Reviving a destroyed Pint



  • "I love it when a Pint comes together"
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    Lots of trial and error, only have 4 bolt holes to put on the front end of the rails and I'll have a fully CAD'd model of the Onewheel Pint rails. Tolerances are pretty good so far but will get them tighter once I actually have some real rails to compare too.

    Last 4 bolt holes are the ones for the controller. Technically I only need 2 from one side to do the others but I have neither since... all 4 are missing so it's not easy to guess and confirm I'm right.

    Nonetheless.... nearly done so I can test her working in one piece. The temptation to stand on it is quite high... bad idea.... it's 3D printed PLA.



  • @Lia if you are thinking about getting some rails milled, you could design in the rear to increase the concave effect, and the front as well now I think about it.

    More or less length given you know your stance?



  • @stinkyface I was tempted too, don't own my own mill so the cost of getting someone else to make these would be nuts. I am slowly constructing a CNC router though so some time down the line I could.

    That said I'll be releasing the files so anyone that wants to do it can. Would be cool if we can get some custom rails for the Pint much like the XR has custom rails.



  • Starting to look like a Onewheel again.
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    Decided to have a swing at getting the board to spin the motor up but need to engage the footpads. Since I don't have any and don't really want to buy pads right now I assumed I could use the same shorting technique I've used on my XR. Alas, I don't have a pinout.
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    After doing a bit of measuring I've found ground and 3.3v but cannot confirm what the other 3 are.

    I assume lower left and lower right are pad left and pad right with centre being the led data pin... but connecting the other 3 to ground doesn't actually trigger the app to say a pad is engaged. It's possible the pads actually engage when connected to 3.3v but I don't fancy sending voltage to something unknown unless anyone can confirm my suspicions.



  • Nobody able to tell me what the pinout is for the Pint...
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    Figured out what pins trigger the Pint's footpad and decided to take a swing at the motor too. In turning it on to test the motor spins I.... forgot my rails were PLA and that the Onewheel doesn't just... gently rotate. Nope it torques it's way into oblivion, not only snapping all 4 rail sections but in doing so ripping the connector out BMS side. OOPS!
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    Anyway... this looks to be correct from what I'm able to measure and trace. Please note the lettering is for this reference and doesn't reflect any component identifying scheme FM use.
    Onewheel Pint Motor and Footpad Pinout.jpg
    No idea what J is for. It's sitting at 3.3v when the board is on much like Pad L(L) and Pad R(K). Oddly enough you can connect Pads L(L) and R(K) to either pin I or ground and they trigger the board.

    If anyone finds out more on this or has a better explanation I'd love to hear. Will update my graphic if I get more data.



  • @Lia You illustrate a degree of patience and attentiveness I can only muster in very short sprints and even then, only if motivated by significant personal gain. It's very impressive.



  • @NotSure Thanks :) I like to tinker, that and getting the pinout should save me money if I can make my own footpad.

    3D model already exists which is what I was using as a placeholder so if I can get a decent set of force sensing pads I’ll be laughing.



  • Can't get ahold of any rails through the usual channels, making my own.

    Since I've made replica rails in CAD and 3D printed to verify my measurements the next step would be to just make my own.

    Milling is tedious and expensive so I've dismissed that idea. Pre-made box section exists though and after a bit of looking I found some that's almost ideal for making rails from.
    ALUMINIUM CHANNEL U - SKU: length: 600mm, size: 1.1/2 x 3/4 x 1/8 (38.1mm x 19mm x 3.2mm)
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    The rails need an inner spacing of 32.5mm from what I've found with these come to 31.8mm. All I have to do is rout out 0.35mm either side and they'll slot on. Then I can trim the depth of the U bracket down to spec. After I'll drill out the holes, countersinking a few, tapping others and then cutting the ends at the appropriate angle to meet flush with the bumpers.

    Easier said than done?
    Maybe...

    I don't have any bits capable of chewing through aluminium with a flat tip so waiting on those to show up. Then I can make a jig to slide the rails into the router to shave off enough material on the inside of the U profile, the rest will be a cakewalk. I'll keep you all posted!



  • @Lia cool! Make sure that jig is sturdy! May wish to consider using incremental jigs if the material proves particularly difficult to rout considering the tight tolerances.



