Really enjoy your videos and your techniques/tips. Please do not take the following as criticism! I use a very different method to square the axis. A piece of 2X4 X .25 mdf to start. Fasten a batten to the machine parallel to the fixed axis (the fixed axis being the one that is attached to the base, not the gantry). Machine that edge. We now have an edge we know is deadly parallel to the base ways. Place mdf sheet on machine against the machined edge. Clamp. Machine two slots as far apart as possible perpendicular to the machined edge. Flip mdf sheet over keeping the same edge against the machined batten. Machine those two slots again about an inch or so from the first set. Measure the pairs with a dial caliper or what have you. The difference in the measurements is twice the amount of error on the machine. This is obviously a riff on the old draftsman's trick of checking a triangle for square. No need to rely on eyeballing anything with this method. Keep up the great work! I recently installed your touch off macro and it works really well. I made a few changes to suit the way I work, but that is just me.
Thanks for sharing and I appreciate you taking the time to share this with us. I used something similar for squaring my tablesaw cross slide. Glad you like the tool setting routine and the is nothing wrong with customising it. After all that is a customised version of another probing routine. Cheers Peter
Why two slots per face? One is not enough? After flipping the sheet over, and making a second slot at some distance, then I should obtain something like a fat "V" shape. So I can measure the top and the bottom of the "V" to get the error... (Note: I mean a slot cutting all through the material, from the top-face down to the bottom-face.)
I used made a change to your method. I made the cross on the paper tape and placed it on the table. Then with a V-Bit I moved the bit into the tape and left a mark. I also did full diagonals not just the math. I was able to get 0.54 mm difference your method. I used my 3d printer and made a tool to measure the difference in diagonals. Was able to get it down to 0.005". Thanks for your inspiration .
Another great tip Pete. I originally had mechanical limit switches on my machine and I could never replicate the home position with them. I recently changed to inductive switches and they seem much better. I can now use this method to be certain.
Thanks I personally prefer the hard limit method for setting square as it is easy and accurate. Mechanical switches probably arent the most accurate of things and a small error makes a big difference on a large square. Cheers Peter
Agreed. It doesn't even need to be held in the collet, it could even be a stick taped securely to the outside of the spindle housing. As long as it has a small point and it follows the spindle's movements, it'll work. I've used this method to attach a felt pen to my router so it can draw out large shapes instead of cutting them.
Hey Pete, Great job on the video and information. I live in Oregon, U.S.A., I am very accustom to the sound of rain on the roof.Keep up the great videos. My remote pendant arrived yesterday so I will be using your video on installing a remote pendant with Mach3. Thanks
I am new to CNC machines and will use Pythagoras as I have done all my life with building. Your video was very informative, especially sharpening the stick and typing the command for location! I have started calibration with my y axis Pepperl + Fuchs NPN inductive proximity switches , leaving my slave on the other side of the bed which also has the same type of sensor unchanged. Thanks again, subed!
use G91 X600 to move 600 to the right of your point (G91 is relative mode). Using G90 X600 will send your machine to absolute X600 coordinates and, depending on your current XY zero, can lead to serious crash.
That's one of the reasons for using limit switches to prevent such a crash or using homing switches and soft limits. One of the primary uses of limit switches is preventing your own minor mistakes turning into serious ones.
Hallo, vielen dank !! jetz kann ich meine CNC-Fräse richtig einstellen, Grüße aus Deutschland :-) Hello, thank you very much !!! now I can adjust my CNC milling machine correctly, greetings from Germany :-)
Peter have you ever heard of the two sheet method. Basically you have 2 sheets of plywood that you cut around the edges. Without moving the bottom sheet you flip the top sheet over and align the sheets along the X axis. Match up a corner on the left or right. The overlap will be double the error and you make that your adjustment to hard stops.
Used that for setting up my table saw sled. Works really well but not sure how I would use it setting up the CNC. Sounds a bit expensive if you are cutting up material to test it. The tape is cheaper. I'm just a cheapskate. 😉 Cheers Peter
Another great tutorial :) I used the 3.4.5 triangle when I was building the concrete raft for my garage, its good enough for the pyramids good enough for me.
Well, i use the same trick basicaly. The difference is i point it directly to measuring tape and move the gantry by X and Y in diagonal and check the diagonal length.
Great video! BTW, I would put those hard stops a couple of mm away from the actual limit of the machine. In this way I can verify the squareness at any moment just measuring the distance between the stops and the "leg" of the portal on both sides. In fact, if the machine loose its squareness, the portal could have a little"crash" when you push the machine to the limits... In case, a small plate between the hard stops and the legs can be used to "flat" the portal legs against the stops surface.
