Adhesion Problems?

A forum dedicated to the stock LulzBot TAZ 3D Printer
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ansonwing
Posts: 41
Joined: Mon Mar 30, 2015 10:17 am

Adhesion Problems?

Post by ansonwing » Wed Apr 01, 2015 5:55 pm

Hello,

I'm trying to print a large piece that stretches from side to side. It laid down the first layer no problem, but when going on to the second layer was getting poor layer adhesion and lifting up. Glad I caught this on the second layer as this is a 30 hour print job! When I used my IR thermometer it shows that on the edge of the bed, the temperature is roughly 75C where I have it set at 95C. As I get closer in, it gets to that 95C so it appears that the edge of the print bed is not getting hot enough. I'm assuming that this is the problem of my problem? The picture shows that after a bit, it gets hot enough that it can stick well.

Any ideas of how to fix this??

Thanks everyone in advance!
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IMG_3868.JPG

kcchen_00
Posts: 1721
Joined: Thu Feb 19, 2015 12:42 am

Re: Adhesion Problems?

Post by kcchen_00 » Wed Apr 01, 2015 7:57 pm

Wow... That's a big first few layers. Is that ABS? I'll give you mu !ethod of tackling it... YMMV :)

Try bumping up the bed a few degrees... For ABS I like 110C or 105C. Don't let the bed temp drop below 100C until the 5 or 10 layers. For a print that big, I'd wait until 3-5mm (if layer height is .2, then 60 layers). During the first layers don't use the fan, let the ABS cool and firm up on its own.

At 3mm if no warping, it should be ridged enough to resist warping from the contraction of upper layers. Start the fan at 30% and lower the filament extrusion temp by a few degrees... At this point in the project you want to help cool the new layers to minimize the shrinkage as the ABS cools. At this point in the print you have to be carefuk about delamination from too low an extrusion temp or low flow rate of filament. Ambient temperature temps play a part here also and an enclosure would help greatly.

If you can maaake the print smaller, use a brim. The brim helps "seal" the project edge from drafts... If air gets under the leading edge of the print, you'll get warping.

Lastly, try fine tuning the initial nozzle height. Use the z-offset in the slicing software to lower the nozzle by -.05 to -.1mm. You'll never achieve this through the end stop knob... use the software offset to your advantage.

Good luck and report back with the finished product! :)

ansonwing
Posts: 41
Joined: Mon Mar 30, 2015 10:17 am

Re: Adhesion Problems?

Post by ansonwing » Wed Apr 01, 2015 9:08 pm

Kicking the bed up to 110 has proven to work better! It's been lifting a bit on layer 2, but it seems theres a chance of smoothing it over. I'll try your methods as I go and let you know how it works out! I am making a 3d topographical map and unfortunately can't make it smaller so that's out. Is this a defect on the printer or is this just something I have to deal with?

kcchen_00
Posts: 1721
Joined: Thu Feb 19, 2015 12:42 am

Re: Adhesion Problems?

Post by kcchen_00 » Thu Apr 02, 2015 1:24 pm

Something you'll have to deal with and manage.

If you need prints that large, look into building an enclosure to keep the ambient temps high.

ansonwing
Posts: 41
Joined: Mon Mar 30, 2015 10:17 am

Re: Adhesion Problems?

Post by ansonwing » Tue Apr 07, 2015 8:29 am

That was great advice, the print turned out beautifully! Still got a bit of lift in the first couple layers, but it was enough that it sorted itself out. I'm definitely looking into an enclosure at this point, as I got a little bit of lift mid print, and I'm sure the enclosure would help with that. Thank you very much for the advice! This is a 3d printed topo map of a specific region of northern Alaska, around Prudhoe Bay. Print took 39 hours! Love my Taz 5 :)
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kcchen_00
Posts: 1721
Joined: Thu Feb 19, 2015 12:42 am

Re: Adhesion Problems?

Post by kcchen_00 » Tue Apr 07, 2015 2:25 pm

That looks great!

ansonwing
Posts: 41
Joined: Mon Mar 30, 2015 10:17 am

Re: Adhesion Problems?

Post by ansonwing » Tue Apr 07, 2015 2:33 pm

thanks! Do you know the reasoning behind the temp drop around the outside border of the print bed and if there's anything I can do about it besides the enclosure?

wantmys2000
Posts: 83
Joined: Fri Mar 06, 2015 11:01 am

Re: Adhesion Problems?

Post by wantmys2000 » Thu Apr 09, 2015 7:17 pm

That looks amazing!

One thing you might try is a full height skirt. I see in one of your pictures that you are already printing a single layer skirt, make it the full height of the print. This will essentially create a printed enclosure around your print and help it maintain some heat during the print from the bed. If the skirt is not stable enough, try making it a few loops wide. Might be the extra few degrees you need to keep the remaining warp out.

Thanks!
Steven

ansonwing
Posts: 41
Joined: Mon Mar 30, 2015 10:17 am

Re: Adhesion Problems?

Post by ansonwing » Thu Apr 09, 2015 7:39 pm

thank you for the compliment! That suggestion seems like a genius idea! I've been toying for a while of building my own enclosure. I'll still consider it, but it seems that a full height skirt is a great option otherwise! Thanks!

kcchen_00
Posts: 1721
Joined: Thu Feb 19, 2015 12:42 am

Re: Adhesion Problems?

Post by kcchen_00 » Thu Apr 09, 2015 8:13 pm

Yep. Enclosure probably the way to keep the entire bed consistent. The bed edge is just less dense with heating wires than the middle.

With other printers, people use an insulator under the bed to help temps. My other printer has a fairly challenged 12V heat bed. I stuck a mylar/bubble wrap called Reflectix under the bed as insulation. Now it gets to 105C whereas it was having issues getting to 90C prior to the insulation.

For the TAZ, insulating the bottom of the bed could help counteract some of the heat dissapation. Just the outer 2-3 inches would probably help.

Just finish off the enclosure, it'll save you headaches with delamination too.

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