Hot end rubbing over print

Hi iv just started printing. Well just set up my printer. I have the pursa i3. I have yet to complete a print. When I start printing the print gets to 3 or 4 mm and then the hot end starts to run over the print as in make contact with the print and then keep printing but not get any higher. After that happens I cancel the print so I don't mess up my printer. Does anyone have advice for me or know of any settings I can change. Please note I am very new to this awesome hobby. Thanks

Start by checking the calibration of the mechanics.

Mtheuma
Its exciting to have it doing stuff...

Quote

keeps printing but not get any higher.

What you are describing sounds like the z axis steppers are loosing steps.
Watch closely when there is a layer change to see if they are moving.

Make sure the z movement is smooth, not hanging up.

It could be that the stepper current is too high (causing the stepper driver(s) to overheat and do a short reset) - turn them down and/or add a cooling fan/heat syncs. Symptoms could be: motor(s) get hot (won't hurt them unless very hot tho), or driver chips burning hot (careful). Be careful not to disconnect any wires or short anything, and adjust carefully with a ceramic screwdriver. There are many, many threads here on adjusting stepper current.

Or the current could be too low - causing too little torque.

Or... it is actually moving up but you are over extruding?

---

My printer: Raptosaur - Large Format Delta - [www.paulwanamaker.wordpress.com]
Can you answer questions about Calibration, Printing issues, Mechanics? Write it up and improve the Wiki!

Are you printing from a PC console UI application such as Pronterface, or from SD Card and a graphics controller?

Either way, you should be able to manually drive the printer on all of its axes - what happens if you manually nudge the Z height from 0 to 1 mm to 5 mm, 10 mm and so on? Check that the machine is actually able to move over its full design range, with no mechanical interference etc.

If it won't go past Z = 4 mm or so, you might need to edit the firmware to set the appropriate build volume, check the end stops, etc.

---

Follow my Mendel Prusa build here: [julianh72.blogspot.com]

I'm printing from a SD card. I can manually move it over all axis but it just won't print past about 3 or 4mm on the z axiz. Il follow that link thanks

CALIBRATE YOUR EXTRUDER!!! There are many YouTube videos showing you how to do this. It MUST be your first step before ever printing anything!