SO3: Can I buy the XXL but only expand to XL?

I’m interested in getting the XLL upgrade kit but only have the space for an XL at the moment. It looks possible to extend only in the X direction (aka XL) and have an XL until I get the space to fully expand.

Has anyone else thought of this? Your thoughts on it working or what adjustments might be needed?


[Edit: change Y to X direction]

The XL kit, as it comes, is intended to extend the X-Axis and comes with a single 40" extrusion for that along with the front and back frame pieces that are wider. With an XXL upgrade, it might be possible to use your original front and back frames with two of the 40" extrusions but I am not sure how the new longer cross straps would work with this configuration given that the wasteboard is intended to run parallel (lengthwise) with the X-Axis. The holes would not match up at all. If you decide to just upgrade the X-Axis (as the XL kit is intended), you still have the problem that the XXL upgrade kit comes with longer cross straps so you have no way to connect the required wider front and back frame pieces under the wasteboard. I don’t think the original strapping metal under the wasteboard would be compatible.

Perhaps @WillAdams has some thoughts…I recall several posts and some wiki content where he was involved in theorizing what changes might be involved in doing various upgrade/dimensional permutations…

Just my 2 cents off the top of my head… :slight_smile:

My apologies, I mixed up X and Y in my original post. I intended to say extend the X (left to right) not Y (front to back).


You wouldn’t have enough structure to get from back-to-front all across the width of the new wider front/back end plates — the existing straps wouldn’t provide enough structure, and the new plates would be too long.

We wrote and theorized about the upgrade kits at length in a thread on the SO forums and there’s a bit on the wiki as well:

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So if I understand what you are saying is that…

The XL expansion kit has two replacement (front and back) plates, a single cross member (left to right), and two short cross members (front to back). It reuses the existing Y-axis extrusions.

The XXL has two replacement (front and back) plates (same as XL), two cross members (left to right, one more than XL), and three (longer than the XL) cross members (front to back).

Is it the two/three front to back cross members that you think are at issue? That the original ones will not provide enough structure?

Does you or anyone see any other potential problems?


Yeah, that’s pretty much it. From:

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If I had an XXL kit and was looking to do this, my inclination would be to instead re-use the front/back end plates, expand along the Y-axis and see how many holes could be made to line up w/ the existing hardware (new and old) and maybe make some adapter plates or something.

Expanding along the Y-axis should be more rigid than along the X, so ought to be more forgiving of infelicities in such a re/mis-use.

Actually, in the XXL kit there are the TWO front and back frame pieces (the pieces that attach to the Y-Axis extrusions) and then 3 hefty cross-members that all run perpendicular to the frame pieces front-to-back. There is no notion of that central strap that runs across the middle to hold things in alignment. The new cross-members are really beefy and have 90 degree bent sides that really stiffen things up. I have pictures of exactly what you receive in the XXL kit (the upgrade kit will be a subset of the full kit but the structural pieces will be the same)… see: SO3 XXL Unboxing

You will find pictures of the new frame pieces and the cross-members.

Also, see the SIXTH picture down from this assembly thread… you will see how the frame and cross-members are meant to go together: SO3 XXL Assembly