Z1R Resurrection

[Swirl]

Looks excellent, I love the modern engineering techniques, love a good love story

[The Living Zed]

Happy with the sprocket I dropped the engine in the frame in the jig and prepared to make the new frame tubes.
I turned slugs to join the tubes for strength and alignment.

[The Living Zed]

I used seamless tube I got from Steel Express in Wolverhampton. It was the right diameter too.
And bent it with a Clarke "Strong Arm" 12 ton pipe bender.

[The Living Zed]

The difficult part is cutting everything just right so it fits together nice.
If there's big gaps the weld can fill them, but you start getting more shrinkage which leads to distortion.
Distortion's great if you're a guitarist, but not for welding frames.

[The Living Zed]

Tacked, welded and dressed.
The wooden block represents the battery box to figure out where it's gonna go along with the shock.
I put the head and carbs on too just to be sure nothing was going to interfere. I'm thinking engine and shocker mountings need to go on there.

[The Living Zed]

Before I carry on I need to go back to the engine sprocket. With it sticking out I knew it would put more load on the main shaft bearing.
I know "Straight Liners" use outrigger bearings to support extended sprockets for that reason. So I thought that's what I need to do.
I need to create an outrigger bearing. I knew the sprocket run true so I figured if I made an insert for the sprocket it could run in a bearing.
I cut the head off a capscrew and had it welded into the end of the main shaft to hold the sprocket insert on.

[Bill P]

Lovely write up and job enjoying it very muchly

[The Living Zed]

So now I've got a bearing on the outside of the sprocket. All I need now is something to hold the bearing. My initial thought was to create a plate bored out to hold the bearing and fit it where the Sprocket Guard normally goes, but the Shift Linkage Cover (Inner Transmission Cover) didn’t look up to the job and there was positional accuracy doubts for getting it all to line up.
“Back to the drawing board” as they used to say, or in my case back to the CAD.
What I wanted to do was replace the Shift Linkage cover with effectively an adaptor to hold the outer bearing. This is done by copying the original part in terms of fit and function, but re-designing the rest of it to do what’s needed. First thing to do was to reverse engineer the cover.
The Shift Linkage cover doesn’t really have any complex form to it so I decided to use the works CMM and digitise it rather than scan it.

This was the only picture of the CMM I could find, checking the barrels, but you can see the Renishaw Touch Trigger Probe. Micron accurate they are.

[The Living Zed]

The CMM was a small manual machine and you can "didge" (touch a surface) loads of points very quickly.
All the points are recorded and then exported as a DXF. The DXF is loaded into the CAD application and the object is drawn from the data collected.
This is a screen shot of the DXF loaded into the CAD app for the Shift Linkage cover. It doesn't make much sense.
As you're doing it you usually make some notes of what's didged and if you load it into the CAD while it's still fresh in your head plus you've got the object as reference
it makes sense.

[The Living Zed]

Then from that you can start joining the dots.

[The Living Zed]

Starting to make sense.

[Ultim8pc]

Wow! Just looked at this for the first time. Bloody brilliant!

[The Living Zed]

At this point I started thinking about how it would look. A fancy CNC machined billet of aluminium holding an outer bearing would look tasty, but then there’s the gear selector shaft and clutch mechanism that depend on the outer chain cover casing plus the starter motor cover. I wondered if the chain cover would fit over the outer bearing housing and that’s why I scanned it. Fortunately there’s plenty of room in behind the chain cover, so now the Shift linkage cover that I was designing was not only an adaptor, but a spacer as well. This was good because it meant I could use all the screws and dowels for the cover and casing to make the assembly stronger. Also the 27mm extension of the sprocket, which is the thickness of the spacer part of the adaptor/shift linkage cover doesn’t push the chain cover casing out too far. See how it tucks in nicely just behind the alternator casing. Just got to modify to suit the starter motor cover.

[The Living Zed]

Jumping the gun a bit there with that last picture.
Anyway - The CAD application I use has two areas. The main area is 3D solid modelling where everything is created and then the created objects are selected into the other area which is for 2D draughting.
From the digitized data I captured from the Shift Linkage cover shown above, I drew up its replacement which I’m calling the Main Case:

[The Living Zed]

Then the bearing carrier that I’m calling the Bearing Carrier: