![Bryan Howard](/img/default-banner.jpg)
- Видео 166
- Просмотров 927 383
Bryan Howard
Канада
Добавлен 24 янв 2006
A channel primarily about DIY CNC machines. Designing and Creating interesting things with laser cutters, 3d printers, CNC machines. Consider supporting the channel on 🔗 Patreon: www.patreon.com/user?u=56767327
DIY Ball Bar for CNC Machine: Laser, Webcam, and Flexure Design
In this video, I go through the demonstration of my DIYI ballbar for the CNC machine using a laser, webcam, and a 3D-printed compliant flexure mechanism
A ballbar is a precision tool used to measure the accuracy and performance of CNC machines. It consists of a bar with precision spheres (balls) at each end, which are attached to the machine's spindle and table. By moving the machine in a circular path, the ball bar can detect deviations from the ideal path, revealing errors in the machine's movement. This data is then used to diagnose issues such as alignment, backlash, or geometric inaccuracies, helping to improve the machine's precision.
I go through a live demonstration, talk about trou...
A ballbar is a precision tool used to measure the accuracy and performance of CNC machines. It consists of a bar with precision spheres (balls) at each end, which are attached to the machine's spindle and table. By moving the machine in a circular path, the ball bar can detect deviations from the ideal path, revealing errors in the machine's movement. This data is then used to diagnose issues such as alignment, backlash, or geometric inaccuracies, helping to improve the machine's precision.
I go through a live demonstration, talk about trou...
Просмотров: 8 173
Видео
Goodbye Prusa. Is this the end of open source 3d printers?
Просмотров 2,7 тыс.Месяц назад
In this video, I unbox the Bamboo Labs P1 with AMS and share my first impressions. I bought this printer with my own money after considering other options like the Voron. Watch as I unbox and set up the printer in my garage, struggle a bit with the packaging, and finally get it ready for its first print. Despite some hiccups, the Bamboo Labs P1 impresses with its speed and ease of assembly. I'l...
My PrintNC upgrades: Better ball screws and longer rails
Просмотров 832Месяц назад
Hey everyone! In this video, I show you the latest updates on my CNC machine. After a couple of days of hard work, I finally got it back together with longer rails and upgraded ball screws (DFU). I discovered a few dead spiders in the process, but the machine is up and running smoothly! For this upgrade, I milled a new tram plate out of wood as a temporary solution. The original aluminum tram p...
More measuring with laser and webcam
Просмотров 1,9 тыс.Месяц назад
In this video, I'm continuing the rebuilding of my CNC machine's Y-axis. I check for the straightness of the rails using a laser and webcam along with a bit of software. At this point, I'm not sure if I'll keep it as is or try to scrape it to be straighter. Join me on this journey of precision and DIY CNC machine enhancement! If you enjoy my DIY CNC projects, consider supporting the channel on ...
Upgrading My CNC Machine: Longer Y Rails, DFU1605 for Z and Y Axis, and Rebuilding Carriages
Просмотров 1,3 тыс.2 месяца назад
In this video, I discuss the upgrades to my CNC machine, including adding longer Y rails, DFU1605 ball screws for the Z and Y axis, and rebuilding all the carriages. Join me as I enhance the performance and precision of my CNC machine with these significant modifications! If you enjoy my DIY CNC projects, consider supporting the channel on Patreon. Your support helps me create more content and ...
Basement renovations with Unreal Engine 5 and Reality Capture
Просмотров 1,1 тыс.3 месяца назад
Unlisted video but maybe some might find this interesting to watch. Using a 3d scan of my basement during framing to help visualize electrical, lighting and get an idea of shelves and furniture placement. Basement has a projector and screen that I didn’t talk about and a tv behind it. LED lighting strips in some areas around the perimeter. Temporary furniture. Drywall is just planes placed in r...
First time thread milling
Просмотров 3,7 тыс.5 месяцев назад
In this video, I'm boring a 3.1mm DLC single flute and performing M6 threading with a 66% first pass and 33% second pass. I suspect the feed rate might be too fast on this first attempt. Join me as I experiment with precision machining techniques! If you enjoy my DIY CNC projects, consider supporting the channel on Patreon. Your support helps me create more content and improve the channel. Than...
