3D Touch G29 Issues

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JamieHandsDev
Posts: 1
Joined: Mon Sep 30, 2019 5:06 am

3D Touch G29 Issues

Post by JamieHandsDev » Mon Sep 30, 2019 5:09 am

Hi All,

I'm having some issues with my Geeetech i3 Pro. Running a G28 works fine, probe detects and z stays at the correct distance from the bed. Then when I run a G29, it probs the front left and front center fine but the front right just continues and crashes into the bed.

I'm running a Marlin 1.1.8 version as couldn't get a Marlin 1.1.9 to work at all. The officia Geeetech also gives the same results.

Any information you can give would be appreciated.

Thanks,

Jamie

GAQ
Posts: 101
Joined: Mon Jan 08, 2018 9:10 pm
Location: Manchester UK
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Re: 3D Touch G29 Issues

Post by GAQ » Mon Sep 30, 2019 7:34 am

Hi Jamie,

Sounds odd that the G29 command fails having correctly probed the first two points,
you'd think it would plough into the bed on the first point or not at all !

What 'Version' of Marlin 1.1.9 did you try to use ?
I used this one with my BL Touch and it worked first time...
https://www.geeetech.com/forum/viewtopi ... 66&t=62412
Link is in the first post in the thread.

Please note that you will have to change the 'Z' axis steps about 1/3rd the way down your config'.h file if you are using M8 x 1.25mm rods as this version assumes the use of T8 leadscrews... (Simple fix - see below)
...
/**
* Default Axis Steps Per Unit (steps/mm)
* Override with M92
* X, Y, Z, E0 [, E1[, E2[, E3[, E4]]]]
*/
#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,400,93}
...

You'll have to change the '400' value to '2560' if you're using M8 rods.
These have a pitch of 1.25mm - The T8 leadscrews have 4 concurrent threads and one revolution moves 8mm.

That's an easy fix and should work.

Another thing to try... Which probe are you using ? - Does it perform the 'Self test' , 'Deploy probe' and 'Re-set' commands correctly every time you run them ?

I spent hours with my first build playing with the software only to find that my probe was working erratically - My mis-fortune. Many people have a cheap probe working perfectly.

Gerry

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