The means of production has been seized

STRider

STRider

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Joined
Mar 17, 2020
Messages
1,223
Age
65
Location
Oregon
Bike
2012 ST1300A
So there's this part on our STs.

It's a small part.

Downright tiny part.

All of about 10x10mm.

Made of brass.

It wears and affects the rideability of our bikes.

And it costs $10 USD!

What this exotic part you ask?

The bushing in your lever that actuates the clutch.

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A while back I decided $10 couldn't be right. For that little part? And apparently the retailers felt the same and that part that was $9.99 a few months ago is now $13.83!!

Enough. I have access to a milkcrate full of brass rod and a high school metal shop full of machine tools (remember that).

I'm going to make my own. Let's call it a "personal on-shoring" of industrial production.

First thing was to get the measurements.

The Mitutoyos say: 9.93mm diameter, 10.01mm tall and the hole...

Well calipers aren't the best way to measure a small hole. Gauge pins are. But... high school metal shop. Such exotic items wouldn't last a school day without getting lost, bent, welded onto some other scrap of metal. Only kidding, but no, there are no gauge pins to be found.

However, I do work to keep the teacher's drill index fully stocked. A No. 8 twist drill was a perfect fit. 0.199" Better than a gauge pin. It can tell me the size and make more of those holes in my brass rod. :)

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First step decide on a length to turn. I'm not making just one. I'm making several in batch fabrication mode. I chucked enough to make what turns out to be nine bushings. So, 10mm per part, plus 5mm for kerf. So about 150mm or 6" of stock and another 2" to chuck it.

I spot drill the end first and then chuck it with a live center during the turning operations.

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Note the condition of the jaws on the chuck. High School Metal Shop

Parting off is always satisfying.

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I didn't have the abrasives for a nicer finish than this. High School Metal Shop But it will burnish during use pretty quickly. Notice the chamfer on the edge of the hole in the OEM part.

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I was so eager to part off the rod once I reached the target O.D. that I forgot about some useful operations best done before parting on the lathe. That was marking those 10 and 5mm sections in the metal itself using the DRO (digital readout - the electronic display of the position of cross slide).

Back onto the lathe.

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Next it was off to the mill where I clamped in some V-blocks, found the center using and edge finder and the DRO and spot drilled where the holes would be placed.

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Followed by using that same No. 8 drill I used to measure the hole in the OEM part to make the holes in my rod. 0.330" to be exact.

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The floor of the hole in the OEM is square - they either plunged a square-ended mill to make the hole, or drilled and finished with a mill. Regardless, at the moment the floor of my holes have a 125° to 135° angle. I'm not sure if I want or need to bother with making it square. We don't have 0.200" endmills. Nor do we have 5mm endmills. 'Murica damn it!

That's where I left it Tuesday. Back to the shop tomorrow (Thursday) to chamfer the holes and part them off. The finish of the ends is irrelevant. As is nearly the length. I want full engagement with the bore in the lever; it just must not protrude to the point where it interferes with its movement into the body of the master cylinder.

Stay tuned...
 
STRider said:
Made of brass.
Click to expand...
Still undetermined what type of brass...
compressive strength, corrosion resistance...

Alpha brass, also known as low brass, contains a higher proportion of copper (approximately 65-70%) and a lower proportion of zinc (around 30-35%). It is the most ductile type of brass, making it easy to shape and form. Alpha brass is often used for decorative applications and electrical connectors.
Alpha-beta brass, also referred to as duplex brass, has a balanced composition of copper and zinc, typically around 55-65% copper and 35-45% zinc. This type offers a good combination of strength, ductility, and corrosion resistance, making it suitable for various applications, including plumbing fittings, gears, and valves.
Beta brass, also known as high brass, contains a higher proportion of zinc (approximately 45-50%) and a lower proportion of copper (around 50-55%). It is stronger and harder than alpha and alpha-beta brass, making it ideal for applications where strength and machinability are crucial, such as screws, nuts, and bolts.
Click to expand...

And yes, the conditions of that chuck are shocking... :unsure:
 
I congratulate you on your determination. It reminds much of my father who always said.

"if you don't like the price of something make it yourself."

The first he said this to me it was when I complained about the price I had to pay for the gears I was buying to replace the ones I broke in my cars differential.

