Special Project Codename EF209 - RC 1/12 pancar

[silvertriple]

Just received chassis parts today thanks to @GoMachV


I will have to print my parts in final mode soon so I can check everything and make them available...

[silvertriple]

I thought I could move on the Zerda soon, but I did a miscalculation for the belt length, apparently. Ordered new ones, longer. And in the meantime, this mean I need to do something...

A friend has fed me with ideas in my reflexion, and he will work with the red parts for the chassis he is going to build. On my side, the target was to make another color...

I printed the parts today, and in particular for 2 parts, I allowed me some fun


I lined all the key parts on the table. I have the ball bearings and the RX (not on the picture). I'll need to take care of the ESC and motor. And remains the hardware : normally, I should have everything I need, but I still need to check. In the first test, everything will be assembled with button head screws. I'll change for countersunck screws once I have the possibility to rework the holes. And there I few sleeves I need to take care for the front shafts, but nothing too difficult...

[silvertriple]

Time to check the assembly is going to go easy...

First front train bar... I straight away noticed that I need to review the bottom part of the clamp either to introduce the nuts by a pause during the print or either reviewing the design to make it easier to insert (it was a bit too hard to my taste. Almost everything is mounted with M3x8 machines screws (not yet countersunk, but that would not change the dims required). 4 M3x8 screws + 4 M3 nuts


One of the exceptions to this is the screws required when using a mini servo (M2.5x8)


Rear train is also mounted with 4M3x8 under the chassis and 4 M3x8 countersunk for the rear side


One of the things I needed to absolutely check was my rear axle : the flat area of the hex is at equal distances on both side (an adjustment will be made to the design of the hex as I did adjust that therorically after the initial mount of the diff - I'll adjust that once I have the motor and pinion in).


I also mounted the carrier on the knucles... 2 M3 Nuts, 2 M3x20 screws (used as shafts)


The initial design I made includes a sleeve 3x4x11 which one would need to cut to be able to mount both carriers. Maybe this is a bit too much of DYI for most (I don't know, I'm not sure, but I doubt most would be happy to do this). I'm considering to remove this and replace the sleeve and the ball bearing by another simple ball bearing. Don't hesitate to shime in, especially if you are interested by making a derivative of this project...



Next is the battery mount : 6M3x8 screws and 2 M3 nuts for the center part (which is going to be removed more often as it is the battery retainer). I noticed I made a mistake on this part, I'll review it...


I still need to deal with the steering links (but that will be easy) and then it will be wheels, bumper and bodymounts...

[silvertriple]

Berfore dealing with the bodyshells, it is time to deal with the wheels... The simple way to have proper foam tire easy to source is to rely on Kyosho Fantom wheels. The carrier would simply required to be drilled with a 10mm diameter for the center hole, the carrier has the same hex definition.

On my side, I'll have at least a set of printed rims/tires for the shelves (not sure the Recreus Filaflex 60A would be good enough to run the car), so I designed something in CAD.


I intend to provide the files for the tires, and for the rims in 2 versions. If someone have a way to make proper foam tires, he could ultimately using printed rims for that... The version I'll use for the TPU tires have some areas designed to lock the tires on. I also designed a nut which won't require any tool.


I printed the rim, and also the nut to check everything was fine...


But the nut color was not standing out enough... I printed all nuts in orange for that reason.



I'll print the tires in TPU by the end of the week, and will add the tie rods very soon. Then it will be time to work out Bumper, led supports and bodymounts...

[silvertriple]

I printed tires with Recreus Filaflex 60A.


From what I can see on my desk, it could actually work, so I'm eager to try them on asphalt to see if workable this way. Backup plan will be Fantom EP-4WD re-release wheels...

I do still have to do something about the holes in the chassis. This is not complex, but if we want to make all the holes similar, this is just about having the right tooling...
First iteration.

Then a second one, with a centering tool and a way to fix the ball bearing in place to drill at the right place.


It will be soon time to work out the bodyshells topic. I plan for 2 bodyshells. The fist one is already in.




I satrted to work out a bumper... Bodyshells will be mounted with screws, removing the issue with the body post being too fragile due to weak point in Z.


I planned for a lip under the bumper at the front of the chassis to protect it...

Next : rear bodymounts and leds holder...

[silvertriple]

I did a rear body mount that is targeted to be printed in TPU and will include leds holder, exhaust, and flaps behind the rear wheels...


I believe the inspiration of this bodyshell is a Ferrari 333SP, but I decided to not use any wing for some reason (something I'll precise once I come to the bodyshell paintwork because the reason wil become clearer - spoiler there is 2 cars, one will be blue, and the other one will be red )
The part was slowly printed (TPU is slow)...


... and quickly put on the chassis



Although the bodyshell is not trimmed we can already do some checks...





This morning I designed washers with a slop on the bodyshell side (printed in TPU) to fix the bodyshell using 4 M3 screws. And the fit is perfect (I made 4 holes with 3mm drill bit)...


I will need to trim the bodyshell next... And for this I may need to design some guides for the blade, at least for the arches...

[silvertriple]

My last post on this topic was last Sunday... Since then, I had quite a time to move some stuff around...

First, arches were unmarked on the bodyshell. I did a small tool (and I believe I can improve it for next time)...


The principle is simple : mark, drill, fix, cut following the line.


