Yep, SketchUCam and completely standard Duet setup. The only issue is the G53 absolute move in Z, everything else is working fine so far (I'm just setting it up, not got as far as hooking the spindle up, just a felt tip so far). I'll have a play this evening to see what it accepts in terms of specifying negative minimum values, etc. I have modified the GCode output from SketchUCam to fix the issue in the interim, but it would be nice to have the machine setup in a more standard fashion.
Of course, thats the point of the discussion prior to tagging you in ^. Just the Z Machine coordinates we are talking about...
I believe you can use negative values in the axes minima settings in config.g (I'd recommend making changes by copying the lines into customconfig.g and changing them there though) - haven't tried it myself, but seem to remember seeing someone else doing it. Be aware though that you will also have to change all the homing files as well, otherwise your settings will be overwritten whenever you home an axis. This is one reason I never bothered to change mine - it is much less work to change the post processor to output G53 moves that fit with the Duet working in positive space and eliminating any code that won't work with Rep-Rap. Alex.
OK - just checked with the Duet g-code wiki (Gcode dictionary) - you can set negative values for the axes minima, but to emphasise a few points from earlier ;- The home position (regardless of where your homing switches are) is ALWAYS back, right, up and that corner of the machine space is ALWAYS the MAXIMUM for each axis. If you set any axis at that corner as 0 - the opposite end of that axis will be a negative value (as per the grbl norm) With Rep-Rap firmware as on the Duet, if you change the M208 settings you also have to change the settings in the homing files - homeall.g, homex.g, homey.g and homez.g. Otherwise the homing files will reset the values for the home position - I have no idea what would happen if the config.g file set the machine workspace as negative space and the homing files tried to change it back to positive space, but I suspect soft limits wouldn't work too well Let us know @James Boulton how the experiments go. Alex.
Thanks both for your input, I have changed the minima and maxima values for Z on my machine to be -94 and 0 and then altered the homing macros to set the Z value to 0 in each after homing. It appears to be behaving as expected with Z0 at the top of the Z axis and Z-94 at the bottom. None of the macros use absolute positioning to move, so the changes are actually pretty minimal, just limited to the G92 commands which set the Z reference. This just needs setting to Z0 instead of Z94. In fact, I have a feeling just setting the minima / maxima values in the config (or custom config to survive updates) and leaving all the homing macros alone will actually work fine also. I missed some of the Z0 sets out of one of the macros and it ended up displaying 0 for Z anyway. I assume this is because Z94 is out of the machine limits defined, so it gets clipped to the closest value in the machine range, which is 0. I'm now happy that if any absolute position moves end up in G code it wont be crashing my Z axis into the table!
No, I think you do have to change the homing files - Rep-Rap allows you to re-configure settings "on the fly" - you could in theory run a job with the router, include code to re-configure for laser and continue to run the laser code - all as one file. You would have to write your own post processor to do that, and your laser would be covered in dust, but it's theoretically possible on my reading of the g-code wiki. When it comes to setting home and axes maxima I believe the lower value is persistent but it's messy not to have files doing the same settings being consistent. I haven't bothered to find out, but I suspect it's only the last G92 in the homing files that matters. People have got very confused when they extended their Z travel, changed the config.g settings but not the homing files - then every time Z was homed it overwrote the config.g setting. Alex. PS - I'm not suggesting you should run laser code in the same file as router code - I'd want to clear all the dust away before running a laser.
Yep, absolutely agree its far better to do it properly rather than rely on the firmware's behavior to make things right. Things change during updates and relying on specific behavior to correct things is never a good idea. It is indeed the last G92 which sticks -- this is purely saying "WE ARE HERE", specifying where in absolute co-ordinates "HERE" is. I don't see the minima and maxima redefined elsewhere, so these values are just set the once in the config. Anything past this point is just specifying a position in absolute space for the current position of the axis. But naturally if you say you are at 0,0,0 in the middle of the bed you can still quite happily crash any of your axes into their limits. Setting up home and machine size limits is rather important.
