Print head hits bed in some prints

[dmollerg]

Don't know if this is the appropriate forum, but I am having an issue with a particular print on the Rostock Max. The machine appears to be calibrated correctly, and I have made several prints that turned out well, but when I load a particular .stl (zheng3_penny_catapult) the printer will invariably, at some point in the first layer, try to travel through the surface of the bed to complete a lateral move. The first time I tried to print, this was prefaced by the head moving in a vertical arc, lifting well away from the print bed, then running back in an arc down and hitting the bed. The second time, after a couple of intervening successful prints (of different models), loading this same model caused it to try to run down into the board as it was drawing a lateral line, hard enough that the Onyx bed and the glass I have on it flexed alarmingly. What I am wondering is if I missed some setup step in Repetier that tells it z=0 is a hard limit, or else if Slic3r is doing something strange with that particular print? Has anyone else run into something like this?

[Eaglezsoar]

If it happens only with the one file, I would suspect something is wrong within that file.
If you are familiar with a program called netfabb, I would get a copy and look at the suspect .STL file with netfabb and see if there are errors within the file.
Netfabb has the ability to repair most errors that it finds. I run each .STL through Netfabb before trying to print it. There is also a Netfabb on the internet at
http://cloud.netfabb.com/

After the file is repaired, you reslice the file and print it.
The file probably contains errors that can be fixed, if not leave us another message and we will try something else. Happy Printing!

[bplemmons]

I'm having a very similar issue myself, net fab shown no errors and the part prints fine at half scale but when I print it full size the head will crash the bed after the first couple of layers...


my log shows several errors that reads invalid delta coordinate move ignored....

Baffled


Here are some pictures...

Bill

[Eaglezsoar]

See this discussion between a user with that problem and repetier:

http://forums.reprap.org/read.php?267,271999,271999

[Polygonhell]

I would listen very carefully for missed steps, the carriages have to move much faster when at the edges of the bed and if the velocity or acceleration are too high in the firmware, you could miss steps.
Or you can try very conservative velocity and accelleration setting and see if it still happens.
If you miss steps, on one tower, the net result is that it tilts the printing plain which could result in a head crash.

[bplemmons]

Turns out that my bed size settings were set over what the firmware could handle even though the part would fit on the plate, Your link the the thread help me figure that out, Thanks
Eaglezsore!!

Bill

[Eaglezsoar]

Turns out that my bed size settings were set over what the firmware could handle even though the part would fit on the plate, Your link the the thread help me figure that out, Thanks
Eaglezsore!!

Bill

You're welcome Bill, best to you and Merry Christmas!