My printer is updated with dual head firmware 1.1, and “Restore failsafe has been performed”.
After the previous print my platform was in park position, a few centimetres from Z bottom.
The mains and USB was disconnected.
With my computer up and running, I plugged in the mains and USB connectors.
In “VERTEX 3D PRINTER Repetier-Host V1.0.6” I clicked connect, and it connected to my Vertex.
I them attempted to click the home Z icon, but my mouse slipped on the edge of my desk, and I accidently double clicked on the nearby 50 mm downwards Z button.
To my knowledge, the platform isn’t supposed to travel downwards without first having been homed in Z? It did however, and broke my flexible coupling in two.
I can repeat the following, but other sequences may also be possible:
1.) Reset the printer.
2.) Connect to the printer using VERTEX 3D PRINTER Repetier-Host V1.0.6
3.) Click any manual printer movement button. A short bump will be heard from one of the steppers. The click to bump-sound delay varies from instantly to a few seconds.
4.) Now the Z-axis may be moved at will.
Questions to Velleman:
A.) Can you repeat this behaviour with one of your printers?
B.) How do I obtain a replacement flexible coupling?
C.) The Z-stepper seams too powerful for its own good. Would it be a feasible idea to lower the voltage of this particular stepper driver?
I don’t know if the platform can move before homing but generally speaking when you connect repetier host to your printer it doesn’t know what values Z is on, so for example if you have printed something and left Z on 150, turned off printer and next day turned it on, when you connect to it with repetier, it will report 0 as position for Z.
That’s why homing is being done before every print, so that printer start from 0 on all axis, or 200,200 for K8400.
Software endstops are being used to stop this when hardware endstops are not provided but still, software has to know where Z is at the moment and the only way for it to know is to do Z home (or all axis home) when printer is started and monitor position changes after that.
Thank you for your reply, but I do understand that homing has to be done prior to all other movement.
That’s exactly why I consider what I reported to be a bug.
The firmware shouldn’t initially allow anything else than homing, and this behaviour is in fact locked out on the K8200.
If it isn’t a bug, then it’s simply bad thinking, but I’d like to think that it is a bug, and that it will be fixed.
I will test it tonight, but Vertex is using modified Marlin firmware, so feel free to download Vertex firmware, open it in Arduino and change configuration that suit your needs. Velleman hasn’t developed firmware so it would be considered as a bug on their side, only modified existing Marlin to fits Vertex.
I personally don’t consider this a bug, because normal procedure when you power on printer and give it a .gcode or .stl file over Repetier Host (or any other program) would be to do homing first with G28 command, so you wouldn’t got that problem that you had in the first place with normal print either from pc or sd card.
You can check Marlin configuration and see/change software endstops setting in Configuration.h and see if there is any difference.
One more thing that you can do is to add another microswitch for Z-max, as Marlin supports both axis max and min endstops, that way you will have stop switch on Z axis for similar problems in the future.
It’s an approach, not as much of a bug. You should always be able to jog your machine, homed or not. I guess more complaints would arise from first home, before moving. With my CNC mill, it remembers its actual position though, even when turned off. I don’t know if this particular hardware has room for storing the current machine-coordinates. I’m always able to jog, if it’s homed or not. But if i turn the motors by hand and put it at a random place the position is unknown. (it’s not a fancy closed loop/coordinate system, it are simple steppermotors, assuming every puls leads to a certain reaction) Homing/G28 sets things straight and tells the machine its actual position.
It’s more of a silly thing in your used version of repetier that homing and moving the axis are so stupidly close to each other. If you controlled the machine using repetier for mac it would be impossible to make this ‘slip and click’ mistake.
@to3dornottobe:
I am sorry to ask this Offtopic question, but I couldn’t resist: Is your CNC mill a home built machine and if it is could you share some detail on it(motors, interface,drivetrain) please? I would like to know because I am building one from scratch with the K8097 interface and some used printer steppermotors and other bits and pieces that I have.
And one of the first things I did is similar to your comment; I keep track of where the machine is because I still am debugging the software for it and not want to home everytime I start a debug session, so I keep track of XYZ positions on disk.
It’s a converted BF20L, using hiwin ballscrews, nema 34’s (upgrading them to Sanyo Denki’s) i bought 230vac stepperdrivers (have them laying around for 3 or 4 years now…) to give it more speed for the 2.2kw 20k rpm spindle. The combination of the high voltage driver and right sanyo denki steppers enable it to have loads of torque up to 3000rpm. Hardware being used to control it is USBCNC (it’s a Dutch company who makes a great product IMO) you can download the software to get a feeling. The cad/cam that is included in the software might be nice for wood, but it’s worthless for machining metal/aluminium. cambam is popular, but I prefer mastercam.
Here are some parts made with this mill; (heatsinks/mounts for homebrew active speakers)
The coolant system is a Fogbuster (US made, if memory serves right) And you need a cabinet around it; aluminium has the tendency to fly…
If you’re looking for a good source for extruded aluminium in Europe, motedis.com (Germany)
Homing is done with 3 proximity switches, they also act as e-stop on all 6 directions.
Collected quite some linear slides over the past few years (THK SHS20, 25 and 30’s) and wanted to make a gantry from epoxy granite with a granite table. (something like the Datron machines, being able to cut light, but fast & stable) But i am now blessed with 2 lovely sons of 2,5y and 4 months. Priorities have been shifted slightly.
@to3dornottobe to be honest, I’m using the latest Velleman version of Marlin with modified steps for extruder, everything else is the same, didn’t had need to adjust anything (YET)
@to3dornottobe: That’s a fine piece of hardware you have! Looks like that one is a bit too steep for my budget.
Gave a quick look at USBCNC (since I am Dutch;looking, no buying) or rather browsed the Fraxeon website a little.
I am a bit surprised that these controllers are actually affordable!
Eventually I would like to own a machine like this or modify one to CNC. You have made some amazing things with it.
I will stick to my homebuilt hobbymachine for now.
@kula; i’ve adjusted these settings too, as well as the acceleration (tuned down to 4000 or so) and changed the PID settings or the nozzle. (autotune)
Thanks for the kind words about the CNC
Deekay, i’m Dutch too.
If you have patience, you can collect nice stuff to make an affordable CNC. Don’t know if you know these guys in Boxtel? there is a large 2nd hand sales, selling aluminium profiles for scrap prices. (i thought around 5e/kg)
