The Onewheel GTXS (Half scale GTS)

[Lia]

I couldn't just stop with the XS. Literally started planning after getting back from OpenSauce. Especially since I want something that I can truly ride at least enough to prove it works and maybe something for next years OpenSauce.

Goals/improvements for this are to:

• Increase from a 4s1p to 6s1p pack with more current available.
• Possibly get CANbus back to a flashed chip that'll piggyback the BMS.
• Use a larger motor.
• Custom VESC.
• Get the float package to work fully with it.
• Use the recurve rails instead of stock for extra rizz.
• Metal controller housing.
• Injection moulded or cast plastics.
• Maybe a custom full pad sensor.

Custom VESC sounds hard...

Cheap-FOCer 2 is open source so I downloaded, converted, modified and redid some bits to make a tiny GTS controller.

That's an XT30 btw, it's half scale. 85mm across and 64mm long. FM branding on there because it's a replica. I'm getting as many details and hiding easter eggs... like the mosfets being the ones from the Pint.

The original project was done in KiCAD. I'm an EasyEDA girl because I use JLCPCB and the library integration is just superior. Sorry (not sorry). Kinda had to redo the schematic since EasyEDA sucks at converting the files. Spend 3 days straight making that PCB after ironing out the schematic but it speaks for itself. Added USB C, Bluetooth natively and some lights that I hope to get the float package to handle.

Also got myself some test models for fitment and started tearing down a 250w esk8 motor. 100 more watts than what I got in the XS.

Basically I'm waiting to get some of the PCBs made so I can test if my VESC works. If it does I can fab the daughterboard for the motor/footpad connector and add that on too.

[NotSure]

@lia said in The Onewheel GTXS (Half scale GTS):

Especially since I want something that I can truly ride

lol omg i would pay handsomely for a working pocket onewheel!

[OneDanGTS]

@notsure said in The Onewheel GTXS (Half scale GTS):

Especially since I want something that I can truly ride

lol omg i would pay handsomely for a working pocket onewheel!

I know that this is all research for Lia's home board . . . I'd like one for each floor of my house, with the power of at least a GT, max speed of maybe 5 to 10 mph, and all cushy so it won't damage walls or furniture. :D

[Lia]

@NotSure I'd love to sell these or partner with FM to bring these to market. Though one thing I realised recently is it'd be a huge liability issue especially considering everyone's gonna try putting pets and their kids on these 😬

@OneDanGTS You'd be amazed how much damage these things still manage. Even the XS was a little terror. In testing it dented my wall, gashed my thigh and knocked over my GT nearly cracking a tile 😅 This little monster is surely gonna cause chaos. Might need to bide by my own warnings and put a leash on it.

Spoiler

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So still trying to pry the tire off the motor. It is THE WORST. Whoever thought casting the tire straight to the motor is actually just evil.

Decided to take the whole thing apart while I was at it to see if I could maybe do a custom hub casing since I'm getting the hub plates cnc'd anyway. Not sure if I will still but being this early in prototyping I might as well do a lil investigation to see if it's worth the effort and additional cost.

In the meantime I've done a first prototype of the daughterboard for the connectors. I underestimated how tight this was gonna be! I was going to stack 1x2 2.54mm pitch headers around an MT30 for the motor port but upon modelling it I realised it'd be too big for the housing to handle at this scale.

To get around it I've had to separate the hall connector and will make an ovular connector for the motor rather than a circular one.

[NotSure]

@lia said in The Onewheel GTXS (Half scale GTS):

@NotSure I'd love to sell these or partner with FM to bring these to market.

They would if they know what's good for 'em!

[Lia]

Upppppdates!
I haven't updated this in forever oh no... okay sparknotes version here we go!

PCBs came and look fab! Like better than I thought. At a glance they look like unpopulated GT controllers till you realise they're tiny!

But I had to make some minor changes so this one has been put in the prototype box. I have a hard time throwing things out and these are too pretty to go in the bin. Maybe a future art project!

The PCB use the Cheap Focer schematic but modified so it's appropriate for this build. As such I can do tests on changes with the Cheap Focer I yoinked from a VESC board that I converted back to stock.

I wanted to use this tiny BT module so I wired it up, flashed it and was able to verify this does actually work. I tried a few others and they didn't work so this was a relief since space is a premium and I want to keep it on the mainboard if I can.

I'll be using ReFloat with this setup as it has decent LED control baked in. The old float package had an issue where activating LED's triggered an error. The error being FAULT_CODE_DRV .

I traced this back to this line in the float app that set the CPU pin B7 to the LED data pin (servo) but if you check the schematic for most VESCs that pin is fault on the mosfet driver. B6 is servo which it should be assigned too instead.