And the result is a near perfect arch marked and it is easy to cut. Small note for next application : reduce the gap for the blade as 1mm gives to much space....


Initially, I thought about not installing any wing neither roll bar... But the fact is, I know this bodyshell is highly inspired from the Ferrari 333 SP, and each time I went next to the car, I could see there is something missing... I had to do something, and this meant a wing and a roll bar.



The roll bar was printed in TPU


The first version of the wing showed me that something was missing to maintain proper position. The wing is printed in TPU so it doesn't break in case of roll over...


I then added two parts to fix the position of the side wing, fixed on the top of the led holder... The roll bar is fixed with screws/nuts on the bodyshell



I will need to find a driver and do the paintjob next...

[silvertriple]

After the bodyshell, I decided to extend a bit the chassis project: create a forked version of the project with no dependancy on Kyosho EF-209 Fantom rear shaft, with the target to allow more people to access this chassis and to print it.

For that, I decided to use a long M3x70 full threaded screw and 2 M3 locnuts as a basis : i needed to have the right side allowing the use of a modified carrier and the modified diff main gear. I had a solution in mind, and I had to try... The two nyloc nuts are set precisely distant of 20mm, the screw being fully engaged in the first one. The shaft will be made of 2 parts, and will be ketp together by the carrier, ball bearings and bevel gear on the left side.


I've printed it and proceeded to the assembly to check




The left end is a square driver, and I included a hole to fix the carrier.


And I designed the carrier to keep this together...



At the end, I had just to modify the diff to allow for the different shaft diameter : I included 2 flanged ball bearings 3x6x2.5mm on each side of the main diff, and the carrier uses the same ball bearings on both ends (while it is a different one on the version with the Kyosho shaft.


Should I consider a printed version of the chassis plate next?

[silvertriple]

I needed a statement color for the next step of this project, which will turn in my first very own design... Bright orange will go nicely with a black Kydex chassis


The nut in the deep area of the upright is used to control the centering of the screw. The fit is tight, and a gentle push is required to put in place


The rest is quite easy... I do not mount yet the pivot balls for the steering rods : this has to be sourced using regular hardware. 2mm rods and small pivot balls are far enough for the weight of the car. Here with the first version of the rear shaft.. While building this chassis, with a different servo than the one used initially to model the right hole position, I noticed another hole was required. I changed the design to put a slot on the right side, and highlighted @GoMachV so he can take the updated file in case one want a G10 chassis...


The rear shaft was revised and rely now on a 160mm M3 rod (shorter would be too short - this is very tight fit - you need to be sure about the supported faces tolerance, if not a 161mm rod will be required) and few M3 nylstop (nylon nuts). The fact there is two of them enclosed is making sure you can tight the nut outside of the shaft without it moving inside the printed shaft.





Once the shaft is in place, the left wheel driver gets fixed on the left side by another M3 nut


Last the diff take place on the right side, and the nut is at the very end of the rod. I had to move the rod by around half millimeter so it fits perfectly...


And for sure the bright orange goes very well with the black kydex chassis...



I'll print rims and tires for this chassis, and I should be in situation to publish the files for it soon...

[silvertriple]

It's more work than most people imagine to organize files in a proper way before a pulication...



Specially considering that it was required to do something so it is easy to build (or at least not too complex - not everyone is a puzzle world champion ). I ony show some of the pages here (everything is on the final publication in one single pdf).









I also have a second chassis to complete now (kydex 3mm based this time)




The files are live for the chassis part already and can be found here :
https://makerworld.com/en/models/1086493

Another publication will follow within the week for the body mounts, bumper, and bodyshell accessories as they are really specific to the bodyshell...

[silvertriple]

After the chassis, it is time to work out the bodyshell accessories...


And there is a lot of screws...


(and that is just the first one, I have other bodyshell to accessorize...)

[silvertriple]

And I just published the accessories set for the bodyshell (BL2909 Turismo WSC par Sabula tech).
https://makerworld.com/en/models/1098301

I have other plans for the bodyshell as well...
Teaser :

[limestang]

Great job!

- limestang

[silvertriple]

3D printed tires are not ideal. I want a better solution

Found some cosplay EVA foam (86 KG/m2 in density), and that may do the job. This type of foam is generally easy to find in shop specialized into cosplay, but you can find it on amazon too. From what I can see having it in my hands, it could be suitable for foam rc tires, and you can get them is various range of density. One thing which is left to do is to find a way to cut donuts in 10mm thick pannel and then find a way to glue them (neoprene liquid glue should be perfect for this).

First cutting attempt was made on the laser cutter at the fablab... Due to laser focusing and the difficulty to get the foam flat (which is delivered in rolls), it's far from perfect. I'll have to try in CNC, but in the meantime I'm exploring ways to work this out with simple 9mm cutter blades with 30°angle and 3D printed part.
Printed part and blades mount

A jig to position the holes

Next the base and something to retain the foam are in place

And gere is the result:


Conclusion : more work needed! The blades are too flexible and too fragile. One of them broke. And if the positionning of the foam is not perfectly seated, it gives unapropriate results...

[silvertriple]

While I still have to deal with the foam tires, this morning the weather was good enough, so I took some time to paint the bodyshell
And yes, it won't be a Ferrari, but something else