How to use Highcooley's Onyx Bed Leveling Aid to 'level' the

[Tonkabot]

Okay, I printed the bed leveling aids, both the little one and the big one. (http://www.thingiverse.com/thing:50505 is the big one, there is a smaller one tex posted in mhackneys 12 step ASSGP thread)

The little one prints and the width at the X tower was .503mm, Y .403, Z .403, center .430. I thought that was fairly close and it does seem to work okay, although I'll keep tweaking it.
However I tried printing the big one (240mm in diameter, I actually printed the 250mm one tex posted), and it is an obvious failure. at the points OPPOSITE the towers,
X' which is between Y and Z, as far from X as you can get, the print head was up so high the filament didn't even touch the bed.

Now I know I may have sliced it wrong (I think it was supposed to be .4mm layers, but the first layer is .35 for me right now), but are the only things I really have to adjust the X,Y,Z end stops, the radius, and the z height? (and isn't adjusting the 3 endstops an equal amount the same as changing the z height?)

Or do I have to go back and use the many point calibration that someone was playing with, that can fix the delta's problem of being least accurate in Z at the X',Y', and Z' points?

[Jimustanguitar]

Grab your reading glasses, http://forum.seemecnc.com/viewtopic.php?f=37&t=4868

It's not terribly common, but there are a handful of us that fight with this.

[Tonkabot]

I knew there was a thread on it somewhere, which I have read much of already. I'll look again now that I am thinking about it. If I recall, it is somewhat solved in software with a calibration matrix...

Thanks Jim

I assume your name is Jim, you have a mustang (car), and you play the guitar. I also associate the avatar picture as how you actually look
I think I just saw a movie that had the same guy dressed similarly wildly [ idioacracy? I don't remember]

[Jimustanguitar]

Yep, Jim with an old '67 Mustang (father son project that got off the ground as in on blocks, but is still there 15 years later unfortunately) and a room full of guitars.

Don't look much like Mugatu though, it just makes me laugh to look at


My solution to the leveling quandary has just been to shim the bed where its mounting holes are. It doesn't true the motion of the machine, but it makes the whole bed printable. I personally think that a tweak of a few thousandths isn't that big of a deal for a piece of plastic that's going to shift as it cools anyway.

[Tonkabot]

Sooo, after rereading the mysterious Z0 thread-a-thon, it seems that there are two things that can be done.

The first is what you did, which I want you to correct if I am wrong:

1) remove the bed and snowflake
2) measure (with dial indicator) the Z at [very near?] the snowflake mounting holes
3) adjust the endstops and arm radius to get it flat
4) What cannot be gotten flat needs shimming, maybe with aluminum foil [or Kapton tape?]
5) put the bed back on.
6) pay some kind of attention to where the clips go because they BEND the borosilicate glass [Really? The glass bends? I thought we used glass because it was [really] flat]
7) now adjust endstops and arm radius again [is this needed?]

I think you [Jim] did more or less that

The second thing that I see can be done [which seems like I should try the above first, and only if it still sucks going on to this] is to use 626pilot's bed software that must be applying a transformation matrix to all the coordinates to mathmaticaly remove the bed flatness errors [which are not really the flatness of the bed, but the slop in the geometry of the frame of the Rostock.]

The second also requires a smoothieboard, which I don't have. I actually have started designing my own variation of a smoothieboard that has an ARM M4 with floating point and more RAM than a smoothie. (a smoothie uses an M3 without floating point math, and even 626pilot said he had RAM size problems with it.)

I'll start another thread for that project because I want a wish list from everyone on what features they want in the motion control board.

[Jimustanguitar]

Remove bed and level 3 points (center point optional and each tower's leveling screw)
Reinstall bed and measure 6 points, one above each mounting screw.
Shim as needed (don't touch the endstop screws) and get everything as close as you have the resolve to stick around for.

[Tonkabot]

Remove bed and level 3 points (center point optional and each tower's leveling screw)
Reinstall bed and measure 6 points, one above each mounting screw.
Shim as needed (don't touch the endstop screws) and get everything as close as you have the resolve to stick around for.

Where are these tower leveling screws? And what do I measure them against to get them level? just each other?