I'd like to build an XY rig. There seem to be so many options but I haven't found exactly what I need. I'm thinking a belt-driven linear actuator (V-Slot® NEMA 17 Linear Actuator Bundle (Belt Driven)) with another rail/cart in parallel and then a lead-screw linear actuator mounted across would get the job done, but I can't see if/how the lead-screw actuator (on the v-slot) can be mounted to the 20mm Gantry cart (V-Slot Gantry Set - 20mm). I'm brand new to this so any help is appreciated!
Thanks for taking the time to reply. Here's a sketch of the concept. Dimensions are about 500mm square
Have you already purchased parts? If not then you are basically describing the Acro System OpenBuilds ACRO 55 20" x 20"
You will need a second actuator on the other Y-Axis, or your X-Axis will go out of square. Take a look at the Parts Store for lots of fittings to fit your needs. Plates and corner brackets would probably meet your requirements
I haven't purchased yet. Thanks for the feedback! Vertical space is a constraint for me. The ACRO system appears to be taller than I need - I can't find any dimensions on the site.
Actually there is a fairly simple way to keep it square. Move your belted axis to the middle of the platform, centering it under the screw drive and then just use the parallel secondary rail to maintain balance. As far as connecting the plates to the screw drive, that's also fairly simple. You merely place T-nuts in the bottom side of the screw drive and run screws up from the bottom side of the plate, through the plate holes and into the t-nuts. Not a perfect system as the heads of the screw used for the wheel axles will interfere with the bottom side of the screw drive rail so you may need some spacer washers. The oversize hole in the eccentric side of the plate may also be a problem getting and holding things tight. A CoreXY type design might be a better option. It eliminates the problem with the motors hitting the rounded corners.
Thanks Rick. I looked into CoreXY and it's really clever! Maybe, perhaps too clever for my first build attempt. I drew out your recommended solution. Your solution of placing it in the middle is a great idea. I didn't draw it out with the larger plotting area, but it would certainly achieve that. In terms of belt vs lead screw is there any pro/cons I should consider? When I redrew it I put the lead screw on the bottom. I have no hands-on basis for designing it either way since I haven't used either.
I want to follow up and answer some of my own questions for the benefit of anyone else who should come across this thread. I have had success with my build, and not too unlike how I drew it up. Using T-nuts to mount everything worked very well. It took some assembly and disassembly and some tricking lining up of hard-to-reach parts, but it was definitely doable. I've had no problem with it staying square on just one belt drive. As is the rails are about 200mm apart and cover the length of about 1m. In regard to belt-drive vs. lead screw, both have about the same speed, precision and noise. One important tip on this design was determining the balance point of the Y-axis. With my design the x-axis is actually pretty well under the balancing point of the y-axis actuator. That's important because it's not putting stress on either of the x-axis rails to tip over. Another thing to note was that I was able to "prototype" this pretty well with the y-axis actuator not actually mounted to anything, but just resting on type of the drive x-axis gantry and the free gantry cart.
This is a really cool project! Have you/would you publish a more detailed Build? Would love to see more details (and video)! Oops - just found the video. Would still love to see video of the final project in action!
