SO3: Simple solution to stepper motor tightening?

since it’s practically impossible to get a wrench on the included nuts to tighten-down the stepper motors, the issue can be solved very simply via additional M5 eccentric nuts.

once on a motor bolt (backwards works best) they make about half rotation at most and then jam against the motor housing itself — they stop spinning freely and become self-wrenching.

no need to replace the original bolts or reverse/cut-off anything; these should be included in the kit?

so i got this reply last night — very nice and very quick!!!

Thanks for the suggestion.

However - we experience the same thing with a standard nut - after about a 1/4 rotation, the nut should jam against the motor housing and become self wrenching as well.

Just for reference - in the next revision, we’ll be changing the bolts to socket head (from button head) which will leave enough room to put the bolts in the opposite way they are being put in now.

and yet i see a few things wrong about this reply:

  1. the motor mount nuts supplied with the SO3 just keep spinning and spinning, and the trick of wedging a tool tip in there also fails.

2a) using the eccentric nut is a one-handed operation — the second hand is needed to pull tension on the stepper motor itself.

2b) the revision mentioned is possibly a three-handed operation (hand on hex key, hand on wrench, ??? on motor tension)?

  1. such a change does not help current SO3 owners who need the already-stocked parts to solve this issue in a simple and immediate manner.

Welcome to being an early adopter for Carbide :wink:

New users also get homing switches, a proper electrical enclosure (and moved so it doesn’t fill with dust), a non flexing z plate and a new board that stops disconnects included in their kits for free.


wow… VERY nice!!

that’s great news — thank you!!!

XL and XXL machines ship with the new Z plate, limit switches, and the new electronics enclosure. These may end up in the SO3 in the future. They do not ship with the SO3.

All disconnect problems are being taken care of no matter what machine you have or when you bought it.

Carbide machines will be changing forever. If you want a machine that’s “done” and will never change, even if there are simple things that would make it better, there are other companies to buy from. We enjoy making changes to improve the machines over time. At any given time, we have have a 5-10 of these being investigated or in process. This is not a function of when you choose to buy a machine, or being an “early adopter”, it’s the way we work.


Thanks for the clarification Rob. I understand always upgrading machines, every company does that. How about giving the people the opportunity to buy the better parts without buying the whole machine over again? Especially the people that are funding you by preordering and waiting for something that didn’t exist. And then staying patient as we worked through all the problems of an early machine including disconnects, belt lengths, etc.

Also since I’ve got you here can you answer a single question. Will you or won’t you offer just the extrusion for sale in the future. Because that will determine if I just go to another company as you stated. I’ve asked on the forum and via email multiple times.

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Upgraded parts will be available for people who want them once we have enough of them available.

We currently have no plans to offer the extrusion alone.

Thank you for the taking the time to answer.

It’s obviously not what I and many others were hoping to hear but at least we can get it out to everyone that the Shapeoko 3 under Carbide is no longer open source as we thought.

Without the main component available to the machine we will be locked into whatever timeline and size decision is made by your team. I understand it from a business perspective I just wish it had been clear up front.

I see expansion kits including the extrusions listed at

Randy (not a Shapeoko owner but keeping current on the C3D offerings)

If you can use the sizes that the expansion kits are available in then definitely go for that. Many of us would like to make our machines in specific sizes. This was easy in the Shapeoko 1 & 2 as the Makerslide was easy to purchase in any length you wanted. With the Shapeoko 3 the rail is only available from Carbide and the new bent steel frame only allows you to use the standard sizes (Altho most of us who want to modify can easily work around the frame).

The new design increases rigidity and is a large upgrade over the Shapeoko 2 and X-Carve designs. Your best bet is to purchase one of the new XL or XXL Shapeoko complete kits if the sizes work for you.

I apologize for getting this thread off topic.

not off-topic to me but very interesting.

learning SO MUCH every day – thank you!!!