Limitless LibertyMkiii's crazy belt drive car project

[LibertyMKiii]

Really lost interest in all my hobbies lately. Not sure what the deal is.... Hopefully I can find my motivation again!
We have been extra busy with the 3 kids lately and just life in general.

I decided I need to finish up this car over this winter and attempted to carve out some time over this past weekend.
I really shouldn't have attempted this mold creation step in the short window of time that I had on Saturday.

I had 60 minutes available Saturday and "went for it".

Step 1 was to apply the gel coat. Given my issues with multiple coats I decided to do a single heavy coat. Waited for it to cure in about 25 mins, with the help of my wife's blow dryer.

Step 2 applied 2 layers of chopped strand fiberglass to make the mold. It was rushed and the fiberglass had some air bubbles/gaps between it and the gelcoat. The gelcoat has little strength being so thin and not supported by the fiberglass where those air bubbles. You can see in the image below the spots where the air bubbles are chipped away while washing the PVA mold release off with a water hose. I'll have to fill them in with body filler and sand it smooth.

 

[rotauq]

Life in general can be such a strain on hobbies

 

[Tex Koder]

Really lost interest in all my hobbies lately. Not sure what the deal is.... Hopefully I can find my motivation again!
We have been extra busy with the 3 kids lately and just life in general.

I decided I need to finish up this car over this winter and attempted to carve out some time over this past weekend.
I really shouldn't have attempted this mold creation step in the short window of time that I had on Saturday.

I had 60 minutes available Saturday and "went for it".

...

It's basically like going to the gym to workout, biking for 30 miles etc etc...
You know it's good for you, but man it's tough sometimes to focus and get going.
Sometimes it's best to find a "training buddy" to help get your concentration back on track.

Know that you're not alone in this endeavor.
Especially when you've got a couple of little ones Demanding your attention CONSISTENTLY. I can Certainly relate!

If you need to talk shop, I'm not that far away. Let's find a mutual place to meet for an hour or two to chat.

 

[LibertyMKiii]

It's basically like going to the gym to workout, biking for 30 miles etc etc...
You know it's good for you, but man it's tough sometimes to focus and get going.
Sometimes it's best to find a "training buddy" to help get your concentration back on track.

Know that you're not alone in this endeavor.
Especially when you've got a couple of little ones Demanding your attention CONSISTENTLY. I can Certainly relate!

If you need to talk shop, I'm not that far away. Let's find a mutual place to meet for an hour or two to chat.

I appreciate that. Do you happen to have a milling machine? I need to finish the front axle and my mill died on me...
I found out today I can stay working remote for work till the new year so my "breaks and lunch" can be well spent

Most of my frustration of this build is knowing that it will sit on the shelf till I can find an airport to run on.
I plan on picking up a Kraton 6s in February, so I can at least enjoy the hobby for "normal" uses again. Once I get that Kraton we could go run some RCs locally together. (Allen Skatepark / dirt track / or construction site)

 

[Tex Koder]

I appreciate that. Do you happen to have a milling machine? I need to finish the front axle and my mill died on me...
I found out today I can stay working remote for work till the new year so my "breaks and lunch" can be well spent

Most of my frustration of this build is knowing that it will sit on the shelf till I can find an airport to run on.
I plan on picking up a Kraton 6s in February, so I can at least enjoy the hobby for "normal" uses again. Once I get that Kraton we could go run some RCs locally together. (Allen Skatepark / dirt track / or construction site)

I don't have such an equipment at my residence..
But, I do know a Harley mechanic who has a South Bend lathe at his shop.. in Dallas.
And, in Carrollton there's a place you can rent large scale milling machines. It's more like timeshare, but you have access to all their industrial tools.

Certainly, sounds good.
By that time I should have a Kraton 6S too by then.

 

[LibertyMKiii]

Tonight is the big night! ( for the body at least)

 

[Doom!]

Hey I saw a couch with that same material!

 

[LibertyMKiii]

Got the body out of the mold and trimmed up.
In this picture I just washed off the PVA mold release. It helps it shine a bit more like it has clear coat.

Going to do some sort of paint job on this one and certain areas the carbon fiber will be un-painted, then all covered in clear coat.
Not 100% sure yet what I want to do with the paint, but it needs to be bright. (white, florescent yellow, and exposed carbon fiber most likely.)

 

[Velodromed]

Got the body out of the mold and trimmed up.
In this picture I just washed off the PVA mold release. It helps it shine a bit more like it has clear coat.

Going to do some sort of paint job on this one and certain areas the carbon fiber will be un-painted, then all covered in clear coat.
Not 100% sure yet what I want to do with the paint, but it needs to be bright. (white, florescent yellow, and exposed carbon fiber most likely.)

View attachment 187863

I like it! Bullet train style

 

[LibertyMKiii]

Got the body out of the mold and trimmed up.
In this picture I just washed off the PVA mold release. It helps it shine a bit more like it has clear coat.

Going to do some sort of paint job on this one and certain areas the carbon fiber will be un-painted, then all covered in clear coat.
Not 100% sure yet what I want to do with the paint, but it needs to be bright. (white, florescent yellow, and exposed carbon fiber most likely.)

Thinking something like this, but a much better job than what I did here with MS Paint Lol

 

[Velodromed]

Thinking something like this, but a much better job than what I did here with MS Paint Lol

View attachment 187877

I like that! Race yellow will complement the carbon fiber nicely.

