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Prusa i3 home and endstop problems

Posted by Smatta 
Prusa i3 home and endstop problems
August 01, 2014 08:20AM
Hi,

Prusa i3 with arduino mega 2560 board and ramps 1.4 - everything build and connected, ready to start. I uploaded the firmware, and installed Pronterface (I am using Marlin). Considering this is my first printer, I am lost.

Everything works 1. motor for extruder is turning the right way, X-axis is going right when I press +X, Y-axis is going towards me when I press +Y (not sure if that is ok), Z-axis goes up when I press +Z.
2. I plugged the endstops on ramps to be X max, Y max and Z min and when I press them and tipe the M119 command I get the confirmation that they are working properly

Problem 1. when I connect the machine and give the command to move (for example) to the right it moves, but if the first command is to move left, avay from me or up it doesn't move. Only when I move them (for example) + 10 right, then i can move it back to that point where I started. So I am not sure if that is normal or not.
2. I don't know how to configure the home position. I tried several times. Sometimes the extruder would hit the endstop but not registered it and only trying to destroy the endstop. After some configuration it now moves away from the endstops when I am trying to home it, no mather what is the position. I don't whant to destroy my work so far...

My endstops are: X-on the right side, Y-behind, Z- bottom

I am attaching you my configuration file and pronterface picture (endstop - M119), also the picture that shows the position of endstops on my printer.

Thank you! smiling smiley
Attachments:
open | download - prusa_i3.jpg (113.2 KB)
open | download - Pronterface.JPG (205.3 KB)
open | download - Configuration.h (19.9 KB)
Re: Prusa i3 home and endstop problems
August 01, 2014 10:56AM
Quote

1. motor for extruder is turning the right way, X-axis is going right when I press +X, Y-axis is going towards me when I press +Y (not sure if that is ok), Z-axis goes up when I press +Z.
sounds ok
Quote

2. I plugged the endstops on ramps to be X max, Y max and Z min and when I press them and tipe the M119 command I get the confirmation that they are working properly
I'd suggest you move your X-endstop to the left and connect it as min
Quote

Problem 1. when I connect the machine and give the command to move (for example) to the right it moves, but if the first command is to move left, avay from me or up it doesn't move. Only when I move them (for example) + 10 right, then i can move it back to that point where I started. So I am not sure if that is normal or not.
That's because it does not know what it's 0,0,0 position is w/o homing, so it assumes starting position as home, therefore it'll only go +
Quote

2. I don't know how to configure the home position. I tried several times. Sometimes the extruder would hit the endstop but not registered it and only trying to destroy the endstop. After some configuration it now moves away from the endstops when I am trying to home it, no mather what is the position. I don't whant to destroy my work so far...
My endstops are: X-on the right side, Y-behind, Z- bottom
Makes sense - connect X and Y as min, move X endstop to the left and you'll be fine. When you hit "home" on particular axis - it should start moving towards your min-endstop, so just put endstop on that side and connect it as min. Max endstops are probably not as critical, since you can define your max/size in firmware.

Hope that helps.


/Larry
(www.filamentshop.ie)
Re: Prusa i3 home and endstop problems
August 02, 2014 12:06PM
A friend and I recently finished an i3 build. I documented it here:
[www.instructables.com]
There is quite a lot of info on setting up the end stops in the Instructable.

For the endstops we put the X on the left side, the Y at the back and the Z at the bottom. We used MIN for all the stops in the Configuration.h
We also reversed the logic of the switches and make them normally open (NO) i.e. when the switch is hit it closes the contacts - so we used the "S" and - on the RAMPS
Check the Instructable - hope it helps

Steve
Re: Prusa i3 home and endstop problems
August 03, 2014 02:44PM
Thanks guys, I have been offline a couple of days, I will try something you suggested as soon as I can. smiling smiley
Re: Prusa i3 home and endstop problems
August 03, 2014 02:54PM
Also, I noticed that Replikeo have send me an extruder body for 1,75 mm filament and not for 3mm (what I ordered) - idler and coldend are all for 3mm, the filament i received is also 3mm. Can I just drill the 3mm hole? Of course I contacted Replikeo, but no answer. Even if they send me another part it would take ages to come to me - I'm from Croatia....
Re: Prusa i3 home and endstop problems
August 03, 2014 03:53PM
Here, I configured the firmware and hardware: Y endstop is now on the ramps min, X is max(i don't have an option to mount it on the left side, but when i start to print myself i will do it as soon as possible) and z is min, also in firmware. SteveRoy: the instruction helped me to understand better the whole concept of endstops in firmware. Now, everything homes perfectly. Thank you so much guys! smiling smiley

I forgot to mention, extruder type is wade's extruder...
Re: Prusa i3 home and endstop problems
August 03, 2014 05:00PM
I use 3mm wade with 1.75 filament. Got some issues at the beginning, but I've used ptfe tubing to make the "hole" size to match and now it works fine so I guess it will work the other way of you drill the hole given that perimeter width is sufficient so over >0.625mm. If it isn't, it might expose the infill.
Probably no need to say that, but before drilling make sure your hotend is 3mm winking smiley


/Larry
(www.filamentshop.ie)
Re: Prusa i3 home and endstop problems
August 03, 2014 07:35PM
As long as your X endtop is confirgured properly there is no reason to move it to min if it works at max. The design of the Rework has the X endstop at max as default. Enlarging the hole in the printed extruder body is not an issue and is the default in some Rework printed parts sets. I'd use a small file or a drill bit as a small file. Unless you have a drill press that is adjustable to a slow speed using power might crack the part
Re: Prusa i3 home and endstop problems
August 04, 2014 06:50AM
I drilled the hole. It extrudes just fine now. I tries to print the callibration model 0,5 thin wall, but the Z axis moved about 1 cm up and then started printing. I guess it's firmware again... I am looking into it now.
Re: Prusa i3 home and endstop problems
August 04, 2014 07:24AM
OK, figured it out, it's Slic3r. Start G-code is: G28 ; home all axes G1 Z5 F5000 ; lift nozzle

So it lifts nozzle but it doesn't lower it down... another line in G-code is the answer maybe?
Re: Prusa i3 home and endstop problems
August 06, 2014 12:49AM
The code that lowers the hot end when it starts to print is generated when you slice the object. You shouldn't need to add anything it should do it on its own. The machine will home, nozzle up then start the print at the point that is designated in the slice, usually around the center of the build platform. Since you seem to be getting familiar with G code save the code to disk and have a look at the file. It will open with a text editor. If it's not heading to the middle of the build platform to start printing it's missing something. Check to make sure the platform dimensions and center of the platform are correctly defined. IIRC in Slic3r it's in the printer settings options, right hand tab if you are using expert mode.

Cehck out the G code after the home to see if it's giving you movement to head to the print area, touch down and print.
Re: Prusa i3 home and endstop problems
December 16, 2014 11:07PM
OK, I need some help. I am all wired up and built, but I have am now strugling with the calibration process.

I have pronteface running, and am having all sorts of issues.Is there a guide on how to set this up? I thought that clicking home would automatically home the axis, but that doesn't work as they just try and push right through the end stops.

Any help would be greatly appreciated. Also, what direction are the + - for the axis suppose to go.

If I am looking from the front at the extruder fan the follow happens when I click the buttons:

- X+ button moves the x axis to my left.
- Y+ Moves backwards away from me
- Z + Moves the Z axis up.

My end stops are

- X on the left hand side (I moved it for testing)
- Y At the front nearest to me
- Z At the bottom just before hitting the plate.

THanks in advance.
Re: Prusa i3 home and endstop problems
December 17, 2014 05:12AM
To get an axis to stop the endstop should be wired to either Xmin or Xmax on your board. I think X+ is meant to move your X axis to the right. At least that is how I have mine setup. You will need to change this in your firmware.
Lets take your Y axis. Y+ moves it to the back, your end stop is at the front, so you need to wire the endstop to Ymin on your controller board. If your homing direction moves to Y+ you will need to alter your firmware.
Re: Prusa i3 home and endstop problems
December 25, 2014 04:28PM
i had the same problem and i fix it with information of parksie, and customize the firmware... and it works perfektly. smiling smiley
Re: Prusa i3 home and endstop problems
January 12, 2017 04:34AM
Quote
vegasloki
The code that lowers the hot end when it starts to print is generated when you slice the object. You shouldn't need to add anything it should do it on its own. The machine will home, nozzle up then start the print at the point that is designated in the slice, usually around the center of the build platform. Since you seem to be getting familiar with G code save the code to disk and have a look at the file. It will open with a text editor. If it's not heading to the middle of the build platform to start printing it's missing something. Check to make sure the platform dimensions and center of the platform are correctly defined. IIRC in Slic3r it's in the printer settings options, right hand tab if you are using expert mode.

Cehck out the G code after the home to see if it's giving you movement to head to the print area, touch down and print.



I am having the same problem. After homing Gcode reads z5, then after a few comands the first layer height is called out z0.300. However the Z height does not adjust to the first layer height instead it air prints following the other Gcode with no issue. If I edit the Gcode Zheight i can get a print to work but not very well.
I have just cleared the EEPROM and reflashed the firmware to correct settings. Any Ideas why this is happening?

Thanks
Re: Prusa i3 home and endstop problems
January 06, 2018 04:02AM
Hi all. I'm having this exact same issue with my Y axis homing to + and jamming against the opposite end to the endstop. I know that I need to change the value in the Marlin to - and from true to false on the homing code (from what I have read) but I haven't a clue on how to do it? I've tried downloading the marlin libary and arduino software but it doesn't open config tabs? With the homing in the wrong place the auto levelling doesn't recognise and with the sensor removed, prints are mirrored
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