If one were to look at our Blog as evidence of the health and progress of our endeavors it would be easy to assume we were no longer in business. Luckily, our lack of meaningful public communication has more to do with the focus of our attention than it does the health of our business. As the first quarter of 2014 has already come and gone, we are going to make a concerted effort to maintain our blog, be more present in social media channels, and generally be as transparent as possible.
So what has the MechArtisan team been up to?
Thermwood Gantry Mill
The Thermwood gantry mill continues to consume our attention but is getting very close. Over the course of the fall and winter we finished up the gantry risers, have made great progress on the new Z axis tooling, and are deep into the new control system.
The risers are filled with a rock and epoxy slurry to remove unwanted harmonics in the assembly. The Z axis assembly is constructed entirely from MIC6 cast aluminum plate. We selected 35mm guide rail and a precision ground ball screw to control position. The controls are PC based with an ethernet motion controller and a small PLC for handling I/O. The control architecture is spread out a bit because we were trying to contain the entire system within the footprint of the machine. This has proven a little tricky to accomplish but the end result will be robust and accessible for debug and future maintenance.
Vacuum Pump
We have a couple projects in the shop which require vacuum either for holding components during machining or for composite layup. Options available to purchase were limited since we wanted a large vacuum receiver and a significant flow capability. As with most of our equipment, the only option which would provide us with everything we wanted was to build our own. We sourced a 3 phase vacuum pump capable of 29 in Hg @ 20CFM, found an old compressor tank, and then built a control which allows digital adjustment of desired vacuum. The end result is a roll around vacuum pump package with quick disconnects allowing multiple circuits to be run simultaneously.
Bandsaw and Lathe
Through the course of various projects the desire for a vertical bandsaw kept coming up in shop discussions. With our limited amount of available floor space we needed something compact. Unfortunately, all of the newer saws on the market were significantly larger than we could handle, so we turned our attention to "Vintage" hardware. After a considerable search effort we happened upon an older Delta 14" metal cutting bandsaw. It has an integral reduction gearbox with an oil bath, and after equipping it with a good blade the old saw has been indispensable every since.
The opportunity came up to purchase back a very stout old South Bend super precision 1307 lathe which was once a part of the GPE Machine arsenal. After unloading the Logan 1937-1 engine lathe we moved the behemoth into place. It significantly improves our manual turning operations capabilities and is far more accurate than our previous machine.
CNC Lathe Upgrades
Over the last year we have had many opportunities to put our CNC lathe to work. The unit was purchased as a used piece of equipment requiring significant effort to get running. We built a new control for it during the commissioning process but otherwise ran it "as delivered". As we racked up hours on the machine we started noticing some drift in the axis positioning accuracy which we didn't consider acceptable. Closer inspection revealed a failing Z axis ball screw and an X axis screw that was on its way out as well. We bit the bullet and replaced both screws with precision ground screws. This of course wasn't a "bolt in and go" affair, and we had to design and fabricate adapters for both axis. The end result of the efforts is the ability to hold 0.0002" on both axis which is significantly better than we were able to expect before the upgrades. While the screw upgrades were underway we also cleaned up some wiring, addressed a couple control noise issues, and built a new keyboard / trackball tray. The lathe is now fully operational and ready to do whatever needs to be done.
That wraps up our equipment projects. We'll do another update soon on some other projects we've been pushing on. Thanks for checking in.