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Author Topic: Newbie homing issue  (Read 1837 times)

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Newbie homing issue
« on: June 26, 2014, 02:48:45 AM »
Hi All

First post on the forums  ;) I have recently completed construction of my in-house built cnc, fairly small with travel of X:805mm, Y:1000mm and Z;160mm. The machine was designed to be dual purpose, both milling (light milling of metals ie aluminium) and plasma. I have already run the machine both as mill and plasma, working great so far ;D

One issue that has been bugging me is that the machine homes at the back right instead of front left, the Z homes correctly at furtherest point from table. The machine travels correctly though and images in tool path appear and cut correctly, so if i press left on keyboard the X axis moves left and increases on DRO as it should, likewise for Y & Z. If i reverse the axis in homing and limits then it does change the homing location, but if i press left on keyboard it travels right, and the DRO then  counts negatively moving towards the right, likewise for Z positive towards material.

I have also tried to change the direction port under ports and pins motor outputs, this also got the machine to home in the correct direction,BUT pressing left or right on the keyboard then jogs the machine in one direction only.

So my rather long winded question is how do i change the homing location from back right to front left?

Some details about the electronics:
BOB: cheap and chearfull chinese 5 axis board (V5 with relay is about the only description i can get on it)
Stepper drivers: CW8060
Steppers: 34HS4802 1230oz-in (dual Y)

Any help here would be greatly appreciated!

Offline Hood

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Re: Newbie homing issue
« Reply #1 on: June 26, 2014, 09:01:23 AM »
What style of machine is it because I was thinking a gantry style, yet you say "so if i press left on keyboard the X axis moves left and increases on DRO as it should"
To me that would only be true for a moving table type machine.
Hood

Offline ger21

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Re: Newbie homing issue
« Reply #2 on: June 26, 2014, 09:14:46 AM »
As Hood says, it sounds like your machine is setup backwards.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Newbie homing issue
« Reply #3 on: June 27, 2014, 03:08:06 AM »
Thanks for the replies, Yes it is a Gantry type. I see I also miss typed there, if I move the x along the gantry towards the right the X DRO increases (positively) likewise for the Y if I move it towards the back of the machine it increases positively

Here is an image to illustrate movement and current homing location
« Last Edit: June 27, 2014, 03:21:52 AM by Squigly »

Offline ger21

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Re: Newbie homing issue
« Reply #4 on: June 27, 2014, 10:19:01 AM »
You just need to check "Home Negative" for the X and Y axis to home in the front right.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html