Hi Peter, I really love your work! (I use your knobs, hold downs, cam clamp, parallel rule etc.) After watching this and your previous videos on not needing home limit switches, I think there may be a tiny flaw in your method... With microstepping, when you put the system into E-stop, the steppers will fall back to their natural detent and this could move everything by up to +/-0.5 full steps... Sorry if I am missing something - it just bothered me a little. Best wishes from Aus.
Hi Perry, You could be right about the up to 0.5 degrees but have you taken into account the gearing effect and thus the actual amount of movement this represents. On a 4 TPI leadscrew the 0.5 degrees represents 0.006" or 0.15mm. If your lead or gearing is coarser than this then the error will be larger and if you are using 10:1 then the error will be smaller, but at the end of the day I am cutting a bit of wood and not components for the next Mars rover. I suspect their error is the equivelent of, or better than, the error you would get from the cheap mechanical lever switches used on many homemade and purchased machines. These lever switches are not precision positioning components but off the shelf switches used for general purpose. They are not designed to reliably operate at precisely the same point every time. You need to pay real money for that sort of functionality. Electronic switches would be the way to go, either light beam or hall effect. People get the impression I don't like limit and homing switches. Personally I couldn't care less either way. All I am saying is I don't "need" them. I have never had a single thought that they would be useful to me or seen my machining suffer from their absence. Dust Bunny mentioned in a comment below the unreliability of mechanical switches on his machine and that inductive ones had improved his homing. I suspect the attitude is, I have switches, it is all automatic and electronic, therefore will always be perfect, but how many people actually bother to test. If you accidentally bump a lever switch arm, which could easily be done, the whole machine could end up miles out of adjustment and without regular testing it will only be noticed when things aren't right. The day I bend a hard limit on my machine I will hardly fail to notice the bruise and intense pain it will cause me. I'm ranting again 😊 Most embarrassing. You are right about the stepper moving slightly when you remove it from Estop. The gearing / lead on your machine will reduce the error by the ratio of your gearing. In my case I don't see the machine move off the hard limits when I remove Estop so the error in my case is very small. I live by the rule of "If it ain't broke, don't fix it." Let me know your thoughts and if you think it sound reasonable. Cheers Peter
CNCnutz (Peter Passuello) Oh dear, I didn't mean to waste so much of your time - you are very generous with your subscribers. Yes, half of 1.8 degrees is not much and I fully agree with your pragmatic approach to all things. On my machine, I do see it "relax" sometimes when it goes into e-stop, but it might be due other factors - and I do use roller chain rather than a rack drive... I do use hall effect home switches - and you are absolutely correct about lever microswitches being a horrible waste of time. I find being able to simply (and accurately) home the machine makes everything a bit easier... It is great to see you back after the long gap - the videos are always fascinating.
Hi Perry, You weren't wasting my time and it gave me something to think about. Actually you just pointed out an error in my calculations. 1.8 degrees per step not 1 degree as I was foolishly thinking. This will almost double the distance. Mine is rack and pinion so would be similar to your drive. Chain after all is just a flexible rack when you think about it. Maybe also stepper drivers will affect how the stepper behaves when it is repowered. I don't notice any issue myself. Good to know about you limit switch experience. Cheers Peter
Thank you for this. I have a CNC plasma I built about 3 years ago. X axis cuts smooth as silk. Same with the Y. However, when it comes to diagonal cuts and the 4 corners of a circle (think 2, 4, 8 and 10 on a clock), I get serrations that resemble the edge of a file. I've tried just about everything else and it seems NO ONE has this problem except me, since I can't find ANY info matching this issue. I've never considered my gantry being out of square may be the cause. I have hard stops, but I'm not absolutely, 100% sure those are even. I'm not sure this is the problem, but it does seem as though when it's running, the X and Y are not playing nice with each other. Guess we'll see what happens.
Can you please show pictures of your cable management arms? I like that idea and think it could work better on mine than tracks for the Y axis movement. Thank.you!
Great video. Could you just put some notes in the description. I have rewatched this a few times over the months just recall it was 800mm x 600mm =1000mm
When adjusting the axis with the spanner would it not be a good idea to put a dial indicator against the right hand side and adjust until you see that its moved 1mm?
