RDWorks Learning Lab 167 Auto Focus Frustration
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- čas přidán 28. 05. 2019
- If you own a Chinese laser cutter this little series of videos about me learning how to use the free software provided, may solve the problem of trying to learn from a virtually unreadable manual.
I am nothing to do with RD Works, I am not an instructor and I am no expert. This series will document the essential bits of many hours of trial and error - Věda a technologie
Thank you, thank you and thank you again, for pointing out the true purpose of the mysterious pen down/pen up option! Cutting 'out of focus' is something I do all the time, for instance to achieve wider pen strokes, or for rough engravings (for cardboard packaging). For many layouts I need to manually adjust the table height and I just couldn't find an option to automate the process. Today I tested it immediately and I have to say that hearing that Z-axis move in the middle of the program... music to my ears! You saved me a lot of time Russ. Keep up this great series.
This is the best video explaining auto-focus and moving the Z axis between cuts on CZcams. Cheers!
Love these videos! Thank you so much
Very good video, very helpful, thank you!
Hi Russ. I am replacing my auto focus however the new one I have has three wire and the old one had 2 will this still work. My new one has a extra black wire. Hope you can help. Thank aidan
Great explanation Russ, did you try a negativ value (-3) at "pen down" to move the table to z + 3 Above z0 ? Waiting for my switch from cloudray. Should be in the mail in 2 days.
Maybe they ref the pen position originally because the head was actually motorized. Vs the table. I think cloudray sells one of these.
think you mr ross for this démonstration
Hi Russ. Fantastic video, thank you. I don’t auto home my z-axis (no limit switch), and I’ve removed my auto focus unit too as it just gets gummed up and needs regular cleaning etc. Is there a way to still use this pen up/down feature without the auto focus? When I “read”pen up position it says 3000mm ish, which is odd given the breadth in vendor settings for z axis is only 480mm. Is pressing the ORIGIN button not the same as setting the XYZ positions as zero and having the z-axis positions pen up/down run relative to that? Does that make sense?
Live focus is actually fantastic but auto focus? Doesn't work with curved/bowed material like live focus does.
The link I left shows a co2 laser with a proximity sensor in place of your red sensor. Because there are no moving parts I think this setup will be more accurate. You showed 1 to 1.5 mm of variance with the red sensor. That piece of metal they call a switch as soon as it moves it can tip forward and back
Hi Russ,
First, thank you very much for your hard work! I have a smaller 40W Chinese machine but much of your findings apply to that as well.
You made me think why the (ideal) focus point seems to move when you adjust power. Have you tried to check on the energy density at different power settings? I remember you were looking at it early on using a piece of thick acrylic but I don't remember you comparing shape versus power settiing. If the shape of the cone changes besides being elongated with higher power then that would explain why the ideal focus point shifts.
Hi Krisz
In reality the focus point remains fixed because by definition it is that physical distance from the lens that ALL the rays pass through but the apparent focus point seems to change with power and speed. Imagine you are an artist with a very fine pointed paintbrush for adding details, If you just touch the tip of the brush onto the canvas then you get a very small dot but if you press a bit harder then you will get a bigger dot or thicker line. Our laser beam has more power towards the centre and could be imagined as a pointed paint brush. If you set what you think is the correct focus point and then run at a faster speed or with less power you will get a thinner line. Does this mean that the focus has changed ? No . Even though all the rays pass through the focus point, at that point, the beam characteristic has not changed and there is still a high energy density spike right at the centre of the focal point that can do damage that is smaller than the spot size. It is a fascinating subject. There is lens theory and lenses in practice. They do not always agree.
Best wishes
Russ
thank you again
Russ, what if you had a spacer -say 10 mm thick (arbitrary thickness) that was placed directly on top of your workpiece at the machine origin point. Then at the beginning of a cycle you could go to that place, get an arbitrary zero point, and then adjust up or down as much as you like. The sensor would never again be in danger of hitting the work and you would always have a reliable zero point from which to work. Regards, Joff.
