Inverted carve -newby

I am trying to get a desktop carver working for a friend.
When using the jog controls all axes move in the correct direction:
X left moves X axis left; Y up moves Yaxis towards the back; Z axis up moves Z axis up.
Machine is a chinese diy kit controlled by Arduino Uno and Motor shield.
I am using Easel software as it allows me to get started without having to learn CAD.

I used the trace function to get a line image of an .jpg.

Here’s the problem:
I set home position thus: X all way to left; Y all way to back (cutter point now being at lower (front) left); Z touching surface to be carved.
When carve starts Y axis tried to move back!

So I have to set X0 and Y0 as Top Left I.E bring Y axis all way to front (cutter is now top left).
Carving now works fine but the carved image is vertically inverted (mirrored).

I have tried various combinations for motor (nema 17) connections to no avail.

What am I doing wrong?

That statement doesn’t really make sense. How can you move it all the way to the back but the cutter point is lower front left?

I’d suggest using jog commands to understand your X/Y/Z directions and make sure the non-Xcarve Chinese kit is setup the same way as an Xcarve would be setup.

When facing the machine as Phil shows (router in front of you), the directions of an Xcarve are X carriage moving right is X+, moving left is X-, moving away from you is Y+, moving towards you is Y-. Z+ is up, Z- is down.

The machine has a work platform that moves back to front, cutter assembly is fixed and moves on the X axis.
As I understand this the zero position is normal XY axis 0 (bottom left).
To get to this position I need to move the plate to the rear ( axis) and cutter to left (x axis) - this puts the cutter to lower left (as in the grid in Easel)

Hope that clarifies.

Thanks for that.

I have indeed done all of that and all works correctly.
My cutter is placed on the X axis and the Y axis is actually the work plate and it is tht that moves backwards and forwards

Thanks for that. The image is very helpful.
In the ‘Shape’ control I have left the default lower left option button selected.
This is something I intend playing with once I get my problem solved.

1 Like

Which video? only a link to ‘image’.

As a simplified example: here’s what I try for:

and here’s what I would get:

(Sorry image would be to the left).

In the first image you can clearly see X0 and Y0 at bottom left.
I have to set X0 and Y0 at top left or the machine tries to end (Edit: move) the cutter off the bottom.

Here’s the machine:


For the cutter to move up the Y axis (to the rear), the plate (table) has to move down the Y axis (to the front).

As I’ve said: I have checked all movement directions on the X, Y and Z axes using the jog buttons - all work as they should.

The problem I’m having is the inverted cut.
Even if I start with the wrong zero coordinates I should still get the image correctly carved not an inverted carving.

I’ll try later to get some pics of it carving.
Thanks everyone.

Edit: $3 =6

Does the machine have homing capability? If so, where does it home to?

If it’s not the front left, you’ll have issues with the directions not being correct.

That machine may be configured that the “front” is looking at the other side, which would explain the carving you get.

You need to understand where machine zero is and what coordinate space it’s in. The Xcarve, from my understanding and experience, by default operates essentially in negative space. Basically the Xcarve space, if you’re looking at a set of X/Y axes is the bottom left quadrant. “Home” is not 0/0 but -750/-750. Work zero is then derived from that point and you get a work 0/0 so your carving becomes positive space.

1 Like

grbl version 0.9g

Yes using an Arduino.

I’ll try the $3 masks later as I have to go shortly.

Thanks for your help.

1 Like

That now makes sense!
When I add to the Y the cutter should move to rear (or plate to front) - Got it! Thanks!

Will try that setting when I get back.

1 Like

Correct. That’s why I said “by default” as in how it ships from Inventables.

1 Like

I did. But he’s using Easel which is developed for the Xcarve and therefore it’d be best to make sure your machine acts and behaves like an Xcarve for optimal results.

My point of positive/negative space was to show how his machine may be operating in a different machine quadrant/space and that he needs to get it into the Xcarve quadrant space, which your posts about $3 and such would get it there. I was just trying to provide some more background on why the potential problem may exist and show the bridge to the Xcarve.

No harm, no foul.

1 Like

Hi all

Sorry I didn’t get back to you earlier, other things at home took priority.

@PhilJohnson PhilJohnson, Thanks for the tip for $3 - it solved the problem. I should have realised it myself as I’m moving the table and not the gantry.

I’m having intermittent problems with the motors at present but I’m certain its just wiring connections. I’ll just replace all the connectors with soldered joints.

Thanks again everyone for your help and advice.

1 Like

The ‘instructions’ that came with the machine did mention to set up as Xcarve default.
That didn’t mean anything to me until I found Easel and this forum.

The problem was my inability to realise that its the cutter that should move whereas in this case it was the table. This meant that Y axis was simply the wrong way round for this machine. As I have absolutely no experience of cnc or gcode I was flummoxed!

Thanks again everyone.

1 Like