So I am looking to build a project that will push boxes out of something like this (except a lot more holes) from the back side. Looking at ~ a 4’X8’ with various holes anywhere from .25"X.25" to say 6"X6"
For my Y axis (normally Z) I was hoping to get rid of most of the assembly because all I need is a stepper and a ball/lead screw to push the stuff however I was wondering how much of it is needed for structural support? I am not worried about the gantry weight specifically because that what counterweights are for.
Accuracy is fairly important but i am not doing anything that would leave sideload so as long as I don’t have too much tolerance issues from belts t that size I should be good.
So you are not looking at cutting anything, just pushing boxes out of the open areas? Do you need 4’x8’ or 8’x4’? Either way I’m not sure the MPCNC is going to be the best base, you will likely prefer the Low Rider for that large of a build. If we rotate in our minds back to the normal orientation, The Z tower (which will be used to push) needs to be fairly tall, to have the range of motion I think you are asking for. That is designed to move up and down, and it assumes gravity is helping. The X and Y rails that go through the center also assume they’ve got gravity on their side (ie., they don’t have any design characteristics to deal with the extra side forces gravity provides if it’s sideways). It might work anyway, though I’d expect you will want to look at more powerful steppers. the largest I see in Nema 17 with a quick search are 0.8Nm, or about 113oz.in.
With the Low Rider you have a lot of the same issues in terms of gravity working against you. You definitely will want to use the original design, not the LR2, since the original is held to both the top and bottom of the table. If I were going to mount the table vertically, I’d put the short side across the table and the long side up and down. Possibly even double up the belts to allow that long run to fight against gravity.
I suppose you’re building some kind of automatic drawer opening system?
If yes, I would suggest you to use the zenXY system instead of the MPCNC (also designed by Ryan). Less bulky, probably much faster too with the coreXY motion system. Much cheaper too!
Also, to push the drawers, maybe a tiny air cylinder could do the trick (easier to integrate, less wiring, you just need a small air pump). It will be lighter and will open faster (if you don’t need to do variable opening positions).
How heavy will these boxes/drawers be?
Please post us pictures of your build, I love this kind of stuff and I hope I’ll have space one day to build one myself!
I think the lowrider version would be better also, but I’d do the long side horizontally. This way you put your counterweights on the ends, so they’re only going up and down, and no side to side motion. It would also be easier to redesign the platform mounts to have a bearing on top. Build your own linear actuator with a t8 lead screw and you could use the current plate bearings rotated and design the actuator’s mount accordingly. Get rid of the Z steppers, use one for the lead screw, and fix the Z assembly in place.