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Hello everyone

 

I've had some time on my hands recently so I've been able to get on with a project I've wanted to tackle for sometime: producing some detailed models of ISO and European tanktainers in N scale (1:160).

 

I've been planning with FreeCAD for a number of years so I could jump straight into producing the CAD files but my first print was still very much a learning experience. Here's what I did wrong :no:

I created the model as two parts (frame with tank as separate model) which meant it was very expensive to print. You'll find a thread on that on RMWeb.

I put attachment tab slots in the wrong places, which made parts of the frame delicate and the frame cracked when trying to use the tabs/slots.

I accidentally uploaded a version of the model with a solid tank. More unnecessary expense  :jester:

 

However it wasn't all negative, one of the things I was most worried about, the print quality of the tank/tube, wasn't an issue at all. The printed model came out with an almost layerless finish.

The material wasn't fragile and the frame printed really well, even right at the limits of what Shapeway say is possible (some parts of the frame were only 0.6mm x 0.6mm)

 

So I ploughed on. The first step was to redesign the first model incorporating the lessons learnt.

Note the following pictures of the latest models are what they will look like when assembled, they actually go to the printers as two or more separate pieces (tank, tank end caps and frames) joined by sprues. The pieces are cut off the sprues and glued together to create what is shown in these pictures:

post-33797-0-36193600-1544800836.jpeg

 

Once, I'd done that I decided I really wanted to test the limit of what Shapeways could do so I choose a tanktainer with intricate frame detail:

post-33797-0-26983400-1544800849.jpeg

 

Then I found a really interesting prototype in the form of a bromine transportation tank:

post-33797-0-69399500-1544800857.jpeg

 

Finally I had a go at a European swaptank:

post-33797-0-77602800-1544800909.jpeg

 

You'll notice none of the models have walkways, ladders or very small details like ADR warning signs as I felt these would come out better as an etch rather than being printed.

 

All these models are currently at the printers but I'll update when I get them back.

 

Simon

Edited by NScaleNotes
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Hello all

 

I've received my prints back from Shapeways so I thought I'd post some photos of the actual models.

Shown in the same order as my original post:

 

post-33797-0-21610500-1545132079_thumb.jpg

 

post-33797-0-21449500-1545132097.jpg

 

 

I'm really pleased with the print of this tank. Not only did the main frame come out really well, the walkway supports visible along the top surface of the tank have come out crisp, clean and intact. The supports are actually 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.

 

post-33797-0-76175700-1545132114_thumb.jpg

 

post-33797-0-62403300-1545132127_thumb.jpg

 

 

 

post-33797-0-93956500-1545132141_thumb.jpg

 

post-33797-0-41328400-1545132156_thumb.jpg

 

 

I've done nothing to these prints yet and some of them do need a little bit of cleanup as you can see the remains of the wax supports. A quick rub with a bit of sandpaper/file and they'll be ready for painting.

 

Simon

 

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They look very nice, any plans to do these in 4mm scale?

 

Hi RP82

 

They'd be very expensive as a full print but I've designed some that can use lengths of brass or plastic tube of the correct diameter as the tank. As these take up less space in the printer and involve less material they are cheaper to print.

I could try converting one of these kit versions to 4mm and see how much it costs to print.

 

Leave it with me, I'll see how it comes out.

 

Simon

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Hello all

 

I've been playing with the three tanktainer prints.

 

The first one is fine, all the parts go together well and it produces a great looking model:

These tiny little tabs slide into equally tiny slots on the back of the frame:

post-33797-0-38801000-1545403219_thumb.jpg

 

The tank end caps drop into the tank as planned:

post-33797-0-08935900-1545403267.jpg

 

However I did realise I might be able to shave a little off the print price by relocating these sprues:

post-33797-0-77136600-1545403371_thumb.jpg

If there were entirely inside the frame then less support wax and printer space would be used during printing. So even though this model printed correctly I'm going to update the CAD files.

 

The third tank, the tiny bromine tank went together perfectly:

post-33797-0-70338500-1545403465_thumb.jpg

 

 

I did find an issue with tank number two though. The frame and tank should print as separate pieces, like this:

post-33797-0-18079500-1545403527_thumb.jpg

 

However one side has fused during printing:

post-33797-0-65768600-1545403566_thumb.jpg

 

So I went back and double checked the material specifications: 0.05mm gap between parts, yes, that's what I did. Then I read a little further and it says you must be above the minimum to prevent problems  :O   I've updated these CAD files now by increasing the gap between the parts to 0.1mm. It shouldn't make a difference to the model but it should prevent the parts fusing during printing.

 

Living and learning...

 

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Hello all

 

I've recently been working on an N scale swap-tank.

 

post-33797-0-42001400-1547813753.jpeg

 

It's got some very fine detail. It's within tolerances for the fine detail plastic but it'll be interesting to see how that comes out.

 

post-33797-0-52474800-1547813759.jpeg

 

 

In the meantime I've also been putting together some etches for the models in the posts above.

Currently waiting for some prints to arrive from Shapeways so I hope to be able to post some pictures of the finished models with etches soon.

 

I've also been asked about making these available in 1:148 which I can.

I probably won't be test printing these myself as I don't model in that scale but as they are basically scaled-up versions on the 1:160 models they should print without any problems if anyone here was interested.

 

RP82: I've decided I probably won't be making these available in 4mm. It would require a complete redesign rather than just re-scaling the existing model. Sorry.

 

Simon

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Hi Simon

That's a shame about the OO scale.

But I wish you good luck with your tanktainers.

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