Z-Axis not true

I have a 1000x1000 x-carve and when cutting a pocket 1mm deep at X0 it’s fine. When I try to cut a 1mm deep pocket at X800 it barely touches the surface of the stock. How can I adjust either the z-axis or the baseboard to compensate for the 1mm drift?

Does that just involve packing it to bring it to level? Nothing more technical than that?

I read somewhere on the Internet that someone ran a facing job over the whole sacrificial wasteboard to get it 100% level with the z-axis. I big job on a 800 x 800 sheet but I suppose it’d be possible.

Just inspecting my wasteboard and it seems that the board is not tightened down to the frame of the x-carve because either the bolts are too long and foul the aluminium extrusion or alternatively I suppose the shoulder of the wasteboard hole could be too deep. Either way there is about a 1mm gap between the underside of the mdf and the top of the frame extrusion. Doesn’t sound right to me.
The wasteboard was supplied with the x-carve but because I’m in the UK, the board is manufactured somewhere in the UK to avoid expensive transport costs from the US.

I found that I had a .030" dip in the middle of the X axis on my board. I would suggest putting a piece of 1/2" MDF on top of the original sacrificial wasteboard, screwing it down, then facing it with a 3/4" wasteboard cutter. It may take 30 minutes or so (with 611 and 3/4" bit), but you only need to carve down deep enough to ensure it is level all around. Putting some pencil marks on the original piece will help you figure out where the low spots are if the first pass doesn’t get everything.

If the wasteboard is larger than the cutting area and put at the lower left corner, you’ll even be able to carve yourself a little square corner to butt stock up against so you’ll know it’s square in the X and Y axes.

Here’s a picture of mine:

I was originally going to do that with the melamine since you can easily remove pencil marks on it, but decided I didn’t want to dull the bit on the chipboard beneath it. Until I replace it, I’m going to just use large MDF scraps as tertiary wasteboards. In this picture, the cut is only .050" deep but gives me a nice solid corner. Since this picture, I’ve had the X-Carve drill through holes to align with all of the threaded inserts, which are in a 75mm grid.

By doing it your way, doesn’t that reduce the available clearance under the X Axis?

it does but you just have to be mind full of your projects that you cut on the wastboard we are talking about less than .5" so you dont loose much and if you do not want to loose any and gain some i would suggest cutting into the existing wasteboard

lol personally I love the look of the inventable wasteboard so i use a spoil board for every cut

another thing you might want to consider it extending your y axis bracket so you can raise the entire machine up that way you can cut large objects

1 Like

Yes, if you use a smaller wasteboard like mine, but that’s due to be replaced with a full-size piece of MDF that will replace the melamine. If you use a full-size piece, you can carve a pocket the full width and length of the axes. You can even make a slightly smaller tertiary board to go on that to let you carve pieces longer than the X-Carve, as long as it is above the height of the lip on the secondary board.

EDIT: Sorry, I misunderstood. Yes, you lose some Z axis clearance by adding a secondary wasteboard. You can always use 1/4" MDF and cut deeply into it if need the clearance.

Another good thing about a secondary wasteboard is that you can resurface it quite a few times before you need to replace it.

Another thing I would recommend checking is to check if your gantry is level. Start by checking your Y axis on the end plates, Make sure they are all at the same height. Measure from the top of the bottom extrusion (The one the wasteboard is attached to, to the top of your Y rails. You have a couple of mm worth of adjustment you can make.

This will ensure all your corners are at the exact same height from the bottom of the wasteboard.

Once you have this height corrected, make sure the X rails are the exact same height from the Y rails. Theres not much adjustment there, but there is some, enough to be off by a mm or so across the X axis. I.e. if the left side is pulled to the top of the hole on the plate, and the right side is pushed to the bottom, you could be as much as a mm off across the X axis.

After all those are as close as you can get them, bolt a 1/2" MDF sheet to your main wasteboard and level it with a 3/4 inch bit. I ran my first one with a 20% ovelap to make the process faster.

This should make your wasteboard 99.99% level.

I’m just in the process of making a 4 section wasteboard to fit on top of the original with the holes that line up with the main wasteboard holes. 4 sections means I can cover the whole 940 x 1000 surface. It was making these and labelling each in the corner with 1mm deep text that brought my attention to the out of true z-axis.
This is my Fusion360 drawing of the 4 section wasteboard

I’ve only got the stock spindle so it’ll take a bit longer to surface I guess.

1 Like