Topic: 1975 CB400F -> Project "something fun to build and ride"

[gsnorcal]

Hi all,

Well, I made some more progress today, but I'm not super happy with it. I was always a little skeptical--mostly due to my own inability--of applying the POR-15 engine enamel with a brush. Today I laid down the POR-15 paint (which acts as the primer in their engine enamel system) followed by one coat of the engine enamel.

I am happy with the color, but disappointed in the brush strokes. I know that it takes just the right amount of thinning to get paint to flow and self-level, but I just don't seem to have the knack. So, after this coat cures, I'm going to do a light sand and then spray a second coat. According to the directions, the timing between the prime coat and first coat is critical--just dry to the touch, but still pulls under finger. However, second coats of the enamel can go on only after 24 hours.







Dave

[Greggo]

Hey there from across the Gate!  Great work so far!!
-
Gregg

[FunJimmy]

Dave

I’m curious about this POR-15 paint system. I read that POR-15 cures faster when moisture is present which makes me think it’s a moisture cured urethane, but the engine kits are described as enamel.

There seems to be a couple ways to go with POR-15 paint including a high heat option, and I was wondering what route you chose.

Jimmy

[gsnorcal]

There seems to be a couple ways to go with POR-15 paint including a high heat option, and I was wondering what route you chose.

I went with their Engine Enamel kit. Contains a wash, an etcher of some sort, POR-15 paint as primer, and the engine enamel. I'm no paint guru, hence the kit route. Paint seems really robust, if I had to say from appearance.

Dave

[gsnorcal]

Some progress. It's always nice to be able to see things in place.

Tonight's goal is to make them minimally functional, which means getting the pinch bolts in place. Then I can worry about details like making them lighter by removing excess material and hollowing them out a bit, as time permits.

Dave

[gsnorcal]

After too much slow progress, I think things are finally looking up! I'm really excited about finishing this build now.

I think the triple clamps are turning out beautifully, albeit a simple design with no frills.



The clip-ons are an eBay find, about the least expensive I could find. Turns out used, stock R6 clip-ons are really spendy. The R6 stock units do indeed sit above the triples like this. So, that's my default setup for now. Also, to preserve the rake, there will be about that much fork above the triple.

Despite the precarious position of the bike on the lift, I just had to climb on and put the bars in my hands. Pretty sweet feeling!



As you can see, I've started cleaning up the frame. I need to fabricate a rear frame hoop, new battery/electrics tray. Then I can start on the seat pan, probably in fiberglass. I'm really winging it on the design, which might be dangerous for me. I have some CBR1000 rear sets that I was going to use, but I'm not sure. They will be more complicated to adapt. I might just grab the "loaded gun" ones, which are simple and designed for the rear drum.



Cheers,
Dave

[FunJimmy]

Dave

The triples look fricken great, and the best part is that you made them yourself.
It doesn't get any better than that.

Cheers

[gsnorcal]

Hi all,

I've had a horrible cold/sinus infection for the last two+ weeks, so no progress. But tonight I made BIG progress. The machining of the triples is complete!!!

From the top:



And hollowed out nicely on the undersides.


I have a little hand finishing to complete, then I will drop them at the anodizer for a black finish.

I think they came out superb given that this is my first real CNC project.

In other news, I should get my rims and hubs back from the powdercoater this week. And the weather looks good for trying another round of engine paint later this week.

Dave

[FunJimmy]

Congrats Dave

Those look fricken great.
Interested in making a second set?

FWIW, I wish I kept the lower triple on my bike silver and only anodized the top black.
There's something light and right about silver triples.

Good to see you back.
FJ 

[socalenduro]

and a 3rd set too

[stript.714]

Holy cow you are a machining specialist . Good stuff

[gsnorcal]

and a 3rd set too

Very flattering, but no way! :-)  These took soooooooo long to complete, mostly due to being in a class environment and using and old CNC unit and computer. If I can get access to this other CNC setup, I might reconsider.

I am willing to share the CAD files however--if I can figure out how to get them from the floppy (yes, that old!) onto the internet. I haven't had a computer with a floppy drive for more than a decade.

Dave

[Syscrush]

I am willing to share the CAD files however--if I can figure out how to get them from the floppy (yes, that old!) onto the internet. I haven't had a computer with a floppy drive for more than a decade.

Wow, I love how you're working on a 40 year old bike and the thing that seems like an antique is the CNC machine.

Great work!

[gsnorcal]

FWIW, I wish I kept the lower triple on my bike silver and only anodized the top black.
There's something light and right about silver triples.

Yea, the R6 stock clamps were that combo, actually. I'll try to visualize that before I drop them off. The design I have in mind is a very black theme. The rims and hubs are gloss black. We'll see--I'm totally winging it.

