3D Printing - Design (CAD) Software

[SlotCarCorner]

[Rleog]

Thanks for this, Steve. About ready to take the leap.

[SlotCarCorner]

Regardless of which CAD software you decide to learn/use, here is a tip. When taking the tutorials, use 2 PC's (or Mac's) if possible. If you don't have 2 PC's, perhaps you can make arrangements to borrow one. Run the tutorial on one PC/Mac and the CAD software on the other. While you can have 2 windows open on a single PC/Mac, you'll find it's MUCH easier to work with the CAD software when running it in full-screen mode (same for the tutorial). Running the tutorial on a second PC/Mac also makes it very easy to pause/rewind the tutorial while you "catch up" performing a series of tasks using your CAD software.

[-Nimrod-]

Sorry, wrong post, all fixed

Cheers
NimROD

[chappyman66]

I am a newbie too. No CAD, but been around them awhile. TinkerCAD has lots of lessons and tutorials as well. I don't have the creativity to do something like a P4.....I mostly have learned to modify what others have designed.
The one insight I would share is that I had to learn to think backwards when designing with TinkerCAD. What I mean is in woodwork, you cut and fit parts, then join them. In CAD, if I want a body post perfectly integrated into the swoop of a body, it's easy....you make the body a negative (or a "hole") and position it on the cylinder that will be the body post ...and when you combine the two the body post gets cut in exactly the right shape. Another copy of the body then is combined with the post and voila everything is perfect. Pretty freaking cool.

FWIW, I have posted a few things on Thingiverse under the same user name.

[proxieken]

I own a small, in house plastic injection shop. I have no formal training but pick up scrap equipment and get it running again. I make mostly simple things from it and sell under the name of Proxie Models.

Picking the proper CAD software is very important, because you are going to invest a lot of time in to learning. I spent time playing around with demos and even a program loaned to me by a kid at work who hacked them somehow. I am glad he did, because the program in question was Solidworks and it was completely un-usable in my opinion for my purpose.

I settled on Rhino 3D. I purchased an older version and have never upgraded because it works well. A lot of programs want you to "rent" them by charging you a per-year license fee. Rhino is one and done. Pay once and you use it forever. There are used CD's floating around on Ebay for a low price. My friend purchased one for $35. I keep re-installing it on new PC's as I purchase them with no issue.

One thing to consider is there are 2 main file types and methods to work. Solids and Meshes. Programs like solidworks are great with curves and solids, while others like 3DS Max are good with meshes. Rhino does both, although not as good as a program that specializes. However, for my needs it has never failed to be able to do what I needed.

Here is a picture of a fender from the Cyclone I made, one is a mesh and one is a solid.


A mesh only has straight lines, and you make it appear smooth by sub-dividing those lines smaller and smaller. This results in larger and larger file sizes and as a result requires more and more memory. On the left in the picture you can see the blocky shape of a mesh that is the drawback to this method.

A solid or surface has a smooth curve with far fewer data points. A circle might take hundreds of points to create in a mesh but only a few in a surface.

Rhino is also non-proprietary. A lot of these programs try to encourage you to stay within their system by having you work with their program extensions. The worst I have seen in Delcam and Powershape. ( I think these are now owned by AutoCAD so this information may have changed) When I checked on them you had to upload a file to them to convert to their format or out of their format and the charge was $75 per conversion. Rhino will import a lot of file types and export as a lot of different things.

Only real issue I sometimes have is the PC gets slow when working with a lot of data points, for example with a mesh that has been sub-divided a lot of times. I usually deal with this by placing some objects on a different layer and then only viewing one layer at a time while working on things.

It does crash once in a while, but overall I have been quite happy with it. I am still on Rhino 4, while I think they are up to 6. Based on the e-mails I get 3D printing might be built in to it now. There are loads of free tutorials to learn with as well.

In the past they allowed you to download and have fun with it but only allowed 25 saves before you had to buy.

Worth a look before you commit. Just my $.02

[ccobra]

So, I'm not the only one that doesn't think to much of CrashWorks. Sorry if I offended anyone with that statement but I've been under a tight schedule to complete a project only to have it crash more times than what my patience can handle. What I like about the Autodesk products is the tutorial that come with each product. It really shortens the learning time cycle.
One of the most difficult aspects of using CAD is where to start and what order to build in. What I do is put a jpg file in the front, side, and top view. Then I start making a half body for the mirror command is your friend. When I get the half body the way I want it then I do the shell command and give it about a 0.060 inch wall thickness. As you go you'll learn that the radius and chamfers you have on the outside had better not be less than zero on the inside of the shell or you'll get the computer barking at you about not being able to make the model.
The nice part about making the body from scratch (so to speak) you can do an assembly of the chassis and the body to check for interference and placement. Plus you get an early look at what it will look like before you print it out and put it on the track.
With this I've modeled up the gears, wheels, motors, and axles that I get from SCC so that when I assemble the end product I know I'll have no issues with wheels rubbing and silent gear meshing.

[chappyman66]

Ahhh....the "shell" command....
If anyone knows how to do it in TinkerCAD I would love to know. That's been a frustrating aspect of the free online version :lol:

[ccobra]

What you might try with Tinkercad to shell a part is to copy the part and move tot he side, then scale it down, put it back into the original part, and subtract it. That's what I used to do with an earlier version of AutoCAD R12. Then you extrude out the bottom of the body. Working with CAD is not as easy as some would think for you may end up having to take a walk or drive just to think of another approach to solve a problem. There may be an easier way but I was one of those self-taught CAD types where my approach is a lot like the way someone would approach a problem on the Press brake, CNC, etc.

[chappyman66]

Yeah...I have done the copy at 98% thing. I was hoping there was something I missed but maybe not. No worries.

[proxieken]

In Rhino, I offset the surface or mesh by the thickness I want the part to be. Usually .050" for the body. You can select "make solid" as an option when you offset and this works OK for some things. With complex body parts it usually creates some edges that wrap around on themselves, kind of like how a decal will roll under itself. So I usually do not click the "make solid" box and instead manually remove those twisted up mesh faces. Then simply stitch the 2 meshes together and you have a shell of the desired thickness.

[HWPSlotCars]

[HWPSlotCars]

Here's a quick sped-up video clip showing one basic method of modeling a slot car body starting with a cube in blender. The subdividing, extruding, etc. This is just a quick demo a threw together to give newbies an idea of the basic process one can use.

[MrFlippant]

Very cool. I'd watch that at normal speed if you spoke about what you were doing, e.g. the tools you're selecting and why, and how you'r using them, etc. Looks like you know your way around the program.

[HWPSlotCars]