  • @NotSure Good idea, if I'm not careful I might send the extrusion into the wall if I go too deep. Will consider doing minor cuts :)



  • @Lia Lol! Literally my exact concern. Good luck!



  • @Lia this is fun. 😁



  • @Lia , what you are doing is amazing! Thanks for bringing us all along with your photos and careful documentation. {{Applause!!}}

    I do wish you could simply order replacement rails, etc.



  • @HorsePlay Love the name!
    Thanks for the compliments and taking an interest :)

    I'd love to be able to buy the spare parts direct from them. I'm at least thankful they do sell replacement parts for the bits that do get damaged with use like the bumpers, pads and fenders to name a few.



  • While waiting on some materials to properly build up a table suitable to rout my rails (tried a jig, was messy) I'm working on making my own footpads. First bit to do was the connector itself. It seems Amphenol LTW make these but from some back and forth on reddit is seems you can't buy them :(

    Thankfully it's not too hard to just make my own
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    Fit is nice and snug with it able to lock in place like the stock one. Got some thin brass tubing coming next week so I can make the contacts inside.



  • Can't catch a break, seems these Pint parts are extremely hard to come by. Tried reaching out to some 3rd party repair but been ghosted so I can only assume they don't have any.

    The controller housing is bent beyond repair let alone the mounting fins completely torn off. With the little detail I can pull I'm currently just making my own. Unsure how watertight it'll be but I can find solutions.

    Currently on the 5th test model and managed to lock in the general shape, bolt spacing, light bar position, power button, cable coupling and motor/pad holes. Need to make a top half and put in some holes for the bolts.
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    Contemplating if I should make my own top half. Would be easier in some ways and a nightmare in getting that curve between the front and back to line up. Transparent filament kinda sucks so might end up making it compatible and use my current lid.

    In regards to making it compatible with stock rails really depends on if I'm just that much of a CAD legend and guess it or if someone could swoop in and get me some crucial measurements since I have a hunch the spacing left and right isn't the same.



  • @Lia what filament you using? I would use either abs or petg and brush on some solvent then some plastic slurry. Would have to use mek for the petg tho.

    I've got a buddy that has one of those cheap $200 cnc contraptions and he used it to mill out a custom aluminum oil pan (i think?) for an old tractor. About the same size. It took a while tho. Those things are meant for wood art, jewelry and other really light duty stuff.

    I've used shapeways.com to bootleg a few Evinrude parts before. They were fairly small tho. Expensive but very effective.



  • @NotSure Curretly PLA, mostly for ease of prototyping and my printer isn't setup for any other filaments. I avoid ABS since it's not as dimensioanlly accurate as I would like without putting in the adjusted tolerances in my models. PETG might be a safe bet but will see how my PLA holds up since I get some pretty tough prints with it.

    Was in the process of making a CNC mill but it got stuck on the back burner due to other projects taking up time and money.

    Tempting to use those other services for alternative filaments. Definitely expensive though, I had a guy on Thingiverse tell me they wanted to print one of my modified OW stand designs and were quoted $700 through one of the printing services!



  • @Lia Yeah shapeways can be pricey. Aluminum SLM is pretty neat tho. Might wanna try uploading a model just to get a quote. I got a decent sized nylon part for $75 a few years back. Works well.



  • Had my sis ask me why I didn't just 3D scan the broken controller housing. 3 reasons that I'll share in case anyone else is curious.

    1. Most scanning apps either don't know how big the actual object is or isn't precise enough which will require extra fiddling in CAD after.
    2. Anyone that has ever tried modifying a 3D scan will tell you how painful it is. No flat surfaces or geometrically accurate angles make for a nightmare. Tried modifying a GoPro mount once that was 3D scanned and uploaded to Thingiverse. Spent hours just fixing errors.
    3. The housing is bent, so even if I pull the geometry I'd have to unbend it in CAD which isn't particularly easy as mentioned above.

    So I've been painstakingly making a variety of test prints along the way, slowly getting each new addition to the model dialled in. I'll of course be making some adjustments to make it more suitable for 3D printing and just a few extra bits for my own purposes.

    Anyone got any requests to add to the design?
    Tempted to make a version that will accept alternative power buttons since the existing one is simply a dome switch under a silicone cover.
    In case anyone wanted to know what the Pint button looked like taken apart.


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