Rostock Calibration

Hey folks,
So I finally fixed my hotend (thermistor went out and its flooded with PLA yikes). After a new thermistor and some handy work with my propane blow torch my hotend is fully functional again

Now I am back to tuning this mystery beast.

I conducted two test prints tonight an I noticed the following:
- infill was sagging downward
- lines are squiggly and zig zaggy
- perimeters and walls were thick and tight
- the 0.35mm layer height seemed to be fine
- infill was not tight
- printed pieces are extremely heavy and dense

I am running the following Delta settings on a printrboard rev B with a standard Rostock design, printed rods substituted for carbon fiber tube and traxxas rodends no changes to standard Rostock dimensions.


//===========================================================================
//============================== Delta Settings =============================
//===========================================================================
// Enable DELTA kinematics and most of the default configuration for Deltas
#define DELTA

// Make delta curves from many straight lines (linear interpolation).
// This is a trade-off between visible corners (not enough segments)
// and processor overload (too many expensive sqrt calls).
#define DELTA_SEGMENTS_PER_SECOND 160

// Center-to-center distance of the holes in the diagonal push rods.
#define DELTA_DIAGONAL_ROD 250.0 // mm

// Horizontal offset from middle of printer to smooth rod center.
#define DELTA_SMOOTH_ROD_OFFSET 175.0 // mm

// Horizontal offset of the universal joints on the end effector.
#define DELTA_EFFECTOR_OFFSET 33.0 // mm

// Horizontal offset of the universal joints on the carriages.
#define DELTA_CARRIAGE_OFFSET 18.0 // mm

// Effective horizontal distance bridged by diagonal push rods.
#define DELTA_RADIUS (DELTA_SMOOTH_ROD_OFFSET-DELTA_EFFECTOR_OFFSET-DELTA_CARRIAGE_OFFSET)

What do you folks recommend?

I have made a custom delta (what a mistake) and have seen almost all printer errors possible. My guess is you have many things going on here.

You will want to address them seperately one change at a tim

- infill was sagging downward
this is almost always a extruder setting... either in Sli3er or your steps per a mm for E axis in Marlin. Extrude 100 mm and do a calculation on steps per mm, measure hte width of your filament and make sure it is correct in slicer. Any steps per a mm calc you do the more you move the less error you will have in your measurement, ie. 10 mm you measure 10.1 verus 100mm and you measure 101.0 you will be able to decern the 1 mm but you may not see the .1. Same with your X Y Z axis (actuals in Marlin) move the machine the full length of your build and measure requested movement vs actual. the nice part of a delat is you have the same steps per a mm on all three of those. (lower in the config.h file)

- lines are squiggly and zig zaggy
Bed level and correct distance? if you start at the wrong distance you will have a first layer that sucks and every layer past will be at the wrong distance and have a squiggly surface to build from. Other than that you may have something binding, or you have a inaccurate build (angles etc.) It should be straight without much effort. The delta math is suprisingly simple and doens't cause a lot of odd shapes if you have the angels and steps per a mm right.

- perimeters and walls were thick and tight
Sli3er settings are the only thing that changes perimeters vs infill. The machine just moves based on the calculationg this made. You will find that if your movement is smooth, accurate and repeatable everything else is in sli3er settings

- the 0.35mm layer height seemed to be fine
Good! ;-) you will get better soon

- infill was not tight
delta rod adjustment would be my guess. Is your size right? 20mm cube is 20mm.... When my infill doesn't touch it's normally becuase my size is wrong. Delta rod is the main x/y scaling adjustment. Technically the only thing you need to change on this is delta rod and or delta radius the rest is just to calculate delta radius.

Delta rod = x/y scaling/size (obivously you want it correct)
Delta radius = "flatness" as you move the end if you have a curve this isn't correct or your build isn't "square" (120 degree angles, square and equal distance, equal length rods, etc)

- printed pieces are extremely heavy and dense
What % infill are you using in Sli3er?

I'm having trouble figuring out EXACTLY what these measurments are...

#define DELTA_SEGMENTS_PER_SECOND 160

// Center-to-center distance of the holes in the diagonal push rods.
#define DELTA_DIAGONAL_ROD 250.0 // mm

-------------------------------^^^--------------This one I understand. I used a fixture to make mine all 250. --------------------------------------------------------------------------------------

// Horizontal offset from middle of printer to smooth rod center.
#define DELTA_SMOOTH_ROD_OFFSET 175.0 // mm

------------------------------^^^--------------This one is from a line drawn between the center "between" the smooth rod pair and the center of the bed? Or from each smooth rod and the center of the bed?

// Horizontal offset of the universal joints on the end effector.
#define DELTA_EFFECTOR_OFFSET 33.0 // mm

----------^^^___________Distance from the smooth rod and the diagonal rod? Offset from what to what?---------------------------

// Horizontal offset of the universal joints on the carriages.
#define DELTA_CARRIAGE_OFFSET 18.0 // mm

-----------^^^^----------------Distance from the u-joint on the diagonal rod and the center of the carriage?----------------------------------

// Effective horizontal distance bridged by diagonal push rods.
#define DELTA_RADIUS (DELTA_SMOOTH_ROD_OFFSET-DELTA_EFFECTOR_OFFSET-DELTA_CARRIAGE_OFFSET)

Does anyone have a diagram of these measurements?

Thanks,
Jeff.

Some delta calibration links

[www.buildlog.net]

[minow.blogspot.com.au]

[forum.seemecnc.com]

[www.youtube.com]

[forum.seemecnc.com]

[gist.github.com]

Quote
wick12345
I have made a custom delta (what a mistake) and have seen almost all printer errors possible.

Now I am trying to correct my mistake !!
big mistake !
tank you !