Topic: 1972 CB500 "An Inherited Basket Case"

[SOHC4 Cafe Racer Fan]

I wonder if this only offers the same performance as stock or is it more akin to a 32 AMP system that can charge at idle.

[fantino]

I wonder if this only offers the same performance as stock or is it more akin to a 32 AMP system that can charge at idle.

Looking a bit closer at the info on the Powerdynamo site, it's rated for 150W, which tracks with the wiring diagram that fuses it at 15A.

The Electrex is rated for 25A output. Unfortunately neither provide an output curve with any of their documentation.

[fantino]

I wonder if this only offers the same performance as stock or is it more akin to a 32 AMP system that can charge at idle.

FYI - this is *approximately* the output curve of the Electrex RPK systems based on the data points I was given from the mfg.



Probably doesn't bump out more than ~35-50W at idle, but it's better than nothing. The reg\rect is tuned for this system specifically and it appears depending on current draw, will just shut itself off at higher RPMs to free up HP.

[fantino]

Not too much exciting to report on the bike itself, I've mostly been taking inventory and planning. I'm taking a couple weeks off in December to use up some vacation time, so I'm hoping to get started on motor assembly.

Through a combination of 3D scanning with my phone and hand measurements I made a "quick" model of my CB500 frame, as none appear to exist online so far. I still plan to make my own tank and body-work, but I'd like to take a more structured approach to ensure form and function are not at odds and take another pass at the design.

The model omits some details entirely (eg. smaller brackets, center stand mounts, side cover tabs, etc), and I kind of phoned it in on some of the finer details to simplify modeling, but it's reasonably accurate, certainly accurate enough to design body work around. I'm providing the model for others, but use at your own risk and verify dimensions for yourself I'll eventually scan the motor, forks, original gas tank and swingarm, if not model them outright.





Here's a link to the 3D model viewable online:

CB500F Frame Model

And also a link for the model in stl, stp and sldprt formats, as well as a dxf of the drawing:

CB550F Frame CAD

I'm also working on finally putting my custom large(r) format 3D printer together, I've been meaning to do this for a long time, and have been sitting on parts for years. It should be getting powered up for the first time this month. This will allow me to more easily print mold sections for composite body work compared to my old printer which could only work in 9x8x9 sections. This setup should be able to do 15x12x15 builds with far better quality.



Happy Thanksgiving!

[fantino]

Took the week off work to relax. Had lots of big plans to take care of a bunch of deferred maintenance on my cars and get some work done on the bike, but alas, I spent most of it on my rump enjoying some barley pops

I did get all the pieces of my motor out of the garage and setup in my den - I'm more likely to make progress inside the warm house than out in the damp garage.

Going to start with a dry fit-up to re-check all of the bearing and piston clearances, make sure they match my notes from a couple years ago.

Unfortunately it looks like a couple of my rod bearing shells came loose from the packing I had them in and got gouged. It's not super deep, but I can just catch them with my finger-nail, so I should probably replace them if I can track down another set.

Getting one pair of shells coated is not very cost-effective, so I guess I'll just put the uncoated pair on the bottom half of two rods where they'll see less load.



Got my printer all wrapped up as well. I'm pleased with how it turned out. The jump in accuracy and speed compared to my old wobbly setup is pretty dramatic and the stepper controllers are unbelievably quiet compared as well. All I can really hear when it runs are the cooling fans, so I might look for some quieter ones.



Some more plodding away on putting the bike into CAD - this is mostly just a fun exercise to pass the time when I don't feel like getting off the couch or getting my hands dirty.

Got the stock tank modeled up (focused on the tunnel to use for the new tank design), and threw some rough models in for the motor\tank\swingarm. I also threw in a poseable figure scaled at my height to play around with ergonomics for the redesigned tank\rearset\bars\seat position before I put too much effort into prototyping.



One last random thought to look into lest I forget about it - with the PowerArc optical ignition setup I have, advance curves can be switch depending on which wires are grounded. My CR26's don't appear to be ported, so if I want to setup vacuum advance, I will need to research the best way to add a port to the carbs\intake to integrate a VOES.

