I wasn't sure about taking part in the '14 sweepstakes because none of my ongoing projects fit into the regulations.
Anyway, I decided to rebuild my long time darling, the G3, a three wheeled, direct drive RC car.
I might have started out a bit late, I think. Hopefully, I can finish it in time.

The car is fully scratch built, trying to limit off-the-shelf parts as much as possible.
Currently, except the the wheels, motor, shocks, hubs, and electronics, everything else is fabricated.

Using a reworked DT750 outrunner with a 1/10 65mm wheel directly bolted on to it, plenty of torque and fast enough to get nasty.
Planning to use a 3S 1Ah LiPo to keep the weight down.
Overall weight is expected to be around 700-800g.

Base plate.
1.5mm aluminium, 250mm length, 93g.

Swing arm.

1.5mm Aluminium, 63mm length, 17g.

 

I tried using some 3/4" L-angles to mount the rear swing arm. Unfortunately, the aluminium was too flimsy to hold it firmly.

Today, bent 1mm aluminium into a couple of L-angles and it's all pretty stiff now.

Waiting on a couple of axles and hub carriers to be turned and milled out for the front end, hopefully, I get them by the weekend. 

All the best sir

Wonderful.
Motor inside wheel is great!

Excellent work.   If you can fabricate the body, you could have the world's first RC Auto-rickshaw

Ashim.

Cool!

Even though the DT750 motors provide a lot of torque, I think it'll be safer to use some gearing (say 1.5:1) with a belt drive. That way the motors won't get overloaded.

Are you going to use ESCs with reversing capability?

Here's something fun I made a while ago to test the DT750 motors...

www.youtube.com/watch?feature=player_embedded&v=YSnDbtCshNU

Yash & Iyer sir, thanks!

Ashimda, I hope I can build the body too, but if I can't, what's lost in looks will be made up for in speed.
If do manage to build the body, it would look the RC auto rickshaw in the screenshot.

Swapnil, yes, the motor does get warm slightly because its not cooled.
Outrunners get warm/hot/fiery if not cooled properly, so even if I gear it down, I suspect, it will still be drawing almost the same amount power effectively, but at different torque/RPM output.
But honestly, I wouldn't want to gear it down because I will be losing RPM over torque that's not required.

Work progressing very slowly due to my exams.

Finished the front shock assembly, independent push-rod style suspension.

Tomorrow, going to complete fabrication on the swing arm and hub carriers, still waiting on the front axles from lathe work.

Really nice concept trike lol of u like callin it that.
Keep up the amazing work after ur exams on this project

Few suggestions,
1. Rc cars generally use in-runner, brushed or brushless to cope up with the torque required for the wheels. Out runners r mostly used on light planes (250-1200gms thrust), reason being air cooled, little torque high rpm just to drive one TINY propeller( few gms). This leads to a design issue since you chose a direct drive, no gears. It's good for low to avg speeds for this weight, but not bashing n speed runs. You can check the limits, but be very careful
2. Use plastic bushings/shims instead or metal washers on moving rocker and shock arm joints. They can be lubricated for quick response from the vehicle. Various ball-pen, gel pen used refills can be sliced to make them
3. Use tread-lock on moving nuts if you can get that, or a glue gun or rc-cement should work. Just some friendly suggestions from another design fanatic

Great job on the build. I love the rocker arms.

Those shocks look familiar. Do you have a buggy?

RumblePirate, Thanks! Trike yeah, but I call it the G3.
Sadly, can't wait till exams end, sweepstakes submissions end by the 10th.
I was cynical about the motor too, at first, but then I can do 15 seconds+ burnouts with the motor barely getting warm on a 3S and it doesn't even go over 20A with the motor rated to 30A peak.
I agree on the air cooling part, I'm yet to test the run time limits.
Shocks have nice ball links in them, I'll try shoving servo mount bushing on to the rockers.
I skipped thread locker and used lock nuts instead, so all good on that. 

iamahuman, Thanks!
I had got the shocks from RCB long ago, they're offroad, yes.

Finished suspension tower today.
I scratched my head over this a lot and then I found some rectangular frame in my junk, voila! Perfect.
Set it back slightly, from the original position because the shock push rod, steering tie rod and suspension arms were colliding.
Steering servo will be mounted up front due to clearance issues.

Tomorrow, fabricating suspension arms and hopefully, shock rods too.

This is shaping up to be my favorite build thread on RCI. Can't wait to see this finished

This is where I started with the trike config 7 years ago back in 2008.

Front end from a broken toy car, I wasn't smart enough to build one back then.
motor from a CD drive
rear swing arm from a hard disk. The most hi-tech piece in there, dial ball bearing!
I had literally ripped the battery off my Tata Indicom landline, it was running on DC, no one found out.
Radio, 27MHz came from a toy car.
Antenna from some China phone.

Tried this suspension setup last night, it's heavy, very rough and crooked. Not pleasing. Scrapped.

Today, used some off-the-shelf buggy swing arms that I had got from RC Bazaar.

Reason being, it's far lighter than my aluminium setup and simpler at the moment.

Push rods for shocks have been setup and everything is working smooth.

The hub carriers I made previously were a bit large to accommodate a body shell (If I build one), so making smaller ones.

Front axles fabrication, hub carriers, steering setup and body work is all that is pending as of now.

"Tried this suspension setup last night, it's heavy, very rough and crooked. Not pleasing. Scrapped."
Who says?
Homemade one was looking just fine!

Iyer sir, It looks nice, but the suspension arms were shaking a lot, undesirably, constraining those from moving sideways is unwanted complication and unreliable too.
Besides, the whole setup was 120g; Vs. the ~40g current one.
So I decided to use the plastic ones without wasting much time over it.

I use hand tools except an electric drill, so it's a little hard to fabricate high tolerance parts. Wish I had a Dremel.  

Ok for the sweepstakes.
But this is only the bottom half of the suspension.
Where's the top half, king posts etc?
And the issue of how much the steering arms be raked to ensure that the turning radius of the inner wheel is less than that of the outer wheet etc...

I think your metal work was good and that you should continue.
When you have the time,
Separate the motor issues and chassis issues.
Think about the chassis parts in detail, draw them up, and get them laser cut in a suitable material.
How do you think they build Morgans?
You should build at least one complete trike by hand (incl shocks. Or forget shocks. Why do you need shocks? Replace with just springs and forget about damping)

I don't know you, but as my vote of confidence, you can borrow my Dremel...

The top half is almost done, I didn't install it because I hadnt figured out the steering servo placement and there's not much space around there.

I have to make a new smaller hub carriers.

I wanted to build most of it myself, pretty much everything I can, but I want to complete it in time. Surely, I'll build a all DIY front end after a while.
I will try laser next time.

I like to push my boundries every time I build something, so I usually try new things, this is my first pushrod suspension build.

Thanks for the Dremel offer, very kind of you, sir. I'll get one as soon as I am not broke anymore.

Almost finished setting up steering mechanism, have to link up a couple more rods and it's done.

Upper suspension arm still pending, figured out the setup, building it tomorrow.