Haha no way I was thinking about this.
Sounds simple, is it just 3 mosfets?
Right now, because of the complicated approval process for the application weâre designing it for, itâs a manual change based on swapping adapters for either kv. In the future, once weâve established a basis as a vendor (in order to streamline approval) weâre thinking about custom escâs that can switch the kv on the fly as youâre describing.
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Ok so like all the phase wires go out to the ESC and it has a stage where it configures KV. Thatâs a innovative way to do it!
Combine that with 15S and it sounds like a dream.
Exactly! You get the benefits of high kv for upper ranges of speed without losing the torque of low kv when you need it.
I was hoping to make a version that was an interstage between motor and vesc and communicate the switching using data from the uart but unfortunately the switching would require changing motor parameters on the fly which I donât think is possible with current vescs⊠
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I mean at least you would know when it would be doing a super brief pause to change kv because you activated it via the remote.
Assuming it wouldnât be an automatic.
Unlike if something happens and you have no idea going gung ho.
It would be nice if it tied into the lighting system to let you know which mode itâs in. Actually a light for VESC overheating would be cool too.
My goal for the custom ESC is for the transition between each kv would be automatic and completely seamless - the control theory to make that happen would be interesting but a man can dream, no?
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So you have two things going on here, changing the axle offset and changing the height of the roll axis.
For the axle offset,
Left is like a zero rake RKP. It will feel very even and plain.
Middle is around the range of offset that a TKP has. It will feel pretty active.
And right just has a huge amount of offset, it would be very divey. Probably feel like a surf style carver in comparison to the far left.
For the Roll axis height, well thatâs ultimately going to depend on the deck theyâre put on, the angle and the foot platform height relative to the base plate.
For the effect on the feel adding roll axis is functionally the same as adding risers or drop.
But going from left to right you have lots of roll axis height down to very little.
The far right truck mounted on the deck in the other pictures would I think be pretty un-ridable.
You have just a ton of axle offset which makes it really divey, but also the roll axis height is so low that the foot platform height could end up lower than the roll axis. So it would be like a double drop, and your weight on the board is kinda like swinging in a hammock.
What you risk happening is getting trapped in a carve where the Gâs are keeping the hamocking deck swinging out and because the axle offset you donât have the control authority to get back out of it.
But it would feel very stable going straight.
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Todayâs 5 min cad idea.
i have been thinking about how to mount motors on my upcoming 4wd build. im not keen on having them hang of the front and back of the trucks, exposed for easy scratches for damage. in a race environment this is especially likely if you have contact with another board, part of the course or even another rider.
Then i remembered this video
Which seems super smart but looks hideous.
keeping the motors up at this angle protects the motors from impacts and also keeping weight further in towards the middle of the board helps reduce angular momentum.
I wondered if i could use the compact gear drive to do a similar setup but try and preserve the compact look that the gear drives provide. these are the results of my 5 min mockup to test that idea.
motor is mounted in tight above the hanger using the 4:1 geardrive.
The whole drive tucks within the wheel radius
Everything is protected and compact.
In order to maintain full steering range I think it would require modifications to the hanger, base plate and possibly deck ends but it would look slick as fuck.
Ultimately i think would would need custom truck parts, i just used the trampa ones here as i have the models already but i actually think the MBS ones would be a far better starting point for this as the shock block system is much narrower than the trampa spring settup.
What you guys think?
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Amazing, if you went this far, you could do some hubs that have the gears and part of the motor inside the tire
It would be probably expensive due to needing large and thin bearings
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itâs one of the drives/projects Iâm thinking/drawing for some yrs now ⊠like you say, just 
stop me for now.
Hub geared AT motor truck
Be able to put the big bearing on the stator already cost me around 280⏠⊠without the motor itself (and modifying them myself before, with my Dremel to be able to let the phases wires free).
I calculate the all drive train (2WD) around 1000âŹ, with all custom CNC parts.
So its on pause for a year or more âŠ
this is using 8072 motors, but the ground clearance should be even better with 63xx !
Or mad with a quad 50xx !!
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Awesome topic mate !!!
Yes, and maybe the new 3Dsas precision hanger ?
This looks awesome. I bet if you could find some others to join towards a batch of 5 you could brings the per unit cost down significantly.
And yeah i have been eyeballing the 3dservisas hanger. it may be perfect for this project if i can design a narrow mount that is compatible. the only thing that puts me off is that i love how my current trampa barrels setup feels and ive never ridden the MBS shock blocks so its a bit of an unknown risk.
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haaa⊠yeah ^^ itâs hard to choose, I would get one of all to choose depending on the ride session⊠(but I had never tried the Trampa barrels)
yes and yes ^^ but please make it happen, it looks f”c£!ng amazing !!!
This is next gen. AT drive ! (IMO)
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I want to see a deck with wheel flares like an indy car but for the motor cans. My biggest reason to move to gears was the enclosed system and short motor plate distance.
2020 is going to be a great year for the eMTB
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What about the wheel gear with teeth inside the ring? You can move the motor to be tangent to the hangar and get a better gear reduction, plus better meshing
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Problems I see are restricting motor diameter and gear ratios. The smaller the wheel gear count, the smaller the diameter it gets.
I like the concept of a direct geared axle motor that has key fit motor and wheel pulleys (like press fit).
That just becomes a direct drive without complex rotational gears and up to the motor kv I guess?
Would still be badass if someone could lock down a âgolden ratioâ that fits most everyone.
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In other words planet gears?
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Ahh never knew that was the magic term. Thank you.
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generally these systems tend to be very noisy as the outer ring gear has large exposed surface that can resonate.
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the problem is that there are so many different use cases. a 2wd street baord (eg kaly @4:1) needs a different ratio to a 2WD ATB (eg trampa @~6:1) which is different to a 4WD that may only need 3:1
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