[gor]

Originally Posted by toddshotrods

Haha! They're building up, but only because I have such a great team beside me. Our new female team member worked ten straight hours with me yesterday, and worked as hard as I did.

The Inhaler is a company project now, so not really my burden, other than design and project supervision. Schism is mine, and I still plan to build Scratch, so I actually have two personal projects.




Yup, that's Schism's engine now. I can't wait to get all that crap cleaned up - yuck! It'll stay clean from here on, because I'll actually be able to reach everything and see when something's leaking.

A guy on another forum posted this link - pretty cool, and fairly similar to the basic concept we have.

also front - electric, rear - ice
Philadelphia Highschoolers Build Hybrid Supercar


http://www.treehugger.com/cars/phila...-supercar.html
their site: http://www.evxteam.org/

Todd, what are your thoughts on benefits of such 2+2 dynamic-wise (launch, cornering, recup (kers)? also - on possibilities of electric supercharger, electrocharger (starter-generator, e-assist, etc : )) ?

[toddshotrods]

I've seen that car before - pretty neat as well.

Originally Posted by gor

...Todd, what are your thoughts on benefits of such 2+2 dynamic-wise (launch, cornering, recup (kers)? also - on possibilities of electric supercharger, electrocharger (starter-generator, e-assist, etc : )) ?

Launch it should be awesome. My plan is to monitor rear wheel slip (via the factory ABS wheel speel sensors) to control application of power to the front wheels. More slip, more aggressive throttle input, up to the max power. That's for straight line acceleration. Only time will tell what this is like in cornering, and whether or not I want to spend the time trying to develop data and programming for front drive in aggressive cornering. That's a whole different ballgame.

Initially, I will just be using the electric drive like a Prius - as an ICE supplement. Eventually, I want to increase the range and power so that I can drive the car on all-electric power more. One definite use is in city traffic. That allows me to have a race clutch, but putt around for miles in stop-n-go traffic with ease. Another is in quiet neighborhoods, like the apartment complex I currently live in. I can leave and return silently on electric power. I don't see any issues with dynamics with a low power system as it's just a boost to the ICE. It's just complementing it, and throttle mapping can be programmed to make this as seamless as possible.

The only practical application I have seen for electric super/turbo charging is as a low speed boost, to eliminate lag.

I would love to have regen, but the lack of commerically available 150kw AC or BLDC electric drive choices may force me to forget about it and just run a simple series DC setup for a while. Later, I would love to upgrade to a BLDC system up front and have regen - mainly for more aggressive braking on road courses, in my case; and for bragging rights (just to say it does regen).

[toddshotrods]

Now that the donor car is pretty much stripped, we're back to the chassis. We only worked on it for a bit today, but got the main hoop and halo bar fit and tacked. The A-pillar bars, dash and seat brace, and braces down into the front and rear frame rails are next.


If you're wondering what's up with the wooden fixture, it's because we're also developing processes and techniques for educational purposes. The slots for the frame rails are CNC-cut and the fixture is leveled and really stable. The idea actually came from the AME SuperCar chassis kits, and the illustration they show of how it can be done with plywood and pine strips. We're not selling unwelded chassis or wooden fixtures; we just used the technique to demonstrate how modern technology can be combined with old school techniques in manufacturing. We're getting ready for an event with Ohio Department of Education in March and will pitch this as an example.

After this vehicle is on its wheels we plan to start fabricating a monster of a steel frame table for production.

[DavidDymaxion]

Drag, Salt Flats, and road racing require pads under the roll bar (something like 6x6 inches for drag racing, and 1/4 inch thick (!) and 22 inches of perimeter for the Salt Flats). I hadn't really thought about in the context of a tube frame -- how does one meet that requirement?

[toddshotrods]

Originally Posted by DavidDymaxion

Drag, Salt Flats, and road racing require pads under the roll bar (something like 6x6 inches for drag racing, and 1/4 inch thick (!) and 22 inches of perimeter for the Salt Flats). I hadn't really thought about in the context of a tube frame -- how does one meet that requirement?

In NHRA it's 6x6x.125 (1/8th)", I do remember seeing .250" thick somewhere, but can't remember which sanctioning body. My rule books are at the shop, so I can't look to see.

Anyway, to your question, the steel pads are for attaching cages to uni-body, sheet metal, chassis. It's because the sheet metal would fatigue and/or the cage tubes would punch through in a roll over crash. I used the pads on C.T. Freeman's Fiero cage, because it was mounted to the sheet metal "space frame" chassis. With factory full-framed, and aftermarket tube framed, vehicles NHRA and most (all?) rules insist that the cage be welded directly to the frame. In the case of vehicles where the main frame members are narrower than the cage hoops you can use tubular outriggers to extend to the hoop mounting points.

