hi igot some trouble with cracking abs

anyone know how to get "crackless" prints?

Yes, but it can be quite difficult. Here are some tips:

- Most important: Avoid draughts
- Increase the room temperature
- Put your printer in a box to maintain a stable ambient temperature
- Increase the layer height

The cracks are caused by the ABS warping - look through the many threads regarding warping issues.

Dave

Good advice from zombiepantslol, would ad to this..

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zombiepantslol
- Put your printer in a box to maintain a stable ambient temperature

let the print sit at bed temp. after printing (my setting is 110C) for an hour or so, den lower the temp. 10C, and so on..

Erik

Also make sure you're printing at the right temperature - a little too low causes bad adhesion between layers which leads to cracking. Not all ABS filaments are the same - I have some that are printed at 230, others at 260. Once I've established the best temperature I put a sticker on the roll to help remember.
Another thing is that printing too fast will also cause weaker laminations..

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denshine
hi igot some trouble with cracking abs

anyone know how to get "crackless" prints?

Apart from the advice that has already been given, make sure that there is no backwash from the hot end fan, and that all the air expelled by the hot end fan is expelled upwards, not downwards or sideways. If you have an Ormerod 1, or an Ormerod 2 with printed fan/heatsink duct instead of the acrylic spacer, you need to block off the vents at the bottom of the ducting, add a chimney, and fit a fan inlet duct to eliminate backwash. If you have the acrylic spacer instead, then I suggest you redirect the expelled air upwards, e.g. turn the heatsink through 90 degrees and then block off the bottom - and fit an inlet duct if there is any backwash. I had cracking like that on prints from my Kossel, and it turned out to be caused by exhaust air around the nozzle.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi! a solution i made with my ormerod is to enclose it with some box to create a green house. This way you don't need to increase the hot end and/or bed temperatures. ABS cracking is due to poor adhesion between layer hence the previews layer was cool to quickly.

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xozip_neutron
Hi! a solution i made with my ormerod is to enclose it with some box to create a green house. This way you don't need to increase the hot end and/or bed temperatures. ABS cracking is due to poor adhesion between layer hence the previews layer was cool to quickly.

Yes, that works but be careful that your "greenhouse" does not get hot enough to overheat the electronics or soften the printed parts - especially if your Ormerod still has some original PLA parts. Lubricate more frequently also.

Dave