It’s been a long time coming.
I finally decided to bite the bullet and get the CNC machine running. It’s been eating at me that I haven’t been able to get anything done on the machine. I have stopped really thinking about CNC cutting projects because the machine was not working yet.
I started to realize that I’ve been building the machine for nearly a year, with nothing really to show for it, and I had finally had enough.
Between the chicken coop project and the abortive Maker Faire Seattle exhibit, a lot of the pieces and parts I need were scattered around the shop. It took a bit to get them all gathered back together.
A couple weeks ago, I spent time getting the motors moved off of the small CNC machine and reinstalled onto the big one. As I did this, I realized that I’d cut some of the motor cables a little too short; I’ll deal with that later.
Yesterday, I reinstalled the vacuum hose and the router power cable. I need to buy another box of ShopVac hose to hook the Dust Deputy to the vacuum. I also need to figure out how to power the machine off of different circuits, because I recall having problems with the little machine tripping a breaker if things spike in amperage. More stuff to deal with later. For now, there’s no vacuum, and the router is plugged into the same power strip as the PC. I also decided to leave the Super PID out for now. Hey, look! I’m building a to-do list! 🙂
I spent a lot of time making sure that the machine could move through its whole range without binding. I have a cool video which is probably too large to post.
With the machine moving properly, I quit for the day on Saturday.
On Sunday, I again forced myself to head into the shop and work on the machine. I looked around and decided that I was completely unable to find yet another reason to delay, and thus I was more or less ready to start cutting. It’s possible I was having some second thoughts about the process.
I decided to do some text for the first cut, but I didn’t want to do “Hi there” again, so I decided on “Hilltop”, and then found a font that would work for an engraved cut (it had rounded serifs). I laid in a scrap piece of CDX ply (like I said, I was not feeling very confident, so I didn’t want to “ruin” a “good” piece of wood if it wasn’t going to work), got it all laid out, and fired it up.
I was as surprised as anyone could be to watch the machine happily cut out the required text.
I was running the machine at 50ipm, which is nearly double the 30ipm that I’d been able to achieve on the smaller machine. Credit goes to the chain drive for that. With the first sign done, I decided to do some speed tests to see what I could achieve. I cut a series of circles at varying speeds and cut depths. The results are as follows:
50ipm, 1/8″ per pass: not a problem. Nice, clean cut.
100ipm, 1/8″ per pass: still pretty good.
200ipm, 1/8″ per pass: the machine did it, but there were some jitters.
300ipm, 1/8″ per pass: yikes, that’s pretty fast. It cut, but there was a lot of tearout.
With these results, I tried 200ipm, 1/16″ per pass, and I decided that it will do it, but I think I would like the quality a little better at a slightly lower speed. Maybe 200ipm for roughing and 100ipm (or 150? haven’t tried that) for finishing.
In any case, the machine is cutting multiple times faster than the old one.
More tuning will need to happen to get all the feeds and speeds just right. RPM will come into it, too, as soon as I put the Super PID back into the mix.
But, the CNC machine is cutting!
TODO:
– cut a new motor cable for X axis
– buy another set of ShopVac hose
– split router/vac and PC/steppers onto different circuits
– integrate SuperPID (including hooking to G540)
– upgrade to PC890 router for better vacuum control (here’s how to mod it for SuperPID)
– integrate Hall switches
– create a feed/speed setup in CamBam for new machine
Projects:
– “Boo!” sign
– Halloween decor
– Xmas decor
– bookcases
– door sign
– …that should be enough to get started.