[MauiK3]

Very interesting thread, watching.

[fantino]

Was snowed in this weekend so I took care of quick little project rebuilding my sad looking starter. I had already cleaned up the commutator and armature by the time I thought to take a pic:



Tah-Dah! Replaced the bushings, seals, o-rings, brush plate and replaced the soldered in cable which was looking rather rough with a stud. I also gave it a paint-job and dressed it up with some stainless bolts:

[fantino]

Plastigauged all of the new microblue'd main and rod bearings this weekend as a sanity check.

Rods: 1-.0015", 2-.0015", 3-.0015",4-.0015
Mains: 1-.002", 2-~.0018", 3-~.0018", 4-~.0018", 5-.002"

So I'd say things are good to go there. I also cleaned up the cases and gave the exposed surfaces a coat of aluminum colored engine paint.



I need to install a key-lock insert in one of the old M6 bolt holes that is damaged beyond what a helicoil can fix and give all of the oil passages one final flush before I start to put the bottom end back together.

[fantino]

More slow but steady progress lately. Got the bottom end put back together. Decided to replace the primary shaft bearings and put in yet another new set of seals cause the ones I installed previously were already looking a bit beat up from the years of storage. The old crank seals didn’t have the flange either, so I was sure to track down a flanged set. Didn’t bother taking any pics of this, but it’s not that exciting to look at.

Did an initial top-end fit up and re-clayed the pistons for clearance. Even with thinner base and head gasket to get to .040” between head and pistons tops, I ended up with .084” as my smallest clearance (on the intake side) which is more than the last time I attempted this - I’m guessing I did not correctly degree the cam last time I checked - regardless, I’m confident valve clearance is adequate at a neutral cam position. I took it apart  three times and got within a few thou of the same answer each time. Well, I actually did it 4 times because I faced the pistons the wrong way the first time 🙃

I also re-checked my piston ring clearances, came in at the same measurements I listed previously, so good to go there. I filed the ring end edges and corners just a bit to be sure there were no residual burrs or sharp edges.

I’m waiting on a set of new wrist pin clips as I seemed to have misplaced my set, and I need to transfer my hard-welded rockers over to the undamaged valve cover. At that point I’ll be ready for top end re-assembly.





Once the motor is re-assembled, I plan to get the engine in frame and get the forks, swingarm and wheels fit-up so I can start sorting out controls fitment and wire harness work.

Waiting to hear back from a fellow in Europe but hopefully I will have an exciting development in the near future.

[fantino]

Bent an oil rail ring putting the cylinder head on, whoops. Waiting into the weekend for a replacement to show up. In the meantime - I mocked up the swingarm and forks to the frame so I could start playing with rearset positions. Just using a thick sheet of plastic to drill holes into until I get something that feels right. I’m folding up a yoga mat to experiment with different seat heights.




I also started working on the tank and seat again. I decided to start from scratch - it looks similar to the old design but the proportions are much better and will hopefully actually fit my body. The last design was just too big. The interior tunnel is almost exactly matched to the stock tank now as well, the old design had some clearance issues.





Lastly... I won’t give up all my secrets just yet, but I just parted ways with a good chunk of change and will have a never mounted MotoGPwerks exhaust up for sale in the near future. It’s going to be magni-ficent

[GV1390]

Some awesome progress thus far!

You ready to let that roundie go yet or what? Cash in hand - let's make a deal.

 

[fantino]

Some awesome progress thus far!

You ready to let that roundie go yet or what? Cash in hand - let's make a deal.

 

Thanks! Feels good to finally get some momentum on this project again, I’ll try to actually keep it going this time.

I’ll be buried in that car - or it’ll bury me. I’m not certain yet 😉 I imagine it’s not too easy to find a (relatively) rust free roundie on your side of the country that doesn’t cost an arm and a leg.

[GV1390]

I actually recently stumbled on a 68' that's fairly clean....not local though.

PM to further discuss. Would help fund the other projects you have pending.