The problem with obvious things Gareth is they are only obvious when you think of them. The trick with putiing the tape with the cross under the point only became obvious after a half dozen attempts of trying to draw a spot under the point and failing miserably. Cheers Peter
All good except I have a problem getting my head around the procedure for adjustment / re-check. If initially you move the Y axis down to -800 and make a mark, then across 600 on the X axis and make a mark you then measure and find you are out over on the RH side (y-800 x 600) by say 1mm. If you then crank the RH stepper motor a tad to compensate wouldn't this then change the Y -800, X 0 point (if only slightly)? On your table this procedure may not make a difference, but (I would have thought) on larger tables, it better after cranking the stepper the same way, to restart again at the origin move to Y -800, X 0 and re adjust your mark, then move across to Y-800 and X 600 make your mark and measure/tweek/repeat if necessary. Cheers, David.
Hi David I did check to mark at the origin point after tweaking the right hand side to make sure nothing had moved. If it had moved I would have adjusted the origin point tape. Logically it would have moved but it was so small I couldn't see it, probably 0.01mm over the distance. The longer the axis the smaller the movement will be at the origin point. The only reason I marked the first move (Y-800 X0) was to check the motor calibration and make sure it did move the required distance. If this distance or the 600mm distance was wrong then I was wasting my time. Fortunately mine are correct but it is important to check that first time. The actual angle the axis was moving in will make no difference to the actual distance travelled. In subsequent tests it isn't needed . I don't even need to go to that point anymore so bypassed it all together. (Go directly to home and collect $200) Does that make sense? (Maybe I'm the one missing something.) Let me know. Cheers Peter
Thanks Peter, I figure there is no better way than to check it out myself! I will see if it can be squeezed in this weekend. Will report back on my result. Cheers, David
Maybe just because the successive positioning of the measurement ruler at the center of a big "X" is far easier than trying to catch a little marked point... but this is just my speculation. In both cases we're speaking of an "eye ball" tecnique. The bigger the mark, the better the result. I recommend to use a magnifying glass in any case.
Peter, I have a 4'x8' Laguna Smart Shop CNC that is out of square. I have worked on it for the last hour trying to get the right side of my "Y" axis to align with the other side. I have release the motor from the side mount and dropped the gear away from the teeth that it travels on. I have tried at least 10 times to release it but can not for the life of me figure it out. It seems to always go back into the original place. I have disconnected the motor/servo on the right side and jogged the left motor but again it realigns as soon as I turn the machine back on. Any ideas? Does any of that makes sense in my explenation? Much Thanks, Bryant Petersen
I know what you mean but not sure what the solution is. I wonder if your machine has linear encoders for homing that remembers where home is. You might have to contact Laguna to find out the process for resetting square. Cheers Peter
How would you square/calibrate the Y with dual stepper motors (with dual lead screws, but should be the same with any driving method), considering that the motors can have different steps/mm? That would need to be set first, no? How to independently check and set the steps/mm for each of the motors driving the axis then?
You can't use different setup on a dual drive. The motors a leadscrews must be the same. Slaving sets the slave axis to use the same settings as the master axis. Cheers Peter
Hmm, OK. I was under the assumption that when we calibrate steps/mm, we mostly calibrate for discrepancies in the motor itself (and not for the machine around it). Was my assumption wrong? Because if we actually calibrate for the motor, and we have 2 different motors, then we would need to have 2 different steps/mm in order to have a truly parallel machine.
Calibration does not compensate for the motors because stepper motors are accurate. If they say 200 steps per revolution then they will be exactly 200 steps per revolution. You need to use matching motors on a dual axis. They don't need to be the same make and model though they really should be. The stepper motors must be the same number of steps per revolution and the leadscrew leads need to be the same. You are compensating for the leadscrew or pinion variation from the advertised. You can use motors with different steps per revolutions on different axis, just not on a slaved axis. Cheers Peter
Got it; we are compensating for the machine, and not the motors, so my assumption was wrong. Thanks. I guess in a perfect world both sides of the machine would still need to be compensated differently, I think, because if the opposite sides of an axis are ever slightly out of parallel, the motors wouldn’t travel the same distance over each one. But in the real world if this was a problem, I guess people would try to fix it more ;)
Hi jamcdonald120 At that point in the video I am talking about squaring the machine. In the early days the Y axis was dual leadscrew drive and is now rack and pinion. I now have only 1 leadscrew on the Z axis and is not part of the squaring process. Cheers Peter
Hi Cecil, I think the pieces you are referring to are the hard limits of my machine. They are their primarily to stop the Y axis driving off the end of the rails and chasing me across the workshop. By bringing the gantry as far forward as I can and putting the limits against each side of the axis it can not only ensure, it doesn't go off the rails but I can also use it as a reference to square the gantry. When the gantry is all the way forward and touching both hard limits the gantry will be square. Cheers Peter
Hey Peter, as always an excellent lesson. I have a question about the gantry squaring process, bringing the gantry gently to the front stops. I'm about to get an Avid PRO kit and they do this function with limit switches on both Y's as a part of the homing function in Mach4. I want to stick with Masso using the G3 for this build. Is there a way to get Masso to do this, maybe with the slave Y run from A?