I am having an issue with the CenterLine Tool and the Pocket a Face tool. How do I set the bepth of the cut in each? I am using them in the process of dialing in the depth of cut from X 0.00 to X + max. The PP1 does not have a very accurate travel in the X direction. This brings me to ask, is there a way to program the X position to adjust the Z + and - to correct for this problem? I would think that somewhere you should be able to have the Z go + or - to keep the cut depth correct. across all X travel. I could measure the adjustment at even 50mm intervals and have a special Gcode or something adjust the Z. Thanks Mark
2 ways. The depth can be set in percentage of material thickness using the entry box at bottom right of the screen. When you click the tool and before you select the line or pocket, you type the depth into the box at bottom right (part of SketchUp) There are also hotkeys that jump between 25/50/75/100%, left right arrow keys do this. For high accuracy depths use the 2nd way, set the depth to 100% and then set the material thickness to the precise depth you need. Obviously you then to select only these lines or pockets and cut them separately to all other depths. When generating Gcode, if nothing is selected then everything inside the safe area will be cut, if 1 or more lines, holes, pockets are selected, then ONLY those selections inside the safe area will be cut. Explained in detail in this video and by that you mean distance travelled is not precise, or depth is not consistant. Distance travelled can and should be fine tuned with the steps/mm wizard in OBcontrol. Depth must be adjusted by adjusting the mechanicals. No, adjust the mechanics to be correct. A shim on the low side of the table should do it. Yes, different software and very different hardware (not Blackbox) can do it. Complicated. Adjust the mechanics instead, maybe have someone from the local makerspace come and help you.
The way to deal with material that is uneven in Z is to do a height map and apply that to the GCode. If you are using Grbl, a number of GCode senders can do that. I like ioSender and a 3D probe for that. If your bed is uneven, you should skim cut it flat.
He has a Phlatprinter 1, none of those are possible since the material is fed through the machine and the sliding surface is the 'top' of the material. see it here Original PhlatPrinter
Thanks for the input The real problem with the PP1 is the bearing rods used to slide the gantury on the X axis is they sag in the middle and do not cut as deep into the material in the middle as they do on each end. I am looking into adding a flat barstock under the gantury that can be shimmed to push aginst a roller attached to the bottom of the gantury and see if that will do the trick. I am using .110 Depron foam so .001 movement is almost a full percent. This is a fun project but is becoming a never ending problem. I will sort it out somehow but it sure seems like there would be a simple gcode to insert into the program that would send the Z in a - direction baised on the position of the X axis. Like at X =0 no additional Z- at X =+100 Z -.0005 at X =+200 Z -.001 and so on. cant there be a sub routine run in the gcode? anyway trying to learn all this is tough. David as for the cut depth in pocket and ctr line Thanks that is great I think I have it now. Will cut tomorrow. Thanks Mark
That is why the PP2 and then PP3 were developed (-: While some of the expensive controllers like Siemens and Heidenhein probably support something like this, GRBL does not. On a conventional router with a table you could probe the material and have the controller GUI compensate, bCNC can do this, OBControl cannot. But this is not possible on a phlatprinter because the 'top' of the material is against the table. 'maybe' a very clever person could build a manual correction table for bCNC. If you are trying to cut 0.001" features in 0.1" Depron you may well be wasting your time (-: I would not look at anything less than maybe 20% increments. Some of the features in SketchUCam exist because Depron is not normally flat enough for precision depths. @Mark Carew will tell you all about it (-: Like being able to cut at 150% depth to be sure to get through the hills and valleys reliably.
