Yet another adhesion issue  

Re: Yet another adhesion issue

Hey, looks to me like your Heatbed is still too far from nozzle, and you could slow down the speed for your first layer. I also have similar problem and the card calibration does not work so good for me, so I made a flat area 20x20x0.2 mm and arranged one in each corner and let him print it. While printing I adjusted the corner screws so that initial lines would just ever so slightly overlap each other. That helped... And you could activate a brim, that will create a sticky outline around your object that gives a lot of additional adhesion...

Re: Yet another adhesion issue

Hi Joe

First thing I have noticed from your video is that you have assembled the extruder incorrectly and have not routed the cables properly. This is not the cause of your current issues, but it will cause major problems in the future unless you get it sorted.

You do have a calibration issue; the nozzle gap is too large. Calibration is very difficult to get right to start with, but is does get easier. Now takes me about 10 seconds; I do a check every 3 or 4 prints as the glue layers build up.

Looking at the video, you may have a frame that is not quite square. Ensure that all 4 feet are firmly touching the table. If not, adjust that.before you go any further otherwise proper calibration will be impossible.

Peter

Re: Yet another adhesion issue

Thanks for the replies! So I checked the feet and they are all touching the table. However, I have had trouble with keeping the heatbed screws in the Y axis frame holes. Oftentimes when I push one in another one will pop up. Is it important that all four screws are pushed into the holes or does that not matter?

Re: Yet another adhesion issue

Joe

Yes it is important that all 4 adjusters are sitting on the chassis.

If they don't then you will not be able to print properly.

Usual cause is a twisted chassis, but you say that's OK. Check the heater; make sure it's reasonably flat (it will not be perfectly flat due to manufacturing process...).

Make sure that the X axis is the same height from the Y axis at both sides.

Make sure that all 4 adjusters are sitting flat on the chassis and start calibrating from that point.

Get as level as you can all round without any bed wobble. Try turning the glass over.

Peter

Re: Yet another adhesion issue

Thanks again Peter. I am definitely having some trouble with the screws popping out of the plate while I'm calibrating, but eventually they stay in. After more calibration it finally started working until one part on the glass where it just would not stick for anything. I found that the zip tie for the heatbed cables was rubbing against the zip tie for the y-axis end stop. This was causing the plate to jump a little as it went over that. I ended up cutting the tie and running the cables on the other side of the y frame so I could tie them off closer to the z adjuster in that corner. That improved it a little, but not entirely. In a desperation play I decided to turn the glass around so it would print on different ends. That at least got it to the point that the print made it past the first layer and looks like it will complete in about 20 minutes. There is some warping on the corners, but I can deal with that for now.

Re: Yet another adhesion issue

Hi Joe

Great, getting closer to a solution...

I think what you need to do now is to raise the corners (or rather the front and rear edges) of the glass. This is exactly what I have don in order to get a pretty close to level glass - there are some pictures of this I have posted recently , but I can't find them at the moment.

What you need to do is to put a 1" (25mm) strip of masking tape (or blue tape) along the front and rear edges of the glass on the underside, between the glass and the heater. This will allow the middle of the glass sheet to contact the centre of the bed but raise the corners 0.1mm.

Peter

Re: Yet another adhesion issue

Peter,

Thanks for the tip. Having a nightmare of a time getting a good calibration again. I want to try the tape thing you mentioned. I tried searching your posts on this forum but couldn't find one with a picture for this. Any chance you could repost or link to them?

Re: Yet another adhesion issue

Yeah, it's there somewhere and a link to it for someone else. Seems that I make too many posts for my own good...

Its not a good photo, but you can clearly see the blue tape under the glass. Also not the rear left clip is positioned differently to prevent it catching on the extruder cables when printing a larger object.

Peter

Re: Yet another adhesion issue

Hi Peter
I see you went to Z axis couplings instead the stock tube and heat shrink. I want to do the same thing where did you get the file for Z rod holder?

Thanks
Scott

Re: Yet another adhesion issue

Hi Joe,

Regarding the feet touching the table....

I recently moved my printer to a different location and after I had moved it, I had a heck of a time trying to level the print bed again. I couldn't get all for corner level adjusters to touch the frame. It always teetered on the left front and right rear adjustment screws.

I suspected that the Y-axis frame had become tweaked when I moved it, but when I did the old "push on the corners and see if it rocks" test, everything seemed to be solid against the table. After scratching my head for a while, I removed the fuzzy felt pads from the legs of the Y-axis frame and it became obvious that I indeed had about 0.5mm of wobble which was being masked by the fuzzy feet, and also happened to be the same amount of slop I had when trying to level the print bed.

I learned the felt pads don't do you any favors when chasing down bed/frame alignment issues. The first thing I printed after it was all back together was the anti-vibration feet so that the printer is solidly on the table.

By the way, the anti-vibration feet work really well at quieting the low frequency rumble that resonates through the table surface and have really quieted my printer even further.

Re: Yet another adhesion issue

Hi Scott

I took the originals and amended them a tad.

This is what works for me... (see attachment)

Peter

Re: Yet another adhesion issue

Hi Joe,

Had a simular problem with the bed rocking slightly, the screws where not staying in the y-carriage when trying to level the bed. Please check is all the feet of the y- base are touching the ground.

With me 1 foot would touch the table no matter what I did, so I loosened the bolts connecting the y axis with the metal prusa frame. and pushed all 4 feet to the ground and thigh-tend the screws again and my problem was fixed. Maybe your problem is simular?

Kind regards,
Kristof

Re: Yet another adhesion issue

Hi Scott

I took the originals and amended them a tad.

This is what works for me... (see attachment)

Peter

Thank you Peter 😀