 

[LibertyMKiii]

Size comparison shot next to my newly acquired / used Kraton 6s. (love this rig)

 

[Sargent_Horse]

Oh wow, much smaller than I had in mind. The turning radius makes even more sense now.

 

[LibertyMKiii]

Oh wow, much smaller than I had in mind.

That's what she said?

 

[TN-RC]

Adding to my intro of this build....


After building several speed RC cars I have come to the inevitable conclusion in this journey where you realize what must be done…. to build a RC speed machine capable of 200+ mph it needs to be custom made.

I absolutely love drawing in CAD and honestly don’t know why it has taken me so long to get to this point. Like all things it does take time to learn the ins and outs of a hobby. Speed running is highly technical and takes engineering to solve the problems the car faces during a run.

Arrma cars are very capable and on the brink of cracking 170 mph soon. The 1/10 4tec 2.0 has nearly reached 180 mph and has more potential still. I had build a very capable stretched 1/7 scale length 4tec 2.0, but didn’t trust the axles, hubs, 12mm hex, and center driveshaft to support the power. Any production RC car will need a significant investment to strengthen the drivetrain and chassis setup to accommodate the batteries and big power. Every out of the box car I had modified seemed to have constraints and limitations that I couldn’t live with. (This is a large part of why I was always changing projects)

I have been avoiding it for a long time, but all paths seem to lead back to the design that Nic Case did years ago when he went 202 mph. This new build of mine is a belt drive solid axle / no suspension design like Nic Case built. The large difference will be that my car will run on production 1/8 103mm foam tires (minus some height from truing the foams down). His car ran on 12s and mine will be on 8s. Also I will be running a body that has gentle sweeping curves and looks darn sexy if I don’t mind saying so myself.

I don’t have any specs for Nic’s car so I went about designing my own based on the parts I wanted to use in the car and my ideal layout. The car will have an XLX2 and battery slots to accommodate 4s LiPos. The motor will be 40mm and can accommodate lengths over 110mm as needed. The motor being used is to be determined, but I will likely start out with testing with a TP4070. The design is such to keep the wires as short as possible between the motor to ESC as well as batteries to ESC.

When trying to go really fast aerodynamics are a massive hurdle. I have a great graphic related to airplanes that illustrates how at a certain speed the power required curve goes nearly straight up. This is like putting dual motors and ESCs in your RC car and not gaining speed. The problem was never power… The issue is aerodynamics!

View attachment 132643

This other graphic is related to bicycles and the power required. Note the GoldRush is a streamliner recumbent (pictured below the graph). The power required is insanely low compared to very expensive racing bikes.

View attachment 132644
View attachment 132645
For perspective:

• 1/7 Arrma or most 1/8 cars the front width is around 305mm. (depending on the tire/wheel choice) +/- 3mm
• 1/10 on road cars like the 4tec 2.0 are around 200mm width.
• My design has a 154mm width from outside edge to outside edge of the front 1/8 wheels/tires.

Aerodynamics can be a wormhole of discussion, so I won’t go too deep into this but, the key requirements for this build was the following:

• Retaining enough downforce for foams to get grip!!!
• Internal components that can handle big power.
• Reduced aerodynamic frontal area below 200mm 1/10 scale cars.
• Proper airflow management for low drag.
• Low losses from drivetrain (belt drive)

This combination should net result a 200mph car if all goes well.

After testing with the car I might consider selling/producing this as a product. I just want my chance to get some runs in and see if I can set a record first . This car requires a significant amount of CNC work which can be pricey. As it stands right now I am estimating this will be my most expensive to build RC car yet.

Are you still plaining on selling it? or are you going to keep it. (I would if it is the WR car)

 

[LibertyMKiii]

Are you still plaining on selling it? or are you going to keep it. (I would if it is the WR car)

I'll definitely keep the original, but might offer a kit produced my my local machine shop at some point if it works well.
I am going to talk with them in a month or two about making the upper and lower chassis.
Might explore aluminum as an option.

Don't hold your breath as I don't think this will be anytime very soon. I am taking my sweet time making sure everything is done right.

 

[TN-RC]

I'll definitely keep the original, but might offer a kit produced my my local machine shop at some point if it works well.
I am going to talk with them in a month or two about making the upper and lower chassis.
Might explore aluminum as an option.

Don't hold your breath as I don't think this will be anytime very soon. I am taking my sweet time making sure everything is done right.

Why are you using aluminum instead of carbon fiber?

 

[LibertyMKiii]

Why are you using aluminum instead of carbon fiber?

Might offer the kit in both versions. The aluminum has the potential to be stiffer, but heavier also...

Unless I made a custom carbon chassis that has some bends in it.
A large flat piece of anything will always have some flexibility versus a piece that has some bends in it.

 

[Sloclone100]

Lol talbot vs liberty

Yea, right. It's the 'engineer' versus the 'big-buck sponsorship'. What Talbot needs to do is spend some of that cash on technical consultants that know their stuff. If not, He'll be spinning his wheels until the right designers make him an offer.

 

[TN-RC]

I almost built one at one point. The issue is the rolling road setup to correctly measure ground effect.
I don't have the budget to do it right. If the effects and data are not right, then its all worthless.

Leaf blower, and where the air intake is light a smoke bomb. Most leaf blowers are 220mph, maybe light 2 or 3 bombs if you are going to use the cheap 4th of July ones.