Homing switches let you know that you are at the end of your travel... or at the point of the switch... but they do nothing for the angle of the machine where x meets y. This must be checked and set manually. Nobody has independent home switches on BOTH sides of the Y-Axis... you would need a Y1 and Y2 driver, and sync them separately... and all your G-Code would be much more complex. The only machine i have seen this on is an XYZUV machine used in wire-cutting. X and U are a pair, Y and V are a pair. You can use a probe to determine the angle, but you MUST have a very accurate 90 degree leading edge to compare against... and even then... without doing mathematical (G10Y20 P1 Ra) offsets... it's best to adjust the machine manually.
I really take exception to the “nobody has” statement! I’m on my third home machine; all three have had independent Y axis sensors and drivers. Mach 3 and UCCNC both support homing and control of a pair of motor drives with independent home/limit switches.
As part of an automatic startup / homing routine it would be convenient. I mention it in my writeup but noted that the first step to get auto squaring working is to square the gantry using the 3, 4, 5 method. Cheers Peter Cheers Peter
CNCnutz (Peter Passuello) 345 method is great but just adjusting a sensor on one side of the gantry forward or back to tweak squareness would be nice and easy and that way every time you start your machine it squares itself without having to deliberately crash it.
I ran cutter down the left hand side of my table which makes it parallel to the Y axis rail. I can put a square on the side and align the stock this way. Cheers Peter
Pete, very well done!!! I like to ask you a couple of questions? Since you have made several machines. One using lead screws and now you have rack and pinion, which one do you prefer to use? The other is why did you go with rack & pinion (R&P) is one more accurate than the other or is R&P better for larger tables? Is there more Torque with R&P? As Mr. Brown mentioned with lead screws you can not move the axis when when motors are disengaged, obviously unless you go and spin the motors manually? You hear a lot of hype about R&P over lead screws and other. Obviously there are various type of lead screws like ball screws which are more accurate. I dont think you are machining rocket engine parts. Wood working does not require accuracy greater than .01 mm. Just curious to hear your point of view between these two types of mechanical solutions since you have built them? I rather hear your point of view rather than some hype from vendors.
Hi Don, That's some interesting questions that would have me typing for hours so I will try and make a quick video to answer it instead as it might help others decide though it is only my opinion. Cheers Peter
CNCnutz (Peter Passuello) Pete that would be great and give some of use a perspective from your experience of why you have chosen to go with R&P option. Granted common sense says that if your table is larger than a certain size a ball screw or lead screw would not be practical since it would be flapping in the wind and would bow with large distance.
Pete, great video but I have a question. How did you square the x-axis with the y-axis. You used an adjustable wrench on the motor shaft but what does that do? Are you actually bending the gantry components to get it square? I wasn't clear in the video.
It turns the motor. I could have pushed the gantry by hand but I would have overshot but using the spanner it have control and can use the gears to my advantage for fine tuning. Cheers Peter
The machine is home made and based on the 4x4 Hybrid. I purchased the plans from www.joescnc.com The machine has been modified to suit the available components in New Zealand and I have now replaced the Y carriages to ones of my own design. Cheers Peter
Hi Peter, Thanks for the awesome video.I am facing exactly this issue on a home-build. I have one doubt though, would this adjustment make the Y-Axis bind up if it is carried out too far,or will it actually improve the movement ? I have a 320mm X 320mm machine which is moving "smoothly" albeit with the squaring error ! Thanks again and subbed !
If the machine is built properly it should run even better with the gantry square. If you find it binds then you will need to figure out why because if the X & Y are not square to one another it will never cut square. Cheers Peter
I look forward to seeing your video on how to do it properly. I have subscribed to your channel so that i do not miss it. I am always happy to learn from an expert such as yourself. In the meantime I have somehow managed to fluke my axis square which will have to do until you put me right.