Do i need to calibrate Z axis ?

Where do i change that value ?
#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,2267.72,723.38}
Is that it ?

 

Tony, Unless Polylac confirms and gives his reasoning for it I would keep it at the firmware setting from the last two updates which you show in the #define above.

See:
http://reprap.org/wiki/Triffid_Hunter's_Calibration_Guide

"// NEMA 17 with SAE 5/16" threaded rod. It has 18 threads per inch (25.4mm / 18):​

(200 * 16) / (25.4 / 18) = 2267.7165355"

"​

Unrelated to your question - the last value in the #define is for the extruder and will depend on your hobbed bolt diameter.

 

Well i tried printing at 0.1 and here is what i have. By the way i had this issue since day 1.
1st image is default 2267
2nd is at 2264.
3rd is printed at 2264 at 0.3 layer height.
0.1 2267
0.1 2264
0.3 2264
Results are similar and on some sides more obvious then on others.
It cant be the hobbed bolt, because it would then not be effecting each layer but the mm's of filament extruded.
Its something else. Its like its not lifting up evenly or not extruding same amount each layer (which doesnt make sense.)

Speaking of hobbed bolt. Mine is not round, when it rotates it wobbles because the recces was not cut straight. Even by looking at it you can see that it was not machined right.
I addressed that in the support forum but no one replied to it and no one sent me a replacement.
I have it black, the one said to work better.

 

Then it is maybe the hobbed bold. When it's not round, it will be faster and slower (like having a bigger and a smaller wheel). If its caused by this, the distance between two wobbels should change when you change the size (double the filament usage = hlav wobble distance).

In another thread recently someone had also problems (but not exactly the same as here) after changing the firmware...

 

It cant be. Printing large prints looks exactly the same, otherwise i would see it go more or less here and there as the bolt makes full rotation but its not. Its consistent.

 

Tonycstech did you ever solve your "ribbing" issue as I am still getting the same pattern on my prints no matter what I do, in fact if I laid a picture of my cube over yours I think it would almost be a match

 

no never. it made me gave up on robo. dont want to invest into metric rods just to find out that its not enough

 

Tony: to my thoughts you have a bend push rod (or how does it call) or both of them. when it moves up the extruder draws a small circular in XY plane. Do a simple test - in manual mode tell it move Z+ 10 mm and carefully watch - there should not be a XY wobble.
another thought is that when it slice it has some repeating uneven roundings of coordinates (less probable) - will you try a different slicer?

 

Perhaps its the coupler?

 

Picked up a 1 meter metric rod to cut in half for $7 and I have nuts I posted I am willing to send people for free.

 

Ordered one today 1 meter long. Will cut in half when i get it.
I can get nuts from homedepot near by, just need to know: rods are stainless steel so nuts need to be copper or what ?
As far as the setup, do i need to do any flashing of firmware ? If so, what changes do i need to make.
Thanks !


Cant wait to get those waves out. Making me razor blade my prints all the time to make them fit

 

Just use the Z step number from http://calculator.josefprusa.cz/ which for the M8x1.25 rod should be 2560.00

You want to use a non-stainless nut like steel, brass. bronze or perhaps nylon like SoLong is using.

 

If you are using the stock Robo what is the z rod 5/16 and how many steps?


Sent from my iPhone using Tapatalk

 

The latest firmware has the correct calculated value of 2267.72.

#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,2267.72,723.38} // default steps per unit for RoBo 3D R1

 

100mm Length M8 / 8mm A2 Stainless Steel


is what i ordered.
What does A2 stands for ?

My firmware does say "2267.72" Updated couple of months ago or so, thanks !

 

Just finished my metric rod upgrade, print was 1 mm under height so had to change the firmware from 2267.72 to 2560 and now it is pretty much spot on. Please not though after flashing the firmware the Z axis did not home , I could move it using manual controls but when homing it moves quicker and the motors just hummed so you will need to tweak the stepper boards.

 

A2 designates that stainless steel alloy:

• Type 304—the most common grade; the classic 18/8 (18% chromium, 8% nickel) stainless steel. Outside of the US it is commonly known as "A2 stainless steel".

 

Did you print any test cubes and did it help with the periodic Z axis wave? That wave is, in theory, due to the Z stepper snapping from a microstep position to a full step when it is disabled on each layer.

 

Laugh at me, i received my rod.
Its 100mm long LOL
What was i thinking, centimeters ?
Paid $4 for the rod and $6 for shipping.
Nor sure if 1 meter of same thing would cots $6 as previously stated.

 

Doh! You could make a robo3d mini me.