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Apples to apples, epoxy granite is better than grout. Grout is still decent and the reason for me using it over epoxy is the cost and ease of use. Grout you just add the correct amount of water and pour it. Epoxy you gotta put more effort into preparing everything and it can still get messy and much more expensive. Keep in mind when doing this to the gantry, you want to add a lot more mass to the static base of the machine else you’ll quickly realize the dynamic motion of the machine is going to shake the crap out of your table. I would aim for at least 5x the mass added to the base that you add to the gantry. And for the base go with grout to save money because its properties other than mass are much less important. For gantry geometry, I went with the hollow CFDST shape, it saves on weight, less dynamic moving mass for the Y servos. Given the same volume of material a hollow shape is more rigid than a solid one. In hollow structures more material is distributed away from the center which increases the structure's stiffness and moment of inertia (resists bending more).

@@BryanHoward Thanks for the clarification Bryan. Much appreciated!

Yeah I looked at those as well. They can get quite costly on Mouser. I don’t see why they couldn’t be incorporated into a flexure design. Especially one that has mirrored flex arms. I went with using the laser and webcam sensor because I’ve already built the software around it and know it can give reliable results. The webcam doesn’t have a lens on it. That was taken off and I’m shining the laser directly onto the silicon. A lens would have all kinds of distortions that would skew the results.

The scale is off because I haven’t calibrated the scale factor as good as it could be. The smoothing slider will have a negative impact if the gaussian hill is clipped too much off the edge of the sensor. I find it should only be used sparingly to remove some of the high frequency noise but no further. I need to properly calibrate the scaling factor using some gauge blocks. It can easily be done by stacking them and offsetting the webcam sensor or the laser (see the previous videos I have on the subject). I’m going to change the camera sensor and webcam in the future. Buying a proper camera module I’ll get the datasheet that’ll tell me the pixel size.

The whole setup is quite rigid that I don’t think it’d need a counterbalance. Also a counterbalance would limit you to only working in the XY plane and couldn’t measure in the XZ/YZ planes. I am looking into a Pi Zero with a camera module over the camera bus. Make it all wireless and work with a raw camera feed instead of mjpg over usb.

The 100 micron offset is just the scaling factor. I tried determining the sensor size (to get the scaling factor) by taking a closeup photo of it with the known length of the PCB as reference dimension. A better way is to use gauge blocks with the sensor configured in one of my earlier laser/webcam projects measuring relative height changes. I won't be doing it with this webcam though. I’m going to be changing the webcam to a camera module that is compatible with the camera bus on the Pi Zero. There is a number of benefits of going that route. But if one had to find the scaling factor of an unknown sensor without a datasheet like this one in the video, gauge blocks would be the best way to do it. You’d need to be working in a temperature controlled room as you can easily see fluctuations of 30um due to thermal expansion.

Yeah it's probably best to get the balls on the same plane for best results. But I think as long as the Z axis is not moving, it won't hurt things too much. I see the main problem being if you're working with absolute distance on the ball bar you don't get that. I'm mapping the data in polar coordinates.

@@BryanHoward the gradient on the camera sensor might be an oval instead of a circle as well.

The main issue you'll have with trying to do it that way is you have a few places where the runout can be on. It could be on the spindle, collet, 3d printed joint and the lapped washer. It's actually pretty quick to get the runout removed with the screws. An improvement to the design would be too use smaller fine pitched bolts with brass heat set inserts. I opted not to do it because I was worried about the brass inserts getting pulled out but I think it would work out now.

@@BryanHoward true. But as long as your bearings/joints are very close to being spherical, then it really doesn't matter (I think)? Essentially the runout reduces to being a case of the centre of rotation is shifted in XY versus the centre of the spindle. So as long as you rotate the centre of the runout around the actual centre point, then all should be well? Renishaw is coming around to this idea with their probing macros for spindle probes. Blum has always worked this way (as far as I know). Quite cool 😎

I'll check it tonight. I think it's quite large because I have not squared and trammed the machine after putting on the be ball screws. I think it's upward of 400 microns. I might make a video on trying to better interpret the results and a before/after on trying to remove error in the machine. Might look at how mapping ball screws work in linuxcnc too.

@@BryanHoward any specific reason you did not go for lvdt?

