More paintball repairs

This time I was reverse engineering a feedneck for a Smart Parts SP8 marker. These markers are notorious for cracking the body around the feedneck mount, as well as the feedneck itself. This is partially due to the poor force path provided by the original designers, who tilted the feedneck off-center without adding additional support. The customer initially requested an all-metal feedneck, however because of the complex geometry that was a very expensive option. We ultimately settled on two designs, one entirely 3D printed, and the other partially 3D printed with a metal extension epoxied in. These fit up great into the marker, and were a really good example of how powerful 3D printing can be for hard to produce geometries.

Power drawbar

Mechanical design for a pneumatic power drawbar to allow Tormach TTS to be used on my PM-940. This project has to wait until the mill motor upgrade is complete, at which point I can purchase the TTS tooling and mount and install this. Not a very complex part, it’s basically a floating steel plate attached to a 4-stage pneumatic cylinder, with a separate Belleville assembly added onto the drawbar. The cylinder should produce upwards of 2,500 pounds of force, which should allow for a very strong Belleville stack to retain the TTS tooling. Since I’m hoping to run up to 3HP through the spindle, I’m kinda entering unknown territory compared to the Tormach machines, so there’s a good opportunity to do some experimentation and figure out the correct setup.

PTP Micrococker bolt, pin and sled

Another case of an old, worn marker. The customer needed a new sled, and wanted a different pin orientation than the original, which required a new bolt and pin. The sled was particularly tricky because there’s a threaded hole with very little meat around it on the front face (left as shown in the above picture), which I ended up making at the end of everything. If I did it again, I would change the workholding so that was done first, then the exterior dimensions were milled. Picture below shows it mounted on the marker before anodizing.micrococker

Watch making

The original reason I bought my mill was for watchmaking. I never got around to putting the fixturing together or starting the project, in part because I figured I’d have to make up a sheet metal die to manufacture the faces. This week I stumbled on photochemical machining for a totally different project, and I realized it would be a great cost effective way to make complex watch faces. So there will be a part 2 to this down the road somewhere.Watch - 3

The Mill

This is a Precision Matthews PM-940CNC. Basically a modified Rong Fu 45 design, it weighs about 1,100 pounds total. Right now it’s running the stock 1.5HP motor, and it got it’s first major upgrade a few weeks ago: a full enclosure. This is great because I no longer have to spray chips everywhere, and I can now add flood coolant to the system.

I’ve already planned out adding a coolant system, a 5HP motor (which is really chosen to ensure it can output 3HP when run at 120Hz), a power drawbar, and an automatic tool changer to it, but the design and manufacturing of those will be separate posts later on.

Plans and instructions for building the enclosure will be up for sale on my site ( soon.