Upgrading a CNC machine never ends
Просмотров 1,6 тыс.5 месяцев назад
Me talking about yet again more upgrades on the horizon. Some configuration for milling a bunch of aluminum jobs. I've decided after talking to some people the I'll build an MQL system. If you enjoy my DIY CNC projects, consider supporting the channel on Patreon. Your support helps me create more content and improve the channel. Thank you! 🔗 Patreon: www.patreon.com/user?u=56767327
🚀 Exploring CNC Vibrations with Accelerometers, Arduino, and Python! 🚀
Просмотров 6 тыс.5 месяцев назад
In this video, we dive into the world of CNC machines and vibrations using a budget-friendly accelerometer, Arduino, and Python. We're taking static tests with no cutting involved, focusing on the vibrations of a 2.2 kW spindle, and bringing the data to life on the computer. 🔍 What You'll Learn: How to read and analyze vibration data from a CNC spindle. Visualization techniques to graph and int...
Stainless Steel Welding Tips: Fixing Bumps and Shrinkage Issues
Просмотров 1 тыс.6 месяцев назад
Hey everyone! In this quick video, I share some tips and tricks for stainless steel welding. In the last video, you might have noticed a lot of bumps and imperfections. This time, I've smoothed everything out, and I'm here to tell you how! I started by using a TIG torch to lay down some lines, focusing on the seams. This approach helped minimize shrinkage, especially at the ends where it's most...
DIY CNC machine (Originally PrintNC) running after stainless steel skirt added
Просмотров 4,5 тыс.6 месяцев назад
Hey everyone! The CNC machine is back up and running, and I've got some updates to share. The front is all bolted down, but unfortunately, there are some problem areas to address. One spot is sticking out by about 5 mm, so I'm planning to use the TIG torch to try and pull it in and get rid of the warps. I'd love to hear your thoughts on this method! I tried using a propane torch and hammer on a...
Test: Not OpenAI Sora. sequence with no temporal consistency. ComfyUI workflow (see previous video)
Просмотров 1,3 тыс.6 месяцев назад
This was an unlisted video test but kinda cool to see and may as well share the results.
DIY Threaded Transfer Screw
Просмотров 1,4 тыс.6 месяцев назад
Welcome back, everyone! I've made some progress on the CNC machine. I got the top plate on and consulted Reddit for some advice. Many suggested avoiding heat to prevent hardening the stainless steel. So, I decided to bend it manually instead. I created a little tool to get inside the stainless and bend it at the weld joint. This method worked pretty well, and I managed to reduce the warping sig...
CNC flood cooling stainless steel skirt
Просмотров 1,1 тыс.7 месяцев назад
CNC flood cooling stainless steel skirt
A VFX artist’s perspective on generating AI assisted images with ComfyUI
Просмотров 12 тыс.8 месяцев назад
A VFX artist’s perspective on generating AI assisted images with ComfyUI
Probing a Canadian Quarter: Analyzing Results and Addressing Issues
Просмотров 1,8 тыс.11 месяцев назад
Probing a Canadian Quarter: Analyzing Results and Addressing Issues
CNC machining a flat surface with lasers - Part 1
Просмотров 5 тыс.11 месяцев назад
CNC machining a flat surface with lasers - Part 1
Precision Pin Grinding and Sharpening: From Rough to Refined
Просмотров 2,6 тыс.Год назад
Precision Pin Grinding and Sharpening: From Rough to Refined
Prototyping a Kinematic Optical Mount for Laser and Optical Lens
Просмотров 2,3 тыс.Год назад
Prototyping a Kinematic Optical Mount for Laser and Optical Lens
CNC machining a Y axes servo motor mount
Просмотров 1,5 тыс.Год назад
CNC machining a Y axes servo motor mount
CNC Vice clamps and supporting steel installed
Просмотров 597Год назад
CNC Vice clamps and supporting steel installed
🔧 Prototyping a CNC Surface Flattening System with LinuxCNC, Python, and a Laser Level Webcam! 🔧
Просмотров 2,6 тыс.Год назад
🔧 Prototyping a CNC Surface Flattening System with LinuxCNC, Python, and a Laser Level Webcam! 🔧
Heavily modified PrintNC CNC machine High Feed Milling Steel
Просмотров 3,1 тыс.Год назад
Heavily modified PrintNC CNC machine High Feed Milling Steel
DIY CNC - BAP400 as a fly cutter with 1 CBN insert, carbon steel
Просмотров 3,6 тыс.Год назад
DIY CNC - BAP400 as a fly cutter with 1 CBN insert, carbon steel
Grouting and fabricating vice mounts on the CNC
Просмотров 1,3 тыс.Год назад
Grouting and fabricating vice mounts on the CNC
🔧 Grouting CNC Tubes for Enhanced Stability and Damping! 🔧
Просмотров 6 тыс.Год назад
🔧 Grouting CNC Tubes for Enhanced Stability and Damping! 🔧
Facing the bottom of a cast iron drill press vice with BAP300r
Просмотров 1,9 тыс.Год назад
Facing the bottom of a cast iron drill press vice with BAP300r
Hello brother, could you show me the diagram to make the connection from micro USB to USB, I would appreciate it very much.
