Delta Firmware - Adjusting for Effector Tilt

I have my delta physically calibrate about the best I can get it, but it still has a small amount of tilt when the effector moves from one side of the bed to the other.

I use an inductive auto-level probe. The probe itself works great, but as it is moved from Y100 to Y-100 for example, the height of the probe in relation to the nozzle changes slightly, enough to make a difference in the Z height at different heights of the bed affecting the first layer of a large print.

I'm using Marlin 1.1.0 RC3 and trying to find settings or g code to compensate for this tilt.

I tried using E3D's calculator: [escher3d.com]

But after making the adjustments twice, the end result is EXACTLY the same. I'm guessing this is intended to adjust for bed level / endstop differences, and not effector tilt...

Except for the lucky or exceptionally skilled, everyone's delta has to have some degree of effector tilt.

Except for ditching the auto-level probe, and manually calibrating, how does one make adjustments to compensate for the tilt with an offset probe?

-EB

Edited 1 time(s). Last edit at 02/11/2016 11:43PM by EvilBetty.

RepRapFirmware allows the probe point heights to be corrected to allow for variations in the probe trigger heights, and I think Repetier has some sort of height correction facility too; but AFAIK Marlin doesn't. So I think you need to remove the effector tilt, or move the probe closer to the nozzle to reduce the effect of tilt, or calibrate manually.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

If you're interested in removing effector tilt then this might help:

Make a piece up like this, and clamp it to your effector. The bottom should stay flat on the build plate as you move the effector around over the surface. You need to do this for each of the 3 pairs of diagonal rods.

Space out either the effector end, or the carriage end depending on which way the tilt changes as you move the effector. It's easy to see how much tilt there is with this system, and if you get the ends to within a mm difference then the difference between your nozzle and sensor will be many times less than that. In fact with this system it's easy to get the difference down to 0.1mm or so, which means the difference between sensor and nozzle will be less than a p00fteenth (technical term).

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dc42
RepRapFirmware allows the probe point heights to be corrected to allow for variations in the probe trigger heights, and I think Repetier has some sort of height correction facility too; but AFAIK Marlin doesn't. So I think you need to remove the effector tilt, or move the probe closer to the nozzle to reduce the effect of tilt, or calibrate manually.

Damn. Ok thanks I'll play around with Repetier again, and also try to tighten up my printer some more.

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There's No Place Like 127.0.0.1

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nebbian
If you're interested in removing effector tilt then this might help:

Make a piece up like this, and clamp it to your effector. The bottom should stay flat on the build plate as you move the effector around over the surface. You need to do this for each of the 3 pairs of diagonal rods.

Space out either the effector end, or the carriage end depending on which way the tilt changes as you move the effector. It's easy to see how much tilt there is with this system, and if you get the ends to within a mm difference then the difference between your nozzle and sensor will be many times less than that. In fact with this system it's easy to get the difference down to 0.1mm or so, which means the difference between sensor and nozzle will be less than a p00fteenth (technical term).

[attachment 72643 tiltmeter.jpeg]

That's a great idea, I'll give it a try. Thanks!

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There's No Place Like 127.0.0.1

The thinnest M3 washers I can find are all 0.5mm in thickness. (Found some fancy anodized ones that are thinner, but cost prohibitive)

What do you recommend as an alternative for shims that might go as low as 0.1mm?

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There's No Place Like 127.0.0.1

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EvilBetty
The thinnest M3 washers I can find are all 0.5mm in thickness. (Found some fancy anodized ones that are thinner, but cost prohibitive)

What do you recommend as an alternative for shims that might go as low as 0.1mm?

With an aluminium can, a 3mm drill bit, and a holepunch you should be able to make up some thin ones.

In my case I had some washers that were 0.3mm, and some that were 0.5mm. This combination allowed me to space out both ends to get the two arms parallel (eg: two 0.3's on one end, plus one 0.5 on the other end gives a 0.1mm difference).

Edited 1 time(s). Last edit at 02/16/2016 08:18PM by nebbian.

Between varying widths at the effector end (and seeing no change), and cutting up a soda can, I loaded up Rich Cattel's Marlin firmware and ran a "G30 A".

Seems to have corrected for all the problems and I'm now printing a nice level and consistent first layer.

I just tested with a large calibration model, and it looks good to go!

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There's No Place Like 127.0.0.1

Hi, i see you have aluminium buildplate - is it any good, how does PLA and ABS stick on it?

EvilBetty, Can you post the configuration.h file

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paveldvor
Hi, i see you have aluminium buildplate - is it any good, how does PLA and ABS stick on it?

With PLA I run between 50-60 Deg C, ABS, 110 Deg C. I can't manage to get the bed any hotter in my 68 Deg F basement.

For both I use a clean bed, with a layer of Elmer's purple glue stick while the bed is cold.

I can usually get a few prints off of it before I wipe it down with a wet rag while it's hot, then %91 Isopropyl after it's cooled, then repeat.

ABS prints are hit or miss on sticking well through the printing process. tinny first layer areas need a brim usually. Large ones usually do OK, but sometimes need a brim to prevent peeling on the corners. I'm still working on that.

-EB

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There's No Place Like 127.0.0.1

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Khalid
EvilBetty, Can you post the configuration.h file

This is for a Folger Tech Kossel 2020, FYI...

(Whole Firmware Folder)
[drive.google.com]

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There's No Place Like 127.0.0.1