Rheinmetall 35,5 cm Haubitze M1 - 3D Printed

[EPOCH3]

Hi - I have always enjoyed super heavy artillery pieces and have modeled many of these in Rhino 3D waiting for the day I could scratch build them. 3D printers have come along ways in the last few years but I never see anything giving me a true indication of what can be achieved on a larger 3D printer (especially in the 1/35th scale modeling area). I decided to investigate and to conduct a few experiments myself. The German Rheinmetall 35,5 cm Haubitze M1 siege howitzer became my first subject.

The model was first designed in Rhino 3D software. The model is still a work in progress but I thought I would share how this project is turning out. I chose to use Shapeways print service but there are others out there. Shapeways offers quite a large material selection but with a recent (and significant) cost increase I chose to do a test print of some parts in the least expensive material first (White, Strong & Flexible material or WSF as they refer to it). WSF is basically white nylon powder fused together by a laser (Selective Laser Sintering or SLS).

While the surface of parts does not quite achieve the smoothness of injection modeled/machined parts I was amazed at how the first couple of parts turned out. I decided to go ahead and try printing the whole model in the WSF material. I will print the same model in higher resolution using different material later this year. The other materials can achieve significantly smoother surfaces but is much more brittle (and also more expensive).

The model could have been printed in as few as 4 or 5 parts but I wanted the structure and barrel assembly to rotate and articulate like the real gun so I chose a version that is about 17 parts.

Everything is 3D printed except the deck plate which I just made out of dry wall sandpaper. I did not think the fine pattern of the deck plate would print very uniform so for this version I opted to use something off-the-shelf. The railings got broken in quite a few places (they printed but were probably broken in shipping) but a little super glue did the trick to repair things.

I am still experimenting with how to surface prep and paint the model. The WSF material is very porous but I got pretty good results just dipping into Modge Podge (like Elmers glue) to seal it, letting it dry and then using Testor's metalizing spray paint. After the paint dries you can use a q-tip to just buff it out in places to get a fairly nice semi-metallic look.

Attached are a few photos of the model (WIP).

I will add other photos as project progresses.
Greg

[ridgback65]

That looks amazing, please keep posting.

[Manuferey]

Impressive details !

Emmanuel

[Marcus]

Impressive.

/Marcus

[EPOCH3]

Thanks - For those interested, the cost of printing this model was just under $300. Not really that bad for a one-off copy. There are tricks you can do such as hollowing out parts as much as possible to reduce material costs and you can also separate parts up and sprue them together like a conventional model kit to save on machine space sometimes. I was going for high detail and minimum parts count on this first build. Time to get back from shapeways was about 2 weeks. I also did a Demag crane for assembly to go with it (refer to pic). In future I will do the separate transport wagons. So far, prints have exceeded my expectations on everything but tires - fine tread patterns for example don't come out crisp.
Regards

[StefanSiverud]

300 USD for a single kit? What's the scale?
Interesting project.

[EPOCH3]

Hi - scale is 1/35th with overall length about 16 inches
Regards

[ridgback65]

That does look impressive. Lot's of potential with 3D printing I reckon.

[EPOCH3]

The sky is fast becoming the limit. Technologies are still evolving and maturing, cost and absolute accuracy and detail are still issues but things are getting very close to the day where modelers can bring their unique projects into the physical world in a fairly straightforward manner that gets fairly close to the quality of a standard kit. The surface quality is not quite there yet but innovation and technology is closing that gap rapidly. I have built models most of my life but had a stroke about 3 years ago. Being partially blind, I lost my depth perception and which made building conventional models really hard. Modeling on the computer is doable since it is in 2D. There is still a lot of "scratch building" work involved with research and design but being able to print my "projects" out in a physical form has allowed me to continue a life long passion.

Regards

[EPOCH3]

Here are a few more samples of 3D projects I am experimenting with - all WIP and all in 1/35th scale.

[ridgback65]

The sky is the limit indeed. I can see so much potential in this it is quite frankly staggering.

[StefanSiverud]

Hi - scale is 1/35th with overall length about 16 inches
Regards

Nice! But is the price tag attached 300 USD?
Very impressive either way - I can appreciate the time it must have taken some time just to make the 3D model.

[EPOCH3]

Hi - modeling time varies quite a bit and for me depends a lot on the availability of good reference material (photos and drawings etc). I use Rhino 3D software which is very accurate and was quite fast to learn. I spent only several hours learning the basics which allowed me to model at the level you see. It has much more capability than I use and most models can be done using only about 20 or so commands. It's a huge help with learning any CAD program if you also think in 3D. Most objects have quite a bit of symmetry in their construction so you do something once and just duplicate and mirror it. Models also evolve - you usually start with simple shapes and outlines and just add more and more levels of detail over time. I also model in 1:1 scale initially and then just make adjusts down to whatever scale I wish to print in. 3D printers also have vastly different build envelopes so you have to take overall size into account when thinking about whether to print as 1 part or break something up into several parts.

Yes, as a hobbyist, cost is still an issue but it's come down quite a bit as patents have expired and competition has increased. $300 for the M1 is a bit high but I think it quite reasonable when you think about it. It would cost me much more than $300 to have someone scratch build it for me(labor is not usually free). I also have the added benefits of changing scales at will and/or being able to hit the print button as many times as desired. The machines used for these prints also runs about $500,000 each so I think $300 is fair.

The Lok model was the first time I actually timed modeling and it took me about 5.5 hours. The model could have been printed in 1 piece but to save money, I decided to separate the parts as shown in the attached photo. The cost on the Lok was about $160.
Kind regards and happy modeling

[wimve]

Well done.
I also do some 3d modelling but only as a computer model. 3D printing, I thought about that and looking at the results it is amazing.

[EPOCH3]

For anyone interested, attached are a couple of additional reference photos:

One photo is of a German Fries mobile Crane in 1/35th scale which was not quite successful. I decided to
try and print the vertical support assemblies as a single pieces and my design was a bit too weak
in places. As such, those thin areas of the print failed (still repairable with super glue though).
I thickened up the geometries that failed/broke and they reprinted fine. Cost was about $67 (the
gantry assembly printed out great as a single piece and was about $27 by itself).

The other photo is a 3-axle truck assembly I did for a friend in 1/50th scale using the more expensive
material (Printed on a 3D system's Projet 3500) which results in much smoother surfaces
(although it is more brittle). This part was about $32 to print and took only 4 days to get back from the
print shop.

Regards