Hi Joff
You are entirely correct BUT it's a fiddly waste of time.With all my experimentation and testing I am for ever swapping lenses. For me it's a nightmare to set up each one. I have 3 lenses that I use regularly on this Lightblade machine and I have a little reminder note in the lid of my machine what two typical focus settings are for each of those 3 lenses. Significant speed difference = significant change of the apparent focus point.. With my step gauges I can set the focus to anything within about 15 seconds. I do not have to go into the Vendor settings, Read the machine data into RDWorks, Calculate what the new head offset should be, enter the new number and write it back to the machine. I then have to press reset to check that the new dimension is what I want, so after all that (3 or 4 minutes) I still have to check it with my step gauge. I often have a fixture bolted at a known position onto my table for when I am using absolute coordinates. I recently switched on the machine and obviously the head goes to X limit and limit to set 0,0. To my horror I could see the table moving up as well. I had to crash the emergency stop before the head drove into the middle of the table and collided with my fixture. I was in a loop I could not get out of except to remove my fixture and allow the machine to reset where it wanted. If you have a digital caliper you will understand how important it is to make sure it is at zero before you measure with it. Yes, it can be very accurate but if you "trust" it it will bite you. A steel rule has no such issues it is ALWAYS right but it's not quite as accurate. As marketing tool auto focus sounds great for the technically naive. When you get your machine, you may chose one that has this feature included. All I can advise is ultra caution.
Best wishes
Russ
@@SarbarMultimedia I adjust my heights often for various projects. You can disable the Z reset in the vendor settings, so it only homes X & Y.
@@swankster1966
My Z auto home (USER settings) has always been off. If you switch it on the table comes up and zeros on the table's top limit switch. When you use your auto focus sensor (with Z auto home disabled) the auto focus runs exactly the same software routine but now sets zero relative to the nozzle because your limit switch is attached to the nozzle..
Best wishes
Russ
has any had the problem of the laser getting off registration the farther away from the origin it goes. so near the origin it cuts a square, at the other end it cuts a rectangle. this problem is intermittent.
Hi Joe
This could be one of several issues so it will be better to speak offline so that you can run some tests to narrow down the source of your inaccuracy. Add your email to another comment. I will be auto copied to my gmail and will answer you and also delete your comment.
Best wishes
Russ
Seems like you've worked things out with your auto focus. There is another possibility: a touch plate. The two wire system you have for the auto focus sensor will work just as well for a touch plate. I've set mine up so that the tip of my nozzle touches an aluminum bar of known thickness on the top of the material. I have a connector on the two wires going to the Ruida controller for Z- that attaches to a pigtail with two alligator clips. One clip goes to a screw on the nozzle, and the other goes to the aluminum bar. As long as I can register the length of the nozzle when I change lenses, it will give me a perfect focus every time.
Sounds like a neat idea but are you aware that focus for cutting (typically 20mm/s) will be 1mm or more different when you engrave at 400mm/s?
Best wishes
Russ
Hi Russ, I recently purchased a Blue 100 watt chinese laser, with a Ruida controller. I have an application where I engrave in lamacoid material (2 layer plastic). At the start of the job I auto focus on the surface, then manually move the table down 1mm - 5mm (depending on the application). I have my scan layers set to "output yes", and my cut layer to "output no". I run the program, and it engraves, and then stops. I then manually move the table back up to 0, set my scan layers to "Output no", and set my cut layer to "Output yes", to cut out the pieces.
I have tried using this pen up/down feature, but it does not work, as the table doesn't move unless I have "pen" selected from the drop-down menu. How are you programatically getting it to move the table while "scan" is selected, as this would be very beneficial for me, as I wouldn't have to stop, change heights, and go again. Thank you for all your effort.
First question I must ask is do you have stepper Z drive or just a DC up down motorized table? You will need a stepper drive and an auto focus pen to make the Z drive programmable. You must first go to Config and System Settings. At top right you will see a Map For Pen Axis. By default this will be set to U. Change it to Z and the magic will begin.. You can control the height for each layer by selecting the ADVANCS button beside Processing Mode.. As I say in this video, the words in this section are absolutely meaningless. Note the alternative paragraphs that should have been there but there is no space. Have fun but always watch if you head is going to crash into something.
Best wishes
Russ
@@SarbarMultimedia Yes to stepper Z. Yes to auto focus. I will try Map for Pen axis, and change to Z.
If I followed correctly, I would enable "Pen up" and set it to 3mm, and then enable "Pen down" and set it to 0. Assuming I auto zero the table at the start, this would lower the table 3mm for the selected layer, do it's job, and then raise back up to 0 before executing the next layer. If I don't enable "Pen down" within the layer, then it would stay at that height for all following layers, unless I have specified a different pen position. Is this correct? I am working away from home right now so can't try it until I get back.
