Help Required: Corner lift

[Kingoddball]

Hello!
I require some help.
It could we hardware or settings problem.

Previous printer and current - I always (!!) get a corner lifting.
No idea what causes it, I have tried different temps on the glass and nozzle.

I don't have a pic right now, but its generally a corner that lifts, sometimes it just curves up, other times it just a dead lift and sits up no matter what.

Printing onto a mirror with a later of Kapton tape on it.

Head bed - 60 to 70 dregrees.
Generally first layer is 70 and other layers around 60 or 65.

Extruder is at around 185.

[jimc]

king what type of plastic are you printing? by your temps i would guess pla. the curling is the natural force of nature when the plastic cools. each layer goes down hot, bonds to the layer under then it cools and shrinks which pulls the cooled layers. now multiply this force for "x" # of layers and your part curls. it the whole reason stratasys has heated build chambers. some plastics do it more than others. pla is easier than abs. abs is easier than nylon. madesolid pet+ is the easiest of all. modeling mouse ears/discs on the corners of your print to hold it down helps alot. if your using pla try ditching the kapton and spray a couple good heavy wet coats of hairspray on your mirror then print on that.

[Davo]

We sometimes add a disc of one layer height to each corner when we don't want a raft, but the build is large enough to worry about lift. It is easy to trim off with a knife and touch with a file to smooth the edge afterward.

[Kingoddball]

Thanks!!
Yes, PLA.
I will try build a little box around it.
I had this thought sometime last year but never got around to it, I have a large tub I could fit the printer inside of!

@Dave: This disk - How do you do this, is this a slic3r setting or modifying the 3D file? If this can be done in Slic3r - Can you make it more than one layer? Maybe 5 layers or something?

[Davo]

Kingoddball,

We open a cad program, define a circle, extrude it to one layer thickness, then save the .stl.

Then we bring it into slic3r with the object to print, and place one at each corner, then slice the entire group as one object (part of the discs overlap with the main object, no problems). We have discussed automating the process, since we already detect corners to define the skirt.

With just one layer thickness, it is very easy to trim off. Five layers high might be tougher to remove without blemishing the main work.

I've convinced the guys here to call them "Davopads" even after their initial drive for less cool nomenclature.

You can see a version in the "Four Parts" video in my signature, but this is one large pad versus four smaller ones.

[Kingoddball]

AH!!
THAT'S AN AWESOME IDEA! (Yep - Caps level of excitement!)

We need thanks buttons here!

I'm happy calling them Davopads

[jimc]

i do this all the time. i have however not found them very helpful when done real thin. well anything helps but when the corners curl, if the discs arent stiff they seem to just lift right up. i guess it depends on the model though and how strong you need them. i keep them modeled and in a folder as davo said then just drop them on the build table. drag them where you want them and your good to go. usually mine vary from 5-7 layers. not sure with pla as i never print it but in abs they just pop right off no problem and you cant even see where they were.

[Kingoddball]

When I get the chance I will watch the Videos - Work blocks all the good websites!

[Davo]

jimc, maybe your pads aren't large enough. We usually use about one inch diameter pads, or else one large one to cover all corners of a smaller build.

[Kingoddball]

@Davo: Are you able to throw up a photo of one?
I cannot view vids at work. If you can throw up a pic I would be grateful. Just so I can see how it looks/works.