Limitless LibertyMkiii's crazy belt drive car project

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Rotor Riot did a thing on flying with Lipo batts and radio gear not too long ago. IIRC the batteries were a carry on item. I reckon the biggest hurdle is convincing the TSA goons that it's not a food item. A big Lipo does look like a block of Velveeta, which, as we all know, is the TSA rubber-glovers' favorite snack after a long hour of cavity searching and tush groping.
 
Small update. Last night I finished sanding the body filler application and got the primer sprayed on.
Took the photo while the primer was still wet for a good reflective surface.

Primer 3 quarter view Capture.JPG


I need to go back with some body filler in some areas :mad:
It is always easier to work/see the flaws once a solid coat of primer is on it.

Primer lines Capture.JPG
 
Small update. Last night I finished sanding the body filler application and got the primer sprayed on.
Took the photo while the primer was still wet for a good reflective surface.

View attachment 142827

I need to go back with some body filler in some areas :mad:
It is always easier to work/see the flaws once a solid coat of primer is on it.

View attachment 142828
Instantly looks so much better once it's coated.

Sucks it needs body filler though, those ripples might just add 0.001 Cw ;)
 
I've heard rough surfaces can be more aerodynamic than smooth ones (less drag due to disturbed wind flow or something). Is that true
It depends where it is and what you want the airflow to do in that area.
In some places the airflow is "attached" and you want it to be... In other areas you don't want it attached so you create vortices or other disturbances in the airflow.
In general for high speed aerodynamics... look at fighter jets or land speed cars as examples, you want smooth surfaces.

There is also something called boundary layer separation. You can see this occurring on the hood of your car or the side windows while driving in the rain. You can see groups of water droplets that seem to not be effected by the airflow. In your head you would think the wind should clear all the water right off the hood or side window. This boundary layer separates the surface from the airflow. It is magic!
 
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Since I tried to make the jump from 150 mph to 170 mph in my full-scale car (Sunday hoons on the Autobahn near Luxembourg City 🤪), I learned the importance of downforce generated from a splitter, belly pan, side skirts, and diffuser. I always scoff when I hear RC speed runners talking about raking the car forward to prevent nose lift... which would ruin that downforce. Seems to me there is a better way to hold down the front without ruining ground effect. I assume your car is going to be dead level (as it should be) and pretty well weighted. Are you worried about nose lift, or is the body shape intended to do it for you? Is ground effect not even a thing at 1:7 scale?
 
Since I tried to make the jump from 150 mph to 170 mph in my full-scale car (Sunday hoons on the Autobahn near Luxembourg City 🤪), I learned the importance of downforce generated from a splitter, belly pan, side skirts, and diffuser. I always scoff when I hear RC speed runners talking about raking the car forward to prevent nose lift... which would ruin that downforce. Seems to me there is a better way to hold down the front without ruining ground effect. I assume your car is going to be dead level (as it should be) and pretty well weighted. Are you worried about nose lift, or is the body shape intended to do it for you? Is ground effect not even a thing at 1:7 scale?

The car is much more level than the average speed runner. I had built in a small 3mm of rake.
The front nose should produce some good downforce and will have an integrated splitter. It probably needs more CFD simulations to know exactly what it will do, but the plan is to run it and see how it goes...

I will look into some sort of skirts to seal the sides to the ground. Mentioned before I do have a tail section and diffuser that will go on the car.
 
Yeah, skirting channels air in order to maintain velocity under the car. If it spills out the sides, you lose the advantage.

@The Bean: Honorary Euro, maybe. I was born in California. I have a house over in DE and lived there for 10 of the last 15 years or so.
 
This may seem like a dumb question, but once the body is on, if you shred a tire, there is no where for it to go, is there going to be any protection for the internals, or do you think that is unnecessary?
 
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This may seem like a dumb question, but once the body is on, if you shred a tire, there is no where for it to go, is there going to be any protection for the internals, or do you think that is unnecessary?
This is no different from any other GT body car. The foam tire shouldn't hurt anything...
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So I have my first big setback. Waited nearly 2 months for a custom built TP Power TP4070 in a 780kv wind. I fully understand that lower KV motors have thinner wire and more winds. I previously had a TP5660 in a 1450kv wind and it has the same amount of wire as any of my other motors. In fact all my TP Motors I have ever owned (6 of them) all had about the same amount of wire.

Not the case on this motor!!! WOW!?

