HIPS, bed detachment with tall print

On Thingiverse there is a saber tooth kitten skull. http://www.thingiverse.com/thing:472463/#instructions
When I print the sabers (separate piece); it gets to the last 20% of the tooth, the print comes off the bed.
Note that these are narrow and tall and slowly overhang. 15mm diameter base, 50mm height,

I am using HIPS natural for this specific piece; with my Taz 4 printer.
I am using the sli3r config provided by lulzbot. I tried the following with mixed results.

  1. ABS slurry (it was on it), no other changes to config (80 for bed as this is what the abs setting used). This gave me 50% before it failed.
  2. ABS slurry (it was still on it), modified the bed temp to the correct 60. This gave me 60% before it failed.
  3. ABS slurry (still on it), 60 bed, brim of 8. This gave me 80% before it failed. (the best result).
  4. Cleaned off slurry, put on glue stick on warm bed, 60 bed, brim of 24. This gave me 50% before failure (equal to worst).
  5. Cleaned off glue, another glue on cold bed, Skirt of 0, brim of 24. This failed near 10% as the 0 skirt caused a disconnect between brim. Repeated with skirt set to 26, failed near 10% again. The glue was acting like a lubricant.
  6. Back to ABS slurry, 55 bed, brim of 12, Skirt 16, AND included Lift of 1 (see below). This gave me 80% before failure.

What I was seeing was that as the head moved between the two “sabers” it would push it down slightly, due to the saber is curved and starts an overhang, and thus cause leverage to pry the brim off the plate. Adding lift caused to not do this in the horizontal plane (switching between the fangs), but it still happened in the vertical plane. It was almost like the filament was going on thicker than what was accounted for in the slice.

So, my two questions.

What is the best way to keep a HIPS object stuck on the bed. Glue stick just didn’t work at all, it acted like a lubricant (is there a specific formula I need?)

How do I account for layer thickness differences that show up so that vertical pressure is not applied in the latter layers?

My solution required two things. Bed at 105 temp, and a ABS glue applied by dabbing. ABS glue works well for HIPS. The dabbing rather than wiping had the most improvement.

HIPS seems to be horrible with even the slightest over hang. While it does stick, it seems to warp upward rather than droop, thus causing the problem I was seeing where it looked like the head wasn’t moving up fast enough and started pushing the previous layer around. Even at angles that auto support would not include any. Frustrating.

I have found the best solution for bed adhesion to be Aquanet Hairspray, I have had good luck with ABS, PLA, and HIPS, Although HIPS has the least grip, it has been working fairly well.

The issue I have been having with HIPS is layers delaminating as it prints. Have to experienced this at all? even with small prints layers seem to separate more then with abs or pla. I just purchesed a bunch of rolls of HIPS as im in a school and the price is cheaper and was told it is similar to a cross between abs and pla and should work well for me. I am using the slic3r settings downloaded from the lulzbot site. Is there anything I should change in those setting? I am going to try to build a plexiglas box for my printer sometime this week to see if that helps with a more consistent temperature. I hope that does the trick. I attached the most recent print with extreme layer separation.


The box should help. What temperature are you printing at? Here’s an enclosure that we developed that is not available for sale, but the source of course is freely available: http://devel.lulzbot.com/TAZ/cat_guard/

Pretty cool, any pictures of of it assembled?

I had similar problems until I either turned off the fan or tuned it. Hips is sensitive to temp change, a hood would help but my space is pretty temp stabile with no drafts so it hasn’t been a priority yet.

I have been able to drop the temp down and still get good bed adhesion, so I think it may have been not enough glue.

https://ohai-kit.alephobjects.com/workflow/cat_guard/

There will be a link to the above guide in the CATGuard folder shortly.

Try using Cura and profiles for HIPS. I’ve had great luck with it, using a glue stick on the PET film - no detachment or delamination at all. More details in my latest post at www.3driffs.com

I am building this soon. Any need to keep the power supply or electronics outside the box?

I was at Loveland a couple months ago and I am sure the rambo boards were all in the same containers as the printers but i can’t remember how the PSUs were set up. I imagine the box doesn’t heat up well enough to risk damaging the electronics?

BTW, I threw a sheet of thick cloth over mine to minimize cooling change and it did help for short prints. The space is temp and humidity controlled so it never gets below 63 or above 71 (40-60 % humidity). I just did a 16 hour print and the “printer sock” didn’t really help. Building my box this week-end.

While the power supply is external and easily placed outside a box, I am also concerned about putting electronics (that happen to have a cooling fan on them) inside the box. Or do you just cut a hole for the fan area?

Is there a lower target temperature you need to exceed to get the best results? 100F?

Is it better to have the filament in the box or outside the box?