Thanks for the quick reply.
@@swankster1966
Yes that seems correct. You will quickly confirm when you start playing.
Best wishes
Russ
Here is a cheapo laser using a 3 wire mechanical limit switch. Again instead use a metal detecting proximity sensor.
Hi Mark
Thanks for the comments and informative links. If you really have a good use for it then I can truly understand your want to improve it. However it is the principle of auto focus and not the accuracy of the sensor that frustrates me. For almost 4 years now I have one machine without and one machine with auto focus. Most users that have autofocus are only using one lens and nozzle.(typically a 2" fl lens). The very nature of what I use my machines for, means I am continually swapping out lenses and nozzles, To set the system up for every change is a major frustration. For 95% of the time my second machine has the autofocus sensor removed and the wiring strapped out of the way. Maybe 5 or 6 times during that past 3 years I have spent time trying to make sense of autofocus as a principle and although the logic of sensing the work surface from the nozzle is sound, the mechanical way in which it is enacted is fraught with risk of wiping out the sensor and the tedium of initial setup. The top limit sensor microswitch on my table is repeatable to 0.1mm when you go to the user tab and set Z to AUTO HOME. That auto sets your table to a fixed zero position instead of using the pen sensor. You drop your nozzle to the correct focus point with a step gauge and it's a much less risky and quicker method of setting a focus if you are intending to use the different focus for different layers.. This method of autofocus using the table switch is still fraught with wipeout risk. You MUST have your table completely clear before you turn on your machine. Anything on the table could rise up and collide with the nozzle. So my Z AUTO HOME is only turned on during the few occasions I need to use this multilayer focus feature.
Best wishes
Russ
Thanks for making my brain hurt...;)
I try turon this pen option but nothing hapend. No move up or down.
Sorry to ask 2 silly questions
1) Do you have 3 or 2 black stepper drive boxes in your control enclosure?
2) Have you been to Config , System Setting and set the Map for Pen Setting to Z axis?
Best wishes
Russ
@@SarbarMultimedia I check it at home copy of RDW Find that default setting is U. Need to check if this same is on machine PC and settings. Also I check quality of XYZ axis settings. XY have no error 10cm set and in measurement square is 99,95mm. But they mess Z it have error x10,5 times. Z travel is set to 250cm ! Machine have 60cm height total.
I tune it up and when I set 3mm of Z move is 3mm move with error maybe 0,2mm
Also like you I don't get this auto focus mess.
@@artcraft2893
OK so you have a stepper controlled Z axis. As you have found, the Chinese never bother to calibrtae
Oops!!!! The fact that you do not have the Vendor and User settings saved is both worrying and a warning.. If you have those details saved you would be able to load them into your home PC. PLEASE make sure the next time you are at your machine you save those two files out to an external file for safety.
Best wishes
Russ
@@SarbarMultimedia Every time(changes) I made backup copy
@@SarbarMultimedia I set it today and success. This pen down/up is ridiculous. It's should be translated on beginning/end go to position Z=.... And during the testing, path optimization gets ridiculous. Machine made few curves on layer black Z=3mm then start made few curves on layer blue z=12mm then back to layer black ... Loots of waste time during change Z position. But there was something in manual for path optymalization by layers order.
one other question, i don't know if you now work for RD works but a new software has emerged called Lightburn, ITS LIGHT YEARS AHEAD OF RD WORKS.
lightburnsoftware.com/
RD WORKS IS STILL GEARED FOR WINDOWS XP AND LIGHTBURN IS EITHER MAC OS OR WINDOWS 10. IT HAS A SETUP FOR A CAMERA TOO.
So glad i did not order my machine with auto focus. Such a waste of time
As I find out, it can be potentially dangerous also. If you RESET or RESTART you lose the Z zero reference. If you run the same program without resetting the table zero, you run the risk of driving the table into the head. Once you have enabled the advanced pen features for a layer. they remain enabled until you go back and disable them. If you generate a new program and thoughtlessly use that same layer again, there is no obvious reminder that you still have the table offset (pen) enabled. Unless you are quick with the emergency stop button, something nasty will happen. For my application I will find it useful but as soon as i have finished this specific tasks I will check and reset all layers before removing the switch and put it back into retirement.
Best wishes
Russ.
Live focus is very nice though but expensive and only a few machines have it. Auto focus is a gimmick for a bad accident waiting to happen.
