ABS Print issues (brittle, not bonding)

I'm using a EZ3D Pheonix printer that I modded to try to get working better. It was working fairy well, then i upgraded the hot end to a knock-off E3D V6 bowden. I was not sure if the problems I am having are from a bad hot end or if I just don't have it configured correctly.

The orange prints are PLA and they were printed on the original hot end. I printed most of the replacement parts out of PLA. Problem being they are not holding up well in the hot environment.

The red prints are with Matchbox ABS. I ordered blue, red, and black. I tried the black and red and got about the same results. Each of the holes is where support was that I tried to remove. The only thing not brittle is the support. It seems to be over extruded. Yet it is set at about 70% of default. I have not dropped it lower due to some areas not bonding on the support.

printing temp: tried between 225-245. It extrudes smooth at 220. I have a Teflon lined barrel so I don't want to go too high.

Using Slic3r, extrude width: 225%, 5 perimeters(added layers with each fail, starting at 2), 4 solids layers, layer height is .1, .2, and .3. Nozzle is .35. I have .25, .4 and .5. The extrusion multiplier is at 1.1.

I started increasing width and percents due to poor adhesion and infill. I recently calibrated the PID and extrude length.

Edited 1 time(s). Last edit at 06/24/2015 02:16AM by Corybsmith.

Have you actually done a proper calibration?
I mean like the PID auto-tuning and checking the extrusion parameters through testprints?
First rule for good prints is to have these parameters properly calibrated.

Yes on both account. When I first got my printer it was all sorts of out of order. Few that got a printer from EZ3D ever got them working. The company is bankrupt now. I have been trudging through manuals and every help site I could find. Once I solved one issue, another usually popped up.

I have run the Auto-tune through the arduino interface and usually repeat after each change to cooling or environment. I have separate settings based on PLA with cooling and ABS without. I have checked the hanging extrusion width(.37), and the test print extrusion width. I have calibrated the number of steps per mm of filament. It was originally way off. Last I checked, it was right on after trying multiple lengths to ensure it was not a fluke. I have a K-type temp sensor that I have checked all the temps with. I also back that up with an infrared temp.

Although the machine needs a few new parts badly, it is a capable unit. I have decent prints at .1 layers with great detail. But it is usually accompanied with another issue.

I am going to try drying/baking a roll of filament and see if that changes anything. I have it stored with descant, but its worth a shot to cover that base.

What about flow rate calibration and have you ever thought of using other slicer such as cura?

When I had problems with ABS not bonding, it was because the hot end fan was also blowing air over the nozzle and cooling the ABS too fast. Some Kapton tape solved the problem.

---

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].