[gsnorcal]

I am willing to share the CAD files however--if I can figure out how to get them from the floppy (yes, that old!) onto the internet. I haven't had a computer with a floppy drive for more than a decade.

Wow, I love how you're working on a 40 year old bike and the thing that seems like an antique is the CNC machine.

Great work!

Yea, that is funny!!! You can see that I am modernizing, though :-)

[MasterChief750]

and a fourth

[TPColgett]

If not a 5th set  I would love to get my hands on the CAD files....I have access to machinists with plenty of toys and bronze age computing apparatus that still read "hard disks" lol

[gsnorcal]

Fun day today. Picked up parts from the powdercoater and from the anodizer.

They did an amazing job prepping the original, rust-encrusted rear rim and bringing it back to life. And the hub came out very well, too.



The front rim and hub came out great as well. I had them powdercoat the three-part hub assembly as one assembled piece. It came out great that way. Seamless.



And finally, my triple clamps. They came out very well. However, as we all know, anodizing doesn't cover up the flaws in my machining. But they look "manufactured" and not homemade, and I'm pleased with that.



I hope to start lacing the wheels this weekend.

Dave

[gsnorcal]

I hope to start lacing the wheels this weekend.

Like I could really wait...

[-CB-Jamie-]

I hope to start lacing the wheels this weekend.

Like I could really wait...

I want them!!! 

[kajtek]

BEST. PROJECT. EVER.

your doing the things i want to! im planning an r6 front end on my cb400, also inspired by funjimmys work. ive tried rebuilt brakes with braided hoses and different master cylinder with a smaller piston but still... not good enough.

would you be prepared to share your dimensions for the machining work you did on your hubs? would be a great help. currently looking for a front end for the right price, then will build a whole front end seperately over summer/autumn as my bikes a daily rider and can have it off the road!

im planning to use the stock triples though, amazing work you've done, i just dont think i have the patience to learn to make.. then make new triples. its gonna be hard enough the get the hub carriers done, in the uk we dont really have the same sort of evening classes i imagine you do, so gonna have to make friends with someone who owns a lathe and learn from them.

whats your plan for the rear swingarm/shocks?

ashley

[gsnorcal]

whats your plan for the rear swingarm/shocks?

ashley

Hi Ashley,

Thanks. I'll share my measurements on the hub. Give me a little time to scan them.

Swingarm is stock, with new IKON shocks. I may brace the swingarm later. Phase 2.

Dave

[kajtek]

Hi Ashley,

Thanks. I'll share my measurements on the hub. Give me a little time to scan them.

Swingarm is stock, with new IKON shocks. I may brace the swingarm later. Phase 2.

Dave
[/quote]

great stuff, thank you

ikon looks like a great choice, i plan to fit bronze bushings in the swingarm, and i imagine financial constraints will decide the shock choice!

ashley

[gsnorcal]

Hi,

Today I set out to paint my motor. I hung a fairly air-tight (ok, breeze-resistant) spray booth. It worked out pretty well:


If you recall, I decided to try the POR-15 engine paint. The recommended application method is brush. I was not happy with the finish. The paint and solvent separated to form light and dark streaks in the dry paint:


So, I contacted POR-15 support and told them I was going to try loading the paint into Preval canisters. They said it would work, but it didn't. It separated again into light and dark, but in a random sprayed pattern. So, I called them again and they suggested trying an HVLP paint gun. So, I borrowed a friends and tried the POR-15 again. It came out the same as with the Preval guns. You can see the mottled appearance in this picture:


So, with the POR-15 primer and engine paint in place and sanded with 320, I applied VHT engine paint (rattle can), as directed (3 coats within an hour). I am very pleased with how it looks. I let it dry for 3 hours, then cured it in the oven for 1 hour at 200F. It passes a rough fingernail scratch test. These were just test pieces. I do plan on applying the VHT engine clear for the final run.


At this point, the major issue is that the VHT might not adhere to the POR-15. Let's hope they are a) somewhat chemically compatible, and b) that the 320 grit provides an adequate mechanical bond.

I was really hoping the POR-15 would work out. I liked the color, and the paint felt really durable. The VHT just feels a bit more fragile. Hard to describe. Perhaps the clear with improve things.

Regardless, the VHT looks great and will have to suffice. Fingers crossed, I'll have the motor assembled by the end of the week.

Dave

[Syscrush]

So, I contacted POR-15 support and told them I was going to try loading the paint into Preval canisters. They said it would work, but it didn't. It separated again into light and dark, but in a random sprayed pattern. So, I called them again and they suggested trying an HVLP paint gun.

What (if anything) did they have to say about the mottled coloring?  Is it a known issue? Could it be a bad batch of paint?