I’ve been noticing that my X-Carve is cutting ever-so-slightly shallower on the right side of the bed.
Normally I would place a piece of paper on the bed a lower the Z axis until I felt resistance while moving the paper, and then adjust the height of all 4 corners of the bed to match.
But in this case there does not appear to be any clear/obvious way to independently adjust the height of each corner of the bed.
Is there a documented process for this anywhere?
Thanks!
/Chris
I’m only guessing because I don’t have one in front of me - but isn’t the waste board just held in down by screws around the perimeter? If so, couldn’t you just loosen all screws 1/2 turn, do your measuring and put shims underneath where needed, then retighten and remeasure?
If you don’t have an indicator gauge to mount in the spindle,you can use a feeler gauge and an upside-down drill bit. Power off, 1/16th drill bit in upside down, move by hand to where you think the highest point is. Move the Z-axis down by hand until the bit just touches the table. Without changing Z, move spindle by hand to the opposite corner, use feeler gauge to see how low it is and that’s how much you shim. Repeat with the other corners.
If you want to get fancy, you can put drill a new hole near each corner and one in the middle of each side and put a threaded insert in them. Then get a set-screw in each threaded insert to act as leveling screws. (like on a router-table faceplate or a tablesaw insert.)
Thanks Joe!
While it would work, I’m hoping for something a little more accurate/reliable than shimming the waste board.
Unfortunately the way the waste board connects to the base with 6 bolts (3 front, 3 back) it would make adjusting the corners difficult.
I find it hard to imagine Inventables does not have a more elegant leveling solution accounted for in the design of the machine, as leveling is a requirement for all CNCs. At least that’s what I’m hoping!
/Chris
And with that nice silk screened layout, I wouldn’t want to take a fly cutter to it either. Another reason I’m thinking of just making my own waste board.
I’ve had a homemade machine for 4 years learned early on to have a wasteboard on top of my wasteboard. I use a half inch end mill to grind it flat to it is always perfect. for material hold down, I use screws through my project into the temp wasteboard but not through the original wasteboard. I have only had to replace my 2nd wasteboard once in that time with hundreds of projects. Easy, fast, accurate, with better material hold-down and it allows you to see exactly your actual live cutting area. I use MDF. I am replacing this machine with the x-carve - hopefully soon.
you could always mill the wasteboard flat with the cnc? 
In some cases that would be an option, but not here.
The bed has a nice silk screened grid on it I’d like to keep.
The bed has embedded metal threaded inserts for clamping work down.
And only leveling the portion of the bed that falls within the work area of the mill would leave a shallow pocket, making it so work pieces that are larger than said pocket would become un-level. and not be properly supported.
(edit - drat just read back and my whole post is more or less a repeat of @JoeMeyer. sorry…)
Seems like shimming between frame and wasteboard to level is your only option. Can you put a fairly benign tool into the collet (so you don’t cut yourself), zero the z to the wasteboard in the corner you think is ‘highest’, then move to different x and y positions and try to map out the spacing to the tool using feeler gauges or something? Write it all down and if there’s a definite trend, you can figure out a spacer combination that might let you drop the high side. But if it’s not a linear sort of gradation (wavy or random) then it sounds more like the wasteboard itself isn’t truly planar.
On my little 3D printer bed (6" square) lack of level and planarity can only be adjusted so far, even with glass atop my heated bed. Just sorta had to learn to live with it, split the difference between the extruder nozzle very slightly scraping the glass at the high spot but not having too much spacing to stick the extruded plastic on the low spots. I think with anything other than a metal base the Xcarve is going to have similar limitations.
I may not be an expert but I would check several things first,
is the table perfectly flat? If not that could change the level of the machine. Not having my Maxine yet I’m not to sure about the corner pieces that hold the rails, is there any chance there is a mismatch? You could try loosening the corners to relevel the side rails. Again just speculation
@RichardRemski I just find it hard to believe such a newly designed machine would neglect to account for one of the most basic and common setup steps on any multi axis computer controlled tool (3d printers, CNCs, laser cutters, vinyl plotters, etc)… I’ve worked with all those types of machines and never encountered one that did not have work surface leveling incorporated in the design. If the only option is shimming the waste board I would be both shocked and extremely disappointed.
@AntonioNunez the table is level, but that would not impact the leveling of the tool head to the work surface. Because the 4 corners use self-tapping screws into holes in the ends of the extruded channel there is no clean way to adjust their vertical offset. I could potentially drill out the Y-axis end brackets to allow for some slop, but that would also increase the potential of that joint shifting, which is not good. It would also b a very difficult and inaccurate way of leveling things.
Right now the waste board is nice and secure and supported along its length. Shimming (or doing anything to independently raise any of the 4 corners) would mean portions of it would not be supported and would be likely to warp.
Another option would be to raise and lower the supporting extrusion that is under the waste board rather than the board. But as that extrusion is what the machine sits on, that would mean the machine would not be level with the table.