Tiny wires Capture.JPG


2mm wire Capture.JPG


Mock up Capture.JPG


It appears that I will be purchasing a higher KV motor, and have to figure out how to reduce the gearing :cry:
 
This is no different from any other GT body car. The foam tire shouldn't hurt anything...
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So I have my first big setback. Waited nearly 2 months for a custom built TP Power TP4070 in a 780kv wind. I fully understand that lower KV motors have thinner wire and more winds. I previously had a TP5660 in a 1450kv wind and it has the same amount of wire as any of my other motors. In fact all my TP Motors I have ever owned (6 of them) all had about the same amount of wire.

Not the case on this motor!!! WOW!?

View attachment 142844

View attachment 142845

View attachment 142846

It appears that I will be purchasing a higher KV motor, and have to figure out how to reduce the gearing :cry:
So maybe a dumb question or I am about to learn something. Is the concern that the smaller wires will not hold up due to amperage/heat?
 
So maybe a dumb question or I am about to learn something. Is the concern that the smaller wires will not hold up due to amperage/heat?
Exactly, the wires are tiny all the way into the motor, they wont take big amperage....

I was just about to ask the same thing. Like could you make an adapter?

Yeah it would be a large 8mm bullet with a tiny 2mm wire inside.
 
Since I tried to make the jump from 150 mph to 170 mph in my full-scale car (Sunday hoons on the Autobahn near Luxembourg City 🤪), I learned the importance of downforce generated from a splitter, belly pan, side skirts, and diffuser. I always scoff when I hear RC speed runners talking about raking the car forward to prevent nose lift... which would ruin that downforce. Seems to me there is a better way to hold down the front without ruining ground effect. I assume your car is going to be dead level (as it should be) and pretty well weighted. Are you worried about nose lift, or is the body shape intended to do it for you? Is ground effect not even a thing at 1:7 scale?
don't mean to threadjack.. In my opinion RC speedrun cars need that rake for two reasons.. When a higher degree of rake is set the entire body itself generates more downforce than if flat, and also, air entering under the car from a small, narrow front opening creates pressure as it accelerates and moves rearward into the expanded area created by the rake of the chassis. This in turn creates the suction effect. Compared to a 1/1 car, a typical RC speedrun car is very overpowered and very underweight, making downforce even more important to stop things like blowovers that you don't often see in 1/1 cars. Of course, the rear shocks need to be setup specifically for speedruns as well. As far as LibertyMkii's design goes, since his is completely different, much more reminiscent of an LSR car then a typical RC speedrun car, I think he will have different aero challenges to overcome than what most of us would have to deal with. Liberty's project is the best thing going on in this forum right now, cant wait to see the final outcome
 
This is no different from any other GT body car. The foam tire shouldn't hurt anything...
________________________________________________________________________________________________________________________

So I have my first big setback. Waited nearly 2 months for a custom built TP Power TP4070 in a 780kv wind. I fully understand that lower KV motors have thinner wire and more winds. I previously had a TP5660 in a 1450kv wind and it has the same amount of wire as any of my other motors. In fact all my TP Motors I have ever owned (6 of them) all had about the same amount of wire.

Not the case on this motor!!! WOW!?

View attachment 142844

View attachment 142845

View attachment 142846

It appears that I will be purchasing a higher KV motor, and have to figure out how to reduce the gearing :cry:
You don't need to . Shorten the leads and splice some 8ga. wire on the ends . Or Wrap some buss wire around the ends to take up space in the cups then solder them in. I have to do something similar with my NEU 850kv motor for my 1/8 scale Hydro.
 
You don't need to . Shorten the leads and splice some 8ga. wire on the ends . Or Wrap some buss wire around the ends to take up space in the cups then solder them in. I have to do something similar with my NEU 850kv motor for my 1/8 scale Hydro.

I suppose I need to pull the rear cap off and make sure about my assumptions..... My assumption is that this wire size is consistent through the motor and it just wont handle 400+ amps.

Are you using a filler/primer? Should help w/ some of the small imperfections.

Yes it is filler primer. It did fill in some smaller stuff, but just a few areas that need a little extra help. I have a light body filler/glaze that will get it fixed up easily.

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Posted a video last night about this and shows the car in a few angles:

 
I suppose I need to pull the rear cap off and make sure about my assumptions..... My assumption is that this wire size is consistent through the motor and it just wont handle 400+ amps.
Remember, wire length is as important as wire size. The filament portion of electrical fuses are thin as hair, yet carry the full current of a circuit up to their rating because the section is very short in length. On the other hand, damn those wires are skinny! I'd feel a lot better seeing some copper ingots bridging the connection.
 
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