3D Printing Cannon Barrels. Constitution Masts.

by John

A temporary diversion from finishing the mini mill, and the Constitution model. Just experimenting with 3d printing of cannon barrels.

I came across a site which offered free stl files for different size Armstrong cannon barrels and I decided to test print some. The site is https://thenrg.org/page-1075420

The designs include muzzle loaders from different countries and eras and they seem quite accurate. I could not find any carriage files on that site.

These barrels were printed on the same printer (Qidi X-Max3), same filament (Qidi Rapido PLA), and the same printer default settings. The differences were that the left one was printed horizontally and the right was printed vertically, as per the next photo.. And supports were used for the horizontal version, and some fine sanding was used to clean up the rough bits. Despite appearances, the dimensions are identical. The barrels are 60mm long.
Clearly the finish on the vertical print was superior. On the horizontal print supports were used, and the finish of the underneath supported surface is worse than the top surface which is shown in the photo. Since the weakest dimension of a 3d print is the layers, the horizontal version would be more robust, but I could not break the vertical version with a reasonable amount of force, so that should not be an issue.

I anticipate that 3d printer users might question how the vertical printed version with its small footprint, remained attached to the build plate as the print became taller…

Well, the build plate has a textured surface, which increases the area of contact between the plate and print. I used a 5mm brim. I try to NEVER touch the build plate with fingers, and if it cannot be avoided I always wipe the build plate with acetone to remove any trace of skin oils. And finally, the X and Y axes of the Qidi move the print head only, and not the build plate, so there is very little shaking of the build plate with its precarious looking top heavy cannon.

Cannot rotate the image. 200mm version of the gun. (scale 1:15). This print is close to perfect IMO. Look at the detail of the George3 cypher. The only faults are the line running the length on top, which is where the Z shift occurred, and the small deficiency on the trunnions which occurred because I chose to not use supports at all.

And an update on the USS Constitution model. It now has masts and a bowsprit, not totally finished, but close to getting some stays (fore and aft supports) and shrouds (side supports). So the masts and bowsprit are just sitting there, and probably not quite in line yet.

And notice that I found a use for two of the 200mm printed cannons. Wedged underneath to stop any wobbling. Hmm. Maybe I can attach the nameplate to one of them…. p.s. the 80pr Armstrong RML in the background is not going onto the Constitution.