[fantino]

No pictures of it, but the top end is back together. I didn't feel too great about the contact area on the hex bolts with the slotted cam gear. I'm sure it's fine - but I'm the paranoid type I'll replace them with some flange bolts and blue loctite for piece of mind. Also because I'm paranoid I checked the valve clearances one last time using the dial indicator method, since it's more accurate:

Intake Clearance ATDC	Degree	Exhaust Clearance BTDC
.100	5	.073
.095	8	.071
.096	10	.065
.097	12	.068
.099	15	.070

Still left to do on the motor:

• Plug for kick-starter hole
• Bend oil hardlines from head to flexible supply line
• Find replacement locating bushings for oil pump (lost em' )
• Install alternator and ignition module
• Re-install primary chain tensioner

In other news - I put in a down-payment with Enrique from the Benelli Motorcycle Club of Spain for a set of his MV Augusta Magni style 4-4 pipes. The MotoGP pipe is great, but I've been lusting after a curved 4-4 since I started my original build thread nearly 10 years ago. I don't see any reason to compromise on my vision at this point

These are similar to Scott S and Flatlanders CR\Pasolini pipes built by the same fellow in Spain but with more pronounced curvature - many thanks to Scott for finding the source.



Speaking of my vision for the bike - I'm ready to call the tank and seat re-design finished. Better fit, better looks, better designed for molding.

I filled out the rest of the model on GrabCAD to test out suspension travel clearance and put together a few renders for fun. My vision for the bike is now crystal clear - all that's left is to do the work









Next step here is to decide whether to design and print molds directly or just print a plug and build a splash mold. I'm leaning towards the former - it's more computer work and printing time, but will cut down on shop time considerably.

[SOHC4 Cafe Racer Fan]

Great looking pipes.

[RAFster122s]

Looks great!  Best of luck fabricating things.

Are you going to add to your rendering the vertical strap they used on their pipes?
I think you Really should as it is going to impact the looks.

Wonder if anyone has played with a sweeping curved brace mimicking the styling of the pipes, granted a straight strap will be much stiffer, just curious if it would give you enough rigidity if a curve design to complement the pipes. You are going to see the brace even if painted black, why not see if you can add something with a little aesthetic looks as well as being functional?
Then, before you commit to metal making one or more out of plywood painting it the final color to see how you like it.
Also, is the brace on the very rear of the pipes or at some point further forward? Maybe the vertical strap on the pipes you show in Italy isn’t for the pipes.  Very cool jig for the production. Something like that could be used to make fairings as well with a complete frame and bolting the pipes up to it. You can make a mock-up of a motor out of blocks of foam roughly shaped...
Then carve and shape a one off fairing from foam that you make gauges/templates from one side to guide shaping the other when you are shaping it. Then build your female mold on the foam layup. That’s the old school method of modeling if you don’t use the wooden bucks and frames 3D modeling has allowed to become much simpler and faster.
It all depends upon if you are building a fiberglass or metal fairing...

Congrats on getting your vision and design nailed down on the computer.

What software packages are you using?

David

[fantino]

David - I think that strap is part of how Enrique has the pipes mounted to the orange Benelli Quattro in the background.



There's definitely going to be work to do once I get my hands on the finished pipes - I'm not expecting these to mount up without some custom work. Once I've got the pipes in hand I can fit-up on my frame with the motor and get the final control locations nailed down. At that point I'd like to grind off what's not needed on the frame and weld on anything new.

The render was just for fun and to test out the GPU on my new workstation - but there's still a lot of functional considerations to work out on the real thing. If 10 years of engineering has taught me anything it's that just because it looks good on a screen doesn't mean it will always work out how you expect in the physical realm

I mostly use Solidworks now, I transitioned to it from CATIA a few years ago.

Composites manufacturing and mold design is a big part of what I do for a living - so I do plan on making all of the bodywork out of carbon\epoxy. Unfortunately the methods I rely on for making molds at work are a little out of my price range, so I'll need to fall back on homebrew 3D printing or more traditional soft-tooling methods

[fantino]

I decided to go the full printed mold route - it should be less than $100 in filament compared to maybe $20-30 in material to print a plug plus the cost and time to build splash molds off the plug which is considerable. I also get more precise control over my excess and parting line surfaces this way.

