I need a simple part made

[floppywonka]

i’ve been shopping for quotes from online machine shops but realized i should ask here in case someone could/would wanna help!

basically i need a 126mm long aluminum shaft at 15mm diameter with 40-50mm holes on either end tapped to m10x1.5. the hole could go all the way through the shaft but it doesn’t need to.

this is meant as an adapter axle to make a front 110mm disc brake thru axle hub work as a rear fixed gear hub with a 6 bolt cog. i’ve already made a version of this using extruded aluminum but threading the through hole is proving difficult with my hand held harbor freight tap and, as you can probably imagine, the extruded aluminum doesn’t have the greatest tolerances.

here’s a couple photos of my mockup though, first being the hub in a frame with a qr clamping it down to see if it would work at all and the second with some 3d printed spacers to keep the hub where it needs to be on the aluminum axle.

one day i hope to have access to a lathe again but for now i gotta ask around if i want this done right. if this is something you could help me with, please let me know what it would cost! you can dm me or post here.

[Daniel_Y]

Is this correct?

floppywonka Axle v1.pdf (140.4 KB)
floppywonka Axle v1.step (10.2 KB)

Feel free to quote it around. The PDF is the drawing, the STEP is the 3D file. PCBway will probably be $60 total. Or a hobbyist could make it for fun.

[floppywonka]

this is it, thank you! i modeled it in fusion before realizing i couldn’t save it as a step or pdf in the free version so this will be very helpful.

[jimg]

@floppywonka

. i’ve already made a version of this using extruded aluminum but threading the through hole is proving difficult with my hand held harbor freight tap and, as you can probably imagine, the extruded aluminum doesn’t have the greatest tolerances.

here’s a couple photos of my mockup though, first being the hub in a frame with a qr clamping it down to see if it would work at all and the second with some 3d printed spacers to keep the hub where it needs to be on the aluminum axle.

What kind of tolerances do you need to hold – especially on the 15mm diameter? I’m guessing that this shaft fits inside the hub’s bearings…?

[floppywonka]

i’m hoping for a tight slip fit, it fits inside the hub’s bearings yes. the hub pictured has end caps that press into the bearings, so the tolerance there isn’t as tight as other hubs where the axle rides directly on the bearings

[Daniel_Y]

@floppywonka

i modeled it in fusion before realizing i couldn’t save it as a step or pdf in the free version so this will be very helpful.

That is a bummer. They are tightening their grip on the Hobbists…

[Benjamin]

Are you sure the step export doesn’t work? I haven’t exported anything in about 2 weeks but then it wasn’t a problem.

[floppywonka]

you’re totally right, i missed step in the drop down

[jimg]

I can make this part for you – but I’d need to know the tolerances for the bearing fits.

-Jim G

[floppywonka]

i’ll stick a caliper on them tonight and shoot you a dm!

[Daniel_Y]

@jimg

I can make this part for you – but I’d need to know the tolerances for the bearing fits.

The part is titled “floppywonka Axle”, the tolerances are suggested by the name

[jimg]

If you can give me the specs on the bearings (e.g. the number printed or stamped on the side of the bearings) I can probably look it up.

[jimg]

Here’s a drawing from a similar (?) Paragon through axle.

SK4025.PDF

Their toleranced dimension for the 14.95mm axle diameter is .589" +/- .005" – would that work for your application?

-Jim G

[floppywonka]

i think that should work just fine!

the hub i built the wheel with has a slightly lesser tolerance than the other hubs i had around. in the hub pictured, the end caps press into the bearings and the axle rides on the endcaps, the 15mm aluminum extrusion i used for my mockup slides through it, though it’s a little tight.
the extrusion wouldn’t go through the other hubs i have where the through axle is meant to interference with the bearings themselves.

the clamping force from the frame once the bolts are tight are what keep everything in place, so i think if you were to use the paragon ta tolerance it would work great.

how much would you need for such a piece? you can dm me if you’d rather not talk money publicly!

[floppywonka]

i double checked this evening, the tolerances from the paragon ta would be perfect! let me know what you’d need to make me this!

[floppywonka]

@jimg hooked it up with the part i needed!
it arrived yesterday and i was able to put it together today and it works perfectly.
i’m not 100% about the 3d printed spacers but they’ll be fine for the moment.
i’m hoping to get the rest of the bike together and take it for a good long ride this weekend.

thanks so much jim!