Initial ROstock Max Calibration proc

[altarke]

I am a bit unclear about the initial calibration procedure in the Rostock Manual; I must be missing the point becaus it seems to me that all I am doing is moving the head from the glass to the to - I don't understand what I need to achieve. How is the adjustment screw on top helps me adjust the head? Is there a You tube video about this that explains the procedure and logic clearly?

Thanks
Ken

[ApacheXMD]

Basically, you are simply defining the distance from the end switches to the "bottom". You define the distance in firmware, and fine tune the screw so the real life distance matches.

When you build the machine, nothing will be perfect, so the adjustable screw is there to fine tune the tower "max lengths".

[Jimustanguitar]

CNC machines like this can move very precisely, but their movements are all relative to where they're starting from. They don't have any way to measure and positively know where they are at, they just take orders and keep moving. In other words, it's like giving directions to someone who doesn't know where they are. You can't say, go from this address to that one, you have to say go 10 blocks this way and then turn left.

Anyway, that's a long drawn out (and probably poorly explained) way to say that these machines base every movement that they make off of where they park. Where the "home" position is. That's why the endstop screws and bed leveling is so important. Because the CNC machine is moving based on where the home position is, not where the bed is at. It has no way of knowing where the bed is. All it knows is where it started from and what directions it's been given.


The initial calibration is to teach the machine where the bed is at so that it can actually print on it. That's why it's important.

[altarke]

I would like to thanks you guys for your quick reply ( and mostly for your clear explanation of the logic of the initial calibration.
I was wondering about few things:

1. is it possible to have the settings of some other Rostock MAX printer as a starting point so one can start printing someting (good or bad but at ;east it's much esier to troubleshoot form a calibration box).
2. Using the LCD display, can I calibrate the printer - it's like telling the printer - while using the LCD control where the 0.0 point is of all axes are. and while on the topic, 0,0,0 is center is the lowest point on the hotbed, or the highest center point above the hotbed?
3. ... So the procedure is to "send the head to the extreme positions of XYZ and visually confirming it's actually there, by using the reptier directional arrows ?
4. Is there any explanation, anywhere about the EEPROM settings that show up in the Reptiere "config ->EEPROM Configuration" Is the calibration process is to ultimately set those settings right to the printer - or just to match the printer to the settings...?
5. Where can I find info about the somewhat cryptic LCD Display messages ?
6. Sorry for all these questions - I am just a guy who loves to model all kinds of objects (mostly WWII airplanes )on the PC and wishes to print out the models - I have no idea about programming EEPROMS or stepper Motors and hotheads.

THANKS

Altarke

[ApacheXMD]

1. is it possible to have the settings of some other Rostock MAX printer as a starting point so one can start printing someting (good or bad but at ;east it's much esier to troubleshoot form a calibration box).

You have to calibrate your printer before printing. Copying another printer's settings is just asking for trouble and will likely break something. Any number of things can be different with your setup; motors could be reverse, pulleys could be different sizes, endstop screws will be in different positions, etc.

2. Using the LCD display, can I calibrate the printer - it's like telling the printer - while using the LCD control where the 0.0 point is of all axes are. and while on the topic, 0,0,0 is center is the lowest point on the hotbed, or the highest center point above the hotbed?

Calibration is pretty well covered in the manual. You can't do it from the LCD exclusively. 0,0,0 is lowest point, center of bed.

3. ... So the procedure is to "send the head to the extreme positions of XYZ and visually confirming it's actually there, by using the reptier directional arrows ?

No not really.

You are simply telling the Rostock that the three tower's endstops are (for example) set to 350mm above the bed. So after it homes to the top (hits the endstops), it knows that if all three carriages move down 350mm, it will be at the center of the bed. Your job is to make that number (350mm) match real life. So you either change the number, or you change "real life" by adjusting the endstop screw. Does that make sense?

Once you get that done, the printer knows how to move to all positions on the bed because the physical geometry is predefined in RepetierMax firmware.

That is just a general explanation. There's more to calibration than simply the endstops, but I'll defer to the build manual for that.

4. Is there any explanation, anywhere about the EEPROM settings that show up in the Reptiere "config ->EEPROM Configuration" Is the calibration process is to ultimately set those settings right to the printer - or just to match the printer to the settings...?

The eeprom setting that you see in RepetierHost can be used to calibrate the printer. There are many settings that can be ignored until you get up and running. The x,y,z max lengths are important here and will require your attention.

5. Where can I find info about the somewhat cryptic LCD Display messages ?

That is a good question and I haven't seen good documentation of the LCD output/operation

6. Sorry for all these questions - I am just a guy who loves to model all kinds of objects (mostly WWII airplanes )on the PC and wishes to print out the models - I have no idea about programming EEPROMS or stepper Motors and hotheads.

When you get up and running, upload some of your models to thingiverse. There's a few spitfires and p51's on there, but no f4u corsair.

[altarke]

Thanks for your reply -

This helps me alot _ I noticed the net, 2nd edition of the instructions set for building the MAX is out. I did noticed a few steps in there were corrected . I did have some issues with the first edition - there were some discrepancies that were very confusing - among them the calibration instructions. So off we go give it all a 2nd shot!!

Thanks
Aktarke