The Onewheel GTXS (Half scale GTS)
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Hiatus over but I'm still a bit slow atm. Health thingy (I'm okay don't worry just recovering still)
Been struggling to figure out a way to stop battery voltage being present at the charge port. A diode is the obvious answer but it introduces a voltage drop which when current is passed will heat up heaps. I could use a fet instead but as the voltage is always present one side I can't easily make a small circuit to block the voltage and turn on when present in the reverse. Giving up I just added an inline smd 3a fuse so if something does go wrong it blows without stopping the board working. That leaves the charge protector to do the heavy lifting keeping the 29.4v from escaping.
If anyone's got any better idea's I'm all ears :3Before trying with a battery I checked if the board could power on and validate the power being received. Sure enough it was happy ^-^
With all my fingers and toes crossed I plugged in the battery and connected it all up. Surprisingly without any drama it worked and I was able to bring the battery back up to something sensible.
So now came the fun bit. Does it go beep beep zoom zoom?
And now with the footpads set to ghost?
Lil demon child. It's after my ankles for sure! However it's got no grip at all with that PLA tire so it's about time I got that sorted. With a 0.2mm nozzle and 0.06mm layer height I have begun printing the halves of the master tire to make a silicone mould with. It's gonna take a while though at this resolution... like... nearly 40 hours per side and that's not including the outer shell for the moulds which will at least be printed in a much lower resolution.
One side is done but still waiting on t'other. Enjoy a glam shot of it before post processing 😊
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@lia awesome as usual...
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@Lia I just caught FM's short on your visit, way to go!!! It looks like you had a great time, and I love how much they loved your work.
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@lia It still blows me away with all the detail and everything is accurate to scale, if i never knew in advance it's half scale , I would swear it's full scale.
Truly beautiful work! -
Thanks guys! They really loved this one. Alec from FM came to find us at Opensauce 2025 and we arranged another visit to HQ. Also swung by TFL the day after ^-^
Kinda forgot to share the progress here. Does anyone want me to do a condensed update from the last update to now or nah?
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@lia I would love a short one, and maybe a few still pictures of the final product. The rails look so good, how did you do it? Is it paint, decal, wrap, ...? Did FM say anything about it being powered by VESC, or was everyone happy just to sweep that under the rug and enjoy your engineering skills?
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I'll try keep this short 😅
Tire was moulded using a 2 part silicone mould with 3d printed inner and outer casings to assist in registration and demoulding. The silicone was made like last time by printing a master with a 0.2mm nozzle at 0.06mm layer height. This was filled and sanded to get an even smoother finish.
That resulted in this majestic bit of rubber
Shortly after I took delivery of the CNC, 3DP and new PCBs from JLC and they looked amazing! Cost about £1k after shipping and taxes buuuuut... like look at how good these came out.
Around this time I also got a thermal camera that I started sanity checking my work. Surprisingly the hottest parts were the 5v buck converter and STM32 package. The FETs even under load and DRV chip were chilling. Likely due to the thermal considerations I took but still they barely got warm. Being Pint FETs I guess it makes sense.
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Some work needed doing for the charger so I got some parts made up and painted.
Tuning the GTXS was a bit of a challenge. I know a bit more about it since rawdogging the XS with just vanilla VESC so with Refloat installed I was able to get it to a near Apex-like tune. And as an added bonus... this
To get the right look for the rails I did some testing with the plastic ones and found I could get away with some resin printed stencils BUT the XS Series decal was way too fine to get spray paint down reliably so one of Nick's friends managed to make a sticker the right size and that worked out for it. The rest are painted on top of a light coating on the anodised rails.
Inside there's a USB PD trigger to request 20v. This then goes to a CC/CV boost converter set to charge a little over a regular 7s setup at 1A. I went a little over to account for the voltage drop from a reverse polarity diode I added that also protects the charge port from exposing Batt+. Even with a cover over the magnetic port I wasn't keen on leaving that exposed.
With the metal parts the build was getting heavy. Without it all together we were already at 3.2kg. Despite this it was able to bonk a little. Sadly the footage I have of this is hella low res for some reason. However it was enough to get a repost on stories from Bohdi on Insta so that's pretty dope.
With a few final touches and accessories to bring with we had it all good enough to bring to Opensauce.
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At Opensauce the GTXS and XS got up to some shenanigans. The Friday afterparty comprised mostly of it and Wren's VESC showing off.
During the Friday setup I was asked to help Ivan Miranda repair his " wheeled Onewheel. I assume he'll have a video on that project at some point. However after we got it working I took a few chances to get a few pics with it.
Future Motion's Alec came to visit us and left his XRC with us while he checked out the rest so we used it as an opportunity to show the scale.
SimpleFOC's robot dog came to visit again and we handed over a little award for riding the first one.
Not long after we set off to Santa Cruz and spent some time with FM. We were only in the lobby this time which unknown to us meant there were some GT XLs around the place. Regardless we had some fun helping film some silly promotional clips and showing the team the little boards again.
We hadn't finished our little trip to Cali yet though. The next day we shot up to Sacramento to visit TFL. Sadly as we pulled up Jeff was leaving as he was ill but the rest of the gang were stoked to see it. Nico especially who after tweaking some of my settings managed to ride it. I have yet to upload the videos of that yet so just trust me bro™
Sadly the video for the above was deleted and nobody knows where it went or how to recover it but TFL did a really funny sketch about Nico handing over a regular sized board to Keaton who then holds the XS. -
@lia I saw it, can confirm was awesome 😊
