Cannot remove ABS from plate, used Advanced 3D sheet

[twiereng 1]

OK, newbie here, using my new Ultimaker 2+. I printed a few small things successfully using PLA and the default settings in Cura 2.7.0 for PLA. Didn't change anything in Cura, just went with .4 nozzle and PLA.

Next made a big jump to ABS, a 5.5 x 5.5 inch box with .25 inch walls and 4.25 inches high. Read all about adhesion and I have the advanced 3D printing kit so put down a sheet of their plastic for better adhesion.

I did not enclose the printer with a cardboard box, or custom unit, but will do this next time.

Well now that I look at Cura I note that nozzle for ABS default is .8mm and I used the .4mm - yikes. Things looked good for the first 5-6 days except some of the support was knocked out of place by the nozzle. In two cases where I had a .5 inch hole in a wall the support was completely knocked out after being built up nearly .5 inch. Last night I noticed that some layers were separating and this morning after 8 days the separation was so bad that the nozzle was hitting previous layers because of warp.

So I did an abort, let things cool down and then tried to get the print off the glass plate. Good luck. You can barely get the edges of the plastic sheet off the glass and then it leaves behind the adhesive. As for getting the ABS off this sheet I tried everything including putting it in the freezer and finally hitting it with a hammer several times. No luck. What should I try next, hacksaw maybe?

Those sheets are something else, can't believe how stuck down the print is.

Ok, so my questions are:

1. What settings, nozzle, should I use for default ABS? I purchased my from Dynamism.

2. Why is the support structure being knocked out of place?

3. What should I put on the plate for adhesion, I'll never use those sheets again. I selected Support and Build Plate adhesion.

4. How do I get this large piece of ABS off the sheet?

Thanks, Theron Wierenga

[gr5 2,270]

I've never used the sheets. Can't help you there.

Can you show a photo? I don't understand the question about support structure being knocked out of place.

If you print ABS on glass I recommend a layer of pva glue - for example hair spray, wood glue mixed with 10 parts water, or glue stick cleaned up with a wet tissue leaving an almost invisible layer behind.

Glass in the freezer works well because glass doesn't expand much when heated compared to ABS or PLA (why are you using ABS by the way? Maybe PLA will fit your requirements? PLA is pretty amazing stuff and much easier than PLA). These sheets probably *do* expand/contract with temperature so putting them in the freezer probably makes no difference.

[twiereng 1]

Here's my image (hope I uploaded it correctly). The pieces at the bottom are support for the large holes and I found them laying outside the model one morning as it was printing.

[tomnagel 126]

Here is a tip of how to remove an adhesion sheet from your buildplate. Don't know if that also works when your object is still attached.

This ABS guide says: "Please note that it may be easier to remove the 3D prints from the build plate if it is still slightly warm at approximately 40ºC."

Last but not least: do you really need ABS? What material properties do you find important?

[gr5 2,270]

I suspect this print would come out okay without *any* support. Especially the back in the picture as you can bridge pretty long distances as long as they are supported on both ends.

Secondly, why in heavens do you need ABS - one of the most difficult materials to print.

The most serious issue looks like that big crack. Is it supposed to be there - if it is, sorry, I'm just guessing. That crack is caused due to poor layer adhesion. It's telling me your entire part is going to be very weak. It may feel strong until you actually *try* to break it and you will be surprised how easily it breaks along the "grain". However there should be no grain. It should be equally strong in all directions.

The fix is not simple. But it may seem simple: less fan, enclose chamber, more heat.

The fan is the easiest part since you have a UM2 - I recommend around 30% - just the minimum to get the fan spinning.

Enclosing is the next harder issue - you want to put a box over the top that can let air and bowden out at the rear and cover the front with clear plastic wrap or clear plastic bag. You want the air temp inside to reach 35C. Bed should be at 110C.

Finally you need the right temp. Too cold and you get bad layer adhesion. Too hot and you get gummy clogs. The ideal temperature is very small range - maybe 5C. Unlike PLA which prints great from 180C to 240C. I recommend around 240C for ABS. Maybe 245C. If you get clogs drop the temp by 3 to 5C. Or print faster. Don't let the filament sit around for a few minutes at temps > 220C as it will likely form a gummy clog.

But there are better materials than ABS that can give you high temp resistance or strength. What property were you looking for that pushed you to try ABS?

[twiereng 1]

Why ABS, for strength. This is an underwater housing and needs to go down to 50 feet. The support is needed for the window in the front, otherwise I'd skip- it.

 

I felt that my main problem was that I needed an enclosure. So I built one and Nuts & Volts magazine will publish my results. 

 

Second try was started Jan. 18, 2018 at 3 p.m. Print continued OK, although lots of support garbage hanging all over. Ultimaker was in enclosure, with temperature at the top at 59C.I read somewhere not to go over 140F. which is 60C. After nearly five full days of printing and no major problems the !@#$%^ thing just stops in the middle of a line. Display shows home menu. I'd like to see an example of someone who can print something this large (5.5 in x 5.5 in x 4.25 in tall) in ABS. My settings were Ultimaker ABS Yellow default in Cura 3.1. Photos attached. I am one unhappy person with my Ultimaker 2+. I can print ABS that's only a half inch high, but that's not what I bought it for. 

[fbrc8-erin 302]

If you came back and found the printer on the home screen and the printer on the home screen, and the bed and head not homed, that usually means you lost power. Even losing power for a couple of seconds will shut down the printer and when it powers back on, it will have no idea it was in the middle of a print. I would recommend a battery back up. I use it for long prints running unattended overnight in case we get strong winds and have a momentary power lapse.

[twiereng 1]

OK, I was home and did not notice an outage, but I guess that's the best answer. 

 

Next question. This box has a window in it that needs support. Everywhere else it should be OK without support. Is there a way to place support in just one area?

 

Thanks, Theron

[geert_2 558]

17 hours ago, twiereng said:

...

Next question. This box has a window in it that needs support. Everywhere else it should be OK without support. Is there a way to place support in just one area?

...

You could design the supports manually, as part of the design process, and disable the automatic generation in the slicer. I often do this, due to the specific requirements of my models. Then you can design-in all sorts of methods to make removal easier, for example extensions so you can use pliers, or holes so you can insert hooks to pull. Or you can add ribs to reduce space and improve quality, etc. See the examples below (these are all very small models, order of magnitude 10mm high). Try this on a couple of small samples first, untill you have it perfect, before wasting a 5 day print.

 

[twiereng 1]

Geert - are you from the Netherlands" All four of my grandparents were born there. This is a great idea and why didn't I think of it. Thank you so much.

 

Theron Wierenga

theron@wierengaconsulting.com

 

[kmanstudios 1,120]

You can also check out the new support features in 3.2 beta. They are pretty sweet.

[geert_2 558]

On 1/25/2018 at 3:11 PM, twiereng said:

Geert - are you from the Netherlands" All four of my grandparents were born there. This is a great idea and why didn't I think of it. Thank you so much.

 

Theron Wierenga

theron@wierengaconsulting.com

 

I am from Belgium, Flanders, but we also speak Dutch here.