X-Carriage Smooth Idler Bolts Stand Proud...design flaw?

When going through Step 02.4 (X-Axis motor install) I noticed that it wouldn’t sit flush with the side of the carriage:

After taking the motor off, I was reminded that the smooth idlers bolts sit proud of the carriage (even though their holes are countersinked):

I wasn’t sure how much off it was, so I setup a baseline by zeroing-out the Wixey:

Then compared to the motor…a full 1 degree off plane:

My fix for this was to cut a couple of thin strips of sheetmetal, double-them over, and wedge them under the appropriate corners of the motor. This leveled me out but I’m not crazy about it:


Should these smooth idler bolts be standing proud like this?
The only good fix I could think of last night is to further ream the countersink for the bolts, but I don’t think I have a drill bit that will handle that (my countersink bits are all for wood).

I seems like a drill bit the same size as the diameter of the counter sink would remedy that. I have also used my wood counter sinks on metal many times - a quick squirt of wd-40 before drilling should do the trick and apply very light pressure. You don’t have far to go.

If not, simply putting four washers on the motor bolts might be a more elegant solution. Mounting steppers on stand-offs and spacers has never impacted the performance of any of my machines so washers wouldn’t be a big deal.

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Thanks Earwigger. I will probably do this…

Metric counter sunk bolts have a counter sink angle of 90 degrees and you can buy counter sinks with 90 degree angle.
Look at bottom of page here.

On the other hand… my answer would be to take the dullest pair of scissors I own and bore out that hole. :slight_smile:

One trouble with using a drill as a counter sink is drill points are 118 degrees.

Washers will work in a pinch though.

sorry to necro this post… youre not the only one. i countersunk the left hole and snapped a photo so folks could see

If you use spacers, and have a pressed(?) on pulley, double check the pulley alignment closely or premature belt wear may be a problem.

Looks like the countersunk hole was not to spec. If this happens you have 2 options:

  1. Return it to Inventables for a replacement part in spec

  2. Use a countering tool to fix the hole so the screws sit flush.

Hey Zach, it’s really cool to see how involved you still are in your product. Having a similar need for balance between ops and strategy in my own professional responsibilities, I really respect how hard it is to keep that up. I hope that you’re just sniping here, rather than this post being one of the many that you continue to monitor.

I would like to add that - while I have been unfortunately diverted recently to other nerdy endeavors - the X-Carve is truly a revolutionary development. It has opened my world to really cool stuff that I could never accomplish with traditional woodworking techniques. Well done, my friend…American ingenuity at its best.


Thanks @Joec

The Customer Success team at Inventables does an incredible job helping customers become successful. They do far more than I could do.

I do spend most of my time on strategy but I believe understanding our customers is a critical input into that process. I learn best through experience and I have found there is no replacement for visiting, talking to, and interacting with customers. You can look at data and reports but they only tell a part of the story.


I choose #2 countersink myself and finish this building weekend. Inguinuity trumps replacements.

this hole has been out of spec for a year now based on time when the original poster opened the thread.

We have done some statistical testing on each batch. We are going to do some inspections tomorrow.

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pull spacing looks good now… thx for suggesting I check.

glad to hear that. I am glad to hear some inspections are done and there will be follow through. Fully satisfied :slight_smile:

Shimmed my recent build with washers to level it, wasn’t sure what to do based on the instructions

Is this the same issue? here is a clip of the 750mm x-carve instructions. I just assumed that the larger hole for the stepper motor is countersunk shallow to create a space for the idler screws. Sorry if I’m misunderstanding.

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I chucked the screws in a drill and took them to the grinder and removed the head down to the taper. They still were a little proud and I was afraid of loosing too much of the hex wrench hole so I countersunk just a tad to make everything flush.

I have a “new” X-Carve that I received late Dec 2016 and I have the exact same problem. I saw the reference in the instructions to this issue so I assumed it was a known issue. I am noticing uneven belt wear because it was almost impossible to get the motor completely parallel to the mounting plate. I’ll have to get a metric counter sink and get those idler screws below flush. Is seems like this is a known issue, both X-Carves I have seen other than mine also have this problem and its mentioned in the assembly instructions.