MF Pegasus Print Quality Issues

[FDM_Process]

Although I am aware that there aren't many people here with the Pegasus hopefully someone with an i3 has seen this issue. The first print I did on the printer, on the left, came out pretty well. I have since switched from ponterface to Repetier use and am using sli3er inside of that. What could be causing the issue on the right with the banding look? It isn't just popping out in one axis those outcroppings go all the way around the print.

I'm printing pretty slow too, maybe 35mm/s. My nozzle should be set right at .4mm, temp at around 195C in PLA.

print.jpg

[BLKKROW]

I had the same issue and switched to PID and an aluminum Y bed. Take a look at this thread:

http://3dprintboard.com/showthread.p...-bed-relay-PID

[FDM_Process]

Thanks for the reply! I do already have an aluminum Y bed. Maybe I just need to run a PID auto-tune on the machine, I can't remember whether or not I had done that on this one. I'll run one once this print finishes and post an update. I was racking brain with what the issue could be. I had checked mechanical tightness thinking there was some kind of resonance with the frame or maybe some loose belts but for the banding to be so even didn't make since to me. After reading that it seems like every 5 layers my temp must be falling then going 5 layers and raising back up which totally makes more sense than anything I was thinking. I appreciate the comment and will post an update either way.

[tsteever]

In order for the PID tuning to work well on the bed you need to have a Solid State Relay installed. I am not 100% certain of this on the Pegasus. maybe the board can support PID operation. That i cannot answer. I know I had to replace my relay board with a SSR on my 12" iv3 in order for it to work properly. Once completed, it works extremely well and I highly recommend using PID when ever possible.

[BLKKROW]

Thanks for the reply! I do already have an aluminum Y bed. Maybe I just need to run a PID auto-tune on the machine, I can't remember whether or not I had done that on this one. I'll run one once this print finishes and post an update. I was racking brain with what the issue could be. I had checked mechanical tightness thinking there was some kind of resonance with the frame or maybe some loose belts but for the banding to be so even didn't make since to me. After reading that it seems like every 5 layers my temp must be falling then going 5 layers and raising back up which totally makes more sense than anything I was thinking. I appreciate the comment and will post an update either way.

You need a SSR installed to run PID, the mechanical relay that comes with Makerfarm Kits will not work.

[FDM_Process]

Sounds about right. I do have an SSR that I can salvage off my old run down modded Solidoodle 3. The problem I am having is with the PID values and entering them in. I think I was able to manually enter them with gcode but on the Rostock Max, in Repetier, I can edit the PID values in the EEPROM settings. With the Pegasus I am not getting the same EEPROM settings. Does anyone know why that is?

[FDM_Process]

Also, I am having a hard time believing that I need a SSR for my hotend when the three other printers I have running right now aren't using one and are running just fine. My issue has to be something else. While I certainly believe that a SSR is better I don't think that it will make enough of a difference to really matter for what I do and again the object on the left was printed on the same machine.

[BLKKROW]

What kind of board are you running?

[FDM_Process]

Ramps 1.4 for the Pegasus.

I have a feeling this is some serious z-wobble. I can literally see my right z-rod wobbling when I move the hotend up and down. I need to find a way to stabilize that before I go messing with the electronics. Try the simplest things first and then move from there.

[tsteever]

The Z rod wobbling can be a source of wobbles. the axis itself is constrained bu the Z extrusions. If those (Or the V-wheels) are loose the rod can force the Z towers to move. Ig everything is tight however, I don't think the rod can cause that degree of banding. All this is said without seeing how much your rod is moving. Can you see the actual z carriage moving side to side when you move the z axis up and down.

I had made some bearing holders to hold the Z rod at the top and keep it from moving. My quality severely went down. Once I removed them and added a SSR my prints got quite a bit better.

The SSR is not for the hotend. It is for the heat bed. The issue is by default the bed uses a bang bang heat control the turns on the heat at a level and turns off at a different level. My bed would swing in temps sometimes by 5 degrees! That difference in degrees will cause variations in bed thickness which shows up in the banding. To use PID tuning on the bed you have to have a SSR as the relay included in the kits (mechanical) is not capable of running a PWM signal.

I know I am saying quite a bit wrong but the gist is there. The SSR is for the heat hed, not the hotend.