More of a design question than a print question - designing a cockpit cradle for 3D printing

[clive_t]

Hi all, not sure if I am even posting this in the right place, but I guess I'll just get the question out there and worry about the rest later

 

So, my current project is giving me the 'opportunity' to detail the cockpit interior, which I a some way into already. However, I need to build a cockpit cradle, and I figured it would be nice to try and use my Malyan PLA 3D printer. The act of printing would be fairly straightforward, however I need to design it and produce the necessary file to feed to the printer. And this is where I appear to run into a brick wall, as I am really struggling to find any CAD software that is (a) easy for my dumb brain to understand, and (b) actually produces the design I want.

 

The design is simply (!) this:

 

 

I've tried TinkerCAD, OpenSCAD and FreeCAD thus far, and all of them have defeated me in my attempts to reproduce this design.

 

I don't want anyone to do this for me necessarily, I am just hoping that someone could provide some pointers on how to actually use a CAD program to produce this design!

 

Any guidance would be very much appreciated!

 

 

[lesthegringo]

Try Qcad to do a 2D .dxf file you can them import into a 3D program. Qcad is free if you disable certain advanced functions by deleting some DLL files. It is also pretty easy to use

 

Les

Edited May 29, 2021 by lesthegringo

[lesthegringo]

Just following up on this - which bit of the process are you having an issue with? I use Solidworks, and I know that each 3D program has it's own little philosophy that you have to follow for the 3D part, but most work on the basis that for simple 2D to 3D structures like the one you seem to want to do, you start with a suitable 2D drawing, then extrude it to the thickness required.

 

The 2D drawing has to be correct for the program to make a 3D model, so for instance it cannot have overlapping lines - imagine the Olympic sybol, it is five overlapping circles, so will not work unless you turn the circles into a series of parallel joined arcs and where the cricles meet the lines cannot cross; think german markings, four 'L' shapes separated by a space. Additionally, every item has to be a closed loop. If two of the lines don't join exactly at a corner, or overlap slightly, it won't work. Also, if you have any extra lines in there (easy to do, you can have two lines, one superimposed over the other without it being obvious) it can't use it. These can be frustrating errors to find as the error is often almost invisible. Patience is required, and when this happens I recommend converting everything to construction lines, then resoring individual loops to build lines so that you can see which subset of lines is causing the problem.

 

Some programs get fussy about 'double nested features' where for example you have three concentric circles - it doesn't know which ones it is supposed to make the solid from. Four concentric circles will work most of the time, and it can then make two rings from it.

 

The famous 'zero thickness geometry' error crops up a lot, where for example you have two squares meeting right at one corner. The progam goes 'tilt' becouse it is not able to calculate down to that fine a level at the point they meet. However if you separate the squares by 0.001mm it is able to calculate it, likewise if the overlap by 0.001 it can do it, as long as you make sure that there are no overlapping lines if it is a drawing.

 

Anyway, having taught myself Solidworks over the years and remembering the pain I went through I am more than happy to try and help you

 

Cheers

 

Les

 

[clive_t]

Thanks @lesthegringo for your replies, much appreciated.

 

I will follow up on the alternatives for the modelling software, but it's useful to know that the term for what I am wanting to do is 'extrusion'! Indeed, that is exactly what I want to do at this stage - take the 2D image in my original post and 'extrude' it to, say, 0.5mm to 1mm thickness.

 

I guess the problem I am having in the first instance is how (or even if) these various programs are able to extrude 2D shapes to a desired height/thickness/whatever .

 

I shall delve into this a little deeper now, armed with my already superior knowledge compared with what I had last week!

 

Thanks again

[clive_t]

Well after slavishly following a couple of YouTube tutorials courtesy of 'DrVAX' I was able, via FreeCAD and some good old Anglo Saxon prayers, to produce this:

 

 

A few hiccups along the way, and I freely acknowledge I could have done this with some scrap styrene sheet and a blade, but actually I am delighted with the results!

[lesthegringo]

Nice one, it will take a bit of practice but you will get there. If I may say, my (admittedly very limited) experience with Resin 3D printers like the Photon Mono X I bought shows that for the sort of thing you are doing they are much more suitable. And for me, the real surprise that I paid a quarter of the price for the Photon than I did for my Lulzbot Mini. The march of progress is incredible!

 

Let us know if there is any help you need

 

Les

Edited May 31, 2021 by lesthegringo

[clive_t]

Yes, I think a resin printer would readily lend itself to something like this.  Sadly, I have no room for one unless I can convince the wife to swap hobby spaces with me - the odds of that happening are squarely in 'winning the lottery without buying a ticket' territory

 

I appreciate your assistance though!