I’m getting ready to build a Lowrider, but with some different features to suit my needs. I want to build it on a steel rectangular tube frame such that the entire unit can be hung on wall hooks when not in use. I have an overhead crane and high ceiling in my shop, so I will put a shackle eye on one side and pick it up with the crane. I’ll be adding some gussets to the corners of the frame outside of the working range of the tool which are not shown in the model.
This will be primarily used for plasma cutting steel, although I’ll probably also build a toolholder for a router to play around with wood projects.
I won’t bother making any hose/wire guides, as I can just hang them above the gantry with one of the overhead cranes while in use.
I want the unit to be one-piece and ready for use without any setup when I take it down from the wall, so I’m planning to use 1600mm of MGN12 rail in place of both the Y rail and wheels to keep it unitized. I’m planning to make the XZ assembly as a steel fabrication as shown in the attached screenshots. I’ll weld it then machine the bearing mounts surfaces square and flat. I’ll use the standard Y drive and Z stop. I’m planning to weld some solid round bar into the ends of the X rails and machine a pilot diameter and drill and tap the ends of the rails such that they bolt and spigot into machined bosses in the steel XZ plates for better strength and rigidity.
This will be my first CNC machine build, so does anyone see anything I’m missing or any problems with my plan?
I kind of think maybe linear rails would be nicer for Y, both haven’t been done yet though (or at least not to my knowledge).
I’m wondering is seeing as you are going to make this out of steel perhaps a better method of moving the carriage might be a proper rack and pinion -
because the belt might turn out to be a little fragile in your environment.
That might be a good idea. It would probably increase the accuracy of the cuts because there would be no belt stretch. I like the cheap and simple approach of the LR3’s belt, but a rack could also be done pretty simply as shown in the model view. I found some 1.5m long 15x15 rack on Aliexpress for $75 each free shipping.
That was one thing that I noted building the LR3 is that you could convert to rack & pinion without even changing the Y motor mount. It could also work with Doug Joseph’s hidden belt mod.
Because of the ease of conversion, it would be easy enough to built it with the belt as designed, and if it solves a problem, you could switch it.
On the other hand, if you build with the rack and pinion, you wouldn’t need the Y rail at all. Both sides could use the wheels, since the rack and pinion would serve to constrain the machine in the X dimension… Looks like you want to go with rails on both sides.
would be ALMOST as fast as a belt, but with higher presicion. Threaded rod being the most accurate but probably too slow for you because you plan on running a plasma which needs to move at a considerably faster rate than lead screws will allow