The Circuit Farm

Keling has agreed to replace my faulty stepper motor; I just have to send it back with a copy of the invoice.
Gecko has agreed to replace my faulty motor controller (I confirmed that it is just the single axis, and not the motherboard, with the help of a friendly Gecko support person).

I should have done all of this earlier in the week; in theory, I could have had a new motor and a new board sitting on my driveway when we get home. But, I went fishing, spent some time with the family, and generally “was on vacation”, and so it didn’t happen. No big deal.

Now we’re headed back to CA so we can have a weekend to decompress before getting back in the swing. So the CNC machine is being dismantled. I am finding that there are large bits that can stay bolted together for the trip, and in general the packing is going easier than it did last time.

The leadscrews make things a little complicated to pull apart. There is probably a way to make that easier, but I haven’t thought of it yet. Anyway, how many times is the rig going to get pulled apart anyway, right?

While I’m waiting for the returns to all complete, I ordered a spare stepper motor (the G540 comes with a spare controller, of course). It should arrive in CA no later than Thursday next week. Then I will be able to keep on testing while I am waiting for parts. woo.

I came to the machine today knowing that I just had a few last pieces to complete before the machine was done.

I drilled the Z-axis motor mounts (no measuring required — I just taped them to an already-complete motor mount), then counterbored the X- and Z-axis motor mounts. Then I installed all 3 motor mounts. I realized as I was installing the Z-axis motor mount that I was going to have to counterbore 2 of the BRA hold down bolts.

While I was doing that, I learned how I *should* have been installing the router gantry all this time — with the Y-leadscrew in, the top of the Z-gantry can be pulled off without the whole thing falling apart. sigh. Things you learn after you need them. 🙂

While I had the BRA off, I decided to throw some washers under the BRA, to tighten up the movement in the Y-axis. That all went back together well. Y-axis is nice and tight now.

Once the motor mounts were installed, I got started installing the motors. Not a problem, those went on fast.

One last thing to do, install the router itself. I knew I was going to have to find screws to bolt it on with. And this is where it’s better to be lucky than good. It turns out that the same screws that are holding on the motors also fit the router! So I removed one bolt from each motor, so that I would have enough to attach the router. And with a little head-scratching, I got the 3 mounting holes and the center hole for the end mill all drilled. The router moutned right up, although I figured out after I had it on that I had blocked the collet wrench because my bolts are too long. Once I replace those with a proper length, that will work like a charm.

With the router installed, I started looking for the next thing to do.

And I stopped dead in my tracks.

X-axis complete, with motor installed.
Y-axis complete, with motor installed.
Z-axis complete, with motor installed.
Router installed.

Machine’s done!

I spent some time hooking up the electronics; 3 motor cables, Gecko, parallel cable, and PC.

And I spent some time cleaning up all the tools and sawdust.

I’m ready to install software and then start cutting!

I borrowed a mouse from my father-in-law, and worked on cleaning up the CNC PC. It didn’t really go all that well, but I do have a working mouse.

I also checked the third critical measurement again, and cut the final 3 pieces of the superstructure, the router bracket, and router gantry bottom. The cuts went pretty quickly. Setting up the drill holes went well, too. I was a little worried about my hand-drilling. But that seems to have gone OK as well. I was getting a lot of chipout on both the saw and drill today. I think I was going too fast.

Once I started trying to put together the router gantry, the troubleshooting began. The first thing I noticed is that I had drilled the BRA hold down holes way too close to the edge of the router gantry sides. The measurement was 1-13/16″ and I cut it to 1-3/16″. sigh. So I set the new holes up and re-drilled. That worked just fine.

Then I noticed how tough it was to get the router gantry installed with the Z-axis in place. I think maybe I’m supposed to do it in a different order. Anyway, I got it in there, but getting the cross dowels into the bottom bracket was very tough.

Once I got everything installed, I realized that I’d cut the pieces too long. It took two iterations of tearing it all apart, setting up a new cut to trim off a small amount of wood, then putting it all back together, before I got to the point where the axis was now too tight. argh.

So I put in some washers to loosen things up a little; I needed to install them on each side before I found the right setup. Then the BRAs were still a little loose, so I installed washers under the BRA. Once that was done, I got everything tightened up one last time, and just like that, the superstructure was all together! w00t!

There are a number of places that need tweaking.
There are a few parts that still need cutting.

On the todo list:
– drill the Z-axis transmission holes and install the Z-axis transmission nut
– measure and drill the Z-axis motor mounts
– counterbore the X-axis motor mounts
– cut the Z-axis rail to length
– cut the X-axis rail to length
– mount the router and cut the router hole

At that point, I think that the “wood” part is done. I’m sure I’m forgetting some small tweaks, but at that point, this becomes an electronics project. With one good afternoon of work, I should be able to get there.

