how i made my freehub/ disc adapters

[Sparky]

i took yall's suggestion of using a bottom bracket cup and welding it all together. it seems to have worked. course, we will have to wait for the streetfighter to be finished before i can test it. but it looks good.

for the disc brake mounts, i used a compass to draw the circles on a plate. i drew 3- outside, axle diameter, and where the bolts needed to be. then, after i cut them down, i drilled out the center, used a dremel to grind it (using my circle to keep it centered). then i marked 6 evenly spaces places on the "bolt" line. which is easy to do with a compass. the radius of any circle is perfect to "walk" the compass around the circumference 6 times. leaving 6 perfectly spaced marks. i drilled on those marks.

then, assembly. i used a 5/8ths bolt to clamp my BB cup, an axleshaft collar, and the disc flange together. in the picture you see a second shaft collar, that was to center the BB cup. turns out it was a perfect fit inside the cup.

drilling and tapping was easy. i swear, sharp drill bits are the best thing ever.

heres pics. enjoy!

http://i14.photobucket.com/albums/a318/sparky96181/quadpics045.jpg

http://i14.photobucket.com/albums/a318/sparky96181/freehubadapter012.jpg

http://i14.photobucket.com/albums/a318/sparky96181/freehubadapter015.jpg

[Sparky]

http://i14.photobucket.com/albums/a318/sparky96181/freehubadapter017.jpg

http://i14.photobucket.com/albums/a318/sparky96181/freehubadapter023.jpg

i gots more pics and can explain better if needed. all told, it wasnt hard, and it seems to be straight and have no wiggles or wobbles. i either suggest it to everyone, or i got REALLY lucky.

[gbbwolf]

Made my brake adapter with 2.5 inch round washer,and a 3/4 shaft collar.
Could have welded the freehub adapter to it I guess.

But I wanted to set up my dual disc brakes at the same distance from the outside tube.

Just so it looked symetrical from the rear.

I swear I will find a camera soon to replace mine.

Nelson

[gbbwolf]

Was just sitting here thinkin of my brake adapters.
And low and behold.
Forgot I hung them from a shepards hook in the front yard, when I painted them.
Just looked out they are still there.
Been a week since I made Em.

I think the paint has cured by now lol.

Nelson

[AtomicZombie]

Hey hey, my kinda hack! - great stuff. The more you put your noggin into things, the less they seem to cost.

Cheers,
Brad

[gbbwolf]

Yeah learning to get by on the cheap takes some practice.

[Sparky]

well, it helps that i do stuff like this for a living. im a goldsmith, so complex layouts and precise hole- drilling are pretty easy to me.

heck, it was nice to use a tap that i didnt have to pick up with tweezers!

[TheKid]

I believe I posted that method a month or so back. I came up with it last year, but haven't had any use for it, so I never got around to building it. Thanks for the vote of confidence. It looks like it will work just fine.

[TheKid]

Yes, here's what I posted on May 11th. I didn't mention the shaft collars on this hack, it was using them to align the hub washers on the axle, and for making a disc brake adapter without the freewheel adapter. (That's what I'm using on the hauler)


Why not make them yourself? All you need is the flat bar and a left side BB cup. Cut the disc, grind it round, drill and file the center hole to 3/4", drill and tap the disc holes, (Or use nuts and bolts) file out the BB cup center hole from 11/16" to 3/4", then weld it to the disc. You could use the BB locknut as a spacer. If you don't mind filing hardened steel, you could use the freewheel side of a hub instead of the BB cup

http://forum.atomiczombie.com/images/misc/progress.gif

To which Brad replied:Have you tried it yet? I had no problem welding a hardened crank arm, but I know the BB cup is super hard steel - the kind that will chip if you hit it with a hammer.

I wonder if it would hold up to the forces of pedalling and braking, which would be extreme, especially between the BB cup and axle where it is welded?

I might just have to test this out one day.

Brad


Well Brad, now neither of us will have to try it. If it doesn't work, I'm sure Sparky will let us know.

http://forum.atomiczombie.com/images/misc/progress.gif

[Sparky]

yessir, thats where i got the idea. major kudos to you for posting it, otherwise i would be waiting on the machine shop to call me and tell me its done. course, that also means i get to blame YOU when people laugh at my ugly welding!

of the 2 BB cups i had to work with, one was black steel, the other was chrome. a test with a file confirmed that the chrome one was of course super hard. i used the other one. HOPEFULLY it wont explode.

[TheKid]

Actually, they're both super hard, and you can also blame me if it doesn't work. However, rule # 1 of experimenting is, never be your own guinea pig, which is another reason why I didn't try it myself.:D

[gbbwolf]

Thought the chrome one I had was hardened steel,seeing how I used it to rethread a bottom bracket.

I dont think I have any that are not hardened though.
Never saw a black one in those 16 bikes I cut up.

But then I bought 3 3/4" adapters from Elliot so I did not need to look for one.

Oh and TK thanks for the idea though that is how I decided to use shaft collars and a 2.5 inch washer for my brake adapters.

