1/16 Long Tom Project
Posted: Fri Mar 20, 2015 6:35 pm
This one is going to take a different tack to most builds, or anything that I have ever done before. It will be a project simply to see whether I can design a 1/16 scale Long Tom using a free 3D software program called Openscad, but do it in a way that will allow me to print each component on a 3D printer.
I will say from the outset that I have never:
1. Used Openscad before to do anything like this.
2. 3D printed anything other than small test parts.
I have had nothing more than 'learn as I go' experience over a few hours with Openscad. I am using this to force myself how to do what I need to do, in order to get what I want, if that makes sense. It is just something to do while I am watching tv, I can do this on my laptop.
There are several things to consider doing it this way, but mainly:
1. Designing components that can actually be transferred to a 3D printer.
2. Making each compenent strong enough to withstand towing behind a cargo tractor.
It will be printed in PLA, which is very close to polypropylene in texture and strength, quite difficult to snap, but flexes a bit under pressure. The parts will need to be self supporting, the barrel may be an issue, as anything over 20cm's will have to be printed in two or more parts.
3D printing presents problems with horizontal overhangs. This can sometimes be resolved by printing parts upside down, on their side etc, or by splitting parts down. Split parts then need to be redesigned with dowels/slots etc so that they all fit back together again.
So after that brief waffle this is where I am so far. The different parts are in different colours, though this may change as the design progresses. Some of the detail is not on there, as at the moment creating a shape, rotating it through different planes and then sticking it exactly where I want it is hard work. Not all detail is symmetrical.
Just to get this far has meant writing stacks of code, but it is teaching me a great deal. This isn't a five minute job that's for sure, and before anyone says it, I could probably have made the whole thing in styrene in a fraction of the time???
I will say from the outset that I have never:
1. Used Openscad before to do anything like this.
2. 3D printed anything other than small test parts.
I have had nothing more than 'learn as I go' experience over a few hours with Openscad. I am using this to force myself how to do what I need to do, in order to get what I want, if that makes sense. It is just something to do while I am watching tv, I can do this on my laptop.
There are several things to consider doing it this way, but mainly:
1. Designing components that can actually be transferred to a 3D printer.
2. Making each compenent strong enough to withstand towing behind a cargo tractor.
It will be printed in PLA, which is very close to polypropylene in texture and strength, quite difficult to snap, but flexes a bit under pressure. The parts will need to be self supporting, the barrel may be an issue, as anything over 20cm's will have to be printed in two or more parts.
3D printing presents problems with horizontal overhangs. This can sometimes be resolved by printing parts upside down, on their side etc, or by splitting parts down. Split parts then need to be redesigned with dowels/slots etc so that they all fit back together again.
So after that brief waffle this is where I am so far. The different parts are in different colours, though this may change as the design progresses. Some of the detail is not on there, as at the moment creating a shape, rotating it through different planes and then sticking it exactly where I want it is hard work. Not all detail is symmetrical.
Just to get this far has meant writing stacks of code, but it is teaching me a great deal. This isn't a five minute job that's for sure, and before anyone says it, I could probably have made the whole thing in styrene in a fraction of the time???
Alwyn
