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This car is awaiting in its box, and it's new...

SG Gemini SLX 1/12


Lexan chassis, ball differeential 1981/1982


There is a single page manual...


And I started by doing a CAD model of the chassis... (rendered here on a black background, as otherwise iit doesn't look that good...)

Front is in. I still need to care of the steering and tires, but that will be for later... The conception is quite simple. but at least the front arms structure is complex and required to scratch my head, and I'm not really sure why it was designed this way : it looks overly complex for what it does, and I believe the same could have been achieved with something simpler...

After my previous post, I shift focus on the rear components...

Nothing really complex here, I tore it down, took measures and CAD it part by part, includingthe diff balls...


And here is the section analysis view...


Next will be finish the rear train, and the parts mounted on the chassis while NIB in the box...

1/12 is a clickbait for me. Thank you for posting this project! Want to see more 1/12 and should also do something about it myself...
Anyway, I also have this car and looking forward to follow this project with your special signature to your builds.

Not exactly sure what I'll do with this car : while NIB, the chassis is having a few areas where there is beginning of cracks (old polycarbonate doesn't really help)... which means I'll have to do something somehow, and vacform is not the way, as the cuts are done before the folding work...

I continued woring on the rear train...
Ball bearings are in imperial and not metric (why doing simple when you can do complex things) 1/4"x3/8"x1/8"... (I struggled to find out )


The rear train is almost complete : only missing the pivot ball and rod end used to maintain it in position.



I guess that main parts being done it will be quick to model everything left, but that won't be tonight...

The rear end of the car is now complete...


Still missing the servo, servosaver, and steering links and it will be possible to move on to the bodyshell (Shkee DB-1)

I completed the chassis... It's simple and the clear polycarbonate give it a nice touch of class...




Next, I need to model the Shkee DB-1 bodyshell...

I did a simplified bodyshell based on the Shkee DB-1 bodyshell I have in hands right now... It's missing some details, but the target is not here to make a mold, as this bodyshell is available (mine fome from Delta plastic and I found it on ebay).


A first rendering is here (more will come later - they are really long due to the clear parts and the black background)...

This is some top notch work!

My laptop worked last night. Around 2 hours per rendering...




I did not made more renderings... I need to think about what next for this car. I'd like to build it, but the chassis is NIBBD (New In Box But Damaged). I could eventually try to find one NIP or try to make a new one. As per what I can see, the chassis is cut, then folded. I made the plan in CAD using metal sheet in Fusion360, so it could be easily cut. But then the question is how to fold the 2mm lexan sheet. Looking for ideas . @GoMachV I know you can cut that, but folding?

One of my friend sent me the following video...


I also found that Lexan can be bent without heating it, but there is spring effect which might be difficult to manage to reach a very specific angle... At least that how my thought process starts : looking at all possible ideas and ways to work it out...

silvertriple wrote: ↑Sun Feb 18, 2024 4:34 am My laptop worked last night. Around 2 hours per rendering...




I did not made more renderings... I need to think about what next for this car. I'd like to build it, but the chassis is NIBBD (New In Box But Damaged). I could eventually try to find one NIP or try to make a new one. As per what I can see, the chassis is cut, then folded. I made the plan in CAD using metal sheet in Fusion360, so it could be easily cut. But then the question is how to fold the 2mm lexan sheet. Looking for ideas . @GoMachV I know you can cut that, but folding?

If you don't want to do it in house there's people like this around. Not sure if they serve your region though. https://sendcutsend.com/materials/polycarbonate/

Also when I was rebuilding my Gemini I was able to find NIP chassis online for it for fairly reasonable prices.

RogueIV wrote: ↑Sun Feb 18, 2024 12:21 pm

silvertriple wrote: ↑Sun Feb 18, 2024 4:34 am My laptop worked last night. Around 2 hours per rendering...




I did not made more renderings... I need to think about what next for this car. I'd like to build it, but the chassis is NIBBD (New In Box But Damaged). I could eventually try to find one NIP or try to make a new one. As per what I can see, the chassis is cut, then folded. I made the plan in CAD using metal sheet in Fusion360, so it could be easily cut. But then the question is how to fold the 2mm lexan sheet. Looking for ideas . @GoMachV I know you can cut that, but folding?

If you don't want to do it in house there's people like this around. Not sure if they serve your region though. https://sendcutsend.com/materials/polycarbonate/

Also when I was rebuilding my Gemini I was able to find NIP chassis online for it for fairly reasonable prices.

I know about the online services, and I'm also quite sure it should be possible to find another chassis NIP in Italy (I did not asked the one I think about yet, but he may have some parts available still)... But there is something more to it : there is nothing that I love more than experiment... Sometimes it is highly time and money consumming, but it its even more rewarding at the end ... And I'm not only posting here, and in the french forum I'm posting as well, I may be able to find someone who experienced this already... I'll see what it takes, and for sure I'll report about it

silvertriple wrote: ↑Sun Feb 18, 2024 12:52 pm

RogueIV wrote: ↑Sun Feb 18, 2024 12:21 pm

silvertriple wrote: ↑Sun Feb 18, 2024 4:34 am My laptop worked last night. Around 2 hours per rendering...




I did not made more renderings... I need to think about what next for this car. I'd like to build it, but the chassis is NIBBD (New In Box But Damaged). I could eventually try to find one NIP or try to make a new one. As per what I can see, the chassis is cut, then folded. I made the plan in CAD using metal sheet in Fusion360, so it could be easily cut. But then the question is how to fold the 2mm lexan sheet. Looking for ideas . @GoMachV I know you can cut that, but folding?

If you don't want to do it in house there's people like this around. Not sure if they serve your region though. https://sendcutsend.com/materials/polycarbonate/

Also when I was rebuilding my Gemini I was able to find NIP chassis online for it for fairly reasonable prices.

I know about the online services, and I'm also quite sure it should be possible to find another chassis NIP in Italy (I did not asked the one I think about yet, but he may have some parts available still)... But there is something more to it : there is nothing that I love more than experiment... Sometimes it is highly time and money consumming, but it its even more rewarding at the end ... And I'm not only posting here, and in the french forum I'm posting as well, I may be able to find someone who experienced this already... I'll see what it takes, and for sure I'll report about it

Oh I definitely get what you're saying, designing and building your own parts is very satisfying!

This is a bit simpler than your last project

I think every vintage 1/12th collector must have one of these by now. I think Massimo must have found a shed full of them at Mantua Models, the number of these I have seen for sale over the years.

There are two options for folding polycarbonate, cold and hot bending.

Cold bending is easier, you just clamp it down and fold it, ideally using a press brake, but you can make a simple bending jig that holds it down and folds it. The obvious advantage is that no heat is involved, but you do have to fold it further to let it spring back so you have to experiment with that.
Hot bending, using a line bender as shown above, does give you more control over what angle it bends to, and you have no stresses in the bend. But ideally you do have to dry the plastic first as if not you will get bubbles forming at the fold as the water absorbed into the plastic will turn to steam under heat.
It's something I have to look at myself some day, as I could also do with making a new chassis for my Schumacher XL.

As the chassis is designed to flex with the folded sides being used to stiffen it, you could look at 3d printing the chassis in a suitable plastic.