Best bed levelling system?
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Thank you all for such great suggestions.
I am still not sure which way to go.I have a no cantilever 2 lead screw single motors setup , changing to 3?
3 lead screws with one motor: pro lead screw always in sync con need manual adjustment
3 lead screws with independent motor pro automatic leveling of the plane cons a little bit more expensive , need software setup , risk of out of sync motors?
with this setup is bed leveling system still needed or the bed plate can be mounted fixed on the frame? Is it possible , and make it sense, combine mrehorstdmd bed leveling system with 3 motors lead screws setup?
I already own the extra Z motors so costs isn't a variable in this decision.These are some photos of my printer take a look , any suggestion is appreciated!
https://www.dropbox.com/sh/7bvnlctmiqushv1/AAB_oR3lea8S2ZBIfeM5EsyUa?dl=0Other question for D-bot owners.
I have 3 wheels Z guide, is it worth converting y axis also to 3 wheels, I read mixed experience about it.@minim can you tell some more of your setup do you have some photos for taking inspiration:-).
Thank you all
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@claustro said in Best bed levelling system?:
3 lead screws with one motor: pro lead screw always in sync con need manual adjustment
Another pro is that if everything is built well enough, you don't need a Z probe. But I would want a Z probe anyway, to set an accurate Z=0 position before a print, to help me adjust the levelling screws, to generate a height map to check that the bed and printing plane are flat, and to make corrections if I didn't get everything perfect..
3 lead screws with independent motor pro automatic leveling of the plane cons a little bit more expensive , need software setup , risk of out of sync motors?
The motors may get out of sync when you power them down, so you need to run the auto levelling each time you power up, perhaps as part of the Z homing procedure.
with this setup is bed leveling system still needed or the bed plate can be mounted fixed on the frame?
It can be fixed on the frame, if you build it accurately. For example, you don't want the leadscrews to have to force a tilt on the bed because you didn't get the XY axis level.
In theory you could also have the bed fixed on the frame if you use a single Z motor, by making provision to adjust the belt lengths between the 3 pulleys. This could be done by having 3 adjustable idlers (instead of just 1 which I think you would normally have so that you can adjust the belt tension). But this is outside my experience.
I already own the extra Z motors so costs isn't a variable in this decision.
Don't forget that you need 6 stepper drivers for this arrangement, so there is also the cost of a DueX2 or DueX5 unless you already need one to do multi extrusion.
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@claustro Only you can decide.
I think the arguments that I and others have put forward for using 3 screws are strong and valid.
One thing you might have overlooked is that with 3 independent motors, whenever power is applied, they will get out of sync by up to 4 full steps. So if you decide to go down that route, then you will have level the bed every time you apply power to the printer.
So with a single motor and continuous belt driving 3 screws, then levelling has to be done manually but once set (and if the printer is built well) then it won't need doing again for months or even years. With independent motors then levelling is easier to accomplish but you have to do it every time power is applied to the printer.
I know which I prefer but I'm not you..........
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@claustro said in Best bed levelling system?:
@minim can you tell some more of your setup do you have some photos for taking inspiration:-).
There is not much more to show than what's in the video. It's a core xy that I designed myself and I use HGR15 rails for the Y axis and HGR12 for X axis. The Z axis has 3x 1204 ballscrews each mounted close to a HGR15 rail that keeps it steady. The cables are still a mess since I'm not done with it yet and I'm trying different solutions to the hotend still before I decide on what I will go with. Also I don't have any home switches so it's homed with stall detection for now and it's been doing good (Z axis has a bltouch tho).
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Ok .
@dc42
I already own a probe and I like all the info it can give me thanks of your great firmware
I m planing to go to the simplest route first.
So I 'll add a lead screw and and an aluminum casted plate ( if I evere will be albe to find it )
I'll stick with one motor solution , so the only extra expense will be lead screw and a new longer belt and new pulley.
If everything will be ok I'wil stick with it , if not I can simply add 2 Z motors and a duet expansion board.I have 8mm chinese lead screw, would be a good idea go for 10mm ones?
Can someone suggest me a trusted shop buy good quality stuff?
Thank you
Andrea -
@claustro said in Best bed levelling system?:
Other question for D-bot owners.
I have 3 wheels Z guide, is it worth converting y axis also to 3 wheels, I read mixed experience about it.I'm using 3 wheel carriages with screw tensioners on X Y and Z and it makes it very easy to tension the wheels.
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@claustro said in Best bed levelling system?:
I have 8mm chinese lead screw, would be a good idea go for 10mm ones?
8mm should be sufficient. You want the lead screws to provide up and down motion. It's up to the linear guide system to keep it in place in X and Y.
Can someone suggest me a trusted shop buy good quality stuff?
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for mechanical parts check your local cnc supplier.
for germany this shop sell high quality equipment (and is very expensive)
https://www.dold-mechatronik.de/Mechanics -
@deckingman said in Best bed levelling system?:
@claustro said in Best bed levelling system?:
.................. I am afraid about aluminum bed for 3 reasons cost, availability and thermal reaction.................
Aluminium tooling plate is the best solution because the bed needs to be flat, and it needs to be stiff enough, and it needs to have good thermal conductivity. This question gets raised with monotonous regularity.
Aluminum doesnt remain flat though. Glass is preferable.
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@kungpaoshizi said in Best bed levelling system?:
@deckingman said in Best bed levelling system?:
@claustro said in Best bed levelling system?:
.................. I am afraid about aluminum bed for 3 reasons cost, availability and thermal reaction.................
Aluminium tooling plate is the best solution because the bed needs to be flat, and it needs to be stiff enough, and it needs to have good thermal conductivity. This question gets raised with monotonous regularity.
Aluminum doesnt remain flat though. Glass is preferable.
Of course aluminium tooling plate remains flat - why do you say it doesn't? For reasons that I and others have stated, you really don't want to fix a heater directly to glass because local hot spots will cause it to crack. Glass on top of aluminium is perfectly acceptable (it is what I use in fact), as are various other surfaces like PEI but glass as an alternative to aluminium is completely unacceptable.
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@kungpaoshizi said in Best bed levelling system?:
Aluminum doesn't remain flat though
There's a very big difference between a thin piece of rolled or sheared aluminum and a thick piece of cast and milled tooling plate. Tooling plate is cast so it doesn't have the same internal stresses and it is milled flat afterwards. It should heat and expand quite evenly and with a proper mount would never change shape or expand noticeably in Z.
A thin piece of rolled or sheared aluminum on the other hand would behave like a bag of snakes. So you're right there.
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@kungpaoshizi Here are two videos of the bed flatness (and every other flaw that translates to variation in distance between nozzle and bed) in my corexy printer at room temperature and at 100C. The bed plate is 8mm thick cast tooling plate with a 0.7 mm thick PEI print surface (and adhesive under that). The plate sits on a three point kinematic leveling system and is lifted by two belts driven by a single motor.
It's flat enough to print edge to edge on the bed with a first layer thickness of 200 um.
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Well, while we digging out videos, here is one did a couple of years ago https://www.youtube.com/watch?v=U733PMTou7M. I use glass rather than PEI on my aluminium bed but no form of levelling or flatness compensation.
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@mrehorstdmd nice, i guess ive been brainwashed by the cheap printers these days
