Here it is; my revised improved Router milling machine. For those of you who did not see my other machine look at my past posts under Mark Sternberg for a quick review. This is the streamlined improved updated version.
This machine is a culmination of 5 years of experimenting with the concept and use of the machine. I am absolutely amazed at its capabilities. I have built 5 of these over the past few years and improved each as I went along. My main goal was to build it for a half way reasonable cost and still have an accurate machine.
The table is 22” by 48” and has 30” of movement right to left, 17” of movement front to back and the head has 15” of movement up and down. The head has an plunge feature operated by foot pedal. The head can also rotate up to 90 degrees either way. There is a rotating table feature and lathe feature not shown.
The table is driven with # 35 chain and 13 tooth sprockets. This pushes the table a little more than 2” with one turn of the handle which is needed for wood routing. Threaded rod was too slow about an 1/8 inch per turn. It is amazingly tight there is no backlash or slop in the cranks and the table is tight too.
There are stops on the table to set your cut distance and stops on the plunge feature for depth.
Because it is so big the table actually unhooks from the main machine for transportation purposes and to get it through doors.
There are many improvements on this machine. Any time you build something like this you have to take into consideration rigidity and the ability to keep all moving parts smooth and tight to keep accuracy to your work.
I solved the rigidity problem by making the frame out of 3/4 ” plywood laminated together sometimes as much as 3 layers thick and all joints are overlapped and glued. This thing is solid and has no twist what so ever.
The next big issue was the slide rails. For this I had 2 problems, because there is so much travel on the rails I needed something strong so it could handle the weight of what is being put on the table unlike a CNC machine the only weight is the router and mechanics.
Dealing with a cost issue I did not want to spend a ton of money on heavy steel rod because there is about 20 feet of it total. So I tried using 1 1/2” emc electrical conduit then sanded and polished the tubes so they were slick, this worked pretty good.
Next, the slide bearings, the obvious would be linear bearings but to get some (12) that size would be a small fortune and would not fit the slides tubes and the bottom ones would be running in saw dust a lot and could be a problem.
Anytime you build a machine out of wood you have to take into consideration expansion and contraction of the wood and how it will affect moving parts and I had that problem in some of my previous machines.
So what I did was found a manufacture that sold their 3/4” thick plastic scraps. I used this stuff for many parts. Anything you see on the machine that is black is the plastic. I machined my slide bearings and slide tube holders out of the same material, this keeps expansion and contraction to a minimum and because it is the same material it is constant with each other and it has worked really well.
I have pretty much worked the bugs out of it. Although it is a wood based machine it is very tight the way I have it designed. Any time you have joints or moving parts you risk movement. Is it as tight as a big cast iron machine? No! But it is well within tolerances of say a slide miter saw. The only thing that can cause an error in a cut is, if you try to cut to heavy and the bit tries to climb. If the bit is sharp and you cut within the guidelines of how you should cut in normal routing it works great.
I even make my own bushings for the rods for all the cranks. The reason being every type that that I have bought there was either a problem holding them in the wood or they were too sloppy. The ones I make are tight and fasten to the wood with screws because I machine a big flange on them. (By the way I machined most of the parts on my original machine).
I do not have any videos of this one yet but you can see my old version that this was based on on you tube.
This is the introduction to the machine.
Router based wood milling machine introduction - YouTube
This is an example cutting a cube within a cube to show versatility.
Router wood milling machine cutting out a cube within a cube - YouTube
The pictures included are, the new machine, a picture of the first machine I built 5 years ago and a couple clocks I milled from chunks of wood. An end grain cutting board I surface milled and cut the outside diameter circle and last is a ported speaker to set a phone in.