Thanks David I will just continue to add simple things to make the PP1 work as well as it can. I think the roller on the bottom of the gantury will work. This is just a project to help me really understand what is needed for a REAL cnc router. I plan on building a really nice 4 x 8 foot Rack and Pinion Router with lots of power and I want it to be very accurate. Learning about the needs and the issues on thins and the Mill / Lathe my first project have helped me understand what is needed. I really appreciate your help in it all. You have educated me as well as MANY others in this. Still learning Mark
I believe that I am starting with Sketchup2021 which is web based. Installation instructions indicate that SketchUCam should be installed in a plugin folder within SketchUp, but I do not have anything related to SketchUp on my computer. Will SketchUCam work with the web based Sketchup or should I look for a SketchUp version that can be downloaded to my computer? Thanks for your assistance. Dave
I have no experience with SketchUp 2021 but I think you still can install .rbz files. Having said that, I would recommend downloading SketchUp 2017. It's not as limited as the online versions and what most of us are using.
Thank you Justin! Took your advice and downloaded SketchUp 2017 and next up will install SketchUcam. The heck with the web version. Dave
Referencing earlier question: I am running a pc with 64 bit windows 11 os. I downloaded SketchUp 2017 but it turned out to be SketchUp Make 2017 which appears to be a subscription pro version. The only SketchUp for 64 bit that I find is a 2016 version from Google. What is the difference between Google and Trimble versions? Assuming the Google version is the one I want, will SketchUcam still work? My use is strictly personal and for a hobby, not inclined to purchase pro versions. Thanks for any help. Dave
Sketchup Make is the "free" version and the one you want: Sketchup Make 2017 (Last free version) Google sold Sketchup out to Trimble years ago
Yes, you need the downloadable version, plugins do not work with the web version. Make 2016 or 2017 are ideal, no need for any version of Pro.
If there is a bug to report in sketchucam is this the place to report it? Hoping to improve it by reporting issues. Using SketchUcam V1.5a-241a161 getting error when creating g-code Error Message 1: Numerical Argument our of domain - "sqrt" Error Message 2 GcodeUtil.generate_gcode FAILED;ERROR: This happens on certain shapes when doing an outside cut. (been using sketchucam for few years). Kind regards Tom
Please see attached sketchup Model settings used in sketchucam Material thickness: 1 mm bit diameter: 3mm multipass depth: 0.2 mm Regards Tom
Hi In your drawing you have arced corners that are only slightly bigger than your 3mm cutter. This causes some tiny arc segments in the cutline, as indicated by the purple arrow Since Sketchup works internally to within 0.001" the ~0.003 mm distance between the ends of the arc segments is regarded as 'equal' and the sqrt in the arc center calculation gets a negative argument and the Sketchup internals cannot handle that, causing the error message. While I can and will do code fixes to detect and handle this situation, in the meantime you can fix your drawing. Select the arc Right click and select 'explode curve' Now add the cutline. Gcode will now generate correctly since those tiny segments inside that corner are lines rather than arc segments, so the center never needs to be calculated. An alternative is a 2mm cutter instead of the 3mm.
HI David, Thanks for the reply. I will try this work around. Forgot to mention I was doing an outside cut. Hope in future version this type of error will be handled. Very much appreciate your support. Kind regards Tom
Hi. I have only recently upgraded to 1.5 and ever since I have had problems. I used to use Chilipeppr but am trying out OBS. I have the same issues on both. Occasionally it slams into my z stop. If I home all, and manually trigger the z stop, it pulls off fine. I set my workpiece top as zero. Upon starting my carve, not only does it cut too deep, but also fails to rise to move to the next pocket. Any help on why this is happening would be appreciated.
You need to home the the machine with Z as high as it will go. Home, Fusion360 and G53 Z moves "G53 G0 Z-5" means 5mm below Z home, so Z home has to be as high as Z will go. Then, when you set your material surface as Z 0, you must to use the 'setZeroZ' button. Note that any action that resets the controller, such as disconnect and reconnect the CONTROL software (or swap to different software while machine is on), disconnect and reconnect the USB cable, power cycle the controller, or pressing the reset button on the controller, will mean you HAVE to rehome the machine before proceeding since all of the above actions make it forget home.
Hi everyone. I'm new of the forum. I'm using Sketchucam. I want to use the machine Morbidelli Author 600. It asks about a *.pgm file. How can I export/convert a *.pgm file from Sketchucam? Thank you
