If you told someone several years ago, that people would use FDM printers to make gear reduction systems that handle like 2kW+, most of them would have called you a nutjob spreading blasphemy. A lot would still do that today I’m sure
Time for another update!
Went out today after reprinting the gear that failed last week.
Only problem was something with one of the motor mounts which i will redo in petg and with bigger grub screws, so that should be fixed by next week. It gave a rattling noise while braking.
After riding under those conditions i consider my inner gear drive testes and tortured, it never failed and no debris or dirt got stuck inside! Only a bit of mud on the outside of the gear but oh well.
I haven’t released anything as of yet because i’m constantly changing stuff atm. But i honestly doubt that you can fit a 63xx motor in 6" wheels with reasonable ground clearance and even if so, you would have to redo every part. Shoot me a pm if you want to work something out!
i FINALLY found my action cam so here is some video!
The terrain was much muddier than it looks in the video and i left out the many times i was stuck because that would be very boring to watch. Still no wear on the gears.
As you can see i was a bit inspired by @Nowind’s Mad Max look
Also got distance tracking to work, verified it with google maps and it should be reasonably accurate. In the end i rode 20km and used 7800mAh out of 12000, i’m pretty happy with this result.
Thanks for sharing this This is crazy D6FJo !! Sound really good (about noise) too ! Really quiet at low speed. Love it !
17Wh/km thats really impressive (for me) with all the off road trail ! (whats your VESC config actually ?)
Visualy your setup looks incredibly light man ! you weighed it ?
I got to finish my custom motor and trucks to test it your way - full 3d printed. Did I miss something or even your mount is printed ? I will reread all here cause its needed
So my VESC Config is 2x VESC 6 connected via CAN BUS and regular Firmware, 60A Motor Max and 60A Batt Max per ESC. I think the efficiency comes from the 130kv motors and the 1:5,5 gearing ratio. Since my max. speed is only 35km/h i pull less amps at cruising speeds of around 20 km/h than someone with a top speed of 50km/h and higher kv and/or shorter gear ratio. Hope that makes sense
My Max amps might be 60A, but i never dare to pull more than maybe 60% of throttle during regular riding on the street
The Board is 11kg and the batteries 3,2kg, so maybe between 14 and 15kg all up weight. My drive itself should be around 600 grams and the 3d printed box for the electronics is fairly light as well. Also there’s no big battery box and no big lights, basically im running only what’s really necessary.
I’m curious to see your project man
Yes my motor mounts are 3d printed also. Everything of the inner gear drive is 3d printed, motor mount, gear itself and cover for the gear. No major failure so far, only little things that could be avoided using different filament and/or design. Only metal parts are the motors themselfes and the pinion gears.
While riding both covers for the gears broke on the underside (because i was lazy and only used my pla prototypes, didn’t reprint them in alloy 910 so far) but the gear stayed resonably clean. Just a bit of dirt on the outer edges on the gears, nothing that would actually interfere i think
Ok, wow perfect offorad ratio with this kv (imo) sure the full shoudnt be that necessary
we got almost the same setup,… except transmission and ratio. (Im more about 30/40kmh cruising on bicyle road, and juste 4.7:1 in 9" = 48kmh and not that confortable when ceiling that topspeed on the 9" low pressure … that is the lack of efficiency I get for sure. But the setup is already insane and effective in all the road/trail configuration. I’m mean the wheels spinning the ground is my limitation crossing. I’m around 20/24Wh/km.)
So I’m conna mod it a bit your way Sir !! But I’m almost already at my maximum ratio with the 6B chain (dont want bigger wheels (for ground clearence) or smallest motor sprocket (for noise and chain angle turn)…
You could expect richting the 30km off riding so ?
Yes I’m was at 14.7kg. I think you win 1kg maybe a bit more.
I’m making a little emtb for training - I would plan less than 10kg and it could be possible with your transmission setup !
Raaah I love this forum and all the inspiration that you share guyz !!!
In fact, this project is just a Frank geared hub mixed your way for emtb and air tire all because of you once again guys ! haha (this will not be used on my 2nd trainaing board cause I guess it will weigh more thant all the actual Dart Vapor rear trucks). Waiting to lathe the motor and show you guys
I’m still getting my bearings at 20-30km/h so i wouldn’t think that 20-24Wh/km is totally unreasonable when i’m hitting 30+ km/h more often. I’m using 8" tires on ~50psi for reference.
Same here, way more power on the wheels that it can actually transfer to the ground off road
Might be possible if i stretch the lipos a bit, but i prefer to run them from 4.1V to 3.6-3.7V per cell. From the 20km i got maybe 8 of them were heavy offroad, rest was street or light offroad.
If you want to test my drive you can hit me up, unfortunately i can only provide the files as i can’t produce the drive for other people right now due to time constraints.
Sounds really great, i like this concept better than using regular hub motors without gearin on MTBs.
Ok, yes, maybe I’m not in a so bad configuration … but 4.15v to 3.55v … (70a Motor max, 70a batt max).
Yes on full flat street like in paris, I could be down to 14/15Wh/km
You get me ! It will be on honor to test it mate !! It will be on mbs matrix II pro but I will make it fit
I will share mine to you after
Are both the motor and wheel gears printed? Or is the motor gear steel? I’m sure you said this somewhere, I just can’t find it. Thanks! Amazing idea, looks badass!
The motor gear is steel, mainly because I couldn’t think of a way to attach a printed gear to the metal shaft. Might try a printed gear someday for science.