kossel calibration problem

I am the new 3d printer player, I have one problem want to ask i did the G30 to do the calibration, after finish i am trying to print the 20x20x20mm but i got y1 19.91 x1 19.89 y219.65 x2 19.88 and height is 20.1.
Can anyone help me solve this problem?

Please tell us what electronics and firmware you are using, and what your figures for y1 x1 y2 and x2 mean. I guess they relate to the dimensions of your calibration cube in some way. The height error could mean that your steps/mm setting is slightly too high, but more likely means that you started the print with the nozzle 0.1mm too high. If the X and Y dimensions are too small, this may be caused by shrinkage on cooling, or you may need to reduce the configured diagonal rod length slightly and then re-calibrate.

Edited 1 time(s). Last edit at 10/06/2015 01:57PM by dc42.

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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].

Thank you dc42 fast reply,

Here is my hardware detail, I am using the RichCattell with ramp 1.4

Here is the setting after i run G30
//Z-Tower Endstop Offsets
// 0.0100 X:-2.39 Y:-5.59 Z:-1.84
//0.0000 0.0450 Tower Position Adjust
// -0.0300 A:-0.10 B:-0.37 C:0.46
//0.0450 0.0100 I:0.25 J:0.00 K:0.00
// -0.0200 Delta Radius: 107.3656
//X-Tower Y-Tower Diag Rod: 224.5000
//Iteration: 43

y1 = 19.45mm
y2 = 16.3mm
x1 = 20mm
y1 = 20mm
z = 16mm

My problem is i am trying to print the 20mm x 20mm x 20mm [www.thingiverse.com] cube, but i get above result. i would like to know how to fix the problem.

If you have counted the teeth on your pulleys, and figured out the right steps per mm, as well as carefully measuring the diagonal rods, and gotten your print surface flat, then your calibration has been done.

The problems you are seeing could be to do with many things, including extrusion rate, plastic shrinking, plastic slumping, poor z-height on the initial layer, backlash, etc. If the steps above have been done, then don't worry too much about that final 0.1mm. I would start printing out some normal pieces and seeing how they turn out. You'll learn more by printing some normal pieces than endless calibration cubes.

0.1mm difference isn´t bad for the first prints.
How does the top layer look of the test cube? Is the layer closed, or do you see through?
If nebbian is right, you might have underextrusion or your filament is thinner than 1.75mm. The top layer is a good indicator for this, but you can do extrusion calibration, too.
-Olaf

Hello,

The test cube top layer is good... only problem is
y1 = 19.45mm
y2 = 16.3mm

Yes sure i will try extrusion calibration,

but i would like to ask anyone,
What is the angle of column and radius error column, Can these setting fix the size problem?

Quote

//X-Tower Y-Tower Diag Rod: 224.5000

How big is the difference to the actual rod length? When XY-rod =224.5, but Z-rod differs much, it can lead to geometric problems seen in your Y1/Y2 length.
-Olaf

Hello,
Thank o_lampe, the org, DEFAULT_DELTA_DIAGONAL_ROD 218.5 and 224.5 is the G30 setting.

Try G30 A0.1 D218.5. Or was it G30 A0.1 R218.5 ?? Can´t remember where I read the detailed instructions...

This will perform autocalibration without changing the rod length.
-Olaf

Edited 1 time(s). Last edit at 10/07/2015 05:51AM by o_lampe.

It's a mistake to allow auto calibration to change the diagonal rod length, unless for each tower you include a bed probe point approximately opposite it and far away from it, outside the normal circular print area. Another forum user (hercek AFAIR) published a plot on these forums a few weeks ago showing why this is the case.

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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].

Thank you for you guys helping, i will check it up tonight.

Thank you again for your help.