Bed mesh on Vcore3.1 500

[surreal zodiac]

Hi everyone,

Can someone guide me through acceptable bed mesh deviation on a 500?

[crystal scroll]

that
0.3mm over 500mm i'd say is quite good
mine's 1mm off from one corner to the other, suspect it's got dinged in shipping

[surreal zodiac]

Thanks a lot, its at least some kind of a metric. Otherwise I can't find any info and cannot fine tune the frame any more than it was previously from 0.878

[crystal scroll]

at that point i'd think it's actually modifying the bed that would be the way to go, it should be fairly simple to knock down those corners a little with something like a lapping block or something, or just even sandpaper
though, make sure you really want to go that way 😛

that center portions of yours is gorgeusly flat though

[civic dove]

wow Norden...yo need to bring the front two Y axis corners UP! The left more than the right but should massively reduce that dip at the right rear and lower the left rear

I though this was a pinned thread here....
https://www.youtube.com/watch?v=h7ZTq2dDTkM

[surreal zodiac]

any tips on my mesh though? 😄

[civic dove]

that video will show you WHY and HOW to get that mesh more level. He goes through some guides and shows you via meshes, what effects what and how to correct same.

[surreal zodiac]

I have already run through it, it got me from 0.878 to 0.31

no matter how I temper now, i cant make it better

[civic dove]

I've a VC500, hot @ .019mm 11,11 mesh

[surreal zodiac]

ok, then I'll check again

[civic dove]

throw a 1" -2" wide strip of notebook or printer paper under the corner of your print bed where the bed is reading further from the probe than the adjacent corner and run a mesh. When you find the variance you can add Kapton tape (or blue painters tape whatever) right on top your magnet sheet to raise that corner of the print bed surface. Search youtube for 'level a print bed with tape...dozens of vids

[surreal zodiac]

Sure, thanks

[civic dove]

https://www.youtube.com/watch?v=xbpDuoYITr0 is one... and an intersting one...a printed surface to compensate, then put the bed on
https://www.youtube.com/watch?v=0FjC4mHGeRI

[surreal zodiac]

Ok, this is interesting. But this should be relevant only if the bed actually is the one that is not flat, therefore I was looking for hints, if its a mechanical issue on the frame or linear rails

[crystal scroll]

that's very possible, i've not made an effort to fix it yet
do you have any knowledge on just how much we're talking? i assume not much as over 500mm it'll become a lot of movement

[surreal zodiac]

The bed being cast and milled would make me think its quite a low possibility for it to be warped and all but im not so sure about the magnetic plate and the PEI sheet itself

[crystal scroll]

ah cheers

[crystal scroll]

what might be a good idea for chasising "perfection" is to configure your probe to do more than 1 probe each time, so that it'll do the average and be in theory a bit more reliable

[surreal zodiac]

In this case i dont think the repeatability is an issue, as i have made already tens of these meshes and it basically shows the same pattern

[crystal scroll]

it could be, the magnetic bed isn't really a precision item
i don't have anything on my bed atm due to the magnetic bed degrading ( probably some chemical i got on it )
so i'm probing the aluminium plate, with an inductive probe that is
it does seem like i might have a little bent corner, but @civic dove 's shout of moving the Y rails up in the front is a really good idea

that's fair
hmm, what probe was it youi had again?

[surreal zodiac]

Im using bltouch

[crystal scroll]

ah ok

was thinking it might be the bolts or magnets with a inductive one, if the high points was near them, but that's not it then

[civic dove]

going back and looking at your orig pic.... since most of your deviation is right at the corners.... it could be as simple as how tight you fastened the very ends of you Y linear rails (or loose) Many people will tighten one end...then the other (for alignment) then tighten everything in between. WRONG.... you need to work your way down the length. Just like the X gantry bow due to dissimilar materials, end for end than the middle tightening the rails does the same thing to the Y rails. Try just relaxing the last two or so Y rail bolts (up front) and see if it changes those corners. BUT.... you'd think that would be all the way across the front of the X axis. But since it's just the very corners.... try stacking a few layers of print surfaces (or anything you have large enough and flat enough) under your print surface and try a mesh. Right now I have a smooth PEI spring metal, but I have a 1/32" garloite plate glued to it. (same 3M sheets as your magnetic surface) the garloite is a print surface as well

[surreal zodiac]

I was doing as per instruction from start to end skipping a bolt and the from the same start fixing all loose bolts

[crystal scroll]

i would not be able to stack anything like paper on it, as i use a inductive probe, i'd have to use something metal, but how far it would activate doesn't neccesarily collaberate with the thickness
I will have to check the rails, i've discovered i have over-tightend the X gantry so much it damaged the exutrsion, it's possible i've done that with the Y rails too

[surreal zodiac]

but let me try to fiddle with rails as well

i have fiddled with frame till now only

[civic dove]

Very easy to do (over tighten.) ha ha been THERE! To this day (even as an old gezzer) I cannot use a socket wrench, with handle in hand. I wrap my fist around the head, and with the handle sticking out between thumb and forefinger kinda throw the handle. Anything up to about a 5/16" bolt I can snap the head right off.
(I've been restoring old British Car for the last 30+ years... old iron in general for over 50+. I force myself to use a torque screw drive on all thse little screws and still snapped a few. 🙂

[crystal scroll]

I used my drill and the clutch on it, turns out they are not that reliable and will torque the crap out of the bolt sometimes

[civic dove]

it's that fast spin and sudden stop ....zips right past the 'torque' limiter of the spring clutch in an electric drill. Do a test yourself.... slooow speed on the lowest setting. than repeat at 1/2 speed. SLOOW speed you might be able to undue the nut by hand even. higher... no way. ha They are designed to not strip srew heads.... not positive drive tiny m3 screws. he he

[surreal zodiac]

Ok, so i did some messing around

1. Retightened linear rails on X and Y
2. Adjusted config to make mesh and z tilting much nearer the fixture points on the bed

Per image it seems, that the bed itself is sagging on unsupported ends - what do you think?

Same mesh from other POV

And same when heated to 60C

[crystal scroll]

i'd say it's very plausible it sags a little, you don't have to put a lot of force on either of those corners to have it start moving around a little

[civic dove]

yep... got rid of my 'potato chip' bed..but over kill
#1056263255842099331 message
with the next iteration already in the works....

These 500 sized beds really need to be thicker (>=8+ mm) 6 (oem) just doesn't cut it. Probably more than adequate for the 300 and possible 400 but not the 5's

[civic dove]

just found https://spannsysteme.shop/produkte/ratrig-v-core-3-500-bed making 10mm beds looks like mandalaroseworks in the U.S. is carrying them (or re-machining them?)

[hard wasp]

Yep, definitely not what we do. As far as we have been able to research, we are the originators of the top magnet designed beds. We definitely do not buy from Austria. All of our products are manufactured right here in Minnesota.

https://mandalaroseworks.com/collections/ratrig

[crystal scroll]

man your store is just full of things i really want

[civic dove]

@Norden you can look at https://discord.com/channels/582187371529764864/987438756145528862
right here in the RR community

NFI just like supporting small companies! 🙂