RE: Adhesion issues and print quality.
It doesn't take much time to just check to see what kind of movement you're getting. Just use something with a straight edge and check the flatness in several spots at room temperature. Then let the bed heat up and check it again and compare I'm sure you will see gaps.
I print on different areas of the bed just to give all the moving parts belts equal use. I was having a hard time with smaller parts on certain areas of the bed and that's how the video came to be.
RE: Adhesion issues and print quality.
First issue I see is the bed is not clean and the plastic is not sticking well. Second issue is bed level could be better.
Soap and water is far better than alcohol. Why? Volume. A gallon of water rinses far better than a dram of alcohol.
RE: Adhesion issues and print quality.
gkmakeit, what exactly is that blade that you are using as a straight edge in the video? IIRC you said that it was inexpensive and available at one of the usual suspect big box stores.
I want to try the bed correction but I don't want to spend the $$$ for a machine shop grade straight edge.
RE: Adhesion issues and print quality.
@jsw
Just make sure you inspect the edge of the tool before you buy. Run your finger (carefully so you don't cut yourself) down the edge to check for burrs or dents. I'm sure you can find these in many other stores, I used the one from walmart. I know they are online, but I wouldn't recommend buying online. There's no way for you to make sure the blades in good shape. If you try this fix take some before and after pictures if you can and post, would like to see if it helped. Since you're not removing or cutting anything you can alway just go back to stock.
https://www.walmart.com/ip/Hyper-Tough-12-Stainless-Steel-Edge-Paint-Shield/125887550
https://www.lowes.com/pd/Warner-12-in-Plastic-Paint-Guide/1000024777
RE: Adhesion issues and print quality.
The results are similar to the nylock mod which is great. I've done the nylock mod and won't go back to stock since it fixed the problem. I wonder how this fares with the bed leveling programs on octoprint and others.
Stay healthy and safe,
Phil
Stay safe and healthy, Phil
RE: Adhesion issues and print quality.
I've heard the nylock works well. I ran into the nylock option when I was looking for a fix. Here's my opinion on why I went a different direction.
The main reason why this issue exists is because the thermal stress when the bed is heated, it want's to expansion side to side. In the stock setup the counter sunk screws when tight restrict the the expansion. When the bed can't expand sideways it starts to bow up or down. When the bed gets back to room temperature it goes back to it's natural state.
With the nylock you are always keeping the heatbed in a "loaded stress" state. When at room temperature or heated the nylocks are not allowing it to go to it's natural state so it's under stress at the time.
With the way I did it it allows the bed to stay in it's natural state at room temperature or heated.
I don't know if this ultimately will make any difference. As they say, if it an't broke...
RE: Adhesion issues and print quality.
Another pointer - instead of printing a full sheet of plastic, most of us use 1" coupons at 9 points: 3 along the left, 3 center, and 3 right. This pattern corresponds to the basic 9 point cal pattern of the bed level algorithm (though the 49 point is better).
Here's a sample of such coupons showing layer one cal issues, grouped together for comparison.
Some folk also use OctoPrint and a leveling add-in to let the printer determine what is and isn't flat.
And, if you get really critical of the layer one surface, direction of extruder movement has an effect, too.
And one final thought: The PINDA is temperature sensitive, it's detection distance changes as it warms, so be sure you preheat the PINDA before running any calibration.
; cool down PINDA
M106 S255 ; turn on fan
M104 S0 ; turn off nozzle heat
M140 S0 ; turn off bed heat
M860 S35 ; wait until PINDA is less than 35C
M106 S0 ; turn off fan
; soak PINDA then level
G0 X50 Y50 Z1 F3000; this is a good PINDA heating position
M860 S37.5 ; wait until PINDA is >= 35C in winter, 37.5C spring/fall, 40C summer
G80 N7 R5; mesh bed leveling