Back in December I showed off some designs for 3D printed tanktainers that I’d planned to have printed by Shapeways. I’ve received the models back and had some time to review them and overall I’m very impressed with the results.
Read on to see pictures of the printed models and to find out what worked and what didn’t…
8 x 8 ISO Tanktainer Type One
This model came out really well. All the parts go together as planned and it produces a great looking model.
The tiny little tabs slide into equally tiny slots on the back of the frame.
The tank end caps fit just as planned.
I did wake up in the middle of the night and realise I might be able to shave money off the print cost by changing the layout of these sprues though. If they were inside the frame then the model would take up less room in the printer.
So I changed the 3D file and uploaded it to Shapeways but it made no real difference to the price, it actually increased it slightly, which was confusing but I’ve been led to believe there are sometimes quirks in the Shapeways pricing algorithm so I’m not completely surprised. For now, I’ll be leaving the sprues on the outside of the frame as it makes them easier to remove.
8 x 8 ISO Tanktainer Type Two
I’m really pleased with the print of this tank. Not only did the fine main frame details come out really well, the walkway supports along the top surface of the tank have come out really well too.
Interestingly, these supports are only 0.3mm x 0.6mm which is technically below what Shapeways say they can print. So sometimes it does payoff to test the limits of these things.
Unfortunately, further inspection did reveal a slight problem with the print.
The frame and tank should have printed as separate pieces. However, one side of the frame had fused to the tank during printing.
So I went back and double checked the material specifications: Shapeway say there should be a 0.05mm gap between parts, check. Then I read a little further and it says you must be above this minimum to prevent problems during printing.
Frustrating but I’ve now updated the CAD files and increased the gap to 0.1mm, it shouldn’t make any difference to the model but it should prevent the parts fusing during printing in the future. I’ll need to do a re-print of the new version to make sure.
8 x 8 ISO Tanktainer Type Three (Bromine Tank)
The bromine tank came out really well too.
So far I’ve only been able to print a slightly earlier version of the tank with the tank ends on sprues outside the frame. I’ve since changed the CAD file so the tank ends print inside the frame to reduce the print cost as shown below.
I don’t believe moving them inside the frame will make any difference to the viability of the model.
I’m waiting for some acetone to arrive so I can clean the models properly before smoothing, painting and final assemby. In the meantime I’ve been working on etches (walkways, tank lids, ladders, ADR sign holders etc) to go with each of these models and I’ll update on my progress soon.