Mounting the MakerMade Z-axis on M2 Sled

In the Summer of 2020, the folks at MakerMade announced their improvements to the classic Maslow CNC design. They called the new design "M2."

I had already built myself a Maslow CNC from a kit and a Ridged R2901 router. While my son and I worked on a mixed-media art project and a furniture project, it became pretty obvious just how unreliable the original Z-axis mechanism was. It was a no-brainer to buy a better Z-axis stage, so I became one of their "M2 Upgrade" pre-order customers.

(The upgrade kit didn't come with a pre-drilled M2 sled, but luckily I managed to barter for one.)

Here is the problem that this Instructable will help you with: The Z-axis assembly is fastened to the sled using six screws and six t-nuts. Unfortunately the t-nuts are free to slide inside the two extruded aluminum channels. So how the heck are you supposed to keep the t-nuts from sliding around?

Short answer: you carefully tape down the t-nuts with masking tape so they are perfectly lined up and stay put long enough to screw into them. Here I'll take you through how you do that with a minimum of frustration.

Masking tape

Sharpie

Ruler (inches)

With a ruler, mark off three lines spaced 2 inches apart. I called them 0", 2", and 4".

I used wide masking tape, but if yours is narrow, you can just do this twice and skip the next step.

You want the screw holes in the t-nuts to be clear of tape and adhesive, so cut notches in the tape, and fold them back under.

There is a handy (unrelated) screw hole in the middle of the channel. Find that. It's going to be your center reference.

Slide the three t-nuts so they are exactly centered on the 0", 2", and 4" marks. Do this for both channels.

Do this for both channels.

You are going to have to eyeball the six screw holes so they line up over the six t-nuts. If you're lucky, the t-nuts won't move while you are doing this.

...and you can't get it back into place with the screw...

Stick a nail, wire, or small screwdriver into the hole to re-center the t-nut, if you think it has wiggled out of place.

I was lucky, and they all stay put.

Try turning the screw backwards until it falls into the counter-sunk hole.

If the screw sticks out of the sled, it probably is not lined up with the t-nut.

Once everything is lined up, you can just screw in the six screws.

I would use a regular screw driver, not an electric screwdriver.

But leave the screws very loose. You need to be able to lift the Z-axis assembly a bit in the next step, and later slide it back and forth to align the router with the big center hole in the sled.

Turn the sled over.

Pull up on the Z-axis assembly while you...

... Carefully remove the two pieces of tape under the Z-axis using tweezers.

And you're done!