I don't normally design molds for FDM, so my workflow was a little different than typical. The design has to consider build volume limitations, avoiding overhangs or support material, build orientation, etc. I now have the tunnel and body molds designed and partitioned into manageable chunks for the printer.





Always good to check your draft angles. I usually shoot for at least 1.5deg - but localized areas can be less on bigger, thinner laminates like this and will still demold OK as long as the part isn't fully mold locked by some negative feature. You can see a little negative area on the tunnel mold, but it's out in the excess so I'm not going to worry about fixing it.



I'll get started on printing the mold sections next week. The parts are already sliced, but I'm waiting for some larger nozzles to be delivered. Jumping from a .4mm to a .8mm nozzle and increasing the layer height decreases the average build time for each section from 40+hrs down to 5-8hrs. The tradeoff here is resolution and surface finish, but this is a large part with organic surfaces and I'll be filling and fairing the surface anyways, so the loss of fidelity isn't critical here.

Cubic subdivision is a good choice for infill on parts like this. It minimizes material usage where it's not really needed and provides good strength in all directions, even at a low infill percentage (this is 10%):

[/url]

[RAFster122s]

Nice...
What 3D printer do you have and how large is it.
Laser printers and 3D printers have gotten pretty cheap these past few years. One of my hobbies is RC airplanes and the low wattage inexpensive laser printers are within reach of my limited budget. I like building with balsa but will model with foam many times as well. Mostly smaller planes except for the sailplanes and powered gliders.  City has gotten pedantic about a long time slope soaring site which is near a prison. Their logic is flawed in why they don't want us flying there...thinking we would fly over the prison and drop something in... The quad copter drones with cameras for first person viewing cameras are the problem children, not our sailplanes and electric gliders that have been flyig there for over 30 years. No one smart would fly from the place I am talking about as the police could catch you before you could leave as one road in and same road out. Anyone with half a brain would launch from a major street not too far so they could fly the stuff in and then hustle back to launch point to retrieve and then hop on the freeway to escape.
The people buying small quad copter drones and not following the laws and having no clue about registration and other laws and criminals using them to fly in at night and snoop around people's property or during the day while they are at work to scope out the place for robbing them. You cannot buy a drone and not know it is illegal to operate them at night
Because every one sold in America has huge warning under the box flap on either end informing them they cannot.
They have made them so easy to operate as they are gyroscopically stabilized and many have failsafes to right themselves and recover if possible.
Now the looming federal ID transponders and restrictedflying spaces are going to destroy a segment of the multimillion dollar hobby.

Sorry for the segue...

Please show us your process, look forward to seeing this come together.  Also, how many layers of carbon epoxy and which resin system do you like working with? MGS, Resin Research, West Systems, etc? Will you be lining the tank? Caswell or POR-15?

Thanks!

David

[fantino]

David - I saw a press release a few months ago about the new remote ID rules for drones from the FAA but I confess I’m a bit ignorant about the implications on other small UAV. There’s an ordinance here that prohibits UAV operation in city park land, and almost the entire city is class B or D controlled airspace due to Boeing Field/SeaTac/Renton Airport all being clustered close by makes it a little complicated for folks to fly here to begin with.

If you scroll up to post #158 you can see my printer, I built it myself mostly from 8020, linear rails, etc. It’s ~12”x15”x15” build area in a coreXY setup running a Duetwifi controller. Due to heat loss at the edges of the bed it’s more like a 10x12 effective XY area.

I’ll take plenty of pics as the physical realm of the bodywork starts to take place over the coming weeks.

The resin will be a novolac/Bis-F based epoxy system, DEN 425 if I can get my hands on a small enough quantity. Otherwise, my fallback will be MAX GRE which is a bis-A/novolac blend tested against pump gas resistance and quite affordable. These resins are more functional (greater # of reactive areas) than bis-A resins, so they cure to a denser crosslink network. The result is improved chemical resistance. Many home builders also do not bother to post-cure their laminates at an elevated temp. Properly done this does appreciably improve strength, service temp and solvent resistance.

