Custom Aluminum Steering Damper for 70-73 XS1 XS1B XS2 TX650

[TwoManyXS1Bs]

A couple months ago, one of our members asked me to make him a metal steering damper knob for his early XS.
Quote: "Functional and similar to the original, but with a polished metal chrome look."

Searched the web and found a likely candidate, 3-1/8" diameter cast aluminum knobs with 9 finger nubs and center protrusion.



Having 9 finger nubs will make this easy to clamp into a 3-jaw lathe chuck.
Ordered 4 of those (minimum order), and some 1/4" stainless steel shafts.

 

[TwoManyXS1Bs]

01- The parts for the steering damper arrived.
The knobs appear to be a suitable size. They're very rough, will take awhile to machine them.



A stock black plastic damper knob is shown for comparison.
Started machining the stainless steel shafts.

 

[TwoManyXS1Bs]

02- The knobs have a casting flash all around the edge, making it difficult to grip and center in my lathe's chuck.
This is the first crude fixture, which allows me to cut clamping surfaces in the nub valleys.



03- Here's the fixture in action, straightening and smoothing the nub valleys.
Did this preliminary machining on all 4 knobs.

 

[TwoManyXS1Bs]

04- Now the knob can be centered and clamped in the lathe chuck.
First operation is drilling and tapping the shaft's hole.



05- Had to grind special HSS bits to machine the inner recess.
Here, the fat center column is being turned down.



06- Machining the knob's interior. Lots of aluminum coming out.

 

[TwoManyXS1Bs]

07- A before and after pic. 3 knobs machined, 1 left to do.
The tremendous amount of aluminum swarf is shown in the tray in the backround.

 

[TwoManyXS1Bs]

08- Took a long time to design this, a fixture for holding a knob so inner indexing notches can be cut.
The spring-loaded indexing finger aligns the knob and prevents rotation from the cutting forces.



09- A knob fitted into the fixture, indexing finger set.
Ready to be mounted to the milling table.



10- Fixture with knob mounted into the milling machine.



An endmill bit will be plunged into the back inside of the knob, and remove about 2mm material.

11- The fixture works.
Indexing notches are about 2mm deep.



12- All 4 damper knobs indexed.

 

[TwoManyXS1Bs]

The damper knobs have a spherical top, with a radius of about 4.5". They sure have a rough cast surface.
I need a kind of 'ball turner' attachment for my lathe, for turning the convex top of the knobs.
So, I designed a Large Radius Facing Adapter for my lathe.



A 4-1/2" arm pivots on a bar clamped to the bed, and the other end attaches to and pivots on the crossfeed nut.
The crossfeed will travel a 4-1/2" arc, and the carriage just goes along for the ride.

13- A damper knob being turned to the large 4-1/2" radius.



14- Completion of the facing cuts.
An unmachined knob is setting to the side for comparison.



The machined surface will be much easier to polish.

 

[TwoManyXS1Bs]

The other knobs have a slight casting flaw in the middle, and way too much material would have to be removed to restore their spherical surface. So, I plan to machine their center half flat, then do the radius cuts on their outer half. I could also do a slightly depressed center, so as to accept some sort of decal. Maybe something like this 3D emblem.

 

[TwoManyXS1Bs]

15- Finished the large-radius facing of the knobs, and machined off the rough casting from the outer edges.
Two of the knobs have a spherical surface, the other two (due to casting irregularities) have a 1" flat center.

 

[TwoManyXS1Bs]

16- The next challenge is to figure out how to improve/smooth the rough surfaces between the outer nubs.



Looking into Roloc and Nylox abrasive wheels. Polishing isn't really my thing, but machined surfaces should make it easier.

17- While I'm thinking on those nub recesses, decided to finish the 1/4" shafts and do a trial fit on my XS1B.



So far, it seems to work...

 

[TwoManyXS1Bs]

18- Tried my hand at polishing a knob. Metal polishing large parts is definitely not my thing.
Any polishing I've done has only been to small things, like small metal contact surfaces of engine parts and firearms.




19- The knobs will have stainless steel shafts with fresh/sharp threads on the ends.
These fresh threads may not screw easily into an old damper's 'guide nut'.

My guide nut's threads were quite dirty and cruddy, but my old/original damper knob's threads were worn enuff to allow it to thread in there just fine. When I tried one of the newly threaded shafts, it would bind. So, recommend cleaning those guide nut's threads, preferably chasing them with a M6x1.0 tap. If you don't have a tap, you can make a thread chaser with a regular M6x1.0 bolt, by cutting a thin slice along the side with a dremel cut-off disc.

 

[TwoManyXS1Bs]

I found and ordered a couple of 3D Yamaha tuning fork emblems. I'm considering fitting them into recesses of the two knobs that have the flat tops. Asian supplier, so those will be 3-4 weeks off.



20- Spent a lot of time dressing out the nub valleys with a fine grit sanding drum on my Dremel.
Then, went after a knob on my lathe with a fine grit orbital sander, then onto the polishing wheels. Started with black emory, then with brown tripoli, finished with Solvol Autosol. In this pic, that knob is on the right. It doesn't look very good. Polishing just isn't my forte'.



21- This pic shows the finished aluminum damper knob, with stainless steel shaft, steel and rubber washers, and a cotter pin. Will be shipped out to our member. He has polishing equipment.

My screwups are a bonus feature. Maybe he can polish them out...

 

[DrewMartin]

Then, went after a knob on my lathe with a fine grit orbital sander, then onto the polishing wheels. Started with black emory, then with brown tripoli, finished with Solvol Autosol. In this pic, that knob is on the right. It doesn't look very good. Polishing just isn't my forte'.

Its honestly probably the material itself. I really dig what you did with them but those knobs were pretty rough to start out with. Since they're obviously cast there's no telling what alloy they actually are without some testing that's not worth it.

What was your final grit before moving to compounds?

I typically work up to 1000 grit paper/cloth before I go to black emory compound but I usually feel as though the first compound works backwards a bit.

 

[TwoManyXS1Bs]

Yeah, the casting alloy probably has a lot to do with it. The way it machined, throwing tiny, tight curls, makes me think high silicon. Nowhere near the finish cuts normally achieved with solid billet. Instead of cutting like hard butter, felt like I was cutting sandstone. Close examination also shows extremely tiny voids. Final grit was #320, and the black emory seemed to remove all surface scratches. I'll try going to #600 on the next one. Open to suggestions...

 

[gggGary]

Cool, love your innovative work 2m.
I am still unclear on how your radius fixture works, stupid me I guess.
Caswells guide says 400 grit then black on sisal that works for me...

 

[nicmcs]

Really like this, I had been thinking of making one for my gsxr front end when I've it together and the motocognito stem bored out.

great skill and execution.

 

[Royboy]

2Many, Great work, I admire your skills!

roy

 

[DrofBBQ]

2 Many,
You have super patience and a great deal of skill. If you compare your work to the original work on a early factory frame ( like the wields) your damper knobs are 1000% better without any polishing. And the logos will be an awesome addition. I'm surprised they didn't include that in the original knobs. How many hours do you have in your project? And you'd have to count at least some of the time you were just thinking about it while doing something else. Great project and great tutorial on how you did it. Love the pictures.
Jack

 

[cycleranger]

18- Tried my hand at polishing a knob.

Very cool engineering project.
I like the billet knob.
Imho, it would look even better if it were smaller.

 

[XSLeo]

Great work. Insetting the tuning forks is a great idea, only problem I can see is indexing. When the steering damper is adjusted will the tuning forks be pointing the right side up? Just a bit of funning you there. Great work.
Leo