Hello, Is it possible to use one gantry plate in-between two v-slot linear rails (20x60mm) so that it can be moved along the X and Y axis? I want to build a T-Bot similar to this design H-Bot…Just for fun at Buildlog.Net Blog, but I don’t know what gantry size I require, and I’m not sure whether it’s possible to have wheels on both sides of the gantry using the same holes. Thanks
Absolutely. Here is an example for C-beams but a similar approach is viable for the belted example you referenced. You can download this example XY plate file here C-Beam XY Example Plate.zip
Thanks Rick 2.0, that’s exactly what I want. However, I don’t have a CNC machine to make my own part – yet! From openbuildspartstore.com, what gantry would I require, to achieve similar results? Is there anything else I need to consider, such as bolt sizes etc? Apologies in advance with the questions. I’m new to v-slots.
Unfortunately there is no single plate that will do the trick. You might be able to make it work with a couple of V-Slot Gantry Set - Universal mounted back to back which would actually be similar to the referenced example. You will need 4 extra wheel kits, 4 extra M5x25 screws and 4 additional 6mm stand offs. You will also need to drill (4) 5mm holes in the plates for the additional wheels. Personally, I would take a scrap of 4mm aluminum and make/drill the plate myself. Hand made plates are really not that difficult.
I think taking a sheet of aluminium and drilling a few holes would be the easier option. Thanks again.
After purchasing the various V-Slot parts and building a suitable gantry plate, I’ve now managed to build my T-Bot. The T-Bot will eventually be used as a drawing machine, similar to AxiDraw, but using SlushEngine Model X LT and Raspberry Pi 3. Here’s my first working version on YouTube. My next task is to read G-Code and make to T-Bot move according to the coordinates.
I’ve made a T-Bot similar to this design. Using stepper motor driver L6470, I can control the movements e.g. up/down, left/right and diagonally using the equations shown here corexy, via the L6470 command MOVE(direction, number_of_steps) using MAX_SPEED(100 step/s). If I move from (0, 0) to (400, 400), both stepper motors move at a constant speed, and reaches (400, 400). Great. If I move from (0, 0) to (400, 100), then I need to reduce the speed of one of the stepper motors by 4 times (400 / 100 = 25 step/s). Fine. However, if I move from (0, 0) to (400, 300), I reduce the speed of one of the stepper motors by 1.3 times (400 / 300 = 1.333 step/s). Slight issue here, MAX_SPEED only accepts integers and therefore the linear path it follows is not correct – one stepper motor will stop before the other, and a diagonal line is not drawn correctly. Is there a way of resolving this issue?
Update, As I was unable to use the methods provided by the L6470 chip, to do what I wanted. I have now used Step Clock mode instead. I have written methods which allows me to rotate the stepper motors a step (i.e. 1.8 degrees); using Bresenham’s line algorithm to draw diagonal lines without having to decrease or increase speeds. Here’s a little video, which follows some basic coordinates.
