- Build a new front onto my enclosure replacing the bifold doors, and more importantly, allowing me to get to the machine's table without scraping the top of my head on the aluminum rail
- Resurrect the ability for my CNC Lathe to cut threads.
- Look at improvements to the spindle on my big mill, the G0704. This is aimed at a few things:
- Ability to start, and stop the spindle from the CNC code - this is fundamental in the real world.
- Ability to set the spindle speed from the CNC code. The GCode command exists for this and I think most all of the "real" machine shops do it.
- Together, these mean a new motor. I will do this with an eye to roughly doubling the speed of my spindle. Which will require new bearings for spindle
- After this, I'm considering being able to tap (thread) holes under CNC control. This one, frankly, isn't super important to me, but it looks like the I can accomplish that without adding much cost to the motor and controller improvements that do the first two.
The new front would be framed entirely of 1x2 standard dimensional lumber. The doors will slide in grooves routed in the top and bottom horizontal pieces, and will be able to slide past the ends, which will allow lots of access to the inside. When the doors close, the center door will overlap the two side pieces to keep chips and splashes inside.
Moving to threading on the dedicated CNC lathe was something that re-occurred to me during the flame eater build. I had to thread some small pieces; nothing I threaded was beyond the size capabilities of the Sherline. When I built the CNC lathe, it was always intended for threading more than anything else, and after some trials and tribulations I was able to get a few test pieces threaded. Unfortunately, that was 10 years and several garage re-organizations ago; it barely runs. In fact, today I wanted to check some aspects of how it ran and it wouldn't run properly. The cross slide (holding the tool) only moved in one direction, away from the chuck. The motion to advance the tool into the work was fine. It took a bit of troubleshooting to find out it was simply a connector that needed to be unplugged and replugged.
In the intervening years, the Sherline world has gotten more sophisticated, with high resolution position encoders and people driving their spindles with stepper motors for complete control of position. I don't want to overcomplicate this, but I also want it to be dependable for little things like that wrist pin yoke I just made that 3 turns of a 32 TPI thread on it.
The spindle motor almost is lower priority because it works as it is, it could just be better (and I guess all of these improvements are like that). Another aspect of the spindle motor upgrade is that a lot of guys update the power of the motor on the 704, because the rated 1 HP is a little light. I don't mind that as much, but from what I see while getting familiar with what's out there, I'll probably end up in the 1-1/2 to 2HP size by the time I'm done.
Why double the speed? I have a "speeds and feeds" program called G-Wizard; what that gives me is a good starting point for how fast I should spin the cutter (RPMs) and how fast the table should move in Inches Per Minute (IPM). Virtually every time I cut aluminum, it tells me to set my spindle to as fast as it can go, giving me the warning that the spindle being maxed out is bad for tool life. I think doubling the spindle speed will allow me to cut at RPMs less than the max.
I'm still contemplating the next big project, and I'm thinking of a simple internal combustion engine. I understand they're less fussy than the flame eater. I naively told Mrs. Graybeard that I'd like to make something like a single cylinder lawnmower engine. There's a popular "first IC engine" by a guy named Webster who the engine is usually named after.