It would be easier to polish copper cylinder. Copper has quite good optical properties.
Hi Bryan, further to my previous comment, please allow me to share a few thoughts. 1) I think that for a CFDST column the use of epoxy granite as the filler instead of tradition concrete would be an improvement to reduce vibrations and reduce bending of the column under load. I also threw this at ChatGTP and our AI friend agrees (which obviously is not a 100% guarantee, but still quite amazing). 2) As for the construction of the ganrtry, I have been doing quite some digging and calculating as well, as my intention is to make the gantry from epoxy-granite with steel rebar reinforcement, which is typical for normal concrete constructions. My gut feeling was telling me that such a solid column construction would be stronger (less deflection and less vibration) compared to a CFDST column. In summary this is what our AI friend had to say about the comparison between a steel (rebar) reinforced epoxy granite versus a CFDST column: "The solid epoxy-granite column with rebar reinforcement is likely to exhibit less bending compared to the CFDST column. This is because the epoxy-granite has a higher modulus of elasticity compared to concrete, which results in a higher bending stiffness and moment of inertia. The CFDST column, while strong due to the steel tubes and concrete fill, generally would not surpass the bending stiffness provided by epoxy-granite in this case. " Obviously there are more factors to be taken into account, but for my own situation I think I will be making the gantry from steel reinforced epoxy granite because I have experience with mineral casting and also because in my location it is very hard to get decent quality tubular steel. I have just ordered parts for a laser alignment system, so let the fun begin soon :)
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!
Hi Bryan, first of all my compliments and great thank you for all of your videos, as well as he amazing job you did with the laser alignment software. I am starting a new CNC project and will definitely benefit from your contributions. Would it be okay to contact you directly if I run into any issues?
Those sound effects at 2:30 are absolutely on point.
Do you need the cable chain? we are a professional manufacturer of cable chain.
Are you worried that with your system where you clamp with the Z- axis to place the base you might be deflecting your gantry and offsetting your mesurements slightly as a result?
Using the washer seems like alot of work for very little gain, consider using a tri-bar kinematic copping, it reduces the uncertainty of the system
I wonder if you could use components of a (high resolution) optical mouse as a sensor
Excellent work! I love it's ability to nicely flex and your experiments with the 3D printed version is nicely done. Love these types of experiments. It would be nice to see this as a standalone tool where maybe it has its own display, logging the values and displaying it on the display in a circular fashion like on the desktop.
I was thinking of using an LVDT (linear variable displacement transducer) en.wikipedia.org/wiki/Linear_variable_differential_transformer as the transducer for a ball bar tester. I figured it would be variably adjustable pretty much in the same way you made the flex coupling. would it be possible to adapt your design to incorporate such a device instead of the laser/camera idea. My concern would be the dynamics of the plastic in your flex joint or refection's on the camera lens from the laser. I would be very interested in your thoughts.
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.
I would switch lapped washers with 3 hardened rolers/pins for true 3 point contact.
If the distance is constant, you can use LED with lens to get smaller dot.
I have thought for a long time that this was a way to get flatness. The difference is that you have done it. Looks like it would be good for detecting seismic events.
19:53 I'd guess the scale is off because of the smoothing. You can make the value drift further to the edge by moving the smoothing slider further to the right. I'd guess it is due to sensor width being devided by the reduced pixel count (e.g. 1920 - 2x smoothing (once per side)) instead of using the native µm~pixel ratio. Thus the µm per pixel increases when increasing the smoothing.
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.
I just wanted to say that the high frequency wobble in the measurement could come from 2 sources in my mind , 1) a c5 grade ballscrew has a +/-8 micron of axial error per revolution and +/- 18 microns of error per 300mm of lead, 2) I've been looking into bearings for my own project. If you're not specifically ordering P6 or lower grades of bearings for the BK/BF housings your axial runout can easily be in the double digits of microns. Otherwise it may just be vibration as you're making a realtime measurement
Very cool! I’m familiar with the commercial ball bars. This is next level for diy CNC calibration. Very interesting data and iterative work. Thanks for sharing!