I designed these frames specifically for a roll cage. That center trapezoidal main box is to create, with the main cage bars, a sort of cell for the occupants. Then, the front and rear frame rail locations were determined to tie the suspension systems into that cell. There will be a lot of triangulation, up and down, front to back, and side to side.

EDIT:
IIRC, the NHRA spec for the plates is actually .118" thick. You start with thicker material to compensate for it thinning out when it stretches (e.g., forming the plates around the contours of the floor), bending cage tubes (outside wall gets stretched thinner). The cage tubes similarly start with .134" wall tubing (for mild steel) which is over the spec (I'll fill that in here later, when I get to the shop and look at the rule book).

[madmike8]

Looking Good Todd! Are you going to make a fiberglass roof? If you do, I might be interested in getting one from you for my T-bucket build.

[toddshotrods]

Originally Posted by madmike8

Looking Good Todd! Are you going to make a fiberglass roof? If you do, I might be interested in getting one from you for my T-bucket build.

Thanks Mike!

Yup! We will hopefully be making the transition to bodywork in a week or so, and it'll be posted here. The roof will be a fun process because we'll be using a combination of newer technology and old school fabrication techniques again. Shoot me a PM or email if you like what you see, when we get to that point.

[madmike8]

I'll definitely be keeping an eye on this thread and your progress!

Thanks

Originally Posted by toddshotrods

Thanks Mike!

Yup! We will hopefully be making the trasition to bodywork in a week or so, and it'll be posted here. The roof will be a fun process because we'll be using a combination of newer technology and old school fabrication techniques again. Shoot me a PM or email if you like what you see, when we get to that point.

[mizlplix]

Great start! A perimeter frame is a very adaptable platform to develop into a custom vehicle.

I have owned a chassis fabrication fixture for over 40 years. I just got rid of it last year when I retired. (sent it to the scrapper, no one wanted it.....).

It was 16 feet long and built out of 8" I-beams set 34 inches apart with 6 inch channel cross-members. It was LOW to the ground and had 4 scaffold caster wheels.

It was painted machinery grey with the top flanges unpainted. The beem centerlines were scribed and center punched for easy layout and measuring.

It had holes drilled in random places for attachments and you could tack weld things where ever you needed for extra brackets.

Over the years, It performed it's magic on many, many vehicles, both new builds and crashed racecars to be straightened.

Don't go flimsey or cheap!

Miz

[toddshotrods]

Originally Posted by mizlplix

Great start! A perimeter frame is a very adaptable platform to develop into a custom vehicle...

Hey Miz, thanks! It's shaping up pretty well. It's a production-oriented design, and I'm testing the ability of moderately skilled workers to build them. The two that did most of the work on this chassis, so far, have natural skills, but practically no experience. The results are fantastic! I did step in on a couple critical areas, but those will be done on machinery, with dedicated fixtures, in regular production. I want them to learn the old school ways of doing things first - by hand, with patience. I also want them to have an understanding of what the machines are actually doing for them, not just be button-pushers.

Originally Posted by mizlplix

...I have owned a chassis fabrication fixture for over 40 years...

...It was 16 feet long and built out of 8" I-beams...

...Don't go flimsey or cheap!

Miz

I have a penchant for over-thinking, over-engineering, and over-building, things - so no concern there! It's going to be a monster, that's for sure! Originally, I had planned for a massive, heavy-wall, rectangular-tube, main frame, with a .500" steel plate on top, with a grid pattern cut in it for layout work, and drilled for fixtures. After checking out a conversation on a hot rod forum, with some of the top hot rod builders, I am leaning away from the solid-top, table, construction, towards an open design. Probably still rectangular tube construction, but I do love I-beam-based fixtures!

My chassis will be very similar to what they're building, and the open fixture designs allow you to work all through the center of the chassis, positioning and tacking crossmembers, braces, gusseting, brackets, etc. The other feature that is becoming more common is increased height - for the same reasons. Depending on what they're building, and personal/shop preferences, the heights seem to be in the range of 2-3ft high. Our current wooden fixture is 13" high and solid - it would be nice to have another foot, and better access in the center...

Another reason I plan to build an absolute monster is this first one will really be a development fixture. It will need to do a lot of things, accurately, and without excess effort. It is going to have rotisserie attachments that allow us to pull a chassis out of the fixtures, straight up into the rotisserie and weld it completely; plus some other interesting features. When we swing into full production mode, there will be two dedicated fixtures just for these chassis. That process will be more conventional where fabricators lay out and tack a chassis on the fixture, it gets pulled and moved to the welding room, where welders finish weld them on separate rotisseries. Then back out to assembly...

Work resumes this afternoon. I want to get the A-pillar bars cut, fit, and tacked in; the seat and dash bars tacked in. That may be a bit much for a half day, considering the fact that I am teaching more than working, but it's the goal.