No point in using the Caswell liner, it is a novolac based epoxy coating and so wouldn’t offer any benefit over the lamination resin in this case. I looked into slosh coating the tank with a 2-part Viton sealant coating, but I don’t think it’s necessary.

I haven’t settled on a lamination schedule yet. Some combination of 6oz carbon and basalt to balance strength and toughness (I prefer basalt over S-glass, price to performance wise). I may or may not add in a couple layers of Kevlar or innegra. The tank is more likely to break at the seams than anywhere else, so I doubt the extra impact strength makes a big difference and kevlar is pain to work with, I haven’t used innegra yet but supposedly it’s easier to work with. I plan to paint the tank, so I won’t be focusing too much on a perfect cosmetic layup either.

[fantino]

Picked up a set of Bridgestone BT46s in the mail this week. 19x3.25F and 18x4.00R. Haven't seen too many reviews on the updated design yet, so hopefully they live up to their predecessors. I need to finish truing up my wheels before I can get these mounted.

I also worked on my external oil lines a bit this week. I tapped an AN tee fitting to accept some brass set-screws which I drilled thru to match the ID of the stock restrictor orifices in the cylinder dowels. Installed the set-screws with blue loctite, though they don't really have anywhere else to go.



I bent up the hard-lines from the head to the tee. I need some sort of bracket to hold the body of the flexible hose securely at the screw between the head and jugs.



I would like to pressure test the lines before I start the bike up to avoid any surprises, so I'm thinking about maybe mixing up some silicone jeweler's putty to make a temporary seals on the oiling holes under the cam so I can pressurize the lines and make sure it holds tight at 60psi.

I also picked up new bolts for the cam sprocket - I didn't like how little contact area the stock bolt has on a slotted sprocket. M7 flange bolts are a little uncommon. I initially found some Gr5 Ti flange bolts online - I guess I should have looked at the bolt standard a little closer (DIN6921) because the heads on these are comically oversized and almost hit the chain tunnel. I also didn't like that the threads were cut all the way up to the head. You can see on the stock bolt there is a thicker cross-section under the head.

Thanks to some past investigative work by PeWe in an old thread, I located a NOS set of flange bolts from a Suzuki that make me feel a lot more warm and fuzzy.



After slicing up the molds, I decided to rework the design. Too much material usage and too long of build times for my taste. Now the mold sections are just 3mm thick walls with the same splits. This cut material usage considerably to 25% and with the addition of a larger nozzle diameter and hot-end brings the per section print time from ~40hrs down to about 3hrs.



Got my first part off the printer today. A few issues on the first couple of layers, but nothing I can't work around.



The remainder of the workflow for the molds will go something like this:

• Epoxy "minor" mold sections together
• Match drill "major" mold sections to bolt and dowel together
• Stiffen molds with epoxy and glass on back-sides
• Apply thin layer of epoxy filler to mold surfaces
• Sand to smooth finish (up to 600gt)
• Seal mold surfaces
• Apply mold release

SolidWorks has a flattening feature which works OK - so I flattened out the tank surface to help make some estimates on material requirements. With some excess added for the flange and to account for the deformation in the mesh, it looks like I will need ~30"x30" of material per layer for the upper section.



Plenty to keep me busy for the next couple of weeks, that's for sure!

[RAFster122s]

Very nice, that is a very nice Suzuki fastener indeed. May wish to antisieze beneath the head when installing as it is often the heads that have the corrosion with time or the part that seemingly welds itself to the aluminum case casing trouble removing years later. But, then again you may never face this issue because that often happens after decades and we may not be around or care at that point...

I hade a chassis a few years back for a small RC pan car I was racing from some colored Kevlar carbon cloth and had a shop autoclave two different colors together for me to give me a red-black twill on one side with blue black on the opposite. It came out nice but that Kevlar was a Royal pita to trim everywhere I routed the chassis slots for batteries and cut the simple chassis out. It is pretty but was much too stiff. The chassis needed the bit of flex the standard thicker colored G10 we were using for the chassis to perform better.  It definitely looked trick and no one had another like it.

