Topic: 76 CB550 Cafe build

[tshrey]

Oh #$%*.  That would explain why I was having such a hard time getting it in place.  Guess I'll punch it out of the carrier and put the spare I have in the right place.

Thanks.

[tshrey]

My garage, thy cruel mistress.  Was having a great day, got the new rear shocks from Cognito mounted.  If you get the standard japanese replacement shocks they carry they are NOT plug and play.  I machined the rear shock mounts to fit the stock units and these have 8 mm smaller top collars and need about 3mm of spacer in the bottom when putting them on a CB550.  Then I moved on to cleaning up the threads on the axle I made; the stock nut spun on fine but the replacement stainless castle nut wouldn't go on more than a few turns without a wrench.  Tried my 18mmx1.5 die to clean them up and my thread cutting on the lathe wasn't great compared to an actual die but it did let me clean up the first 3-4 turns which let me thread the replacement nut on.  Ran it all the way on and off half a dozen times with valve grinding compound to machine the two surfaces against each other.  On the last attempt the bastards seized against each other.  So there goes an $18 castle nut and about two hours of my time machining.  Sum#$%*!

[calj737]

Sounds like you cut your threads too tall. Look again at the majors and minors, and cut the majors shorter. You don't need that extreme engagement on a 1.5 pitch thread. It's possible the nut's threads were cut fairly tight too... I hand fit the nut while the stock is still in the lathe. If she won't spin on by a firm hand, cut some more. A castle nut is about "capture", not torque.

...And skip the lapping compound and use AntiSieze (always) with stainless nuts/bolts.

[tshrey]

I was definitely being lazy.  I cut the threads like you said and checked with the stock nut and had a great fit.  A month later I got the new castle nut and it wouldn't thread on without a wrench.  Being too lazy to get everything set back up on the lathe I figured the grinding compound would let the two pieces machine each other.  It seemed to be working.  Until it wasn't 

[RAFster122s]

Hit it with a torch to see if you can salvage the axle and/or nut...  Might need to buy a couple castle nuts at this rate... teasing
Sorry it is not playing nice.
David

[calj737]

Hit it with a torch to see if you can salvage the axle and/or nut...  Might need to buy a couple castle nuts at this rate... teasing
Sorry it is not playing nice.
David

Sorry, absolutely TERRIBLE idea. If you heat a stainless bolt with a stainless nut on it, absent a thread release compound, they will fuse together permanently. And I mean PERMANENTLY. You could turn the nut off in the lathe and save your axle, but be slow as you approach the threads.

[tshrey]

Ha! I had the same thought about the torch and it didn't work, guess I won't bother to try freezing it

Guess I'll be ordering another nut and a couple more feet of 20mm rod...

[RAFster122s]

Hit it with a torch to see if you can salvage the axle and/or nut...  Might need to buy a couple castle nuts at this rate... teasing
Sorry it is not playing nice.
David

Sorry, absolutely TERRIBLE idea. If you heat a stainless bolt with a stainless nut on it, absent a thread release compound, they will fuse together permanently. And I mean PERMANENTLY. You could turn the nut off in the lathe and save your axle, but be slow as you approach the threads.

Sorry, Ignorance on my part...
Thank you for chiming in and potentially saving his axle...learning something new is good.
David

[tshrey]

After pricing out another stainless rod, another castle nut, shipping and my time machining I'm just going to send the stock axle and nut, along with the chain adjusters, out to get a new satin chrome finish.  Should be a wash in price, saves me hours of time and gets the adjusters taken care of to boot.

[calj737]

After pricing out another stainless rod, another castle nut, shipping and my time machining I'm just going to send the stock axle and nut, along with the chain adjusters, out to get a new satin chrome finish.  Should be a wash in price, saves me hours of time and gets the adjusters taken care of to boot.

Use stainless tubing, or even CroMo tubing. Doesn’t need to be solid. Saves you money, weight, and you can redo it quickly because you can find it in MM sizing.

[RAFster122s]

Just consider having the bolts replated with zinc and clear chromate conversion. No need to go chrome...
Or go with cal's recommendations...sound advice.

