I'm going to make my own hubs

ride_whenever
ride_whenever Posts: 13,279
edited October 2008 in Workshop
Hey everybody,

I'm now qualified to use the university milling and lathing facilities, so was wondering the details of making my own track hubs. what sort of metal should I use and what heat-treatments are necessary?

The plan was to use sealed cartridge bearings press fitted into the shell. Does anyone know if i can get technical drawings of a decent track hub in order to get critical dimensions such as flange thickness and shell thickness.

I was thinking 6061 alloy with a T6 heat treatment, but if something else would be better then fire away. Would steel be more suitable than alloy?

Comments

  • Monty Dog
    Monty Dog Posts: 20,614
    6061 T6 would be more than adequate for a fixed hub IME. Your best bet would be to try and get a hub to copy, particularly as you say to get the right flange thickness, spacings, bearing fit etc - suggest you look at the Formula/Systems EX/Ambrosio - basic robust model with cartridge bearing etc. Important details include the finish of the spoke holes - chamfered edges otherwise spoke breakage ensues. Also worth considering getting it anodised for corrosion resistance - you have to accommodate the thickness of the coating to ensure the spoke holes aren't undersize either. A steel hub body would be pretty heavy and you still have a corrosion problem - unless you use stainless. The hub axle will need to be tempered steel - might be better to buy a spare from somewhere.
    Make mine an Italian, with Campagnolo on the side..
  • Consider the proposed spoke pattern as well, the reason some of the billet manufactured custom hubs say no radial spoking is that the flanges are just not as strong as a cheap of the shelf forged hub from Campag or Shimano. Good fun to self build your hubs though.
  • You won't need to heat treat the hubs. Stock 6061-T6 already comes heat treated.
    Also you won't need to worry much about change in dimensions after anodisation (unless it's hard anodised). From what I gather the thickness is usually under 25 microns (0.025 mm).
  • ride_whenever
    ride_whenever Posts: 13,279
    Cheers for the tips guys, so i cannot make one with radial non-drive and 3cross drive side on the back, as the spoke will probably pull through the flange!

    How hard is anodising? Or do i need to source one locally?
  • Bugly
    Bugly Posts: 520
    how hard is anodising? You are joking?

    Basically its creating a oxide layer on the Al, generally done by passing a direct current through an electrolytic solution. Dyes are added if colourd finish is desired.

    You could leave it sitting around and eventually it will be covered with a oxide layer.
  • Monty Dog
    Monty Dog Posts: 20,614
    My own experiences of machining to tight tolerances and anodising is that you sometimes don't get consistent thickness of coating which means that press fits become interference fits - worth talking to a coating specialist beforehand. You'll probably have to hand chamfer the holes on the inside of the flanges as it's pretty tricky to get in there with a machine tool. Anodisers you'll find in the Yellow Pages under metal finishers. You could still do a radial non-drive flange - just have to make sure it's thick enough and all the spoke holes cleanly finished to prevent stress raisers and cracking. I'd strong recommend anodising or your nicely machined hub will look pretty tatty within a short period of time and corrosion will shorten it's life too.
    Make mine an Italian, with Campagnolo on the side..
  • ride_whenever
    ride_whenever Posts: 13,279
    Chamfering the holes, is that putting a bevel on the edge? It shouldn't be too hard, we have a chuck in the workshop for doing drillings round the edge of things, even for really odd numbers like 37! If it just needs a bevel then i could do that on the milling machine at the same time surely.

    As for producing a uniform coating, what electrolyte solution is normally used, I'm a chemistry Phd student so I'll just blag the power supply from the teaching lab one afternoon and run it. As for dyes, what are used to stain the oxide layer? IIRC someone mentioned that you can do it by boiling the part in food colouring.
  • alan_sherman
    alan_sherman Posts: 1,157
    Make a rear hub that will take a commercially available freehub body (shimano is a safe bet) then drill it for triplet lacing. Niche filled
  • rogerwp
    rogerwp Posts: 26

    I'm now qualified to use the university milling and lathing facilities, so was wondering the details of making my own track hubs. what sort of metal should I use and what heat-treatments are necessary?

    Check out the video on this page, it's a great "howto" on making an anodised hub.

    http://www.specialistschools.org.uk/voc ... ering.aspa

    :lol:

    Roger
    Wheelpro

    PS. New updated version of my wheelbuilding book is available. Free upgrade to existing users, just go to the WP site.