So you need to reassign this in the code or use ReFloat instead of the float package as it's assigned correctly there with the option to adjust it.

This solves me needing to learn to compile a custom package thankfully...

... yeah nah I still need to 💀

I need to make a custom LED profile for the headlights as I plan on adding configurable main beams. This means I need to make changes to the package and recompile then flash it to my VESC. I hate... and I mean haaaaaate software so this pains me to have to do.

After some utter BS figuring out all the nonsense required to do this I got Ubuntu18 LTS to run under WSL on Windows and compiled my own changes to ReFloat. I will get more into this when the time comes.

If you need to compile this yourself you need to be on Ubuntu18 LTS or lower. Some of the dependencies needed are not available on later versions and refuse to install so don't waste 4 hours like I did trying.

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Back to something I'm more comfortable with. The real world... not stinky software!
(those that do it for a living are gods idk how you cope 🙏)

PCBA is gonna cost heaps so I'll be soldering this up myself. As such I got myself the right gear for it. A big hotplate and digital microscope :3

I accidentally cooked a BT module when testing so I used it to check if my custom footprint for that module was accurate and if I could solder these components. Thankfully it looks like I'll be good!

Some amazing peeps on insta have offered to send me some of their dead focers for doing prototyping on so I'm waiting on those to arrive. In the meantime I've been test fitting some components not native to the focers like a USB C port and the side mounted XT30.

The USB port took some doing as the available footprints for them on EasyEDA do not match what USB ports I can order. THankfully I managed to modify one to fit 😅

Sadly the motor I ordered wasn't great but I found an even better one and had to strip it down to make custom plates to help mount the hub plates too. Got to crack out my 6ton press to get the bearings off 😊

Modelled loooads of the board over a weekend and got most of the big bits done. Renders as always look utterly fab!

Controller housing printed perfectly and the controller fits!
As a bonus I cut my own phase brackets and soldered them to check the fit and how hard it might be to do.

I the managed to work on the battery box. Originally I spec'd it for a 6s1p 18650 pack but after some deep pondering of my orb (fusion) I realised I could barely... and I mean barely squeeze another cell and make it 7s1p!

It
Is
Tight!

Those are my test cells. Some dead ones recovered from an old ebike battery that I use for validating CAD. I have ordered some Molicel P28A cells as those have

But with the lid and some rails printed up it all goes together nicely.

And as teased in the pic I managed to replicate the GT Performance Treaded tire 🥰

I'm going to print a master of the tire in 2 halves like on the XS. Glue them together, sand and prime so they look smooth then add some sidewall detailing like the Onewheel logo and tire specs.

22 hours later and I have me a mean looking tire to go with the little guy.

I think that covers everything up until now 🥰

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Apologies for not updating this all here as often. I have been teasing bits over on my insta so feel free to follow and get those as I post them ^-^ otherwise the more detailed process shall remain here!

[NotSure]

@lia said in The Onewheel GTXS (Half scale GTS):

22 hours later and I have me a mean looking tire to go with the little guy.

Brava! Looks awesome. How soon till I can buy one on Amazon?

[Lia]

@notsure If only 😭

[Lemur]

@lia Amazing work!

[Wheelwizard]

Looks so good!!
Onewheel needs a super brain like yours.

[Lia]

Thanks @Lemur and @Wheelwizard 🥰
If they ever open up a department for "toys" I'm their gal 🙏

[Lia]

Nearly forgot to make the maghandle. That'd have been tragic.
It's surprisingly fun to play with and snaps back nicely with 2 tiny 3mm magnets tucked away in the axle block and handle 🥰

Probably gonna leave this as plastic because it looks like hell to machine which means expensive.

All the current bits laid bare and it's very familiar looking. Like you'd just gutted an actual GT.

A lot less physically going into this than the XS but don't be fooled. The lack of components doesn't mean this has been any easier. That custom controller still needs populating and testing which has taken the majority of my R&D time.

Speaking of testing. 42km/h freewheel speed ain't bad especially with just plastic test pieces and an incomplete axle 😅
With 35 amps max current available and just shy of 30v this little monster is not a toy. Still cute, but a right ankle biter if it ever ghosted.

Finally... I can safely say I have nearly completed the CAD.

I wanna go with recurve rails but I have no dimensions for the angles and where they are in the rail so I might ask (beg) FM for a rail. Also wanna give that rear pad the high kick version for extra flair. I am after all trying to make a tiny GTS so why not give it some of the cooler accessories.
I was considering FST but that's a lot more faff and I'd have to get even more creative with a sensor 😩 It's huge maybe especially since it's not like your hands could take advantage that well.