3D printing process evolution.

[Barc 1]

I just thought I would post another update on my 3D printing experience.

1.It has become my main source of modelling. I haven’t heated up a soldering iron for chassis construction in months.
2. I now print as I build a project. Project pieces evolve. Most of my first sets of wheels etc, ended up not used and sent to the recycle bin. I literally have thrown away half of what I printed away as my later effort eclipsed the earlier version. So keep this in mind when you get into this
3 Filing system for saving all these files has caused my head to explode . I have settled on a system where each file is a subset of a particular model of car. If I want to make a Porsche 997, every component required is filed under it. Makes it more like a kit, and my brain seems to like it that way.
4. 3D printing has become the driver for my slot car experience. The ability to print and build whatever I like is golden experience, I am amazed at how many cars I have built this past year.

Cheers

Dan

[Kevan]

This sounds familiar Dan, I need to throw away chassis that I've improved (loads!), I print a chassis and test it, now and again one is a keeper but I'm the same, the only time my soldering iron is used is to wire a motor in.

The brass & wire chassis are still quicker than the 3D ones but I love the CAD side of it, designing something from nothing is almost a hobby in itself, the ability to 3D print it then drive it round is hugely satisfying.

Recently reading through the 'Crap Car Proxy' brought ideas to mind, I've just got to enter that next year with some 'creation'

As far as files, you have to be organised, make a spreadsheet of cars dimensions and wheel base. Likewise organise your 3D files, make a 1/32 or 1/24 folder for each car and keep proper scaled versions in there and any modified ones like wider, longer, lower save in a separate sub-folder. Once you're 100% happy with a modified files save it as 'final' as it's easy to get lost amongst all the file iterations as your model evolves.

As far as sliced files go I rarely use them more than once, I prefer to 'just check in case'

Also I recently realised I haven't been saving hollowed and drained files, I'd load the slicer (Chitu for resin) then hollow then drain then slice but realise I should be saving a hollowed/drained stl copy for future use as draining can take ages to do.

[chappyman66]

Totally agree.
1) My main source of interest in slot cars has always been scratchbuilding. 3DP has allowed me to have cars I can't otherwise have or afford.
2) For my home track use, the mild motors mean a plastic chassis is fine. I can make any configuration for any car I want. It's completely liberating. I have soldered chassis, and they work fine....but I love my printer.
3) Filing system? Oh yeah, that.....TinkerCAD helps me, but being organized (keeping everything together as a kit) is very smart. I will have to start doing that, as I used "CTL + F" often.

After two years.....I can't imagine working without my printer. Pretty sad, but there it is.

[slothead]

How do you guys go about creating a chassis if you already have a body for it? Over the years I've custom built a bunch of oval track chassis as needed, using a variety of materials from styrene to brass. The ones built on a homemade jig all using the same specs and running gear tend to work very well. The chassis built for some model bodies where the width and length vary tend to be problematic. Differences in wheel & tire height effecting ground clearance and creating a reliable guide mount tend to be the major issues.

When making a chassis on a jig I've solved the clearance problem by using the intended wheels & tires to set the height and location of rear axle tube. A guide with braids was pre-located exactly where it was going to be and the chassis built forward to it from the rear axle so ride height was consistent and chassis weight distributed like a tripod. The front axle tube was put in place last, again using the intended wheels & tires, so they just barely touched and the needed wheelbase was achieved.

How do you account for these things in the 3DP design phase?

[chappyman66]

Generally speaking, I use the same style of chassis under most builds. With 3DP it's all done in CAD so you take the "component files" and put them together into the style and length required.
This is a screen capture from TinkerCAD showing the pieces of the chassis I normally use. It has good stiffness, lead wire grooves, and multiple mounting options (which I trim off as needed before printing).



This is another style I use, with any motor configuration I need:


It's very easy....measure the wheelbase, and align/overlap all of the chassis pieces to get the correct wheelbase, export and print the file. Usually I can import the body file as well, so I superimpose the body on the chassis and adjust width and guide position if needed before exporting and printing.

For ride height, I use standard pods and whatever wheels the model requires. @alexisingreece has developed an ingenious method for adjusting the height of the rear axle using the small spherical bushings that Slot.It uses in their "eared" pods.
For the front axle, that's obviously adjustable with set screws.

[slothead]

Thanks for the prompt reply. I'm not ready to take on the 3DP learning curve (too many other unfinished projects) but I do appreciate understanding more about the process. If/when I do try 3DP it would be to create chassis for oval track model bodies or fabricated sprint car bodies.

[alexis in greece]

The software i use is Freecad.I have designed a series of basic chassis parts and a mounting plate:


guide end


Center piece


front uprights

side pans

I create a new file for each new chassis and i merge the chassis parts into the file.Then i start modifying the parts according to the models needs.

All the parts of my new chassis for Team Slot Audi Quattro


Then i fit all the parts on the mounting plate using assembly workbench


Then hide the mounting plate and export the chassis to STL


bottom


Side

[Kevan]

I've designed and printed pods of all types, the difficult part is the bearing mount. I've used adjustable height spherical bearings and adjustable height ballraced axles but you can't beat an injection molded pod. The advantage of printing your own is you can set the axle height at whatever suits your needs.
I use a pre designed chassis and cut/shut to suit the bodyshell then modify the side pans. I like to give the front and rear of the chassis some form to blend into the bottom of the body rather than a flat piece of plastic. Some cars need more chassis work than others, I've just finished one for a Revell BMW 3.5 CSL with a slotit SW pod.