Possibly Missing Spacer in X-Carve Upgrade Kit?

I noticed an inconsistency in the parts provided, in the X-Carve upgrade kit from the Shapeoko 2. There is a difference in the spacers that came with the Shapeoko 2 (25312-14 3/8" x 5/16" x #12 bore) and the ones that are needed for the X-Carve (25312-23 Aluminum Spacer 5.1mm ID 9.5mm OD 9.5mm LG).

So, to my reckoning, the S2 spacers are actually 9.5 x 7.9mm spacers, with an inner diameter of 5.7mm, making them 1.6mm too short. I see a couple of other folks mentioning this, but no answers posted. Is there something obvious that I am missing?


  • Alex

Here is the full list included in the Shapeoko 2 upgrade kit:


Thanks for your response, and I do, indeed, agree that the spacers are not part of the S2 upgrade kit BoM. I’m just trying to determine if there is a part in the original S2 that I’m supposed to use, instead of the specified 9.5mm spacers.

I checked the Inventables catalog, and there isn’t a part number 25312-23 available, though the 25312-12 is close.

Any thoughts? I’m assuming that the many folks who have completed S2 upgrades must have figured this out.


  • Alex

Are you talking about spacers for the smooth idlers on the X Carriage assembly?

The upgrade kit assumes you will reuse the ones that were used on your SO2 shown below.

I also found the original spacers to be too short making the carriage plate push the delrin nut and make the whole assembly bind.

I fixed it by adding one of the regular M5 washers under each spacer for each of the four posts. That made them the correct length and fixed the binding of the z carriage.

@J_AlexanderJacocks and @Peter_Jakab I’m sorry, I mis-understood the original question. I think Shapeoko 2 Upgraders use the included Flat Head Socket Cap Screw M5 × 35mm to complete this step. @BartDring can you confirm this solves the problem?

Yep, I was talking about the smooth idlers, and the spacing of them from the walls of the carriage. In the S2, I ended up using 2 precision shims and 1 spacer, for a total length of about 9.9mm. Since the X-Carve specifies the spacer be 9.5mm, I wasn’t sure if the 0.4mm difference would cause a problem, or not.

Any comments from Bart would definitely be welcome. And, thanks to Peter, for his suggestion to use the S2 spacer + a M5 washer. I haven’t measured the M5 washers, but I believe that they average around 1mm thick, as well.

  • Alex

Alex - do you ever get a response? I’m literally on step 1 of the upgrade and ran across this issue. For now I will go with the SO2 spacer and 2 washers leaving me around 9.89 or so.



I didn’t, but I used the same combo of 2 washers and a spacer, and it works fine. I’m guessing that was what was intended.

In the end, it seems as though the spacing really isn’t critical, as the pulley can be positioned at a variety of places, on the shaft of the stepper motor.

Good luck,

We’ll have Bart take a look in the new year when everyone is back in the office.

I pressed on with the two washers. It seems to fit but I’m not operational yet to know.

There were many, many areas of the instructions where the upgrade kit didn’t match the SO2 parts. I had to run out and buy bunch of bolts and nuts. Not sure if it was because my SO2 has a couple mods or not but it definitely slowed me down and was very frustrating.



What items did you find where the instructions didn’t match? I actually found them to be very good, except for this bit about the spacer. Some things were different, but obvious (for instance, regular nuts vs. nylock nuts, since the S2 didn’t use nylock nuts), but most were well-documented.

Also, I didn’t have to order any extra parts. There should be a fair number of parts left-over from the S2, actually, since the X-Carve has quite a few less parts in the X carriage.


  • Alex

I talked to @JohnHayes from our Customer Success team. He said Tom is right and in the end, it seems as though the spacing really isn’t critical, as the pulley can be positioned at a variety of places, on the shaft of the stepper motor.

He maintains our instructions and he is going to add a note to the instructions for people in the future.

@J_AlexanderJacocks let me start with explaining the state of my machine. It is (ahem, was) a stock SO2 with the Z axis upgrade only. I purchased the NEMA23 upgrade but never got around to installing it. I recently upgraded to the Makita router when my stock “dremel” went tango uniform. I started a log of every “discrepancy” between the X-Carve instructions and my setup but I quickly gave up after step 2 (literally). In short, I had handful of 20mm bolts when the instructions asked for 25mm. I had 7.8mm spacers when the instructions wanted 9.5mm. I had “normal” nuts when the instructions wanted nylon nuts. I had “normal” aluminum colored, but tapped maker slides when the instructions wanted black, untapped. Essentially, nearly every nuance of my setup was different from the instructions in some way. This is not my first rodeo, but on the flip side, I’ve found certain aspects of the SO2 to be highly subject to variances. So my trepidation mounted as I continued to deviate from the instructions at nearly every single turn. Some deviations seemed like things that should be noted in the instructions (like 7.8mm spacers with 2 washers instead of 9.5mm - or, maybe, include those in the upgrade kit); some were “self inflicted” (e.g., Makita mount -> which I do not regret!). All in all, I believe the machine is more stable and will produce better cuts; I’ve only done some basic calibration tests, but I’m getting slightly better accuracy than the stock kit (believe I my accuracy when in the toilet when I added the Makita). Though based on recent testing I will have to say my accuracy seems to plummet with my feed rate. I’m still testing, so stand by :wink:

@Zach_Kaplan - I didn’t find the spacing to be a significant issue. I would say, however, including the nylon nuts with the upgrade kit would be really nice :smile: On the plus side, my SO2 turned X-Carve was nearly square and true after the upgrade. It only took a little futzing to get it adjusted. One note on the instructions, the Acme Z-Axis upgrade had a completely different gear ratio, so I was getting 50% “speed” from Z until I realized it. I think that should be noted in the instructions somewhere. In hind sight I should have been more diligent documenting the variances to helps out the collective community, but apparently I suck as a steward of the human maker kind :wink: