3D Printing of  Miniature Heavy Weapons.

As reported previously I have now used 3D printing to produce heavy machine guns for my army.

I have explained in other postings that all the artillery weapons in my army have been constructed using a readily available object as a gun shield and chassis to which  I attach an axle, trail and barrel. For this platform my field guns use a cut down plastic shelf support stud, heavy guns are based on a paint tin clip while horse artillery guns use a home produced resin cast of a trail spade from an Airfix 5.5 inch gun. However I have never been able to find a platform for my heavy weapons machine guns. As a consequence I have previously had to superglue axle, trail and gun shield together carefully, avoiding the inclusion of my fingers whilst trying to produce a realistic looking model.

Recent internet surfing brought my attention to 3D printing. After a little research I concluded that it may, subject to cost, provide a way forward in respect of  a platform for heavy weapons. I found a local supplier of 3D printing services and made contact. It turned out that this small local business owner had been involved in producing wargaming scenery using 3D printing so my requirements became a little easier to explain, just imagine explaining to a non wargamer or modeller just what I was seeking !!!!!! The upshot was that I built a prototype platform as carefully as possible and met up with Dave the business owner. My initial idea was that he could scan the prototype and print from that programme. However Dave told me me it would be better, and no more expensive, for him to write a CAD programme using the prototype as a guide. In addition, the original prototype included a gun barrel. Dave told me the printing process did not allow protrusions as these could droop due to the heat during printing.. I therefore removed the barrel leaving just the hole as part of the model. Dave gave me some cost indicators that were fully within my budget  so I agreed for him to go ahead and write the CAD programme and print some pre production models.

The pre production models were created and I found them perfect in all respects. Dave confirmed the final costs which I agreed and he proceeded into production. About ten days later I collected the printed models and paid my bill. The following photo shows what I got.

I had four sheets like this together with a number of pre production models and some others that had come apart from the flimsy base sheets. Apart from the holes in the shields for barrels the models also had the towing eye in the trail. The next steps were to separate the models, clean off the sprue and add the gun barrels. For barrels I use small elongated plastic necklace beads from Hobby Craft. I found that the holes for the barrels had to be reamed out a little but that was good as it gave a tight fit so that dripping a little plastic glue around the joint was easier.

The  picture above shows part of the initial batch of 32 with barrels installed. Next step was to drill the holes in the axles for the wheels, (cut down drawing pins) and superglue them as shown below.

With construction complete I primed the whole of each model.

The models were then painted my standard olive drab and then the wheels were painted black. The final result is shown in the photo below.

The picture below gives a good idea of the level of detail in these models which are only 22mm long and 10mm high and the same in width.

There were some leaning points during the process. Firstly the printing material was ABS which is similar in consistency to Airfix plastic soldier figures. It proved time consuming to remove the base sprue which may have been easier if a harder substance had been used, maybe more like Airfix plastic kit material. Secondly the drilling of the axles for wheels was difficult as the plastic, being so soft, melted a bit. On reflection, it would have been easier if I had had the holes printed or again, a harder material had been used. Finally the material was gray, virtually the same colour as my primer, so it was a little difficult to see exactly what I had actually painted than if a different but still pale colour had been used.. All  that said I am delighted with the models and these leaning points are simply the result of experience and in no way detract from Dave's excellent work.

Finally the technical details. I ordered 200 models. The total cost, including the CAD creation, was £50 which I thought very reasonable indeed. The print resolution was 150 microns, about twice the size of a human hair.

My supplier was david.banks@telford3dprinting.com. whom I strongly recommend and thank for his assistance and very helpful attitude.