[RAFster122s]

I bought some extra 12mm stock Honda flanged nuts.  Would having one or two of those benefit you in any way?
I got them from South Sound Honda in Olympia, WA

[tshrey]

Thanks for the offer RAF but no, at this point I've gone the full Cal route and replaced everything on the bike with ARP 12pt flanged nuts and bolts.

Cal, what size would you recommend for tubing for the axle if I went that route?  It has to be 20mm outside and the minor of m18 threads is just under 15mm so that is 5mm of wall thickness already.

[calj737]

20mmx8mm wall. Worst case, ream the ID a bit if you can only find thicker (or leave it).

[tshrey]

Big day, finally made progress on one thing I was dreading doing.  The taper-to-taper spacer is done!!!



I have a combination bridgemill/lathe, so getting accurate angles cut it not trivial to say the least.  I started with 1.25" aluminum stock and got the angle pretty close with a simple digital angle gauge.  Started cutting with the compound slide and kept at it until it was an interference fit with the cbr rotor.  Once I had that angle I switched over to steel and cut the outside of the spacer with a length of rod on the small end so that I could use that to chuck in the lathe. 



Back to aluminum, switched over to an internal cutter and again measured to get close and kept cutting and adjusting until I had a good fit.  Here I put sharpie all over the crankshaft end and then put the spacer over it and had sharpie transferred over the whole surface of the aluminum so I knew I was good.



Back to the steel slug and transferred the angle into it.  Perfect fit on both surfaces.  Going to put valve grinding compound on the inside and outside and spin the pieces against each other to remove my machining grooves .




Any thought to whether I should send this out to get hardened?

[GV1390]

Heck yeah. Looking forward to seeing some more updates on this thing!

[SOHC4 Cafe Racer Fan]

Damn.  Getting that part hardened (cryo treatment, I presume) could be expensive for such a small item.  You should have made a bunch (for us!) and reduced your unit cost. 

[RAFster122s]

Having this solution for the 550 to have a high output stator would be most welcome. So, you have my attention!
David

[calj737]

You can certainly heat treat that yourself up to a pretty high Rockwell. I’m not sure what the original was, but if you still have it, you can find out. Might have to go past a machine shop where they have hardness files. I suspect a solid heat treat and quench would do it, all by your lonesome. 

[tshrey]

Damn.  Getting that part hardened (cryo treatment, I presume) could be expensive for such a small item.  You should have made a bunch (for us!) and reduced your unit cost.

The precision involved meant that even after getting the angles correct I spent two hours on the lathe cutting the unit.  Not exactly something I could make in bulk.

[calj737]

Damn.  Getting that part hardened (cryo treatment, I presume) could be expensive for such a small item.  You should have made a bunch (for us!) and reduced your unit cost.

The precision involved meant that even after getting the angles correct I spent two hours on the lathe cutting the unit.  Not exactly something I could make in bulk.

Got a SINE bar?  If not, get one (or make one). With your Mill/Lathe, having this tool is invaluable for producing deadly precise cuts of unknown angles.

[tshrey]

The problem comes more from the inherent errors when trying to measure an angle, not reproducing it.  I can use trig and my DRO to get angles down to .05 degrees, but trying to measure the inside diameter of the outside end of the CBR rotor, then the inside end of the large end of the tape and then the distance between those two measurements, well at that point I'm really not certain to within a few tenths of a mm.

I should get a sine bar because it would make it quicker to set things up when I'm trying to cut a known angle.  It's kind of amazing that I can't get the specs on the taper of even the 2008 rotor online, it seems like everything lives online these days.

[calj737]

A decent pair of inside micrometers, a depth gauge and a copy of the Machinists Handbook would likely point to exactly which taper that is. It would be unusual for that rotor to be some unusual, arbitrary taper; instead I’d expect it to be very standard. Knowing which it is, is often determined by the MH.

You can also use the Sine bar for internal measurements of angles. Setting it a known distance, parallel to the outside edge, then measuring the offset between the points. Like using a gauge block really.

[RAFster122s]

Dang Cal! You are a wealth of knowledge and experience.

[calj737]

Dang Cal! You are a wealth of knowledge and experience.

But don’t call me “respected” or an “expert”. Thems fightin’ words