Gatton CNC Build Part 10 – Router Mount and Tramming Plates

In this installment of my Gatton CNC build, I modified, drilled, and assembled the router mount assembly, then added two plates to the sides of the Z box that will allow me to adjust the router mount when it comes time to tram the router. Read More

So what is tramming? Well, without getting too deeply into it here, tram is the squareness of your router or spindle to the table. Adjusting that squareness, whether it be along the X axis or Y axis, is known as tramming. The two plates I made will help me to more precisely adjust that squareness, then lock it into position while I tighten the mount, securing it to the Z box.

The first modification I made to the router mount was to take it over to the table saw and cut about a blade’s width off of each side of the mount plate. The router mount plate needs to be slightly narrower than the Z box front panel to give the mount room to move when it comes time to adjust it.

In deciding on what type of nut to use in the router clamp, I used 1/4” 20tpi weld nuts. I think square 1/4” 20tpi nuts would work just fine for this as well. I wouldn’t use standard hex nuts, as they could easily break loose and spin inside the hole, where a square nut wouldn’t be able to. Follow along with the video to see further details of the assembly of the router mount.

The tramming plates are very simple to make out of 3/4” plywood left over from the construction of the gantry. In fact, I made mine out of the leftover scrap from the gantry bottom panel. Using the measurements in the picture below, I first used a 3/4” forstner bit to drill a recess into the back side of each plate. One thing to keep in mind when making the plates is that you are making one for the left side and another for the right side. These two plates mirror each other, so make sure you drill these recesses on the correct side of each plate.

With the recesses cut deep enough that a #10 – 24 T-nut will sit below the surface of the plywood, I then used the correct size twist drill bit to drill the rest of the required holes. The size of the bit needed will depend on the outside diameter of the shank of the T-nuts you use.

Outside faces of tramming plates. Click to enlarge.
Inside faces of tramming plates. Click to enlarge.

With everything stained and finished, I assembled the router mount, then loosely attached it to the Z box using standard 1/4” – 20tpi hex head nuts (after first trying socket head cap screws and deciding against them.) I then aligned the bottom edge of the tramming plates with the bottom edge of the Z box, and clamped them into place, keeping the back edge of the tramming plates held tight against the edge of the aluminum angle on the Z box.

Once clamped into place, I drilled pilot holes, and secured the plates with #10 – 1 1/4” long exterior grade woodscrews. I used my impact driver to drive the screws most of the way in, then finished tightening the screws by hand to prevent the screws from going all the way through the sides of the Z box.

I then let the glue on the router mount cure overnight before mounting my Porter Cable 890 router motor.

That’s all there is to it!

As usual, thanks for stopping by, and remember that if you have any questions or comments for me, feel free to leave them here, or you can email me through the Contact Us link up at the top of the page.

Good luck with your build!

Have a question or comment? Leave it in the comments below. If you’d prefer, go over to the Contact Us page and submit it to me there.

Until the next update, take care and have fun!

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Gatton CNC Build – Progress Report 1


As I type this on September 12th, 2017, my Gatton CNC is basically finished. I can plug in the drive box and use it at any time. I’m struggling to refrain from doing so, however, because there are still a few things to be done. Chief among them is cable management.Read More

On my old Shoestring Budget CNC, my cable management system boiled down to an, “It looks good hanging right about there,” approach. On the Gatton CNC, however, that’s just not going to cut it. Or maybe it will. Let me explain.

The Shoestring Budget CNC was pretty small, as I explained in Episode 2 of my Gatton CNC build series. Also, the gantry moved along the X axis. All of the power outlets that I used for it were located at the rear end of the CNC, so that meant that all of the cables could be draped over the back of the gantry and left to hang there, without worry of them being damaged by anything. As the gantry moved toward the other end, the cables simply moved along with it. When the gantry moved back, there was enough weight in the cables that they slid back with the movement. Well, this is not the case with the Gatton CNC.

First, the Gatton CNC is much bigger than the Shoestring Budget CNC was. That meant that I had to get extension cables for the stepper motors. Second, the gantry is oriented so that it moves along the Y axis, rather than the X. That in itself is taking some getting used to, but it also means that the power outlets I’ve been using are located to the left of the gantry now. So I have much longer cables that have to be guided in a certain direction over a much larger area. So, yes, that means I need to dig deeper into cable management so I didn’t run over a cable with the gantry, or cut into it with a bit spinning at 16k RPM.

In my case, I lucked out. A gentleman by the name of Andrew Hague, of The Old English Workshop, has been building a Gatton CNC of his own. He’s heavily into 3D printing, and he’s been gracious enough to send me some prototype drag chain mounts he’s come up with for his Gatton CNC build. I hadn’t considered mounting drag chain before, but with these mounts in hand, I decided that I should give them a try.

Andrew was nice enough to also send me an alignment jig that he designed for aligning the X axis lead nut block to the stepper motor hole on the gantry upright, and another jig for aligning the Z box lead nut block to the stepper motor mount and support bearing. Both of those jigs worked brilliantly, and I’ve since passed those on to another Gatton CNC builder so that they can use them, then pass them on to another builder, who can use them, then pass them on to another builder, and so on. You’ll find complete info on the alignment jigs in the video description of Episodes 7 and 8 of my build series (the link to the playlist is below,) including links to the Thingiverse pages, where you can download the files to 3D print the jigs, or have them printed for you.

I’ve also added a couple of modifications to my Gatton CNC. One modification is the recessed under-gantry lighting that I featured in Episode 6 of my build series. So far it really works a treat, and it’s a modification I should have made to my Shoestring Budget CNC when I recut the gantry in 2016.

Under Gantry Lighting

Second are a pair of plates I’ve created that will help me when it comes time to tram the router. There will be much, much more on those tramming plates in Episode 10 of the build series.


Tramming Plates on Z box, with router mount installed.

So where do I stand right now? As I said earlier, the major construction is finished. I’m waiting on the drag chain to arrive, then I can rout the cables, hook up the drive box, then fire this puppy up! There will still be more work to do after that… but that’s for another update, down the road.

For now, here’s a link to the YouTube play list that includes all of the episodes of my Gatton CNC build.

Have a question or comment? Leave it in the comments below. If you’d prefer, go over to the Contact Us page and submit it to me there.

Until the next update, take care and have fun!

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