The Kakashi EMTB | 8S Lipo | E-Toxx Belt Drive | Trampa | SK3-192Kv

Hah, I assume that is not the max speed this board is capable of… Can you tell the theoretical max of your setup? Would love to find out what gearing ratio you got and what is the max possible speed with this thing (beauty)… :slight_smile:

Its a 12:72 ratio with a 192Kv motor, 8S and 200mm wheels so should be 22mph max. It was a lot of fun to ride and I’m going to take it along a bike path along the river over the weekend if it is still dry. If I can find my gopro I’ll take a video.

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I have experienced a similar problem on an eMTB I built with Dual MAX6 ESCs, twin SK3 6374 motors and 6s 16,000mAh battery . . . my solution was to develop a small board/firmware that I have placed in between my receiver and the ESCs to ‘manage’ the PWM signal.

Effectively, when the remote PWM signal is increased, my board/firmware ramps up the speed to that requested in a series of smaller steps over time (i.e an acceleration curve). This means that, even if you slam your remote to full from neutral, the acceleration is ‘managed’ so that you have a smooth (and safe) increase rather an immediate leap/‘jerk’ to the higher speed/power. In a similar manner when the brake is applied, this too is deployed in a smooth (and safe) way.

When there is a loss of signal from the remote, my board/firmware sees this as a sudden and massive reduction that is then managed to effect a smooth deceleration to a stop. Should the remote suddenly cut back in, rather than causing a ‘jerk’ that throws the rider off, the my board/firmware transitions this into to a smooth acceleration and increase in speed.

Since I built my board/firmware into my eMTB, I have experienced no issues of the type you describe and I now enjoy a relaxed riding experience as smooth as butter . . . effectively, I have ‘tamed the monster’ to a degree that my children can now ride the eMTB smoothly and easily.

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That sounds really interesting. I have a few friends who want to ride my eMTB but I’m more worried they are going to hurt themselves. This little management module, something to care to share with others?

So finally a nice and dry day I could take Kakashi out for a ride. I’m not so terrified of riding him now and really enjoyed the ride in the park. Carving is just so much fun!

Here is a pic from today (Bonus castle)

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Yes, happy to share. Take a look at my build where I show it mounted on my eMTB (http://www.electric-skateboard.builders/t/dorian-wiskow-emtb-build-trampa-holypro-17-twin-sk3-6374s-twin-max6-escs-6s-16-000mah-lipo/10859/8)

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Wow, that’s great! I believe you have built the ‘‘throttle ramp’’ function I was talking about in about 2 threads…

Will check it out… I do hope u offer some diy or ready built modules for this!

When you had the issue with bursts of acceleration, which hand was the remote in - the one nearest the back (and the receiver) or the one nearest the front (and farthest from the receiver) . . . The reason I ask, is that in my experience when holding the [Winning] remote in the hand at the front of the board I had frequent intermittent signal loss. When I changed hands and held the remote in the hand at the rear of the board the problem went away.

I always had the remote closest to the receiver. The range on the Wining remote is terrible compared to the mini remote. Since switching I have had no issues with sudden bursts of acceleration, the difference was night and day between the two remotes. The only issue I have with the mini remote is my big hands but it is so much more reliable and the range is huge in comparison though I have not tested its full range yet. I have gotten 15m away with 3 walls between me and the board and no issues with responsiveness or control. I could hear it but not see it lol.

I’m not sure if the issue with the Wining remote is the controller or the receivers. I might try pairing the remote with the mini receiver but then I’m not sure if I would still trust it.

IMO your body should not block the RF signal at such a short range, if if does then it’s just plain dangerous. I have had zero issues with the mini remote and control inputs just feel so much smoother.

Today I quickly grabbed my board during my lunch break and went for a ride after work. Just as I got to the park it started raining a little and stopped so I went for a ride. Damp grass is a little bit sketchy so no hard carving. I still managed almost 19mph according to the google fit app. With the 8S2P 10,000Mah battery pack I get about 25 minutes of constant riding on grass and averaged 12mph for 6 miles of riding before the battery’s ran out.

I’ll get to ride again in a few days if the weather is good enough. Too much fun these eMTB’s once you get the hang of riding them. I had the fear to start but now I’m getting the hang of it.

I’m going to have to think about bigger batteries at some point as I’d like to have about 30-45 mins riding time and I did cheap out on the batteries to start.

Good stuff @EssEnn … nice pic! Where abouts in the uk are you? The weather really sucks in this country doesnt it! Its a pain in the butt to scroll back up to the top now im typing, so i cant easily check, but which batteries are you using?

Just wanted to say great job on the build, the thing looks beast!

I live in Windsor, Berks. How about yourself?

I have 4 x Zippy Flightmax 4S 20c 5000Mah packs in 8S2P.

Thanks man. It is pretty beasty and a lot of fun to ride.

@EssEnn Im in Lancashire mate, the wet and windy north ! :-/ Ive ‘cheaped out’ on my batteries too but they were just a try out pack … Floureon 3300mAh off ebay … 2 x 4s packs for 30quid, 45c. Just to get me going really. Once im built up and riding/testing i’ll try some other packs and see how they perform

@smudgeUK You probably have more riding spots then :wink:

The packs I have fit perfectly in my 309 drybox and that is with some padding in the lid and base. I will be getting some bigger Mah batteries in the spring but the weather is about to go crap so I won’t be riding as much.I have a few ideas I want to try out and a second esk8 I’m thinking of building (for runs to the shops and city cruising). Summer is going to be sick though. I want to find some nice forest trails to ride!

Yep i admit there is a fair bit of countryside up here, but i think i would rather have the sun you southerners get in the summer :wink: Ive gone for an open top ‘sled’ for my battery holder, the idea being that if for some reason i require crazy range i can just rack 'em and stack 'em :smiley: Wanna jump in a thread in eleccy section about the arduino throttle idea?

If I need more range I’ll just keep extra batteries in my rucksac. I actually find that my legs get tired after 20 mins of riding but that’s just getting used to it.

Looking into Arduino’s, there is a lot the can be done with one and they look really suited for esk8’s. Time to learn to code I guess :wink:

So while winter is here and I’m a fair weather boarder, I have had time to think about my build and was thinking of building a Li-ion pack. Then I looked on Amazon and found Samsung 25R’s for £3.81 each so I just bought 80 to build an 8S10P pack. I’m such an impulse buyer!

So now I have to figure out the design, what to out them in, find and buy a BMS, nickle strips, spot weilder (or find someone in the UK to do it), charger, a dry box to fit it all and any thing else I have forgotten.

Any suggestions?

Just askin, why dont you go with 10s8p?