Since I’m getting more orders for tank files on Wargaming 3D, I thought I would share some tips for those who own resin printers.  I use a Formlabs Form 3 for printing my models, but for those who have a different machine, such as the Anycubic Photon S, most of what I’m about to discuss will still apply.

DSC_0041
We will lead by EXAMPLE

When I first started printing, I had lots of problems, particularly with coloured resin, which has very different physical properties from Formlabs white resin.  To be fair, Formlabs is up to version 4 white resin, but still on version 1 for the colour base.  Hopefully, they will re-formulate it by the time I mix up my next batch, because the coloured resin is extremely fragile when coming out of the machine, and tank guns are very easy to break when removing the supports.  I would compare uncured coloured resin to candle wax in terms of both softness and brittleness, unlike the white resin, which doesn’t really need to be cured at all.  The advantage of coloured resin is that, unlike white resin, printing with a 25-micron layer thickness is an option, so higher levels of detail with fewer print lines are achievable.  Post-processing problems are one thing, but printing problems were another, and while they seem to have gone away with the latest firmware update, I have yet to run another large batch of tanks.  In addition to the firmware update, PreForm has also had a software update, and certain things have changed since I started using it, most notably the placement of supports.

The first problem I had with supports was with the old version of PreForm, and I explain how I solved it here.  As of the update, however, the software has a tendency to add supports that it never did before, and I find that they are unnecessary.  Below are some of the new support placements:

Tank printing tips 7

These are all along the ridge that represents the row of track lugs.  There is a very good reason that I don’t make this part of the tank realistic, even though I could: cleaning it up is a ludicrously time-consuming task, as I demonstrate here.

In addition, the software is rather insistent on adding supports to the individual teeth of the drive sprockets.  These supports, much like the supports that run in between road wheels, cause more problems than they solve.  I made certain to remove them when I printed my latest T-10M test, but I foolishly left them in when I printed the Grozniy Klinok.  I’ve spent way too much time on both of those, so I probably won’t print a replacement hull for the latter for a while.  Besides, I need to fix the supports on the treads, which you’ll see later in this article.  The supports on the sprockets look like this:

Tank printing tips 1

While they look like thin wires in the software, they run together when printed, and become impossible to remove without also removing part of the part of the sprocket itself.  Given how small these teeth are, and how well they’ve turned out on previous tests when totally unsupported, I would say that these supports are not needed.  The software disagrees:

Tank printing tips 2

Trust me, it’s not a problem.

The software also adds supports to the suspension arms and wheel hubs that it never did before:

Tank printing tips 4

Tank printing tips 5

Both these and the duplicate supports on the torsion bar sleeves aren’t necessary, and I find them to be detrimental.  Unnecessary supports trap liquid, and make clean-up difficult and time consuming.  The support locations should look like this instead:

Tank printing tips 6

You can see the track lug ridge supports through the suspension, since I hadn’t yet removed them when I took this screenshot.

The final issue I’d like to discuss is not currently relevant to any of the tank model files that I sell as of this post.  None of my 1:285 scale tank models have treads, but a few of my 1:220 scale models do.  The only historical one I’ve tested so far is the King Tiger, and while I’m happy with the results (mostly), there is still room for improvement.  In the screenshot below, the top track has the supports as generated by PreForm, while the bottom track has the supports that I put in:

Tank printing tips 8

I decided to make this change because I’d like to test this support scheme before printing another Grozniy Klinok hull (a six-hour build by itself; the entire tank is six and-a-half).  The idea is that, by alternating the support locations on the treads, the tracks will be supported by struts, rather than a continuous wall of plastic, which can fracture in less-than-optimal locations.  You can see the difference in supports below:

Tank printing tips 9

I will write another article in the future letting everyone know how this last test works out.  If you found this article from the Wargaming 3D link, consider following me both here and on Steemit, where I post most of my new pictures, including works in progress.

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