Solved R1+ Adhesion for PETG

Hello,

I am struggling to print something in PETG on my R1+. Per the attached, I am just getting terrible adhesion so the perimeter is lifting off the bed and no longer forming a curve. Here are the specifics:

- PETG filament
- Simplify3D slicer
- First layer is 90% height, 100% width, 30% speed
- Temp is 240 extruder, 80 bed.
- Gizmo dorks PEI sheet on the R1+ glass bed
- Glue stick on top of that because I know that PETG can be brutal to remove, so a great suggestion was to use something like Glue Stick as the release layer

My problem is that the Z-offset on the R1+ control panel set at 0.65 which appears to be a bit too high based on these pictures, but as soon as I move to down to 0.60, the nozzle rubs up against the print because it's too low. That's only a 0.05 difference. I could try 0.63 or something, but I think this is trying to be too exacting and I think I have to try something a bit more reliable and foolproof.

I have BuildTak on my R2 v2 bed that I just started using which seems great, but I'm very concerned about not being able to get PETG off at all if I do that.

What are some options?

- Rip off the PEI and go glue stick on the glass bed, would that help?
- Rip off the PEI and go BuildTak and hope for the best?
- Buildtak and glue stick?
- Buildtak on an aluminum sheet binder clipped to the bed so I can pull it off and twist it to get the PETG parts off?

I feel like right now my margin of error is terribly thin that even small tweaks that I have tried won't stay reliable.

Any thoughts would be awesome!

 

Mark,

1. Thanks as always. I have never done anything with the firmware since the day I got it. How do I tell what version it is? I have the little LCD screen thing and it says ROBOR1PLUSV2 ready if that means anything.
2. The big challenge I have is that my print goes from WAY too low to way too high in a matter of 0.05. Someone, perhaps you, said the answer is to have the z-offset set in the GCODE in S3D instead of the printer, would that matter? I just always felt that doing that is a bit of a pain because if I have to fiddle with z-offsets (which I seem to always be doing), I have to scrap a bunch of gcode files and re-generate them all.

Thanks, and I know this is a tough challenge as the first layer is the holy grail of 3d printing, especially on the older R1+.

Thanks.

 

Perfect. Ok, I guess I will stop fiddling with the Control > Z-Offset and "Store memory" command in the display. I thought that to be handy, but I need to heed advice previously given and now given again and stick with the M565. I assume I just add this block to the startup gcode in S3D? (I will start with a really high z-offset and fiddle from there once I see my correct starting point):

M565 X0 Y0 Z-0.65

(assuming 0.65 is what I want as the z-offset)

http://reprap.org/wiki/G-code#M565:_Set_Z_probe_offset

thanks.

 

Thank you @Geof and @mark tomlinson, you guys are awesome as always. Good news, I was able to get the M565 working perfectly on my 2nd try and hopefully it should be solid from here. I also realized I was forgetting to clean my PEI sheet with alcohol between prints and hadn't in a very long time. I was thinking that wouldn't matter with the glue stick, but the glue stick did seem "tackier" once I had done that. And thank you @Geof for mentioning the potential issue regarding if you have to replace or pull out the hot end, that was going to be my next question!

 

By the way, I tried to run this same exact print and this time it looks fine from the nozzle distance to the bed as it's printing but it isn't creating a full first layer, there are gaps between the passes and it's not sticking. I may tinker with having S3D do a 200% first layer height to see if I can dump out more plastic and see if that helps.

But I also wonder, since I'm using glue stick, is there any rule of thumb on how much thickness +/- this adds to the bed each time and maybe I'm not putting on the same thickness each time? Just seems rough that it needs to be this perfect, but maybe...

Thanks!

 

Thanks @WheresWaldo. I know, that's what I would think too, and maybe it's operating like it's supposed to, but if you look at the screenshot from S3D and the 2 pictures when I put it at 200% first layer width, there are just big gaps because it is extruding (or thinking it is extruding) really wide passes. And FYI, I stared at the nozzle and boy the height looks absolutely perfect. I actually heard something similar from someone at BuildTak who mentioned to me: " I, too, have never noticed a difference when changing S3D’s first layer WIDTH, but increasing first layer HEIGHT definitely modifies the first layer."

Anyway, I'm running this print now and I'll see how it does with adhesion and then figure out if these gaps are going to be ok in the final print or not as it's definitely not going to be a nice smooth bottom layer

Thanks.

 

Thanks so much. So yes, I am using 0.2mm layer height. I went big and went all the way to 200% width in that example I sent and indeed the print was unusable as the print had way too many gaps. What's perplexing to me is that it looks like it's functioning as S3D intended as the print looks exactly the same as the screenshot, i.e. the screenshot told me it was going to print really thick with all of these gaps. So I'm not sure why anyone would want this type of look and I asked S3D and I didn't get a real conclusive response.

So basically it just seems like every time I adjust the first layer width, it doesn't print plastic any closer together (which is what I want), it just prints thicker stuff that is further away from my first pass leaving all of these gaps shown in the screenshot and print and I'm no further ahead. Is there another way to have it take the normal pass of the extruder along the original route but have it dump out more plastic in the process so that it "flows" out the sides making one pass more likely to touch the other passes?

 

Ultimately though all of these problems are only on the first layer, so we're talking about adding two processes, one for the first layer and one for everything else? Bit of a pain but I'm game to fiddle to make this work so long as there isn't another easier way

 

Perfect, all makes sense, thank you. I'll give it a try.