I was using CNC's back in the late 70's and nothing like this was ever seen. I can understand the need if you are working below 10 microns. but we were working above that level and in a total uncontrolled work environment 0-35C on large pieces 600mm up to 7000mm so expansion and contraction mattered more, but was never allowed for ..... The CNC machines were WAY better than the manual machines, ball screws vs ACME and digital readouts vs dial and dial indicators. For those that don't know - all of the Gcode was written by hand and was transferred to the machine by "paper" tapes that had holes punched in it. Archaic by todays standards - but the results are the same - just involves WAY less coding and walking. :) 70's was the peak time for manual machines - ball screws started to enter and the machines themselves were well developed.

People now have it too easy with all the advanced CAD and CAM software. There's parallels with software where nobody writes low level assembly which I guess you could say is similar to writing gcode by hand. Way too easy for someone to buy linear motion components and a spindle from China and through a CNC machine together in there garage too.

​@@BryanHowardtoo easy makes it sound like it's a bad thing 🤔

What's a ballbar for?

@@lukealchinsmith makin babies Or in the case of a cnc machine, exactly what this video talks about. Determining the error in things like squareness, circularity, backlash and some other dimensions of a motion system.

@@lukealchinsmith ​ @compucar03 When creating a circle one axis REVERSES at the start of a new quadrant. The test shows the quality of both your mechanical and control electronics. It also shows the orthogonality of your mechanical structure.

I think the software currently will handle it but it won't necessarily be better. What counts is the physical pixel size and when working already with 720p and 1080p cameras you're already in the realm of fighting with heat distortion. I'm currently finishing up with a very interesting application of the webcam sensor that I'll be posting a video about. Currently looking at using a 720p OV9281 image sensor over CSI to a Pi zero board as it can run at 120fps raw which gives much more bandwidth of data coming in.

@@BryanHoward Good point about the system limitations, I read similar on a thread about this on a hobby machining website. Thank you.

Collet fan. Works better than the air compressor. www.printables.com/model/287185-collet-fan

The glasses that come with the laser cutter don’t specify which wavelengths they filter, so I decided to discard them. After doing some basic research on laser safety, I invested in proper protective eyewear. While some comments suggest that the provided glasses are safe because Creality is a reputable manufacturer, I’d rather not take any chances. My concern is that, without prior experience in laser safety, it’s hard to make an informed decision. I imagine many others who buy a laser cutter like this are in a similar position. It would be reassuring if Creality included some basic information about the laser’s specifics and if the supplied glasses clearly indicated the wavelengths they protect against. When I order dedicated laser goggles from a reputable manufacturer on Amazon, with the specific wavelength clearly marked and positive user reviews, I feel much more confident in their safety.

From an ender to a p1s must have been amazing leap! Someone in the comments said the line was due to speed. see @PanMarcepanek comment of what setting to change to fix it.

It was, I just need a robot to clear the build plate when I’m printing remotely!

@@tonyray91 Custom post gcode to smack the hotend into the part after the hotend and bed are back to ambient temps. Just have to figure out how to remove the pre extrusion line at the beginning of a print.

yeah the spindle isn't designed for it. You can get down to low rpms depending on how much load is going onto the spindle. This is about as low as I've gone in steel @ 3k rpm: ruclips.net/video/guddMZIETKs/видео.html and going in the opposite direction here's 24k rpm in steel: ruclips.net/video/8v-yXavlFhU/видео.html when it comes to cutting steel on these gantry cnc machines, they need to be made as ridged as possible if your using insert tooling like this. I usually gravitate to using insert tooling in steel due to them lasting far longer than solid carbide tooling. cheaper too.

@@BryanHowardthank you for your reply. Yea i have seen both of them and the “fly cutter” is actually pretty scary. Maybe having 2 inserts at 6k rpm is the way to go

@@TheRealBleach1000 I don't think my machine is ridged enough to handle it at 6k. Probably not rated for that rpm either.

It would work. You’d need to be working with thicker steel than what I’ve got. The main issue I’ve found is when thinner steel tubes, you’d have to take off so much of the corners getting the center of the tube where the rails bolts to flat.The profile of the tubes it kinda dips in the middle where the rails are. Next time if I were to build a cnc from scratch, I’d either start with thicker tubes that I can surface a whole bunch of material off without compromising the tubes or to weld some 1/4” flat bar onto the surfaces where the rails would bolt to and get those machined and ground flat.