Newbie looking for help 
I recently got a Printrbot Play and after several issues my Play is now built and I have had 1, 95% sucessful print of the 3mm Box (slightly raised corners)… However my Z axis motor is being a dick.
In Cura, I follow the guide and load the play.gettingstarted.ini, load the 3mm box and print with USB.
Once connected I Home X, Home Y, Tool up 30mm whcih raises the Z as expected…
Hit print and and auto level kicks in (probe was set with shim prior and the light works fine) but when it start to print the Z motor gradually lowers the extruder into the bed… i’ve triple checked my probe and it appears fine…
This is my first 3d printer and as I mentioned previous I had issues with this kit from a bent extruder cart (replaced) to a broken probe clamp (remade) and the extruder pulling filment out of the extruder instead of into it …
Since I have had a reasonable print from this printer already I have no idea how to tackle this now…
Any advice would be apprieciated.
Looks like your M212 Z setting to me. Don’t know how to do this in Cura, but in Repetier, check that setting value
Thanks Andre,
I did try raising the Z setting in the + direction but eventually the extruder nozzle hits the bed…
Yeah takes a lot of fiddling around.
I think, not sure, but latest @Printrbot have the Z reversed no ? - is up and + is down no ?
Oh and @David_Selwood add @Printrbot to your posts, they are watching so is @Brook_Drumm 
Thanks for the heads up +Andre Courchesne, with +Printrbot having the Z reversed would make sense… but when I use Cura to move the extruder up… it moves up. I guess that to move +Z manually in the sotware that the actual print process would act the same… or is there something I am missing?
maybe need help in using G+ too! 
I think I may have identified the issue. The hot-end was being pushed down slightly by the filment giving the impression that the Z access was inverted. It was down in the clamp by at least 2mm. I did not tighten the extruder clamp enough… I was wary as the horror of a stripped motor thread was not inviting! I am now in the process of re-tramming and going through the M212 adjustments again. I will have t keep an eye on it.
Thanks again.
@David_Selwood
so it was a kit where re-tramming is natural to have a correct adjustments …
you better just buy motors, noozle, µ/cpu and design everything else yourself next time
@christophe_malvasio
I had been through the tramming process so many times… It goes to show how much learning there is with 3D printers. I am so happy that I was able to find the issue… now its getting the darn PLA to stick!
@David_Selwood
learning is very good
@christophe_malvasio
Absolutely, it can be very disheartening but also very rewarding… at present am very happy with my @Printrbot
Quick update, I have been away from my @Printrbot Play for a few days but things are still going well. Smaller prints are comming out good with a lower print speed(35) and a slightly higher starting temp (213) not had much chance for larger prints. As for sticking the PLA… masking/painters tape and a coat of hairspray… by the time extruder is up to temp it gives a good tack and you can run 10 to 15 prints with just a light coat between prints.