CoreXY firmware

[Kamil]

Hi,

Could somebody post a firmware file for corexy kinematic motion if any exist? I have Printrboard Rev.D I would like to make a moving table for a microscope. I have never touched Printrbot firmware therefore I need some help at least how to start it. I read that there are the configuration files on the github forum however I do not know which files I should use and how to start compiling it. Any help will be very approciated.

[RetireeJay]

Go to https://github.com/MarlinFirmware/Marlin and download the zip file version.
When you unzip it you will have dozens and dozens of files.

I recommend the following environment for editing, compiling, and uploading (see viewtopic.php?f=22&t=10160). Sorry the thread is so long and poorly organized, but it's the best reference I can point you to.
1) Notepad++ for editing
2) PlatformIO for compiling. Note: You need to put a PlatformIOAddons folder in the same folder where your new Marlin directory resides. I've attached a zip file with the required entries to go in this folder.
3) FLIP for uploading - assuming you are running a Windows computer attached to the Printrboard.

Open Configuration.h and find the entry to enable COREXY. Save (using the same file name) and then compile. If these instructions are way above your head, consider whether you really want to tackle this project! You will need to be able to modify Configuration.h and have a rudimentary understanding of the syntax of a C++ program - although you don't need to be a C++ programmer.

[cbxbiker61]

The old printrboards are really at their limits (flash size/cpu speed) just running traditional kinematics. It would be a heck of a lot easier (time is money) to buy a Smoothie compatible board, such as the Smoothieboard or an Azteeg X5 Mini. Smoothieware is really superior when you want to do alternative kinematics like corexy. All of the config is done by simple editing a config file on the SD card, no firmware flashing required.

[Kamil]

Thanks for replay I will get to try.I found on Github forum two examples quillford/printrcore and smartfriendz/smartcore (sorry I could not post the links). There are any different from the one you proposed?

[RetireeJay]

Are you sure you want "CoreXY"? It uses a system of two long belts to position the head, with both motors stationary, mounted on a frame. I think that microscope platforms typically have rack-and-pinion drive instead of belt drive.

Plain vanilla Marlin, which comes pre-installed on the board, will allow you to control motors for X and Y - and Z if you want. Microscopes don't need complex, high speed motion, so Marlin is up to the task. Or, as has been mentioned, there are other less expensive choices such as Arduino or RAMBO or Smoothieboard (the latter may be overkill, but I guess it's easier to program). Part of the cost of the Printrboard is in the controllers for a Hot End and Heated Bed, which you don't need.

Your other challenge will be to create software on your computer (or Raspberry Pi or Arduino, etc) that will take button or joystick inputs and translate that into G-code for your microscope. I've used microscopes, and I know that you don't want to take your eyes away from the 'scope to look at a screen, position a mouse cursor, and click for the desired motion.

[Kamil]

Finally, I have managed to run it on Friday. I did not have enough time to replay.

Yes, I want to do CoreXY. I wanted to use as many spare parts as possible from my old Printrbot Simple. I have just bought longer belt and few pulling. I had some aluminium plates left and Bosch profiles 20x20mm from my last project. Actually, I designed it to work with our one equipment that we have in the lab. It is a closed in-vitro chamber for the blood flows. As it is closed system and the microscope is inside the box, closed as sterile way as possible therefore while the experiments is running nobody can opened the box because it can contaminate the cells that are inside. Therefore I thought that I can use old Printrbot Simple to make moving table. As I am limited in space CoreXY gives me (I think) the optimum space to work with. I want to move my microscope in XY directions as well Z plus I want to turn the focus knob using a motor (I want to used the one from the extruder). I have just finished on Friday the plate and implemented (compiled) the software from Gihub (I used Arduino software for compiling). So far it is working as I wanted. I will need to check Z direction movement (not fixed yet the motor) and the microscope knob (not done yet). I decreased the acceleration of the motor and it is smoothly moving At this moment I am using only Repertier -Host but maybe after I will try to write something easy on my own (Easy and understandable for biologists :p, I am sorry I should not). Ah, I have a camera on the microscope then everything is on my computer and screen I do not need to be next to the microscope.

One more question. Which thermistor has Printrbot simple? I need to off it in the program. I will have to find it. I will not use the extruder and it seems without extruder it does not work.

Thanks for help.

[RetireeJay]

Actually, you will not want to use a thermistor. Because if you did, you would need to heat it up to approx 200C in order to enable the Extruder motor to work. In your case, it will be much better (and cheaper) to use a simple standard resistor that simulates a thermistor at around 200C. Choose either 470 ohms or 390 ohms (you can't just short-circuit the pins because that will look like an over-temperature fault; open circuit looks like an under-temperature fault).

Or, it might be even easier to disable the thermal protection feature in the firmware. Taking a quick look at Configuration.h, I see a line like this:

Code: Select all

#define THERMAL_PROTECTION_HOTENDS // Enable thermal protection for all extruders
#define THERMAL_PROTECTION_BED     // Enable thermal protection for the heated bed

If you just comment these lines out, you may be able to run without a thermistor. Or there may be other lines that you also need to track down; I'm not certain.

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//#define THERMAL_PROTECTION_HOTENDS // Enable thermal protection for all extruders
//#define THERMAL_PROTECTION_BED     // Enable thermal protection for the heated bed

[Kamil]

Thanks, it was what I was looking for. I will get it try.

[Kamil]

By the way, somebody tried to control Printrboard through Labview? Any hits?

[RetireeJay]

I've never seen it mentioned in this forum (since January 2013). But if you Google "LabView G code" you will get quite a few hits. Good luck!

[Kamil]

Actually, I needed to change in Configuration.h, just change the TEMP_SENSOR_0 from 1 to 0.

I have manage to control Printrboard through Labview via VISA. It is pretty simple you need just sent G code and it works like a charm. LIke G1 Y10 F4800.

Thanks again for help.

[RetireeJay]

Hmm... looking in more detail at the temperature sensor possibilities in Marlin 1.1, I found this:

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*         Use these for Testing or Development purposes. NEVER for production machine.
 *   998 : Dummy Table that ALWAYS reads 25°C or the temperature defined below.
 *   999 : Dummy Table that ALWAYS reads 100°C or the temperature defined below.

So if you're building a machine that doesn't have a hot end (CNC, laser cutter, microscope stage, etc) one alternative is to say there's no sensor at all by using sensor type no. 0 (as Kamil discovered); another alternative is to use a dummy sensor type no. 999 in software and set it to a high enough temperature to enable motion including extruder control, i.e. greater than 170. Actually, using type 0 sounds simpler. Good job, Kamil!