10Ah (3x 4s5Ah x2) per ‘layer’ and can stack up to 3 layers for 12s30Ah. Everything at 20c constant / 30c burst.

To power everything up I simply use an XT90S antispark loop key with a little 100A ANL fuse

This holds up very well against the 250A burst current I am pulling at maximum like in the beginning of this video:

I always forgot to show you one little detail, which imo is a big improvement over the stock MBS spring truck system.

Instead of using a spring and an egg shock (dampa), I’m using an elastomer compression spring to get better / softer steering capabilities and better dampening of speed wobbles.

I’m using E 1556/ 32 x 63 from Meusburger (https://ecom.meusburger.com/e/index.asp?id=2298&rnd=32287 ) original manufacturer seems to be Effbe (http://www.effbe.de/index.php?id=30&L=1 ).

In combination with some simple aluminium bolts it is a drop in replacement for MBS and Trampa spring trucks.




This is a comparison of the usual spring/damper combination and elastomer springs:

I’m running these in my Monster an in a Trampa/Next crossover board of a friend for more than a year and am totally satisfied with the feeling of the ride.

Later on Trampa copied the design and started selling these as ‘bullets’…

If you are interested, you can get the original here:

7 Likes

I bought a cheap, used MBS Pro90 board of ebay

Where in hell you got this one, Bro? :open_mouth: …and cheap!! :open_mouth::open_mouth: Is basically unobtanium!

@257, you got to come see this one!!

2 Likes

Yeah man, this was in 2014 / 2015… This build grew for quite some time…

As you can see in the videos I rode this beast harder and harder. Whenever something broke it got replaced or rebuilt with something stronger:

Early 2016 I started my second build based of a MBS Core 94.
Because the MBS Pro 90 deck had more pop, I switched it to the small stunt board.

The Core 94 did not survive long on the monster and broke in the middle.
Nevertheless I filled it with CA glue and rode it for some more months:

So it was time for a complete rebuild:




One of the custom axles broke, so all of them were replaced by ones made of high strength steel:



The welds in the trucks failed, so the trucks were machined to fit another set of bushings:


The small NTM5060 motors survived the torture but were upgraded for beefier, diy sensored c6364 motors. Bigger motor won’t fit because of the headlight and wold also crash into the deck while turning.
Nevertheless they take 120A motor current very well and don’t even get warm in this 4wd setup:




10 Likes

This build is great man, truly one of a kind. I remember being super impressed when i saw this thing running at Paris.

Cant wait to see what comes next.

5 Likes

6 yrs lead, still on top !
Thanks for sharing again, it’s so inspiring :v:

3 Likes

It’s the man the myth the legend @Duffman!!!

Wish I can see this board in person some day!

6 Likes

Come over for a trip. :wink:

2 Likes