Hi, Im watching your autofocus problem. I've actually been messing with autofocus for a year on and off. I have the exact autofocus SENSOR you do. I call it a sensor because that's what it is. The difference between the proximity sensor on the say table or on another part is those parts are always metal. There are 4 defined proximity sensors.
czcams.com/video/zYdKN0jaxLs/video.html
Click on the link above. Im no genius like you, I just one day accidentally ran across a laser maker that used plain proximity sensors and a little LED blinked the second it stopped. There is an inductance sensor which is most common and those detect metal. There is a capacitance sensor that can detect non metal but if you open your sensor you will see that the plunger as it pushes in gets near the end of the proximity sensor. But that button is wobbly for sure. Im trying to figure how to use a proximity sensor. some are not adjustable but some are adjustable from 0 to 30 mm, the no adjustable are usually 4 or 5 mm gap.
i hope you use that big brain of yours and make a video using a proximity sensor. you've got 3 or 4 on your machine already and if you notice the page that has the setup for your so called switch also has x and y there. Those are not switches but proximity sensors.
i don't know if there's a way for you to contact me so ill keep watching to see if youve found it.
all the wiring is the same
Brown = +
Blue = -
Black = signal
This is on your red switch type sensor or the other proximity sensors. they ar super cheap on ebay i've purchased 3 or 4 different ones.
Hi Russ. Fantastic video, thank you. I don’t auto home my z-axis (no limit switch), and I’ve removed my auto focus unit too as it just gets gummed up and needs regular cleaning etc. Is there a way to still use this pen up/down feature without the auto focus? When I “read”pen up position it says 3000mm ish, which is odd given the breadth in vendor settings for z axis is only 480mm. Is pressing the ORIGIN button not the same as setting the XYZ positions as zero and having the z-axis positions pen up/down run relative to that? Does that make sense?
Hi Owen
So, the auto focus switch was acting as your table limit switch? That seems very unusual. Can you drive your table into the top lead screw bearing. or does it stop before doing so?If it stops then you have switch somewhere. If it does crash into the top then you will have to install a cheap lever operated limit switch to prevent it. If you look at your controller CN3, your sensor switch will be connected between 6 and either 4 or 5.. Those are the connections for your switch.
If you press the ZU button , one of the items is Axis Reset. Press enter and you will get to another menu. that allows you to set each axis zero independently.. Z will only work if you have a limit switch to run to. This Z reset function is EXACTLY the same as pressing the autofocus option. Until that reset/autofocus function is initiated (and completed) then your Z display will be the default 3000
If you want your Z to be included in the reset function then you have to go to the USER tab and request the Z axis reset. BUT it will only auto zero if you have a limit switch
Once you have set Z to zero the numbers you put in the pen up/down window can only be positive and positive numbers will drive the table down. Those numbers must be actual table positions and not relative movements. ie TO a position and not BY a difference.
see also czcams.com/video/ki8bFEAcJG8/video.html
Hope this clarifies
Best wishes
Russ
Thanks Russ, great help! It appears there is nothing plugged into CN3 at all, and there were definitely never z limit switches installed. I can Push and pull the table down/up until it collides and makes an awful noise (hardware limit? ;) ) I want to play with laser origami, so I essentially need to reinstall the auto focus system right? Sounds like I need to install a Z-limit switch anyway then, thanks very much, really enjoying unlocking and exploring a whole new range of features in a machine I’ve had for six years and put about 3000 hours on just feeding. Best regards, Owen
@@owenhoman-booth5224
H Owen
If you have not strippd out the wiring for the autofocus sensor can you trace back to where it is connected into the controller to because I am very curious. Is this some sort of Chinese bodge?
There will be no need to install the auto focus switch once you install an upper limit switch to set your zero. You will not need a lower switch because ONCE YOU CALIBRATE THE Z AXIS (it will not be calibrated at present) you can go to the vendor settings for the Z axis and set the Breadth to a distance that just avoids crashing into the bottom lead screw mounts.
Best wishes
Russ
@@SarbarMultimedia Thanks Russ. Yes, I took it about when I first got the machine over 6 or 7 years ago, removed the wires for both the autofocus and laser dot from the energy chain. I suspect it WAS connected to the CN3 as the whole terminal strip has been removed, so I think you're right, it was probably using the autofocus for the z-axis limit. I'm buying that air-assist solenoid package from cloudray today, so I'll include a limit switch for the z-axis and see how I go. Awesome help, thank you!