SO3 XXL - A noob requesting help with sheet metal cutting

I have had the Shapeoko 3 XXL for 2 weeks now and the process I have been going through as a noob has been one of the most frustrating experiences of my life and that is saying a lot. So for my request, I am going to try to paint the picture as simply as I can.

  1. I am no master at SketchUp but I am good enough with it that the projects I have that I want to get done are no problem to complete using it.

  2. I have a plugin in SketchUp to export the models in DXF format and the only way I have gotten that to work is the lines feature. Good enough I guess?

  3. I know enough about Carbide Create now to import the DXF and set the toolpaths no problem.

  4. The shapes I am cutting are out of 20-gauge (.04") thick aluminum sheetmetal that is 20 x 12 and I know how to zero the CNC enough to get the job done.

Here is my dilemma and I am at a loss as what to do. I do not feel comfortable running the job without the use of construction tabs in the toolpath. Here is a picture of what I want to cut:

None of this would be an issue if I could just set the construction tabs via Carbide Create. So I went to Easel’s web-based app because I see it uses tabs. But I cannot import DXF files into it Easel and I can not import the gcode that I have saved from Carbide Create. What the heck am I supposed to do??? It seems like every time I find another route to take it leads to another dead end due to whatever it is I cant do with that app but can with this and they dont import/export to each other…

Any help will be appreciated but please in responding dont assume I will understand, or in otherwords please dumb it down for me.


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Probably the easiest thing to do here would be to export an STL from SketchUp and then do the CAM using MeshCAM (but that’s an additional purchase for a Shapeoko).

In order to get tabs from Carbide Create you would need to draw them in, then do Boolean operations (along w/ suitable duplications) to get areas which you could cut as pockets leaving the tabs in place. Sort of like this:

Recent discussion of this sort of thing:

If you still have trouble with this, feel free to post the .c2d file and I’d be glad to work up step-by-step instructions.


First of all thank you so much for replying as I was not expecting an answer for some time. This makes sense, my only concern for the most part has been this is a sample of one of 18 products I have been doing by hand that all have their own unique measurements. For example this is 10.1" tall and 12.5" wide. How would I measure out the 10.1" in carbide Create?

I would love some step by step if that is ok with you. Would it make sense to draw it all out in, holes for tabs included, in SketchUp first?

Thank you again.
FDR5 - IO.c2d (56.9 KB)

It should work either way — probably faster if all is drawn up, but that creates the possibility of difficulties caused by overlapping / intersecting geometry.

Working this up now.

I really appreciate it. I know its a pain exporting DXF files from SketchUp cus it does translate circles into circles. I just tried my hand at boolean and failed as every time I tried it was removing one part or another. I have the trial version of meshCAM and I cant figure it out…

Begin by selecting the pocket and noting the center location:

X 10.796
Y 10.001

control c to duplicate the selection, click away, the re-select it to get the position dialog:

Set the X and Y positions to match the original, then reduce its size so that it is inset by at least endmill diameter + 10% in all directions:

Draw in the geometry for the tabs, then click on the original to select it, the control click on the geometry for the tab so that the latter has a dashed selection highlight:

Select the command Boolean Subtraction — repeat for any remaining tab geometry:

Select the central geometry, duplicate and reposition it as many times as needed to make one instance of it per punched out pocket geometry (in this case, duplicate it twice), then select one of the punched pocket geometry pieces, then control click to select an instance of the central geometry (note that it may be necessary to do a drag-select, then control click on an undesired bit of geometry, alternately, zoom in and out as needed):

Boolean Subtract it from the punched pocket geometry:

Repeat as needed (note that you may wish to preserve the original outer geometry of the pocket so as to make a pass to at least half the depth so as to define where the cut ought to be — for clarity this was not done in this tutorial):

Repeat for the outer geometry, save that you will enlarge the initial copy.

Hopefully that will get you cutting — if not, let us know where you find it confusing and we’ll try to add any additional needed detail.

You will then assign pocket paths to get to full depth (in addition to the initial pocketing of the original geometry and its duplicate if you choose to do this).


First of all, I am so grateful for this! Thank you for taking the time to hold my hand through this process because this is all so new to me. I have worked in IT for years and know computers thoroughly but this is a completely different concept to wrap my brain around.

My only issue is I currently have 18 different models with their own unique measurements of the above design. Of each of those designs, a customer can choose to have upwards of 20+ customizations per product (i.e. how many grommets which are what those oval cutouts are for, and where the grommets will be which have standard locations per unit). So that being said I will need an easy way to be able to make these designs ready for production and I really do not want to go through this process over 60 times per 18 models with an increasing number of models. Does that make sense?

