Part tumbling is a method of deburring and cleaning relatively small objects. This is done by capturing the parts and media inside a rotating container. The agitation continually moves the media around all surfaces and corners of the part, smoothing them out resulting in a uniform finish. The media can be anything from specialty ceramic shapes to ball bearings to even sand. This process can be done in either a wet or dry condition. Think about the beach, the rocks there are smooth. This is due to the waves repetitively rubbing together the sand and stones which result in smooth round shapes.
[imp22b] recently got into ammo reloading and needed a way to clean his used shell casings. The casings are brass and after a little research online, [imp22b] found that a wet tumbling process with stainless steel pins for media was a DIY proven method for this casing material. He then went on to find a commercially available tumbler to model his build after, in this case a Thumler Model B. There is certainly no need to re-invent the wheel here.
As you can see in the photo, aluminum extrusion was used as the frame. Mounted to the frame are 4 pillow block bearings with shafts between each pair. A motor drives one of the bearing-mounted rods which in turn rotates a container resting on the rods. [imp22b] started with a 1/15 hp motor that he had kicking around but that wasn’t powerful enough so he did have to step up to a 1/3 hp unit. The container is made from off the shelf PVC pipe pieces and holds the media and casings along with some water. A bit of Lemon Shine and Dawn detergents are also added and help clean the parts. After a few hours of tumbling, the casings look pretty darn good.
If you’re interested making your own simpler tumbler, check out this one that uses a hand drill or this one that uses a coffee can.
For those that are into reloading their own ammo you know that getting an efficient assembly line process figured out will make your sessions much more enjoyable and productive. [Msoejacobsk] knew that he could buy a case feeder for his system, but didn’t want to shell out two hundred bucks for it. After a bit of thought he was able to build this case feeder for around ten dollars.
The purpose of the rig is to orient each empty casing correctly and feed it to the reloading hardware. This is accomplished by first separating one casing at a time using this angled tumbler. The disc that makes up the floor has slots cut in it which are the size of one casing. When that slot gets to the highest point of its rotation there is an opening through which the casing falls. To ensure proper orientation a V-shaped piece of heavy wire has been place in the middle of the opening. This acts as a fulcrum, letting the heavier base pull the casing in that direction. You can see this happen in the clip after the break.
Continue reading “Case feeder makes your ammo reloading more efficient”
[Kuba_T1000] built a multi-barrell Airsoft minigun with an unbelievable firing rate and an almost inexhaustible ammo pack. The gun is made entirely from aluminum which meant some time on the CNC machine. The six barrels don’t rotate but they are all used, resulting in the carnage shown in the video after the break. That large box you see is the ammo pack, which can hold 16,000 BBs and uses an electric feed system to reach the necessary delivery speeds. It is certainly not something you’d want to run into as part of an automated turret.
Continue reading “Airsoft minigun packs quite a punch”