June 29, 2019 at 6:19 am #104672
I was thinking about using a 3d printer frame for laser engraving. Considering the laser sits a a fixed point on the Z axis do you think its feasible to omit the Z axis motors? I’m thinking that you could adjust the focal length manually with threaded rods and hold it in position with a nut on either side of the carriage. Any thoughts?June 29, 2019 at 7:09 am #104674
Sure could. You could use 3/16″ threaded rod to save a few dollars. You’d need something to replace the bearings in those blocks.
The advantage of having a cnc Z is that you can use a script to try different heights to find the best distance. If you have a different material thickness, you can also just adjust it up perfectly.
You’ll still need to get a level bed, though not as precisely. So being able to drop the Z down to the bed will help with that.
So how much will you really save vs. the advantages of having a Z?June 29, 2019 at 7:10 am #104675
Also, you should consider using a grbl controller. the laser engraving is still better than marlin, afaik.
1 user thanked author for this post.June 30, 2019 at 6:23 am #104723
Well part of this is driven by the challenge of building this out of the spare parts box. I have a cheap laser and the focal length is 58 mm so I was thinking I could just adjust the Z by hand and lock it in.
As far as the GRBL part goes, I know what it is but i have almost no idea how it works. Do you have a preferred website that you could share?June 30, 2019 at 11:33 am #104745
FWIW, Marlin will work fine. The grbl github has the manual, I think. But it’s simpler than Marlin, so probably any guide will get you there. I can’t remember what I read when I tried it the first time.July 8, 2019 at 5:34 pm #105609
So here is the update. I am reusing the printed parts from a DOLLY clone for the frame. I learned (enough) about GRBL and loaded it on to an UNO with a CNC shield. I was on a roll with the build and didn’t want to stop and wait for parts so I 3d printed LM8 bearings, toothed pulleys, mock NEMA17 motors for the Z axis, and a GT2 belt extender. I also used some 5/16 dowel rod in place of the 8mm steel rods. I’ll(probably) replace all these with the REAL parts when they arrive. I also need to design and print a bracket for the laser( or maybe the twisted up wire will hold up).
Attachments:July 8, 2019 at 7:24 pm #105620
Whoa! Use those dowels until they fail, I need to know how long they last, that is too cool!July 8, 2019 at 10:00 pm #105630July 9, 2019 at 2:23 am #105645
I am surprised how well the dowel rods are working. I sanded them down with some 120 grit and then put on a coat of beeswax. By no means are they as effortless to push than “normal” rods, but they do slide very well.
I am using LaserGRBL for the Gcode streamer( http://lasergrbl.com/en/) . I have never used GRBL before but I am impressed at how well this is working. I also flashed the hex file from 3dpburner onto the arduino in place of the latest GRBL from github. It worked with the github but the jog command was sluggish. It may have been a setting I overlooked but a big part of this project was to learn new things.August 2, 2019 at 4:52 pm #108201
Wow, never went that far yet. I remember one YT video trying to build the cheapest Prusa clone.
I was always thinking of using cheap rods from the hardware store and print the bearings, together with the usual 8mm rods that would reduce the costs already significantly.
In the video, he uses hose-clamps and a bit of hose as a coupling, and pretty sure it is fine. I printed some for the MPCNC, after crushing with the aluminum ones into the base plate. You can kiss them Goodby after that. The printed one do just fine, actually because of that, I found out that the stepper motors have quite a bit play in the axis as well.
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