Mini Dooling/McCoy Teardrop Tether Car Cox .020 powered

Yeah, I could never justify spending that much money on a real one.

I thought about making a Frog, but the teardrop would be quicker.

Looks like you got a real good start on that car there.

I see Ron is going for speed , good start brother ,, i did get my controler out to find out i need more batteries LOL

So, I have to ask. It the one pictured just a wheel screwed directly to the engine with the prop screw rather than a propeller?

Right now the wheel is just mounted on in place of a prop. The picture I took was roughly 1hr’s worth of work. Everything is in the planning stage at this point.

The wheel feels just shy of 1/2oz. I will be running it before mounting it. It may be enough to act as a flywheel however, it’s not balanced so I can only speculate as to how it will run. I’ll probably do that in the next day or two.

Right now all I have into it is the cost of the engine which I think is $15. Everything else is just stuff I had laying around. I did buy a can of paint for it today so add $5.

I am not entering this in the contest as it’s a conflict of interests. I am doing it just to show how easily it can be done. Hoping to drum up some competition!

Are you going to enter Roddie? I was thinking that I really could have used some of your O-ring aluminum wheels.

Thanks Roddie, I will measure tonight. They may be too light though.

Ron

1.75 on the rear And 1.25 up front.

The best I can say and come up with on this one is....

I tried to run it up on prime last night, it did run, but the engine itself is an unknown as it was bought at a swap meet and never disassembled and cleaned. I will be doing that shortly. The wheel attached is pretty sizeable for that .020, it probably weighs 10x more than the standard .020 prop.

I am still mocking things up, so I haven’t been serious about the engine yet.

Funny thing, I watched a you tube video last night of the full sized teardrop tether. I found out what I thought was the rear end is actually the front. The fat end is the front of the car...

To me that doesn’t look right. So I am doing it my way, pointed end out front. My luck is that it is designed that way for a reason. It will probably become airborne. I’ll add some weight to the nose just in case.

Ron

Regarding starting a car engine, I've seen it where people turn a bicycle upside-down, spin up the rear wheel with the pedals and touch the wheel of the car against the tyre. Seems to work pretty well.

Thanks Rod, I was hoping you would chime in.

The bicycle is exactly what I am going to use. Years ago I read an old RC modelling book that had a picture of a guy starting a Jerobee car using a bike wheel. It stuck with me. Any thoughts on the flywheel?

Ron

Some progress, I have the layout done, need to notch the lid to accept the cylinder and attach the axle and design bridle mounts. I have some aluminum stock that should work well for that. After that it’s break it all down, paint and re-assemble.

Looking good, and coming along nicely.

Looking good Ron , how did you get the extra wood out around the engine mount ? That is strange about it going (running ) what looks like backwards ?!

Dremel. Lot’s of sawdust!

Yeah, check out this link. Looks like it runs with the fat end up front.

I bet there was .. Man that thing was turning up darn good But didn't sound like a .020 to me LOL I wish they still did these races around , that wood bee a lot of fun !!

If you look at the teardrop car and think of a dragster (it kinda looks like one of those front-engine machines from the ’60s), intuition tells it should go ”pointy end forward”. Especially if you think performance = rear wheel drive

Aerodynamically though, it is more efficient going with the blunt end first. Kinda like a fish, or raindrop. Take a look at ”belly tank lakesters” from the Golden era of motoring:





Blunt end first, pointy end back just as it travels under the belly of a P-39. More about that particular beast:

https://bringatrailer.com/2009/11/25/there-aint-no-rules-1948-era-bellytank-lakester/

Either way, great work Ron If you had a reed engine on it you could run it first one way, then the other and see which one is faster

Thanks Kari, yeah a reedy would have made it simpler and would have allowed running in either direction, but the TD is more powerful.

So, it’s all mocked up, time for sanding and paint work. Not much longer now