Hoping someone from Inventables can chime in and shine some light on this.
Well, in my 3D printer, the way of adjusting for bed level is turning short leveling screws at the corners of the bed—in essence “shimming” between the actual print bed and the structure to which it is tied. For 3D printing of course the bed changes temp thus warps/unwarps, and (in the case of my ancient Solidoodle2) the part that the leveling screws push down against is laser-cut-plywood which also moves all over the place with temp, humidity, or just plain crotchetiness I guess. 
Putting shims between rails and wasteboard or the wasteboard and its stiffeners is pretty much the same thing…
I still suggest measuring the out-of-true to get some idea of what it really is - waviness, a slope, a curve (either ‘sag’ or ‘bow’ of the wasteboard). Might help you come up with the best way to deal with it. If it’s waviness for example shimming won’t do much good.
And of course as you point out MDF isn’t the most stable material over time - it does tend to slowly mold itself to its support (or lack thereof). I’ve got a couple jigs I made of it that have leaned against the side of a fridge in the garage off and on for years. They have a distinct ‘curvature’ to them now (I clamp to my workpieces when using them).
Is anyone else even having these issues? Maybe the endplates you received were not within tollerance and that’s why yours is off. I just have not really seen anyone else complain about this issue…weird…shouldn’t have to level the bed with something made like this.
This may not be a good question but why wouldn’t you put a larger straight router bit in and use that to level the waste board? I am guessing it is because of the silk screening but for those of use who made our waste boards what is the harm?
So, when I mill my wasteboard down, there is indeed a pocket. To accommodate larger pieces, I have a piece of mdf that fits into that pocket. Then my larger work piece sits on top and can take full advantage of all of the space between the rails and out both ends. Of course, I have lots more Z clearance than the excarve in its traditional form.
Any Inventables folks have a solution for this? I’m hoping that I am just missing something obvious, but I’m growing a bit concerned that bed leveling is not accounted for in the design.
With the MDF waste board it is almost impossible to get a level milling surface from one CNC to another as the MDF is not milled flat in the sense that a work surface for most mills is. There are 3 choices over all and only one will be the way to get a true flat surface and it is not cheap or easy. The one true way to get a flat surface and one which you can then measure the squareness of the mill off of is to use Mic6 tool plate for a waster board and then place holes in it like the MDF board with inserts. Like i said, not cheap or easy. But it is milled to within about .005mm I think it is over a 4" run so it is pretty much dead flat. The second and most common “upgrade” option is to go with a metal slotted bed like this :http://us.misumi-ec.com/vona2/detail/110302261820/?HissuCode=HFSQN4-15250-[50-3000%2F1]&PNSearch=HFSQN4-15250-[50-3000%2F1] (2X 250 wide X 500mm long pieces) will give you a much flatter bed than the MDF and MUCH cheaper then the Mic6 tool plate will. If you wish to stay with the MDf waste board then I would place a small piece of pine below your object to be milled whichis slight larger then your project. Mill a pocket flat in this then clamp it and your work down with your clamps. This will give you a flat pocket to place your work in and will allow you to keep your nice waste board.
Trying to level the mill and or waste board will give you a few issues in that on a MDF waste board you will not know if it is the MDF or the mill which is out of line. Only with something like a tool plate surface which is milled flat before you buy and mount it to the mill, can you know if the mill is truly level and true or if is has a very slight error in the setup or assembly steps which is causing an error in the leveling aspects.
I get that MDF will never be 100% level, but I’d like to get a lot closer to level than where the machine is now, which would be quite easy if there were a way to adjust things.
Upgrading to a slotted bed would be nice for the future, but for now I just want the bed level enough so engraving is not noticeably shallower on the right side of the bed.
@ChrisEllerby
Is there a way for you to check for flatness of your Waste Board? On mine I checked it with a long side of a metal T square that I know to be flat and ridgid along it’s length. If you do, check for warp on the X and Y axis and on both diagonals. Seeing if you’re MDF is close to planar in the first place might be a step towards a solution.
Chris try this. It worked enough for me. Use a caliper to get a measurement of the distance between your Y rails and the MDF directly below it from each end. Chances are these are not perfectly parallel meaning its likely not your wasteboard at all. You actually do have a very small amount of play where your y rail end plates attach to the lower frame and waste board, (where the sliding nuts are). You might be able to cheat each end up on one side and down on the other a tiny bit. And if you needed more you could remove these nuts and sand them narrower to give you more play. Now be sure that the distance on both sides (both rails) is the same. Its pretty likely that your waste board and extrusions under the waste board are flat enough as long as you have it all screwed down tight you should not need shims. This is all assuming the surface your X carve is sitting on is perfectly flat to start with. If it is not add a piece of 3/4 MDF under everything. Good Luck Chris!
And I forgot to mention to do the sale thing on the X axis , measure each end and use the tapped screw attach points and the V wheels to adjust.