Already on the PC todo list:
– save off anything that needs to be archived
– install the CNC software
– test the motor cables
– install motors

If all goes well, I should be able to attempt some sawdust tomorrow or the day after.

I got a good solid evening in today.

I decided to drill the holes to attach the Y-axis rail, because it was bothering me. That was pretty easy, although I busted a 1/8″ drill bit. Probably needed a new one of those anyway. Both the holes in the table and the holes in the angle went fine, and everything lined up without much drama at all. Oh, I installed one set of cross-dowels backwards. oh well. I’ll pop those around at some point.

Once the rails were on, I could concentrate on the Big Problem, boring out the holes for the Y-transmission nut (which are cut in the Z-gantry bottom, naturally). I decided to do it by running a drill bit through the axis bearing, and pressing the piece up against the end stops. That worked fine. The Y-leadscrew went in fine, without rubbing on anything. nice. The Y-transmission nut took a little work, mostly to get the hold-down bolts in place with the minimal room I had left (and without uninstalling too much stuff). Once that was done, I hooked up a drill to the Y-screw and had fun running the Z-gantry back and forth. Cool!

I decided to get the X-transmission nut installed, too. A short digression on my WA workspace.

I am trying to stay as low-profile as possible, since this is Not My Shop. So I brought as many of my own tools as I could, and cleared out my own space in my father-in-law’s shop. I did borrow a couple of sawhorses to set up the rig on, but if you can imagine trying to balance a 3/4″ piece of plywood edge-on atop a sawhorse, and then do another one 4′ away at the same time, well, you get an idea of what I’m dealing with. I look forward to getting this thing back on the table at home. In addition, the space I cleared out is large enough for the machine, but only barely. It has about 1′ of room on the machine’s right, about 2′ of space on the left, about 6″ of space (or less) in front, and a decent amount of space (3′ or so) to the rear. It’s a tight fit, and there is not a lot of room for a person to maneuver around the machine, so every move takes a little forethought.

I appreciate my father-in-law’s generosity, letting me take up a decent sized chunk of floor space in his shop. I’m just saying that it’s a scramble, OK? Back to the show.

I decided to install the X-transmission nut in the same way as the Y, run the gantry all the way to one end, mark the spot through the bearing (I tried directly drilling; between the end stop on the rails, and the transmission nut being centered in the Y-gantry bottom, my bit wasn’t long enough. Workarounds. So I put down a pencil mark, ran the gantry back out, and drilled the hole. I was doing a 3/4″ hole because the 5/8″ hole had been giving me problems in Y, in retrospect, 5/8″ would probably have worked just fine here. No biggie. The nut went in fine, I needed to throw some washers on the hold-down bolts, a fine idea that I will probably implement in Y at some point. I used the drill to run the axis back and forth, and marveled at my working X-axis!

I installed the fully-complete motor mounts on the Y-axis. I temporarily installed the almost-complete motor mounts on the X-axis (they need counterbored holes for the motor mount screws).

I installed the rails on the Z-axis (they are held on by friction). I have decided the the bottom Z-gantry side is OK at its current width, although it will be a tight squeeze. I may still cut it down a little while I’m cutting out the final pieces.

At this point, I have a 99% complete X-axis and a complete Y-axis. The Y-axis simply awaits the motor to be installed. The X-axis needs holes counterbored for same.

I suppose I could have done the counterboring, but I decided to hold off.

Instead, I moved on to the PC, intending to clean it up a little and get the software installed, so I could test out the new cables I built the night before last.

After wiggling the table a little to see if it would support the PC (seemed promising), I got the PC hooked up and turned on, and that’s when I found out that my mouse is dead. sigh. The PC also needs to be wiped. It was complaining about low disk space, and it’s generally unhappy. I spent some time deleting stuff, and finding all my old junk on the machine, seeing if there is anything worth salvaging. There is some stuff, so I will continue my testing while I’m in WA, then save off all the stuff I want to keep once I get back to CA. Actually, I could probably blow away a memory card and fill one up (a 32GB card would pretty much get anything off of the 80GB HDD I wanted). We’ll see how that goes. I got myself about 8GB, then gave up in frustration when the mouse really wasn’t going to work.

I tried the mouse out on my Macbook and it’s really dead. sigh. I knew I should have brought one of the wireless mouses.

Topping the todo list:
– counterbore the motor mount holes in X (that will complete X)
– cut the router gantry pieces
– drill the Z-motor mounts (including counterbores)
– cut the Z-axis screw to final length (keep the “good” end)
– install motors
– borrow usable mouse
– archive PC files to memory card (archive memory card files to Macbook first)
– install CNC software on PC
– test cables
– install router

The end of the build is getting really close. I can taste it.