[Nick the Porsche]

Hi all,
During the tedium of lockdown one of our club members suggested that we buy a 3D printer so that we could make replacement parts and chassis’s etc. We dutifully had a whip-round and bought a budget (£300 ish) printer.
While said club member was mooching on line he came across a print file for a 1/24 scale Mercedes W163 Grand Prix car. He paid for it and downloaded it. We scaled it down to 1/32 and printed one off.
I then set about making it into a working slot car. As it’s a prototype I decided to keep it simple. I used Penelope pit lane slimline chassis/ motor etc and pcs spoked wheels .
The original car file was a two part affair with lower section having integral motor mount, but once it was scaled down the lower section was useless as no type of motor would fit. I had to graft some thin plastic strip to the bottom of the body to cover the chassis properly. We would later modify the files to accommodate this.y

 

[Nick the Porsche]

W163.build continued........
I then fitted motor, guide, gears etc so that I had a working chassis. I mounted the body using a simple single body post at the front ( Amato ) and built up the inside of the body at the rear with moulding putty.
Slotit long countersunk body screw we’re used as when fitted they don’t protrude too far and when loosened off slightly allow body float/ movement.

 

[42redcat]

Looking very promising!
Sorry to go a little bit off-topic, but what printer did you buy?

 

[Nick the Porsche]

I believe it was an Ender 3 by Creality.......... all a bit 21st century for me !

 

[matthew77]

The printed body looks good.

 

[Chris61]

You printed with a filament printer!
It's very clean.
Do you have a picture before sanding?

 

[HO RacePro]

That printed out very well! I am curious about your printing material and parameters. I am hoping you kept a record or can recall them.

Did you use the Cura slicer? What version? Or did you purchase the gCode rather than an STL file?
What filament did you use? Hot end temp? Build plate temp? Print speed? Layer thickness?
Did you print with a brim? A raft? Or just directly on the build plate. Did you use an adhesive? What specifically?
Did you use an internal support? What kind?

Yeah, I am asking a lot, and I apologize for that. Trouble is, printing is still a very fussy process and sometimes a small tweak in a key parameter can be the difference between success and failure.

I haven't yet tried to print a body. Tons of chassis components, but no bodies yet. But you've inspired me to try. I hope to benefit from your experience.

Ed Bianchi
York Pennsylvania USA

 

[Nick the Porsche]

The body as you see in photos is before any work whatsoever. I’ll post pictures later of work after primer and sanding.
As for the many questions from Ed, I can answer none of them, like I said, it’s a bit 21st century for me.
I will however try and find some of the answers when I speak to my friend who printed the body.

 

[Chris61]

The body as you see in photos is before any work whatsoever. I’ll post pictures later of work after primer and sanding.
As for the many questions from Ed, I can answer none of them, like I said, it’s a bit 21st century for me.
I will however try and find some of the answers when I speak to my friend who printed the body.

It's more like a resin print, it's so clean! But I see that you quoted the Ender 3 which is filament!

 

[chappyman66]

If you zoom in, there are layer lines around the nose and the headrest behind the cockpit.
Based on those lines, I am going to say printed flat on the plate, but it's either been sanded or perhaps it's PVC that has been vapor smoothed. Very low layer height, 0.06 or 0.04 mm.
I have come close to that performance with my Ender3, but not quite as smooth. That's an exceptional print. Very well done.

And yes....when you scale a chassis you have to remove the motor mount (and guide / bushing mounts) and scale or fit that separately. Easy to do with CAD, though.

 

[42redcat]

If you zoom in, there are layer lines around the nose and the headrest behind the cockpit.
Based on those lines, I am going to say printed flat on the plate, but it's either been sanded or perhaps it's PVC that has been vapor smoothed. Very low layer height, 0.06 or 0.04 mm.
I have come close to that performance with my Ender3, but not quite as smooth. That's an exceptional print. Very well done.

And yes....when you scale a chassis you have to remove the motor mount (and guide / bushing mounts) and scale or fit that separately. Easy to do with CAD, though.

Easy if you’re competent with 3D CAD………

 

[Chris61]

Indeed, we can also guess some residues of filament underneath at the level of the exhausts!
But I can't believe that the body came out like that, without sanding, from a filament printer !
Moreover, the engine hood grills and the front grill can't have this quality...
is possible, I would like to know the parameters
I may be wrong...let's wait for confirmation

 

[chappyman66]

Yes it's possible, if you optimize everything.
But those hood openings are fabulous, yes.

 

[Nick the Porsche]

Having built a working slot car, I tested it at our club. I always test before painting for obvious reasons . The car ran fine. The original cockpit and seat were pretty horrible so I removed them and replaced them with a simple plasticard interior.
I then rubbed it down with 180 wet and dry, then again with 400 grade. 3D print materials are pretty hard

to work with so I find it’s easier to build up slowly with primer filler and rub down with 400 grade again between coats. I use zero model paint applied with an Iwata airbrush. A final rub down and the 3-4 coats of zero paint Mercedes w125 silver paint.

 

[Chris61]

View attachment 293089

Yes it's possible, if you optimize everything.
But those hood openings are fabulous, yes.

It looks really good (but not as good as the Mercedes )
I'm not there yet!

Did you try to print vertically ?

On the other hand, the Mercedes is printed really thick...

 

[chappyman66]

The Merc looks spectacular, congratulations.

Yes, the 906LH was printed vertically (my preference these days). Nope, not as nice as the Merc. That's a great print.

 

[Nick the Porsche]

I have spoken to my pal who printed the Mercedes. He didn’t save the settings and as it was a while ago, he couldn’t remember the exact settings.
However, he will be printing another body in a week or so for another club member.
I’ve asked him to save all the settings and print method. I will post them when I have them.

 

[Chris61]

I have spoken to my pal who printed the Mercedes. He didn’t save the settings and as it was a while ago, he couldn’t remember the exact settings.
However, he will be printing another body in a week or so for another club member.
I’ve asked him to save all the settings and print method. I will post them when I have them.

And you confirm that it is indeed a filament printer?

 

[HO RacePro]

Filled, sanded and painted that Mercedes looks immaculate. But you don't really use sandpaper do you? I can't see how you'd get all those curved surfaces -- especially the exhausts -- smooth. Do you use sanding sponges?

Asking for a friend.

Ed Bianchi

 

[Nick the Porsche]

No sanding sponges. I use standard wet and dry paper, usually cut into small squares about 30 x30 mm. Sometimes I make small sanding sticks or blocks by glueing ( with contact adhesive) wet and dry paper to 5mm foam board. This allows you to block sand curves keeping things flat rather than allowing your finger to follow the imperfections that you’re trying to get rid of. The process does take patience, sometimes 5-6 coats of primer filler with plenty of drying/ hardening time, gently sanding between coats. It’s all in the preparation...... same as full size I suppose. Sometimes it takes a few days to get the desired finish due to drying and full hardening etc. The important thing is to use lots of lighter coats rather than 1or 2 very thick ones.