Horizontal spindle CNC build, looking good
Using wood as a flexure?
@Mike_Kelly_Mike_Make no, prototyping, to make sure the thickness is correct
@xue_roger are you planning on using bearing supported lead screws on both ends? Because you really should. You should also make your lead screw as short as you possibly can too. Extra length and mass won’t do you any favors running it at speed. But with a lazy enough pitch that mitigates things somewhat. Still, if you can squeeze more out of a design, then why not?
@Paul_Frederick X lead screw is supported on both ends, with bearing. all other axis are supported at three points, with bearing and motor and acme nut, the two points are about 3 inches apart from the motor end.
@xue_roger I won’t belabor the point. Your machine will do that when you start running it. Now at least you can’t say that no one ever told you. Motor bearings don’t really count as fixed on one end. Well that’s precisely what it counts as. What it doesn’t count for is fixed on two ends though.
@Paul_Frederick does screw nut count as support? The reason I didn’t support other axis on both ends is to maximize the travel
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@xue_roger at least you have the bearing support on the motor side. I guess you’ll have to see how bad whip is when you run it. The other piece of advise I’d give for building a CNC is get things running early. A lot of folks wait to do their electronics until after the machine is finished. I would consider that a mistake. I think they wait because wiring the machine scares them? But having axis running helps you out with assembly and alignment. Running an axis back and forth tells you it is running smoothly. Running loose tells you that you’ve wired things up right too. Once a machine is built it gets hard to tell what is causing a machine to not run right, if there is some issue. That’s the trap that people fall into. The bottom line is you’re going to have to wire a machine up eventually anyways. So you might as well do it early so you can use the electronics to move things around while you’re building. As opposed to spinning the lead by hand, or attaching a drill to it, etc.
Yes, I have electronic and motor already. The machine is not ready to move yet, needs to square up the frame first
@xue_roger this is a really slippery trap. The whole build a machine, wire it, then run it ploy. Which sounds plausible. But in reality that’s the absolute worse way to build a CNC machine. Sure it can work. Then again I can win the lottery too. The way to build a CNC machine and not have it being like a game of Russian Roulette is to run it at every stage of construction. Other than that you’re just stacking the deck against yourself. Why wouldn’t you want joints moving as soon as possible anyways? It does help in the construction process to move parts of the machine occasionally. Even if you are the alignment king that you think that you are. Run and be sure.
@Paul_Frederick to be fair, I did run X and Z axis, but for Y axis, it’s not possible until the full machine is aligned. I have pretty high confidency, since the the setup on Y is identical to X and Z, as long as the two rails a parallel, is should work. And even before I start build with metal parts, I verified the idea with wood parts, make sure it moves
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@xue_roger I’ve tried a number of skate bearing linear slide mechanisms. I was only ever to get one to run well. At that it was pretty finicky to align too. I used the sandwiched spacer phony V bearing method on round rods. I only had 2 pairs of drawer slides so I had to come up with something else for my Z axis. If I did have 3 pairs of drawer slides I’d have used one of those instead. But after a fair amount of fiddling about I managed to get this to work OK https://i.imgur.com/arzFmKQ.jpg
I am new to building but this looks epic. Saw your mpegs too!
This thread is imported content from when Google+ went away, and none of the participants in this thread have (yet) joined us here on MakerForums. Not sure what you are talking about by “mpegs” here.
I saw them on his blog.
Ah! Have links?
This is his blog spot. He seems like a real nice guy. I’ve been talking to him about building my own and flean from his advice.
Thanks for sharing!
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I am finishing up a CNC rebuild right now and the more the merrier on pulling together DIY CNC enthusiasts!