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filament labs updates: designing a new 3d printer bed and z-offset system [updates]

So here's what I'm realizing as the place where most prints fail. Their either fail (in the Tronxy X5SA especially) when the bed level is off (and that happens a lot), or when the z-offset is wrong. And for the first initial amount of time this is usually fine in the printer but these days there's been some drift.

Turning these six screws is really annoying for two reasons. It's very un-intuitive and it's so easy to get wrong that you can end up bending your own build plate if you don't know how to adjust it properly. And this also is affected by drift on the stepper motors encoders which I think one of the motors has a lot of because the bed level was off by 2mm at the end of the print. I'm also going to try oiling the shafts of the printer.

Some notes from this video:

  • We need to level the bed at the correct bed temperature which means we want to pre-heat the bed, then level it, before the print and we want to do that automatically.

  • We then (after the bed has been leveled) want to set the z-offset automatically (hopefully).

Those are the two goals for the design of the next version of the Castor Printer. We also want to look into this:

What is the most accurate sensor for auto-bed-leveling. Also notice everyone is using a glass bed these days and I'm still using the strange bed that's has all the rough surfaces. The video concluded with a GLASS BED the best sensor to use is the LJC18A3-H-Z/BX - or we can do what Dremel did and use a limit switch or this: https://www.amazon.com/ANTCLABS-BLTouch-Leveling-Premium-Extension/dp/B076PQG1FF BLTouch auto leveling sensor kit. And I also saw this online for the tronxy GCODE editing:

M8084 Z1.5  ; Set Z-Offset to 1.5mm
M8500 ;  Save settings.
G0 Z10; Lower Z axis to prevent crashing during homing.
G28 ; Home Axis
G0 Z0 ; Check for paper tightness

So we need to look at M8084 and M8500 as GCODE commands. And there's one more point to make now: https://howchoo.com/g/m2ywngq2mja/3d-printer-glass-bed

Here's one for us: https://www.amazon.com/330mm-Borosilicate-Glass-Plate-Polished/dp/B079NTN9SN/ref=sr_1_2?crid=WEBV5IQQVQDQ&dchild=1&keywords=borosilicate+glass+bed+330x330&qid=1597157573&sprefix=borosilicate+glass+bed+330%2Caps%2C144&sr=8-2

Why should we make our printer have a glass bed:

  • GLASS IS MUCH LESS LIKELY TO WARP over time. And inexpensive glass is manufactured FLAT, VERY FLAT.

  • Glass is easy to clean no more scrapey-scrapes.

  • The Borosilicate glass bed has extremely good thermal shock resistance. As opposed to brands like the Home Depot glass brand (fine for the casing but less fine for the bed).

  • HAIRSPRAY is the most effective method for bed adhesion --> honestly we can include some of this with the printer (from product POV).

So the changes we want to make to the bed/leveling system are as follows:

  • Replace the really bad bed we have with a borosilicate glass bed that doesn't warp (use hair-spray for adhesion).

  • Replace the mechanical springs and etc as a leveling system entirely and have the printer do it entirely on its own.

  • Oil the z-axis because it seems like one of the rails is sticking.

  • Maybe change the sensor from proximity to a simpler touch system.

So I thought this is how auto leveling of the bed works but I feel like my printer isn't doing such a great job of it. I wonder how the z-offset comes into play here and does it account for that? Especially in the auto-leveling. Regardless, I think that the bed could still use a few upgrades and I think the printer should auto level and set the z-offset automatically when it turns on (or maybe even before a print, after the bed warms up but while the nozzle is warming up). It would be interesting if we were able to use the nozzle itself for auto leveling like CNC machines use the bit and then z-offset is accounted for already. https://www.kickstarter.com/projects/stinger2/the-stinger-ii-auto-bed-leveling-print-head-for-3d this is also an interesting idea.

Also another very cool piece of technology here:

But apparently the Duet WiFi board can do something very similar let's see:

https://www.duet3d.com/DuetWifi ! This is the 3D printer board I think we would use in our printer because it has all the features we are looking for and it is open-source. And note: we can use the https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe BL Touch probe which is apparently one of the best auto leveling systems on the market. So I do think that that is decided then - because the BL Touch apparently has one of the lowest standard deviations of any printer sensor on the market. We could also think about using an Nvidia Jetson as the 3D printer controller? Something good to look at: https://www.instructables.com/id/Installing-BLTouch-Auto-Bed-Leveling-on-the-Creali/

So the electronics for this might be a set of annoying decisions actually.

#updates #omgrobots #yay

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