That is a nice first section. Glad it is coming together quickly. Stalled projects are not fun to mess with when pulling them together takes forever. The investment in the bigger nozzle will pay for itself in energy savings and speed as well as the ability to do other things in the future of similar scale.

That sounds like a lot of fun working with the new material. I always enjoy learning new stuff and planning the details on a project. I haven’t had the pleasure of working with basalt yet.  Easy enough to build a construction foam cure oven for the layup with foil HVAC tape adhering panels together.  You can use a heat gun or series of incandescent lamps or a heat lamp with a set of thermo switches to control relay to regulate your oven temps turning lamps on and off as needed within the enclosure.  Just keep the bulbs far enough from your foam board as you do not want the risk of a fire.

Are you going to vacuum bag or two part mold the layup?

An inexpensive vacuum pump can be built using a aquarium pump inside a metal coffee can siliconed to a board with couple brass tubes soldered into the can to pull the vac. It really pulls a decent amount of vacuum and you cannot beat the price if you don’t have the need for an expensive vacuum pump. Imagine you have one already or access to them easily.

I guess I wasn’t thinking about it much huh?  Using a highly fuel resistant epoxy from the getgo would be the smart move in the construction rather than risk a liner epoxy doing the deed...

Enjoying watching this one come together...

[fantino]

Those dyed hybrid kevlar weaves really do look trick, but you're right, they're a real bear to cut or sand.

I've let this project stall out for far too long, so I'm with you - anything to get this moving along is definitely worth it, keeps me more motivated when the progress is steady. I've been printing all weekend, I'm about 1/6 of the way through the upper half mold now. I think once I get the new nozzle installed tomorrow I will be able to have all the sections printed by the end of the week.

Clever idea for a DIY vacuum pump! At work, we use a 100gal shop compressor hooked up in reverse to a big quick connect manifold, so fortunately I don't have to worry too much about rigging anything special. I'm planning to do a vacuum infusion for these.

As far as the oven curing - the developers who own the house I'm renting are tearing it down in a few months, so I'm just using the kitchen range in the vacant basement apartment for the time being Probably not very food safe but I'm pretty certain it's destined for the dump, haha.

[fantino]

Halfway through printing the upper tank mold! There's some ugly areas because I'm not printing supports for overhangs, but overall it's very workable and more importantly going FAST.

Taped the pieces together for my own satisfaction, but I'll be bonding the sections together by mixing up some epoxy with fumed silica and clamping the flat faces to each other.

After that, the mold surface will get filled and faired with a brushed on layer of epoxy, glass microspheres and fumed silica. The silica makes the epoxy thixotropic so it doesn't sag or run and the microspheres act as a filler to make sanding easier (sort of like bondo, but provides a more robust and less porous surface - added bonus to not have to deal with the nasty smell of styrene from the bondo).



I'll put up something in the classifieds soon, but in case anyone reading my thread is interested - I was going to clear out a few parts that I've been holding onto:

OE (TEC) points plate assembly, a set of 5ohm Dyna coils and red Dyna silicone spark plug wires - all brand new, never used or mounted! I was thinking $140 + flat rate shipping in the US, which is 20% off the cost of the Dyna stuff plus a free OEM points plate.



CB500 swingarm which has been refurbished with bronze bushings and the axle zerked by HondaMan himself. The felt washer is definitely gone, but I should still have the cup washers and phenolic pieces. Zero miles on this since the refurb, has been mounted a few times $75 + shipping.



Also putting a feeler out for these new, never mounted MotoGPWerks pipes. Not sure what the going rate is for these nowadays or if Chris is even still making them regularly, but I'm guessing I can at least cover the cost of shipping for the new pipes if I sell these PM me if interested.

[RAFster122s]

That is some nice pieces you are letting go of... Chris has not been making the 550 pipes as the frustration of some sellers made him abandon them for a while. He was willing to do lots of 10, but, that is a tall order often. People flake on you unless you get a good deposit.
The points plate is worth at least $50 but more realistically they go for about $100-110.

Someone is getting a nice deal, imho.