I think you'll enjoy this method of squaring. Look up "the 4 cut method crosscut sled". It's a way to simply take 4 straight cuts then take some measurements and do some math. It's a woodworking method for dialing in crosscut sleds to have a really accurate cut in relation to the guide slots on the table.
Thats super cool and interesting! Thanks for sharing your progress!
Would a 18650 on the bottom of the bar along with a pi zero w work as a counterbalance to keep it level enough and remove the cable headache?
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.
Like The Project, could it be that your 100 micron error comes from the fact that both points arent on the same plane and if you move out a certain distance along the axis the hypothenuse is maybe longer ? and second idea maybe try an z yoint for your complient mechanism or mirror one side of the joints because at the moment you laser is not moving at a straight line over your sensor. would like to maybe one day build along, love it wonderfull project for diy enthusiasts
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.
From the video, it doesn't look like the two balls are on the same Z height. Would it be advantageous to have them at the same plane while doing the calibration? or is having them just on the same ball circumference good enough? Did you have to consider polar coordinates when drawing the results?
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.
🤩
Awesome project! Very nicely done.
This is a super cool project. I love how approachable this solution is. I’m currently getting my DIY CNC mill up and running again after moving and will definitely be looking into characterizing its error with a DIY ball bar like your’s. Thanks for the great videos!
Now I know what a ballbar is. Nice approach and I especially like the flexure with the laser. Since you're using lasers, throw in a mirror or two and get down to the nm range.
Love your work and the way you share all of the development - its amazing what you achieve with a web cam and a laser.
Another awesome video man thank you
I think you can just measure runout and then correct for it? Rotate the spindle precisely by 90 degrees and measure the change. Half the 180 degree error gives you runout and as long as you know the spindle orientation it's just a linear XY offset. Essentially just add it to the initial position and treat it as a constant
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 😎
🦾🦾🦾🦾
For the buckling of the flexure you can make the blades thicker in the center, leaving only the "hinges" thin and flexible. Also increasing the overall thickness of the assembly should help with stiffness in unwanted motion directions.
What is your max error during 1 rotation. Curious what it is.
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?
All this reminds me of my CNC machine tool career in the 80's. We used a HP laser to check the ball screws and Hamar lasers to check alignment. Now if someone could come up with a DIY laser like the Hamar it would a real help for DIY CNC builders.
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 🤔
another banger idea!
Awesome work! A video on simulating the compliant mechanism would also be interesting!
Neat! I'm working on making a ballbar adaptor for my 3d printer right now! Using a QC10 so different method
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.
you are awesome
Excellent
Hi, amazing application thank you for this effort. Does anyone know if the software recognises different web camera resolutions as 2k and 4k webcams are readily available now.
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.
This is a good idea and I'm glad you like 👍
Excellent
What is the white disc on the spindle?
Collet fan. Works better than the air compressor. www.printables.com/model/287185-collet-fan
I am using a Digitus Adapter that has an ftdi chip built in. Communication works fine with a null modem Adapter. You can achieve the same effect by switching the transmit and recieve pins. Maybe this will help someone. 😊
Hello, how are you? I would like to know if you share the file for this project or if you have a video lesson teaching how to configure this project.
So Creality a still shipping these with those green glasses. Are they definitely not useable/safe? If so it would make Creality legally liable for any issues here in Australia.
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.
I had an Ender3 Pro, now use a P1S it’s a different world. My Benchy also has that line along the hull, I used the green that came with the printer, don’t recall a difference in the gloss level though. I like Bambu Studio so much better than Cura.
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.
I love watching people who use TOOLS all day long and grab a Bambu and are in aww at the simplicity of them. Your rocking the right ones though. Prusa and Bambu. You have NO crappy printers there. Hope you enjoy your P1S. Your about to go on a adventure. Welcome back to the Rabbit Hole.
hey man been watching your channel for a while, also working on my own cnc too. what i was wondering was how low of an RPM the spindle can be operated at. you did try some agressive drilling at 6k rpm, but how about milling/drilling steel? can it handle 3000rpm os we can do some light cuts on steel? thank you in advance
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.
For holding the stainless… it’s pricey but 3M VHB tape. They have a special variety for panel mounting.
Personally, I would like to see what would happen if you tried flattening the high spots using a piece of precision ground steel and fine sandpaper. Or a good flat sharpening stone.
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.