FINALLY DONE! 1970 Vespa 50s electrification project

TilmanBaumann said:
Hi,

how did you determine the material and thickness requirement for your swing arm? What steel and thickness did you use?
I'm building one right now, and I think I'm building a tank. :oops:
I honest to god started with a 10mm thick 80mm wide flat section of steel.

photo_2018-09-19_17-43-37.jpg

If I don't fsck-up the welding I can use square tube for the arms for sure.
Click to expand...

Hey,

First of all, you need to design the swingarm so that the forces from it's surroundings (mostly reaction forces from the shock and brake) yield as little bending and twisting as possible. Compression, tension and shear (to a certain degree) is favourable.

Square and round (or simply hollow) sections are brilliant because they can handle forces in most directions.

So if you make sure your forces are not acting with an offset to whatever your chosen section is, and if you keep your lengths of flat stock to a minimum (very prone to twisting, and even buckling) you're probably onto something!

Hope that gave some kind of general, boring answer 😅
 
Btw my sections are from mild steel, 355MPa yield, all 2mm thick.

The front is 40mm round tubing
The middle pieces are 40mm square, and
The rear pieces are 40x20mm rectangular.
 
I think I will use some 40x20 section as well. (Stainless I think)
Gives me some girth and is way lighter. I can always tack stuff on it it wobbles.

Thanks for your help.
 
I reached a milestone today, and sent the swingarm in for final welding!
I used last night to drill and file out a slot for the spherical bearing cup to be welded in, and I got it both further back and up than I thought I would, so super happy with that. The welder at my local machine shop said he wouldn't have time for it anytime soon, but I'm alright with that.
Some pictures from yesterday evening:

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Ohh and a little delayed bonus shot from the FLUKE IR thermocamera, showing maximum temp on the BMS during our 100A run. That's 56 degrees C.

IR_00835.jpg
 
Well things have been moving along, but at the pace of a turtle.
I procrastinated the making of a battery box way too long, and when I finally had one made which I was to some extent pleased with, it didn't fit the scooter :lol: :confused:

So what I have decided to do now is: I am just wrapping the batteries in a home sewn "case", and I am implementing all the support that the batteries need in forms of cell foam cushioning inside the scooter. This saves me a ton of space!

I am in the midst of trial fitting the battery, BMS and everything else into the scooter, to get it to the point where I can safely test drive it. This will give me a good indication of how and where I should locate things when time comes to do things permanently. I am having way too many questions nowadays to do final decisions at this stage.
 
The scooter is now running, and it goes like hell! How incredibly fun!

Sorry for not keeping you updated on the progress. I've been hard at work the last few months to get it up and running before summer holidays. It is now back in the basement for some final adjustments, which I assume will take at least three to four months, since I haven't exactly gotten more time at hand sine i got my second child.

I will try to post a video or two.
 
Well, I guess it's time to be honest :D This is the very first test run! Had some substantial amount of rubbing between tire and frame. I hadn't tried the full range of motion of the suspension while having the wscooter up in the air. Rookie mistake :lol:

https://www.dropbox.com/s/50tiw5p6m6d1m6a/video-1590682078.mp4?dl=0

After some fiddling, we had all successful test runs. Had a lot of fun testing the scooter that day.

https://www.dropbox.com/s/exvhck6h6wwmijn/video-1590682084.mp4?dl=0

https://www.dropbox.com/s/sl27g9x8zigq8v5/video-1590682101.mp4?dl=0
 
Great result :bigthumb:

I hope you'll keep the patina and not paint or polish the scooter. It is a beautiful example of an EV restomod.
 
Wow, that looks incredible. Nice work! Any chance you'd be willing to share the swingarm CAD files?
 
Thanks guys. Generally I hand out 3D and even 2D drawings of everything I do. For this one, I'm gonna hold on to them for just a little while, in case this could add up to something in the future. Hope you understand :)
 
Totally understand! The route I'm trying to take is to re-use the stock engine/transmission assembly but I might fall back on a custom swingarm if I'm not able to do what I'd like. Thanks for all of the awesome photos!
 
EddySPalm said:
Thanks guys. Generally I hand out 3D and even 2D drawings of everything I do. For this one, I'm gonna hold on to them for just a little while, in case this could add up to something in the future. Hope you understand :)
Click to expand...

It is the future, have you had time to consider? I am building a large frame Vespa, but I have the same concept.

Thanks, and nice work!

Jim 8)
 
Well, not enough to change my mind just yet, but thank you for the interest ! Since a largeframe would need many of the measurements altered; maybe the photos I've provided is all you'd need ? A little more design work, but you're going to habe to do some anyway 🙃
 
Some updates. In no particular order, I've been:
- Changing the CA PCBA for the third time
- Turned POM bushings for the swingarm
- Painted the swingarm
- Re"wrapped" the battery. Looking much cleaner now, and easier to handle with all the wires and connections coming out from the top
- Added DC-DC converter with isolated circuits for 12/60V.
- Completed bracket for moving shock mount to final location
- Completed swingarm by fabricating reinforcements where the nuts for the motor shafts will tighten against. Pretty satisified with the results given that they were my first actual welding project : :lol:
- Ground rust off of front rim. The tire shop called it "rotten". Can't believe how stone cold of a heart some people can have :lol:
- Added "keyless Go" system from m.lock
- Had a tire with original size fitted to motor/rear rim. No rubbing guaranteed. :thumb:
- Lots of wiring, but I am pretty confident I am more or less there now!


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The build is looking good. Did you consider making polyurethane bushes for the swingarm for some vibration damping? Those seem ideal thickess for PU.

Cheers
Tyler

 
tylerwatts said:
The build is looking good. Did you consider making polyurethane bushes for the swingarm for some vibration damping? Those seem ideal thickess for PU.

Cheers
Tyler
Click to expand...

That would be a really bad idea as the swingarm would then not only be able to rotate but also move in other directions. I suspect that would result in very "interesting" ride qualities... :shock:
 
I did think about it.. The originals were rubber, so definitely made to take up some vibrations. Buuut, the temptation of using what you have on hand, you know... And, to what extent will the new motor vibrate, compared to the old one ? 😅
 
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