Basically, in a nutshell, I am going to pay for Fusion 360, even though my designs thus far are really not overly complicated, just so I can have the ability to use tabs and not have to export this and export that and going through upwards of 4 pieces of software to do it. I feel like all of this could have been avoided and I wouldn’t have wasted an entire Saturday trying to find the most optimal solution had Carbide Create just had the ability to put tabs in and select where they go. Easel does a great job of that but they won’t accept my files from SketchUp which is the epitome of the roadblocks I have been faced with in this process of learning this all from scratch. So being back at square one at this point makes me feel like its -100 of square one because the time I had taken in the past to learn SketchUp is now caput because I have to learn Fusion 360 instead and be out $25 a month for it.

FWIW, my inclination for this sort of thing would be to just code it up using something like METAPOST, and develop a filenaming convention which makes it obvious which file has what features.

Tabs are a frequent feature request and will hopefully be added in an update sooner rather than later.

Another commercial option which supports them is Vectric VCarve (Desktop/Pro, maybe other versions / variants) — a workholding option which might allow you to dispense with them would be a vacuum hold down system. See and the plans at:

I don’t have a problem with making a design file for each once I get the hang of it and once tabs are a feature this all would not pose a problem. The vacuum table idea does sound good but there are some customers that want diagonal ventilation holes cut out that will roughly be 3/8 - 1/2" thick and I couldn’t guarantee that as they are being cut out they would be sufficiently held in by the placement of the vacuum table. That and I just don’t have the confidence or experience in making sure this thing is fully squared and level.

As an example, I recently trammed a supplementary wasteboard on top of the original wasteboard so it would be perfectly level according to the machine. Then I go to do a job putting holes into it for threaded inserts to find that the top outer hole for the inserts to sit flush are not as deep in the center of the board but they are fine on the outer perimeter. I thought tramming would be the last thing to get this thing perfect but now I am pulling my hair out again.

Dialing in precision can be a circular, tail-chasing thing, especially the first time one sets up a machine. Just start from large to small, working your way in to the center of the machine, and do this in a consistent, systematic fashion each time and eventually it will all fall into place.

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I use CAM software called Cut 2d by Vectric and it does tabs (really easily). The entry level version is only about $150 and has more that paid for itself in time saved every time I work up tool paths and g-code for a project. My point is, CC is a great tool to learn basics on, but at some point you’re gonna need more functionality than it provides. It’s then time to start investing in some additional software like MeshCAM or other CAM software.


Estlcam can easily create tabs from your SVG (or DXF?) export files from Sketchup.

As @WillAdams said, tail chasing is easy to do as it sounds like deformations with inserts are what you’re experiencing. I’ve gone to underside T-Nuts on my secondary surfaced waste boards and have been much happier with leveling consistency (through 3/4" MDF). I suppose even thicker material would be more resilient.


2nd vote for Cut2D, amazing product at an affordable price.


Yeah I think I’m going with Fusion 360 as it seems to encompass a ton of it into one app. Thank you though as I am always on the lookout!


Also, anyone wanting better accuracy would be well-served by using a more stable substrate than MDF — I used HDPE on my SO3 initially, and it was a marked improvement over the MDF.

I wish we could find a reasonable aluminum option for the XL and XXL especially, but it’s simply a problem of the mass / volume.

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My understanding is that Fusion 360 currently has a sheet metal cutting / bending function that is in beta testing. So I would expect that you could see that functionality added very soon.

Why doesn’t Carbide look into aluminum alternatives (like HDPE) then for us XL, XXL users? I’d snarf an alternative bed that’s more rigid and then surface waste boards from there. Perhaps a 1010-1015 offering?

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Were you able to find HDPE with a tight thickness tolerance? I mostly see +/- .025", which seems like quite a range. I’ve been making some things from cast acrylic and the thickness over just a few inches seems to fluctuate by as much as .01 or .02".

I would have preferred using plastic to the particle board I ended-up using, but particle board and MDF are very uniformly flat, so I used some particle board I had on-hand and my DI shows it being very uniform (+/- .003" over the range of the carriage).

But of course I can’t use any coolants or lubricants.

Would you be able to point me in the right direction for where to get a big enough sheet for the XXL? After tramming a secondary 2’ x 2’ MDF board and still having a small disparity I’ve had it with this MDF waste board. I’ve been Fiddling with this thing for over two weeks and haven’t been able to produce one product yet. Any help would be appreciated.

Tabs certainly have their place, but I always question my work holding when I need to use them - for example I cut some sheet metal jobs with 1/8" aluminium, and instead of using tabs I used the ‘tape and superglue’ method, which negates the need for clamps or tabs…

Just put masking tape the bottom of the material, and on the wasteboard, then use some CA superglue to glue them together, ensuring its flat and square.

I have found using tabs often leaves a little notch where the endmill dwells in the one spot for a moment so I don’t like using them.

Software wise Fusion360 will get you where you need for free, and the vectric software will cost you but has a much easier learning curve