Tube Frame Testing

[John Clutch]

I'm very new here. I haven't built a model in thirty years, so I thought I would give tube frame fabrications a trial run to see what it's like working with styrene. It's definitely a great material to work with. I started bending the rods with a pair of needle nose pliers and taped the sections to a block of birch plywood to get a feel of it and see the working time of the glue. My direction for jigs and templates has changed a bit, and I'm glad I decided to "wing" it for this first small project. 

I went to my LHS to order my Foose Camaro and to pick up some supplies. Drill set, glue, some styrene rods and decided to get a 1/25 Corvette. My father had a 1969 Chevelle, and always wanted to turn it into a pro touring car with vette  drivetrain and suspension. He sold the car before he had a chance of building it, so I thought I would surprised him with a model of one. That's not going to happen now because I made a rookie mistake and picked up the AMT 2009 vette "showroom replica" with no drivetrain in it lol.......so on to what I learned so far......

1. READ the box! Don't assume it's a full kit lol.

2. Styrene rods when cut with a hobby knife will fly into the abyss, so watch what you're doing.

3. Styrene rods have memory.

4. Keep a wire in the glue syringe to unclog it, the cap is false security.

5. Protect all clear components like the windshield. I threw it back in the box and scratched it up. 

 

Thanks for looking. Feedback is always appreciated.

6. I can't load pics from my phone lol

Edited July 20, 2015 by John Clutch

[John Clutch]

I had to take a pic for it to post. It won't allow me to pull up pics from memory.

I didn't spend anytime fitting this to the vette body, other than the main hoop. I just winged the rest. I just wanted to get a feel for the material. I'm.not planning on using it.

[russosborne]

Wow. Looks awesome.

Are you sure this is the first?

Russ

[John Clutch]

Russ, Thank you!  Yes this is my first lol but not my first at fabrication. Metal fabricator by trade, never built a turnkey drag car but I have done a good amount of work on them, been building and drag racing nitro and electric remote control cars since the late 90s and Im constantly creating. Speed is my ultimate challenge, and rc does that for me. But it lacks in visual creativity and I hope to fill that void in my life with modeling.

Clutch

[John Clutch]

Here is my latest creation. I build everything except the engine, exhaust and electronics. Its a rear axle clutch system. First one designed for rc cars. I saw the concept on modified mopeds, except the clutch is on a jackshaft, and thought I would try the system. It works but there is ALOT of fine tuning to be made. Getting the right clutch weights and spring rate is my challenge at the moment.

EDIT: Im not sure why my image disappeared, so here it is again.
 

 

Edited July 21, 2015 by John Clutch

[aurfalien]

Hi John,

What advantages in RC would a rear axle clutch give you?

Seems a like an awesome endeavor.

Edited July 21, 2015 by aurfalien

[John Clutch]

Moment Of Inertia

The less mass a rotating system has, the less work is required to move it from a stand still. Very important concept to take advantage of at all cost, whether 1:1 or scaled. And in drag racing, the less torque that is required to move an object, the more the motor can be tuned for horsepower. At the weights these cars run at, having too much torque is wasted energy. You only need so much and anything more than that doesnt help contribute to performance. You can have two 500c.i. motors. One is in a drag car, the other is in a monster truck. The truck requires alot more torque so the tune will have to be bias to that, where a drag car is lighter and requires less of it.

Rotating Inertia

Since the entire drivetrain system is moving before the clutch engages, it helps accelerate the car off the line a bit. The weight of the clutch bell, rear axle and wheels is all that needs to be put in motion. Granted, the engine still needs to pull all of the drivetrain down the track, but I think I can use that weight to my advantage, as soon as I figure out exactly what the bare minimum is to get the job done. I built an incredibly light drivetrain initially, and it proved not to work because the clutch simply did not put out enough force. So once I figure out exact what the system wants, it should fly.

[aurfalien]

Wow, that sounds cool.

Are you doing this via trial and error or is there some math/previsualization involved to help speed the R&D process?

Edited July 21, 2015 by aurfalien

[John Clutch]

I always start every project from a mathematical point, to give me a starting point to work from. Centrifugal forces have alot of different influences that are hard to put down an exact mathematical formula to. Material, dimensions and conditions effect it, so you can only start from a "guesstimation" lol. At this point, the math is somewhat close, but Im off the paper and into the physical until I can come up with a combination. Once the car starts doing what I think it should be doing, then Ill evaluate the numbers again.

 

Edited July 21, 2015 by John Clutch

[aurfalien]

Wow man, sounds uber time consuming.

Still a killer endeavor.  I see a patent and $$$ in your future as RC is big.

I've a client were its a bunch of grown up kids basically and its RC every where from cars to flying fish to mini heli copters etc...

It gets anoying when the Nerf guns go off but it beats cubicles.

[John Clutch]

Yes, its very time consuming. I always build my own cars, and they are different from most others. Sometimes they are a complete failure, sometimes they set national records. I have a world record for a combination (0.12ci motor, 11" wheelbase doorslammer) that hasnt been challenged since 2006. The class has allowed bigger engines (with weight penalities) and most if not all are trying a bigger motor combination, but performance is not much better than what I can do with a .12 motor. Ive been away from the hobby for a few years (physically but never mentally) because life gets in the way.

[aurfalien]

Dude since 06', wow.

It will be a decade next year, how cool would that be?  Your decade long record.

[John Clutch]

I also have plans to go after two rc land speed records. But that adventure will require alot more planning than willing to give at this point. And most of the planning is being able to accept the fact that there is a 90% chance of losing the entire car on a single pass, because its a very fine line between going fast and complete destruction. lol

[aurfalien]

Do it man do it.

Think eye of the tiger!

[John Clutch]

How I would love to do all that I want, but time and money is a very limiting factor in my life lol