Everybody has their first cannon, right? Well, here's mine. "Doubting Nick" wished to see photos, so here they are. It's not quite complete, but it was far enough along to test. Works fine, no doubles as far as I can tell. Has a little trouble feeding but I think I know how to fix it. Shiny! This cannon doesn't utilize a piston like most cannons do. This style of interrupter is explained here: MWU:OFFENSE-101 'The Geek Breech Cannon' | R/C Warship Combat Schrader valve for testing on the air compresser. Enjoy!!!
Congratulations. Building your first working gun is like a Jedi building their first lightsaber. You'll find that each time you build another set you make changes to improve it. I think the PPB group is on the Mark VII version. The metal fitting inside of the compression nut you have going up to the breach should be the white plastic type. They hold air much better than the metal ones. Your tweaks can be harder with it. The old guns I made with the 90 deg bend at the up feed started to expand at the 90 from the bbs passing by and pushing up and out all the time. It took a couple years and maybe 1000s of bbs but they started to fail after a while. This was regular copper like the mag is made out of. Can't tell if you are using a harder material.
Thank you for the compliments everybody. The metal used for the uptube is steel brake line. It is stronger than copper so maybe it will last longer. Actually, everything is made from brake line, just the mag and barrel are polished. Thanks for pointing out about those fittings. I'll replace them with the plastic ones soon.
Nice looking You might want to add a small gas line to the back of the magazine from the input, to help the BBs head towards the tee. But very well done indeed!
Nice job Caleb. That breach design looks familiar! I'll bring you some silicone o-rings that will work perfect for it next tank battle. Steve
@Tugboat, Once I get the parts, I'll add that as well. Steve, I'm not surprised that the breech looks familiar to you. I took the simplest aspects of siveral different cannon designs and combined them into this. So part of your design got in there. I hope you don't mind Thanks for the O rings, I'm sure I'll use them.
making good use of the 3d printer i see. I assume the loop is just a result of 'these are the fittings i had on hand' and not some devilish new idea?
Nice. I'm curious, how did you attach the tube fittings to the ant farm? Also does it hold pressure well?
I used an ABS slurry to attach them. It's a little tricky to do, but seems to produce a solid joint. What exactly do you mean?
Does it leak? lock up the O ring (over tweek) and put it in a bucket of water and bring it up to pressure. If it leaks fix it and it will be worth the effort. Only issue is the hole in the bucket that happens after several of these tests, use your least favorite bucket.
@Beaver: What thegeek said is more or less what I meant. I'm trying to figure out why my first ant farm leaked. My extrusion multiplier seemed ok. I did use some cheap no-name brand filament, though. Can I ask what you used? How did you slice it and what temp did you print it at?
@thegeek Ah, I see. I'll give a try. Did you try filling the coil with acetone and holding it for five seconds then let it dry? Also try painting the outside with acetone to help seal it. I use filament from MakerGeeks. It's good stuff. Sticks well to Elmers glue and doesn't smell at all. I used Slicr3 to slice, 20% infill- 4perimeters- 0.1mm layers. Extruded temp was 240C and bed temp was 100C. Hope that helps.
