Opinions please on the nylock bed leveling mod for the Mk3S+  

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@technical-ted

I just printed something that was also 240+ mm wide -- coffee pod tray for the cupboard -- and past experience has proven corners will lift. It is almost unavoidable on a Mk52 bed heater (stock on the Mk3).

Ways to minimize the lift: for the PLA I was printing I set the bed to 75c after a few layers were down. Simple and effective. I wouldn't even be afraid to go to 80c. I think it works because setting such a high temp for PLA actually gets the edges of the print bed to 60c. lol.

If it is lifting elsewhere, not from the corners, then a thorough soap and water cleaning will help.

Ears would help, too. But something that is so wide there's no room for them.

ps: and the nylock mod will not help this situation. If your layer one tests are good to the four corners, then you also don't need the mod.

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

Thanks for the reply.

Yes, I get corners lifting.... doesn't seem to cause any problem so I'm not worried or attempting to fix that.

I'm talking strictly the 1st layer. Kind of treating it as one, big 1st layer test. My sheet is clean. I'm just getting variable first layer consistency in lay down over the entire area of the sheet. Mostly perfect overall, but a little bit too high Z in a small area, like there is a dip in my sheet. If I adjust my live Z to correct in that area, it's too close in other areas. 

So I'm not playing/experimenting with stopping the lift. I just want a "perfect" 1st layer over the entire print area. Or at least that's what I'm playing with and trying to achieve. Thought the nylock bed leveling mod might help that.

Thanks!

Ted

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

I did the nylock mod, now use pieces of silicone tube. This works great and tubes keep tension on the screws holding the bed. 

I didn't have any problems with the bed before the mod, but didn't like the over constraining fixing of the bed with 9 screws.

One thing you should try is loosening the 8 screws along the edge of the bed. And tighten them again after getting the bed up to the temp you normally use.  That will release some tension in the bed when it is getting hot.

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@technical-ted

You haven't said whether you have a Mk3, a Mk3S, or a Mk3S+.

You may need to use Bed Level Correction to make fine adjustments over the full bed perimeter. Corners generally can be high (causing over extrusion). It's the natural warp of the bed frame and heater. The amount of warp changes with temp. The PINDA doesn't do a good job compensating for the perimeter warp - the interpolation used in the firmware is defective in my opinion and exacerbates the warp error.  So, setting the trim values manually is about the best you can do. 

If you want to have fun though, sure, try setting up the nylock mod, the mod allows a bit more control; plan on setting up Octoprint with the bed level add on to make the most of the mod.     

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@Tim

It's in the title of my post... Mk3S+

Thanks for the suggestions,

Ted

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@technical-ted

Dooh!

Here's that bed level plugin -- seeing the bed readings visually will help you trim using any of the methods - nylock mod or built in compensation.

https://plugins.octoprint.org/plugins/bedlevelvisualizer/

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@Tim

Thanks for the link. I actually have a Pi and camera set up, but not attached to the printer. I read where Prusa says you lose some functions with a Pi connected so I've only been using it to monitor when printing. It saves me from getting up and physically checking the printer as often.

Thanks,

Ted

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@technical-ted

Printing from Octoprint may have limitations; but for bed level it shouldn't impact anything.

So many people use Octoprint as their preferred solution, I doubt there are any real issues using it full time. Prusa is probably just being cautious. Like saying if you do have printing issues when using Octoprint, of course the first thing to do is try printing the gcode from the sd card.

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@technical-ted

I do not like the nyloc mod particularly and favor spring mod or silicon mod instead. The nyloc mod is fiddly, does not eliminate backlash and IMHO risks to wreck your heatbed.

As for the bedlevelvisualizer: The pi does not have to be connected permanently to the printer. You could just occasionally plug it in for the check.

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

Without a pi connected you can also use Pronterface (I haven't myself)

Send a G80 to the printer to run the bed levelling, and after that a g81 to see the values like this:

Recv: 0.07083 0.11250 0.09333 0.09167 0.09750 0.10583 0.10167
Recv: 0.10833 0.14833 0.11917 0.10000 0.13167 0.16417 0.12917
Recv: 0.10833 0.14667 0.13167 0.11396 0.13083 0.16167 0.11333
Recv: 0.10750 0.15750 0.12417 0.09333 0.11875 0.12833 0.10250
Recv: 0.13583 0.25917 0.29250 0.17167 0.12250 0.14000 0.08417
Recv: 0.14667 0.29167 0.36250 0.17833 0.13917 0.14583 0.07417
Recv: 0.10500 0.21333 0.19417 0.09917 0.12750 0.13250 0.08750

Copy and past those here: https://pcboy.github.io/g81_relative/

This will show you how your bed levelling is in numbers like this:

Raw values:
-0.02 0.00 0.01
0.01 0.00 0.01
0.01 0.01 -0.01

Degrees:
14°CCW 0°CCW 7°CW
7°CW 0 7°CW
7°CW 7°CW 7°CCW

Fractional Turns:
0CCW 0CCW 0CCW
0CCW 0 0CCW
0CCW 0CCW 0CCW

This is what I used to do my bed levelling before I found this plugin: https://plugins.octoprint.org/plugins/PrusaLevelingGuide/

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@baklin: I actually do use an old fashioned serial terminal program instead of my raspberry pi. It's just not Pronterface/Printrun.

I prefer seeing the numbers to adjust my spring modded bed. Unit is mm. The M3 screws have a pitch of 0.5mm per rev, So, for e.g. 0.1mm too high turn 360 degree /5 = 72 degree cw. No rocket science.

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@blauzahn

Thanks. I'll have to look into those other mods...

Thanks for the info, Ted

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@baklin

Thanks! Very helpful!

Ted

RE: Opinions please on the nylock bed leveling mod for the Mk3S+

@technical-ted

Keep in mind that the built in bed level correct can get you pretty close all by itself. No mods required.