Polycarb adhesion

[RC-modeler 3]

Hello,

The part above is my first more or less successful print with polycarbonate.  This is part of a Yeti mug cap for a friend.  While the part is useable, it just barely made it.

This is printed from Gizmo Dork PC, on my UM2+.  On the first couple of attempts I tried using glue stick on the glass with no success; I would normally abort the print after 15 seconds.  I then went to ABS juice, which seems to hold onto the PC pretty good. The first attempt with juice did not have a brim and about half way through it was warping so bad that I again aborted the print.  On the print shown here I added a brim.  The part is 2mm thick, so 10 layers, and during the 9th layer I felt pretty confident that this was going to turn out great, it appeared to be held down perfectly.  But during the 10th (last) layer I could see that the edge was starting to lift and taking the inner half of the brim with it.  As the print finished the outer edge of the brim was still attached to the glass.  A few minutes later as the machine cooled down the part warped enough to lift the brim up all the way around.

The failure occurs in the bond between the ABS juice and the glass, as the PC and ABS appear to be fused together nicely.  So are there any good tricks to get the ABS juice to stick to the glass better?  I have thought of trying Kapton tape on the glass, but from what I have read it sounds like the tape will be lifted off the glass.  Does anyone know if the commercial products like Wolfbite hold to the glass better?

Print settings – 260 deg C extruder, 110 deg C bed, 0.4 mm nozzle, 0.2 mm layers, 30 mm/sec speed.

Edited October 17, 2017 by Guest

[tinkergnome 927]

Have you tried the adhesive sheets? They are claimed to work well with PC. A front enclosure doesn't hurt either.

Edited October 11, 2017 by Guest

[MechDesigner 3]

I have pretty good luck with ABS and PC on painters tape as long as I wipe and dab dry the top of the tape with isophrol alcohol, I add glue stick to the tape, kind of thick and lightly spread with a paper towel. I start the speed at about 90% and after the brim is done I go back to 100%speed. After the brim is done I tape the edges of the brim

down with painter tape.

Also have to have the front enclosure as mentioned,

[tinkergnome 927]

After the brim is done I tape the edges of the brim

down with painter tape.

This approach never worked for me. It always lifts the brim together with the tape from the glass plate (even with very large pieces of tape). I assume the success rate depends on the geometry of the part. Or is there a special trick?

[MechDesigner 3]

After the brim is done I tape the edges of the brim

down with painter tape.

This approach never worked for me. It always lifts the brim together with the tape from the glass plate (even with very large pieces of tape). I assume the success rate depends on the geometry of the part. Or is there a special trick?

Yes painters tape, mine usually pulls up on the back right of the part and I tape

the three sides, smaller parts are pretty easy (2-3inches), larger parts are challenge,

using a larger print tip is really the only tip for larger parts so they print as fast as possible.

Yea, before I used painter tape on the glass it pulled the tape up. Maybe taping the brim on the tape that's on the glass is stronger. I have had larger parts that the brim was taped down and the tape and brim was stuck but the part pulled away from the brim as it warped. The tape I put on the glass is about an inch larger than the part.

[eldrick 65]

Is there a typo in your first post? From the GD web site: "Printing temperature : 255°C - 300°C depending on part and printer type".

I've used PC-Max and eSun PC, and printing in the 240-250C range works well on glue stick for me. Both of these brands suggest print temps in the 230-260C range. It does seem to take 2-3 layers of the glue stick, to get enough surface roughness for adhesion, but I haven't had a part come loose yet.

Glue stick needs to be applied on a cool bed. If you put it on at high temps, you get a shiny surface and poor adhesion. Applied at room temp and allowed to dry, I get 10-12 prints on the same spot before needing to refresh it.

Initial layer height seems to be critical. I see first-layer traces come loose if the height isn't exact - like within 1/8 turn on the adjustment screw (or one more layer of glue stick).

Edited October 14, 2017 by Guest

[RC-modeler 3]

Is there a typo in your first post? From the GD web site: "Printing temperature : 255°C - 300°C depending on part and printer type".

I've used PC-Max and eSun PC, and printing in the 240-250C range works well on glue stick for me. Both of these brands suggest print temps in the 230-260C range. It does seem to take 2-3 layers of the glue stick, to get enough surface roughness for adhesion, but I haven't had a part come loose yet.

Glue stick needs to be applied on a cool bed. If you put it on at high temps, you get a shiny surface and poor adhesion. Applied at room temp and allowed to dry, I get 10-12 prints on the same spot before needing to refresh it.

Initial layer height seems to be critical. I see first-layer traces come loose if the height isn't exact - like within 1/8 turn on the adjustment screw (or one more layer of glue stick).

 

Yep a typo, I am running at 260 C, which is as high as my UM2+ can go.  Folks that are having success with GD PC seem to be running 270 - 300 C

I'll give glue stick another try and see if I can get the first layer to adhere. There were a couple of time I put it on while the bed was still warm, so that might have lead to some of the problems.

Edited October 17, 2017 by Guest