Was Looking in the hardware isle when I saw shaft adapters and started thinking back to that thread you posted.

Nelson

[AtomicZombie]

I would bet the welding process aneals the metal somewhat. If you have an oxy torch, heat the hard steel red hot then let it cool very slowly - this will also help.

Yes, I do remember that conversation now.

We shall call this method "TheKid's Freehub Hack".

Brad

[TheKid]

It's amazing what you can come up with when you don't sleep.

[gbbwolf]

Sleep is for the weak..
What is SLEEP.
Oh that 4 hour thing I do once in a while.

[TheKid]

I tried using the freewheel threads on a hub to thread a piece of pipe, since it is made from hardened steel. It seemed to work great, but alas, I was fooled because I didn't ream the pipe first. It was 1 1/2" OD x 1 3/8" ID, and that's the size of the hub. I'm going to try tomorrow to find tubing that's slightly less than 1 3/8". 1 1/2 OD with .083 wall would be ideal.

[marcusj]

I basically really like this whole approach but hit a small snag because I'm in metric-world (Europe). My rear axle is 20mm, not 3/4". Since I'm making a Kyoto Cruiser, at least one of those cups is going to have to clear the 20mm shaft.

Those bottom bracket cups have a hole that will just take the 3/4" shaft. No problem, I thought, I'll just pop the cup in my mini lathe and whip off that extra 1mm or so to clear the 20mm shaft.

Ha!

My boring bar just deflects away from that cup inner diameter as the hardened steel laughs at me. Duh, these are bearing surfaces so they're going to be hard. Hmmm.

I am thinking that the bearing cups are going to take a quick trip to the local metalworking workshop and visit Mr Gas Axe. A couple of minutes with the gas cutting torch should open up some ugly but usefully large holes to clear the 20mm axle.

Or it's on to plan B (actually, on to about plan J, I think, by now) which is to take a couple of inches length of my 35mm stock (see how screwed up us Brits are with metric and imperial!) and bore it to 20mm (a PITA process with mild steel on a mini lathe) and cut the 24TPI imperial threads for a couple of cm along the OD. I think I'll order a couple of large blacksmith's drills on ebay now to prepare to save time on boring - I have been putting that off for ages, but will be a real time saver in the future. Boring is, well, boring, with a 350 watt motored lathe when cutting steel.

[John Lewis]

If you heat the cups to red heat and allow to cool slowly they may become soft enough to work. In the old days we'd soften hardened steel by putting it in the fire until red hot and then bury in ashes to cool overnight. That might not help the thread though. I think a torch is the go and keep the flame away from the threads.

Alternatvely you could grind them out carefully with a Dremel or die grinder. If you do it in the lathe make sure you cover the ways and all and clean up after.

John Lewis

[Richie Rich]

I've had good luck using a tapered grinding bit in my drill. (See attached pix).
It took awhile and there wasn't much left of the grinding bit, but it got the job done well enough so that I could slide in 5/8-inch axle.

Give it a try...

...Richie...
.

[marcusj]

OK, looks like a sensible approach for those trying to use this method and working with 20mm stock for the axle.

First: Anneal the part by placing it for a while in a really hot fire (like in some red hot coals) and then let it cool gradually - perhaps just let the fire go out with the part in it. (This might work well for me by just slinging the part in our wood burning stove at night and then collecting it in the morning.)

Second: Then try in the lathe and if still too hard to turn, then grind with the conical drill attachment. The annealing should at least make the drill grinding job less painful (and I don't like running lots of side load on a drill - their bearings weren't really designed for that, I believe).

Thanks!

(Also trying plan J, too. The first attempt doesn't fit - the thread pitch is correct (despite my lathe being 'only metric screwcutting' - I have a very, very close approximation to 0.06%), but either the total OD is slightly too big after machining or I didn't cut enough metal. Only goes on about 4 threads and then gets stuck. Perhaps I needed to take more spring cuts. Shall try again this week and not take the part out of the chuck until I've managed to get the freewheel on all the way!)

[marcusj]

Also trying plan J, too. The first attempt doesn't fit - the thread pitch is correct (despite my lathe being 'only metric screwcutting' - I have a very, very close approximation to 0.06%), but either the total OD is slightly too big after machining or I didn't cut enough metal. Only goes on about 4 threads and then gets stuck. Perhaps I needed to take more spring cuts.

Filthy bodge complete - shaved a smidgen more off after doing the best job I could to remount the short part in the 4 jaw chuck and re-align the cutting tool with the thread in the part. Freewheel now spins on like a dream. So, now I have a short, half-threaded cylinder to drill out 20mm, cross drill for the grub screw and weld onto the brake mounting flange. Good compromise approach for those with a small lathe - turning down a single lump of steel the diameter of the brake flange to the 1.375" for the freewheel thread would have taken weeks.

I just need to make another threaded spigot for the other freewheel. Which I will most definitely check that the freewheel fits all the way on before removal from the lathe!