If you have the tools, like you in this case it is easy, but how much time to you have in the project? Or is this just a therapy session. I myself do a lot of therapy sessions. I like being in my shop.
 
ST1100Y said:
Still undetermined what type of brass...
compressive strength, corrosion resistance...



And yes, the conditions of that chuck are shocking... :unsure:
Click to expand...

Valid question. However, one I'm not terribly concerned over it given this part's application. The load it experiences is entirely compressive. That 1.7mm thick wall that the rod that depresses the master cylinder bears all the load. And the bushing is entirely contained within the bore at the end of the clutch lever. If it's alpha brass and deforms, that should just manifest as an accelerated version of the wear and deformation the OEM version exhibits. Hence making a bunch, not just one. :)

Oh, that's not the worst of it. See that cut into the rear jaw of the vise on the mill? That wasn't done by a metal shop student. Nor a robotics team member. No it was done by an adult mentor. A mentor that's a PROFESSIONAL MACHINIST. And a biker too boot. :rolleyes:

But in his defense, he was executing an operation that would have been safe in his shop. But not on a mill that's been used by shop kids. The mill head was out of tram which resulted in the end mill crashed into the vise jaw. Assisted by the power feed on the X-axis. I repeat, High School Metal Shop
 
Grabcon said:
I congratulate you on your determination. It reminds much of my father who always said.

"if you don't like the price of something make it yourself."

The first he said this to me it was when I complained about the price I had to pay for the gears I was buying to replace the ones I broke in my cars differential.

If you have the tools, like you in this case it is easy, but how much time to you have in the project? Or is this just a therapy session. I myself do a lot of therapy sessions. I like being in my shop.
Click to expand...
Now that our robotics competition season is over, our students are honing shop skills and doing things like 3D printing and machining trinkets to sell to the students before summer break. Keychain fobs with the graduating year and school initials CNC machined on the Haas that was donated to us.

I can supervise them doing things I know they know how to do. Or in this case be the adult in the room while they do their work, and yeah, I get to tinker on my own project and practice my own shop skills.

Yeah, it's therapy.
 
STRider said:
Oh, that's not the worst of it. See that cut into the rear jaw of the vise on the mill? That wasn't done by a metal shop student. Nor a robotics team member. No it was done by an adult mentor. A mentor that's a PROFESSIONAL MACHINIST. And a biker too boot. :rolleyes:

But in his defense, he was executing an operation that would have been safe in his shop. But not on a mill that's been used by shop kids. The mill head was out of tram which resulted in the end mill crashed into the vise jaw. Assisted by the power feed on the X-axis. I repeat, High School Metal Shop
Click to expand...
hmm...
being trained on the lathe (and as devoted, awing follower of https://www.cuttingedgeengineering.com.au/ ) I often wonder how and why folks damage expensive precision machinery... :confused:
 
It sounds like a lot of effort for a tiny piece, but I've often gone down that rabbit hole myself. And knowing Honda, they probably put as much or more into the original design. If anything, the cost of the original is somewhat justified by all of your own machinations to reproduce it.

My guess for material is a good corrosion resistance and easy turning/machining despite having been cold worked for strength. Annealed rod would not be wise. My stab would be a 623 aluminum bronze.
 
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Hum, I think I'll check my parts bins to see if I can scrape up a few of the ones that aren't damaged.

In all the miles I've ridden, I've only changed out one. :unsure-2x:
 
Erdoc48 said:
I have zero skills in this regard (not a machinist/metallurgist in the least)…how does this piece come off the clutch lever in case I wanted to take a look?
Click to expand...

if you remove the lever its in the part that drives the piston, here's an exploded parts diagram, but I don't know if it will help much.
 

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Thanks! That actually shows it well. I guess it gets a small dimple in it (from what I’ve read here) and makes the clutch squeeze more difficult. I’ll look at mine and see if they need replacement.
 
I was going to do the same thing when I had access to a machine shop. I was going to use aluminum nickel bronze AMS 4640 as it is an effective and commonly used bushing material.
I was also going to make bushings for the clutch lever so that they could be replaced rather than having to replace the whole lever. Often this bushing is also worn requiring a new lever. I never got around to it however. I never understood why Honda didn't make the bushing in the clutch lever using the same material as they used for the brake lever. The brake lever doesn't wear like the clutch lever does.

Good job, well done. Make a bunch of them so that we will have a supplier when Honda no longer sells them.
 
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