What I Learned from Building a Giant CNC Router Kit

Editor’s Note: CNC Router Parts sponsored a project for us recently (it is going to be awesome), but I also wanted to document my experience building the machine that I needed for the project. This article is not sponsored, I just thought you might enjoy seeing the process and learning some tips. 

I was pleasantly surprised with how easy it is to fully assemble a giant CNC router kit. I have a few complaints, but we’ll get to that in a bit. First, lets set the scene.

I was really expecting this to be a somewhat long and confusing or frustrating ordeal. The last kit I really messed with was a reprap Mendel, and if you’ve been there, you know there is a lot of time spent tweaking things…endless time. Working together with Nathan Skalsky from CNC Router Parts, this machine was assembled and operational in less than two days.

What Arrived

Many boxes arrived. Some were a bit heavy, but there was nothing that I couldn’t lift, or that required freight shipping instead of normal UPS shipping. I piled up the boxes as they arrived over a few days.

Prepare

To prepare for the build I cleared tons of space and bought a dust collection system. I knew I was going to be cutting a ton of MDF, which is horrible for your lungs. Skalsky suggested I get a system with at least a 1 micron filter, which I think is great advice. I had it sitting there, waiting for the machine, so at no point was I filling my shop with uncontrolled MDF cutting.

I also made sure I had enough power to run the thing. The version I got was 220v, so I had to ensure my shop had the wiring and an appropriate circuit breaker.

Tip: Buy a full set of ball-end hex keys. Some spots will need to be reached at an angle and that ball-end is wonderful.

Take First Steps

We began by assembling the legs and main body of the kit. CNC Router Parts has these custom little fasteners that slip into the extruded aluminum. They’re pretty neat and allow you to piece this thing together using only a few hex keys. The most frustrating bit you’ll find here is the nature of the extruded aluminum. When you’re placing the cross members, you’ll find that if you get out of alignment at all, they bind in place. It can be hard to tell if your fasteners are too tight (which causes pinching) or too loose (which causes binding) when one won’t move. It really is a minor gripe though, as we were able to align these cross members in a pretty quick process.

Tip: Have a friend help. Long pieces will bind if you slide them from one side. Having someone on the other end moving at the same time as you allows for easy relocation of cross members. Also, the instructions give a distance to space the cross members. Don’t worry about getting it super exact, you may be moving them a bit later.

Mount the Rack and Pinion

You’ll add the bearing rails first. The next step is adding the long precision ground gears, known as the “Rack” to the sides of the bed. This slides into place with more of those nifty fasteners. Be sure you’ve got it in the correct direction (perfectly ground ends should touch each other, sloppy ground ends go on the outside).

Tip: You don’t have to get the rack on both sides of the machine perfectly aligned to each other (I was stressed about this). The machine figures out alignment later.

Add the Gantry

First, add the linear bearings to the system. Then attach all the gantry pieces. This will involve tossing on some neat linear bearings.

Tip: Add the little nipples for inserting grease to the bearings before you put them on the machine. They can be quite difficult to add afterwards. You’ll want a friend to help hold the gantry as you mount it to the vertical pieces. This isn’t a one person job.

Install the Z-axis and Spindle

This was pretty easy. A few bolts here and there and it just plops into place. I did this part without the muscles of an additional person.

Tip: When installing the spindle, try to get everything as straight as possible using the instructions. It was really easy and, as another surprise, I didn’t have to readjust the spindle at all after installation.

Add Wire and Electronics

We laid out the cable trays and the plastic cable guide and started laying wire. You really just need to go slow and be methodical. Give yourself plenty of slack at each section.

Tip: Use tape to label the wires at both ends. You’ll save yourself lots of confusion.

Tip: Mount your sensors deep in their holes so that they don’t protrude away from the machine as much. Measure and get them all mounted at the same depth to avoid adjustments later. Then mount your emergency stops where they’re easy to slap, but where you won’t accidentally bump them while inspecting the machine when its running (I had to move one because I kept accidentally brushing up against it).

Prepare a Waste Board

Normally, you won’t have a problem here, but we did. This machine is the 5’x10′ model (which is actually closer to 6’x11′!). I really wanted a single piece for my waste board – the bed of the machine – where you mount your stuff to cut. In my area, finding a 5’x10′ piece of 3/4 MDF was quite difficult. No local retailers had any. I turned to Facebook and found that this is a common problem for people. We had to find a local wholesaler who had some and then get our retailer to order it for us. Get this stuff delivered. It is huge and weighs roughly 250 pounds. It sags a little too much to let hang out of the end of a truck.

If you’ve got an 8′ machine or smaller, this simply isn’t a problem at all. Only the big ones will run into this.

Once you’ve got your waste board in place, you’ll want to run a program to prepare it. Before you can do any preparation, you have to mount it. This means cutting mounting holes the entire length, with recessed areas for bolts to go. After cutting mounting holes, you may need to adjust your cross-supports so they perfectly match.

At a minimum, you’ll want to “face” it. This means taking a fat router bit and shaving a few millimeters off of the entire surface. This is what makes the bed perfectly square to the spindle. In many cases you’ll also want to add mounting holes for your clamps. CNC Router Parts supplied a file for the set up I used, and so far it has been extremely convenient.

The Good Stuff

I could almost assemble this entire thing myself. Really, if I got creative with some workhorses or stacked up boxes, I probably could do everything but the waste board (that took 2 people just to lift and carry).

This was quick. I really thought it would take a lot longer. While I had the advantage of Skalsky having already built a couple of these, it really seemed like I could have pushed through it almost as fast.

The directions were clear and easy to follow. The software directions on their site had all the appropriate links for steps I needed to take.

The Not So Good Stuff

Not really about the machine, but their website is a bit confusing. Things are organized in weird ways that require that you really do your homework to be able to purchase a machine. You’ll need to select your frame, electronics package, and spindle separately. At least you’ll be educated in what you’re getting though.

The end stop sensors stick out and seem like they’re just begging to be broken. I’ll need to create a guard for this immediately. I know how clumsy I am, and this will get bashed. Although, in retrospect, I guess I can just mount them deeper in their holes so they don’t stick out so much.

Maybe I’m just spoiled by how Lulzbot ships their printers with a complete tool set, but I really would have appreciated a basic toolkit with the bare necessities needed to build the kit.

Post-Build Experimentation

With any new tool I like to make a cephalopod (typically an octopus).

While the anatomy may be questionable here, there are still 8 tentacles.