TOPIC:

Hello,

I did a few buggies in CAD, I did reinvent some partially... Next year the first event of the year I intend to attend is going to span over 4 days early May (8th-11th), and the thematic of the event is "Creation and System D". I'm not sure how it would translate in English, but basically, it consist in messing something and the mess works
Therefore, I have to do something for the track side of the even so I have a very special car. I also decided I would focus the track side on 1/12 this year as I have much much much more fun running a 1/12 pan car than an 1/10 touring car...

Anyway, I want to do a special project. It will be a 1/12 pancar very simple. Something that I could do relying on 3D print, a shaft widely available for the rear train, a few cut pannels (either Carbon Fiber, FRP, or other) that can be combined together with the printed parts to make an 1/12 chassis. A quick search shows that the rear shaft of the Fantom is widely available (and you may even have one if you replaced the metal shaft by a carbon shaft). 
The bodyshell will topic will be treated only when we have a chassis plan.

This will be my starting point. Kyosho, part EF209

And I obviously converted in CAD so we can start thinking...


And yes, I have added another project to my already huge project list...

Slotcar Mirage T type front suspension I think would be easy for you to design. Maybe use Hornet steering upright?

I thought about the Hornet uprights. I had already this argument with a friend who is going to work on this project with me...
There is things for and things against.

For :

• easy to source, cheap and available

Against :

• not challenging enough
• no possibility of configurations
• expensive if you consider print (FDM) and price of bolt and a sleeve made with a tube you cut with a small plumber tool

That being said, it remains an option. The way I see this project is step files rather than stl so (theorically) easy to reconfigure by anyone. I really want to push the idea that a lot of things are possible, and that is just a question of spending the time to understand how to work with this. And even for someone with no knowledge of 3D software, as long as there is someone sitting next to him able to, lot of things could eventually modified. Think about wheelbase; wheel is more difficult as it can only be done by the wheels offset at the rear once you start with a defined shaft. And that open a lot of possibilities... (and somehow, you may consider this just as a variant of your fantastic scratch builds )

By the way, if anyone wants to shime in with ideas, don't hesitate to speak . I'm all for it, if I wasn't, I would not have opened the thread...

I do have that Parma Hot Rod body... It needs a chassis at some point and I think pancar chassis will be the most fitting hehe...

Try to find a trinity street spec. 

The Hirobo project gets closer to print order.
I've decided to draw some parts for this project...

The support of the rear left wheel, and the nut...


I needed to check that my thread is working fine, so I did a test print (have some ideas to play with regarding the wheel nuts, so I had to play with this and get a working nut...



The thread on the shaft works with the adhoc metal machined thread, so it's perfect (no offset, but slicer setting may impact).
The nut was printed with 0, -0.1 and -0.2mm offset to test. (again, slicer setting may impact), but at least that gives a good indication of the tolerance needed for it to work...
0 doesn't work as expected. -0.1 does engage but not possibility to get more than a turn. -0.2 does engage and the thread work. I will have to check if it is the same for power base process, but I would expect it is similar from what i've read somewhere...

That's all for today!

I decided to figure out the overall position taken by the motor pod on my shaft


The plan is quite simple actually :
Bring in a differential design I know being tested and validated on one of my cars (spoiler : many ), one I have already the design in Fusion360 : I'll use the one form my Marui 2WD gearset as a basis.


I will have to modify the main gear to be more suitable for the targeted use (let's target the same ratio as the Fantom, that makes less thing to think about )
For the diff itself, the center of the diff gear will be used as is, with the way I use it on Marui cars and same for the small small bevel gears and their shafts.
The big bevel gears will be amended in order to work out with the new shaft : left side will be attached firmly to the shaft, while right side will have to be redefined to position and drive the right wheel attachment...
And all of that should allow to have a proper diff for my chassis...

Looks simple enough in my head, that should work

Tonight, the program is to deal with the differential and as well with the right wheel carrier...

I first made the wheel carrier, which is an hex with a thread at the end and two ball bearings : one going at the end of the shaft and the other one going on the shaft. Then I brought in the diff components from my Marui gear set, and defined the way to set the big bevel gears on the hex, the installed the right one, then the diff center, and defined then the hex to push on the other side to fix on the shaft to have the left wheel driven.


Once I had that done, I modified the spur gear to be 71T 48dp because that what it is on the Fantom (I also modified the diff so there is better protection of the gears...



To get the right carrier printable (it has a modeled thread), I had to modify the thread and increase the diameter to make it M10.


I modified the internal thread of the nut to be in correspondance, and I may also change the nut size...

Next step will be to define the motor pod...

Before anything else, I decided to print a differential to check everything was fine in the design.


The diff works, and it is no surprise...


I did an adjustment on the wheel carrier (I could have done it somewhere else, but this was what I believed the easiest... Once the adjustment is done, the diff is set in place, the space for the motor pod is as expected and the nut allows to set the diff more or less tighten, just like it is on the Fantom.


This being done and validated, motor pod will be the next piece...

Motor pod is mostly easy... I did target pinion range between 14T and 27T (48dp), and made slots accordingly so we can position the motor for this. The reference point is the single hole, and I may adjust the position later on as everything is depending upon the position of this hole and the rear axle, accordingly to the targeted possible interdistances.Everything else is pretty simple. I planed for 2 holes to fix the pod on the chassis plate on each side, and one hole on the top for the upper deck.



Here, this may not be finalised parts : I keep the right to adjust a few things based on what will come next. The chassis plate will require an opening so the motor can be set for the smaller pinion... I will have to focus on the front train next.