The parts arrived today (both the electronics, on time, and the hardware, 3 days late). Life’s good!
In anticipation of having BRAs, I borrowed 4 pipe clamps from my friend John (thank you!) on the way home.
I spent the time before dinner building out BRAs and fondling the rest of the goods. Those motors are gigantic.
The Y-axis BRAs had some untapped holes, so I pulled out the 5/16-18 tap and banged those out. I checked all 3 sets of parts that needed BRAs, and it turned out that because of the way the bearings are mounted, the C & D parts (the Z-gantry sides, which hold the Y-axis BRAs) needed more drilling. There was no measurement for where to put the tiedown holes, so I arbitrarily chose to put them 1″ in from each edge. It needs at least 1 1/2″ to clear the bearings. No biggie. I banged those out, and mounted all 6 BRAs and all 6 leadscrew bearings. 1 1/8″ is a perfect size for those.
I then tackled the “tough” problem for the night, getting the “critical measurement” on the X-axis, upon which the length of the Y-gantry bottom and Y-table depend. It took all 4 pipe clamps, 2 Da Kine rack straps (love those things), and 2 levels to get it all together. Kristi came and helped for part of it, too, when I lost one of the X-rails (oh, I cut the 1″ rail for the X-axis, too; miter box worked great for that). The critical measurement is 26 1/16″. This is 10/16″ shorter than the plans call for, but that’s to be expected, since I carved away a bunch of the edge on day 1 while trying to even things up. I need a table saw. I marked the Y-dependent pieces and clamped them together. I’ll cut them tomorrow night while the kids are awake. I probably could have gotten away with it tonight, but I didn’t feel like testing the sleepers.
With the measurement done, I decided to see what I could do about progressing the build some more. I attached the X-table legs, and suddenly I had a CNC table sitting around. It’s cool! I installed the X-axis leadscrew temporarily. It works fine. I will know for sure once I get the X-axis transmission nut installed, which attaches to the Y-gantry bottom.
With the legs on, I decided to continue where I left off last night, which was cutting the motor mounts. Let me take this opportunity to say that I did not do well, here. 🙂 I ended up cutting the central hole slightly off center, which means that there are only certain orientations in which the holes all line up. sigh. So I spent the next 2 hours fiddling around with motor mounts, trying to get a motor attached so I could see if I’d gotten things right. In the end, I got it to work (and without re-drilling anything), but seriously. Measure twice, cut once.
Right before stopping, I decided to measure and drill the new BRA mount holes for parts C&D. That went fine. Then as I was mounting up the BRAs, I realized that I was provided angle-headed bolts instead of pan-headed bolts to mount the BRAs (which is a better idea, in my humble). In the book, they show angle-headed bolts used for attaching the table together, and pan-head for the BRAs. In this kit, the angle-headed bolts are for BRAs, and the table halves are held together with hex head bolts.
I am of two minds about this. First, I don’t feel like counterboring all those bolt heads when I’ve already got the table together. On the other hand, I am not happy about how the edges of the table are not coming together, so I may want to reinforce the connection by making more attachment points, and what do you know, I have some extra bolts for that now (I provided my own angle-headed bolts and nuts to attach the halves).
Also, with the BRAs attached (they take 28 nuts and bolts all by themselves), I am almost out of the 1/4″ nuts provided with the kit. I suggested to PHD that this was going to be the case, since the kit has ~100 bolts, but only ~80 nuts/cross dowels. I will keep track of the parts I add to the kit in order to complete it, and will send him a list. I can think of 10 1/4″ nuts that I’m going to need to provide off the top of my head, and I feel like there will be more. No biggie. Just want to help the next guy who buys the kit.
I got so many new toys today that I am overwhelmed with trying to think about each of them. I spent the most time playing with bearings and the motor.
The X-table is so close to finished I can taste it. I just need to drill the rails and the mounting holes for the rails, and I’m done until the Y-gantry is up, at which point I can mount the leadscrew.
To be done presently:
– cut the Y-gantry parts to size.
– measure and drill the Y-gantry parts and get them mounted
– build out another motor mount and test-fit it to the Y-gantry
– cut and mount the Y-axis rail, so I can take the next “critical measurement” (which I will be able to do with bar clamps on-hand)
I know that my tone of upcoming work has changed somewhat. That’s because having parts makes all the difference. Now I’m on a roll.
How far can I get before I have to go to Washington? At the rate I’m going, and if I can do the last few saw cuts I need to do when I need to do them, I could be close to fully complete. I might need to boot up a PC and see if I can start getting Windows installed. It occurs to me that I need to have a machine with a working parallel port with me. I hope I can get something done with a laptop, but I am not confident. Also, I need a straight-through DB25 cable, which is apparently not like a printer cable. hm. Maybe a trip to Fry’s just to be certain.
Anyway, if I pack up the CNC and take it with me, I can certainly complete it with 2 weeks off while I’m in WA. I need to start a packing list for the CNC. I would need:
– the machine
– the electronics
– a PC with Windows (or a recent version of Linux) and a parallel port (+monitor+keyboard+mouse if it’s a desktop).
– some clamps
– a spare piece of wood or two
– a parallel cable (buy a couple of DB25 ends at Fry’s — gender?)
– a bunch of extra wire (Ethernet should be fine)
– some resistors (wattage? accuracy? value?)
It would be best to test the electronics in a “dry run” before taking it all up there, but having a voltmeter, small toolkit, carpenter’s square, power drill could be useful.
Get all the cuts done.
Get all the holes drilled.
Get a PC running.
Test the various parallel cables for usefulness.
At that point, I think it’s ready to transport. And no need for a lot of the heavy tools (drill press, saw, etc).
But worry about deadlines later. Just keep working. This is a good pace.