three wheel car

People in general think 3 wheeled cars are unsafe in general. It's going to be uphill battle:-)

I see that the Scoot you linked will draw ~3 bikini clad ladies. For $7500 that's a pretty good value. What do you think the Go3wheeler will do in the ladies department. The napkin sketch looks good to me but I'm not sure what a lifetime of spray tan oil does to perception of appearance for the average bikini wearer.

Seriously though you are getting SOLID free advice from people. I would strongly encourage you to either begin showing some facts to change peoples minds about your product or heed the advice and re-visit most of your design. What you have presented so far shows a very basic misunderstanding of engineering principles related to tube frame chassis design. That's fine if all it is a quick proof of concept to get some basic performance dialed in and to mock up the body. I am confident a lighter, easier to manufacture design could be developed that would add little to no weight very little cost and a lot of safety compared to what you have.

go3wheeler wrote: People in general think poorly engineered and thought out cars are unsafe in general. It's going to be uphill battle:-)

FYP. Especially here.

There are a lot of engineers giving a lot of free advice in this thread. If you had to pay for it, you could have purchased the Scoot by now.

RossD: You just gave you free advice about receiving free advice from Engineers from a Professional Engineer. That's worth something and makes my head hurt.

Seriously a lot of the suggestions being given here are good. A popularly designed frame shouldn't weigh anymore then the one you have now. SAE cars are under 400lbs and they have four wheels and I would trust most them a lot more then the frame you have shown here. Please if you are serious about making a product for the road, go back and take another look at your frame.

Here's some more- not even for the chassis.

Based on your design and layout, I'm betting that you will need somewhere around 3-5hp to move the car at a constant 50hp. Call it 7 to do 70.

Now you may think that your 16hp industrial engine is a good one to do that. And it WILL make that power range, no doubt.

The problem is the stated goal is fuel economy, and I'm 99% sure that your motor isn't going to make 3-7hp all that efficiently. One step better would be a single cylinder carbed motorcycle motor- two major gains over your powertrain idea- CVT belt efficiency isnt' very good, and just having basic spark control will radically make things better. Add in real fuel control + actual speed-load-conditional spark control, with compression and cam timing to match, and your fuel economy would be huge.

Otherwise, I'll bet you get somewhere around 50-60mpg, which appears good, but really is half what you shoud be capable of with a 450lb chassis and a streamlined body.

Just a suggestion.

From one borderline canoe to another:

That said, it's fixable. Free-body diagrams and spreadsheet programs are free. It's worth buying a few books on frame design, and I would second the idea about hiring an FSAE or Baja student to go over your design. Just be sure that they keep it simple.

If you go back and read this post from the beginning you will see that this is a nothing more than a prototype and far from final product. We are not concerned if some of the tubes not where you want them to be. We want to test the concept before we get in to details. We will have less welds and a lot more pre bent tubing in the final frame. Most of the brackets and panels will be laser cut. The weight, dimensions and fiberglass body will stay the same. We can go through DMV inspection, get the VIN#, find out what it takes before we even get to even thinking of selling anything plus we get to play with different engine and EV setups. Keep checking back here and like us on Facebook for a lot more progress.

Ah, if the frame is just a placeholder for a future proper design, I take back my concerns. Most performance vehicle design starts at the suspension and then the frame once the inboard points are locked. For a little scootabout, that's probably overkill, especially if you guys have experience with previous products. That ebay listing looks like a nicely polished product aimed right at your market.

I guess I'm having a hard time understanding why you want to test the concept using a poorly designed frame. It just seems counterintuitive. This isn't a new concept. Lightweight 3-wheelers have been around since the early days of the automobile. They were quite popular for a time during post-WW2 Europe. What exactly are you trying to prove?

Ian F wrote: This isn't a new concept. Lightweight 3-wheelers have been around since the early days of the automobile. They were quite popular for a time during post-WW2 Europe.

yes, yes they were

We are not doing anything new or trying to prove anything. Three wheelers started before four wheeled vehicles. We are making good progress on the car build.

I have Rack & Pinion on my mind

Warren v wrote: Ah, if the frame is just a placeholder for a future proper design, I take back my concerns. Most performance vehicle design starts at the suspension and then the frame once the inboard points are locked. For a little scootabout, that's probably overkill, especially if you guys have experience with previous products. That ebay listing looks like a nicely polished product aimed right at your market.

If this frame is just a placeholder and the final design would be something very different - a folded sheet metal design made on a press brake and welded, for example - it would make perfect sense. If the final design is tubular construction, though, I'd still probably want to have all the tubes in place just to be sure they don't interfere with anything.

go3wheeler wrote: People in general think 3 wheeled cars are unsafe in general. It's going to be uphill battle:-)

Well, the way I drive...

Interesting design with not much frame at all. Our frame looks like overkill:-)

http://www.sceadu.com/products_sd1.html

go3wheeler wrote: Interesting design with not much frame at all. Our frame looks like overkill:-) http://www.sceadu.com/products_sd1.html

These four point racing seat belts are perfect for the seat we have. Safety is number one priority in our design.

go3wheeler wrote: Safety is number one priority in our design.

That's some funny stuff right there... you should do stand-up...

Ian F wrote:

go3wheeler wrote: Safety is number one priority in our design.

That's some funny stuff right there... you should do stand-up...

I'm glad you got a good laugh out of it Man. My work is done:-)

Updated front and rear Go3wheeler frame section shown

before

after

go3wheeler wrote: Updated front and rear Go3wheeler frame section shown

You still haven't capped the ends of the transverse dash tube. (Did you do the ones behind the sheet metal nose?)

That revision is a lot better. You should put horizontal gusset tubes to the node in front of the top of the rear bulkhead, though. In any sort of impact, the long run of tubes will buckle quite quickly, especially since there's a joint effectively pre-buckled. A little more triangulation on the sides would help a lot, too. Remember, sheet metal reinforcement adds almost zero strength in compression, it's just good for shear and tension.

Also, Joey, when did GRM start caring about open section transverse tubes?

I would suggest adding these. The vertical tube to the kink on the uppers could be eliminated.

It's improved but still has a ways to go. Have any sketches of the production frame concept?