DIY cnc? anybody familiar with configuring GRBL?

[707offroad]

My friend gave me an old MAXNC 10 and I've retrofitted some small nema 17 steppers and a Sainsmart prover grbl controller.
I'm trying to get the stepper motors calibrated and I really have no idea what i'm doing.
I've tried changing the values for $100, $101, and $102. but I don't fully understand what i'm doing.
my stepper motors have a 1.8 step angle
leadscrews are 1/4-20 allthread

What values should i be changing

?

Thank you in advance

707

 

[Boss]

This old Tony on the YouTube made one that was pretty cool. Might be worth checking out. That's all I got. I try to stay away from shit that makes my head hurt .

 

[SomeGuyFromOlympia]

This Old Tony is legit
and funny

 

[DVanVorous]

Start from the fact the "lead screw" threads are 1/20" or .05" travel per thread. 1.8degree step angle says that a 360 circle has 200 steps/360 rotation.

Personally, being a bit of an idle curiosity type, would mount a dial indicator on each axis and put a number in and see how much travel/change and which axis changes. Then mutter under the breath, ask the forum again, or better yet track down an idiot book with all the answers you need...except the ones you need answered.

 

[yozsi]

Aww, ain't that a cute little toy

 

[yozsi]

I'm assuming you've read this already

GRBL Settings 101: A How to Guide

So your machine is under its own power. Nice work! But how do you know it will do what you tell it too? Click to learn how to adjust the GRBL settings.

diymachining.com

 

[subybaja]

This is the closest I can come to being useful here.

 

[cervelorod]

Inventables uses grbl ( blech ), and they have setup docs that might be helpful. You can use easel for free to generate code for grbl also. I converted mine to Gecko / Mach3.

 

[707offroad]

I must be doing something wrong. If i set my $100, $101 and $102 values to 3000 it gives me about .98" movement when jogging the machine one inch.
When i use the formulas to calculate these values I come up with a $100, $101 and $102 value of 1259.84252. that value gives me about .38" movement when jogging the machine 1 inch

 

[bgaidan]

Set those values to 3061