Bob's EV SLC Build Log

Bob Winn

Supporter
MDF prototype came in. What a pain the workflow was. Fusion360 has a real issue exporting DXF files for laser cutting. Had to manually edit them in adobe for single cut lines. Real adventure.

But, fits like a glove. A couple pieces need slight modifications, but I'm going to aluminium and steel next week. Pieces are not bolted in place, so sitting a little low in the rear.
 

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Bob Winn

Supporter
Couple more shots of the subframe on the motors. I haven't removed the inverter from one of them yet, but I had to make sure I could get frames in to the units, and that everything was aligned. I need to add a couple access holes for nuts, but it looks ok.

Going to cut a few parts more out mdf, and the go for it. Then start on the front motor mount.

Is there a login to to access the build manual? Realized mine didn't come with a manual.

Bob
 

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Joel K

Supporter
Great work on the build, I am enjoying following along. Very interesting to see how you are mocking up the mounting system. Never seen those prototype pieces done that way before.

If you contact RCR, they could provide access/login info to the manual.
 

Bob Winn

Supporter
Yeah it's not they way I have done it before either. But the clearances where so tight, the semi-symmetric design, and the with the number axis i had hit just made sense to try something new. Plus with 3d scans of the motors and chassis available it was a logical choice. The cost of laser cutting metal has dropped too, I can probably get the whole frame and motor mounts for about 800$. That is really cheap compared to water jet or CNC. I have seen alot of RC guys do similar construction techniques for drones and planes in wood, GRF, and carbon. One turned me on to this (attached) paper on slot and tab design and strength analysis for metal construction and it all kind of clicked. Plus, if anyone else wants a subframe, or wants to tweak the design for use in something else, copies are very easy. Where as if I one off-ed a subframe as I have done before, making another is almost the same amount of work.

These slots are all 0.2 mm tolerances on the tabs, and it makes for a really tight fit without glue. It is near the limits of the laser cutter for accuracy, especially and the curves. And with riv-nuts and other interesting fasteners, in not sure you absolutely even need to machine the parts at all anymore. Just cut, weld (or glue!), add your hardware, and install.

But this is kind of what I am doing this project for. It really is a prototype for techniques and ideas I have been playing with for some time. I could have just built a by the book (what ever that is) SLC, but I hope to push the envelope here. Wait to you see the battery design....nothing like it in the automotive EV space yet.
 

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that a lot of work there! but amazing! I recently review my project as it may turn into a race car (that has to be efficient for 5 laps only). So i keep the original design 1tesla rear drive. In order to gain some weight i may switch from tesla batt to LG chem batt (2p6 config) and 2 loops cooling. however the LG chem seems not be availabler anymore (look like LG want to supply only manufacturers). i hope you already have your batts or have an alternative solution. Still waiting for customs athorization to import and planning my trip to RcR in october (can t wait to discover fran's package to set up the tesla motor within the frame). good luck and once again congratulations for your ambitious project
 

Bob Winn

Supporter
I have a set of LG chem's, but I am going to use them on a different project, a pulse autocycle i picked up. Going with a custom battery here, kind of like alot of electric motorcycle guys are building. Trying to link up 4 strings of LG chems was just going to get to costly with battery management, and getting it all to fit was going to a real compromise. Getting 12 in there will be no issue for you.. I know someone that might have 6 or 12 still if you are interested. I am doing another round of MDF prototype right now, after bolting this one all together I needed to make a number of small changes, and I wanted to see it all in real life before I spend the money on metal.
 
Fusion360 has a real issue exporting DXF files for laser cutting. Had to manually edit them in adobe for single cut lines.
I use it all the time. Have had exhaust flanges, trans adapter (Graz to 1UZ), steering wheel all cut. Just make a drawing from the 3D and exported the drawing as DXF.

My laser/water jet shop has always been happy with the files.
 
I have a set of LG chem's, but I am going to use them on a different project, a pulse autocycle i picked up. Going with a custom battery here, kind of like alot of electric motorcycle guys are building. Trying to link up 4 strings of LG chems was just going to get to costly with battery management, and getting it all to fit was going to a real compromise. Getting 12 in there will be no issue for you.. I know someone that might have 6 or 12 still if you are interested. I am doing another round of MDF prototype right now, after bolting this one all together I needed to make a number of small changes, and I wanted to see it all in real life before I spend the money on metal.
That s fantastic bob! i m definitely interested for 12 of them if they are in a good condition/ low age/good voltage/ good price otherwise i may have to stick to the tesla ones. Thank you very much for the information. Here is my email for the seller: [email protected] I keep you updated
I m flying to Superlite factory on october 23rd to finalize everything and already took appointment with Fran there.
i will research a bit on customs batteries as well to see how much it would cost to build a 400v/50kw batt for my project.
 
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