Building a CNC router

[HomeCNC]

This is my first router I have designed from scratch. I am designing it around the linear ways that I got from e-bay.

I am building the spindle right now. I chose to not go with a router because of the excessive noise and not being able to use my R-8 collets from my mill. I am going to power the spindle with a DC motor so I can get variable speed. If I run the pulley system on a 1:2 I can get 5000 RPM which will be fine for my use.

[CNCadmin]

Great looking router design.I like your placement of the guiderods

and bearings on the Y axis. I have questions about your spindle

motor speed.....isn 't 5000 Rpm too slow for a wood router?

For a 1/4" wood bit I would think 25-30,000 Rpm .

[HomeCNC]

Normal wood routing uses 2 flute router bits. I will be using solid carbide 4 flute end mills with this machine. I not only want to machine wood, but metal as well. My shaper table in my wood shop only turns about 5000 RPM and has no problems with wood cutting in surface quality even on end grain.

[CNCadmin]

What is the cutting IPM?

[HomeCNC]

MasterCAM says the feed rate for wood with a 4 flute cutter running at 5000 RPM would be 50 IPM. This will be no problem. My setup using .200 pitch ball screw stock running on a 2:1 ratio with my servo motors I can get 76 IPM on a linear move.

[E-Stop]

Very interesting. I have been considering building a CNC router for about a year now. I've done a little work on the design but not near what you have here. I've got the linear rails for the "X" and "Y" and an almost complete "Z" axis slide unit. Plans are to use a router (which has already been bought and is still in the box). What size of work envelope is your router? The rails I got are 110" for the "X" axis and 56" for the "Y" axis. I wanted to have a work envelope of at least 8 feet by 4 feet so that we could work on an entire sheet of plywood, if needed.

Please keep us posted of your progress. And when I get started, I'll post some pictures as I go.

[HomeCNC]

E-stop, You are thinking of a much larger router than I am building. My X rails are 42" long and my Y rails are 28" long. I have a work area of 24 X 24. My Z rails are 18". I want my router to sit on a table I have.

Are you designing your table to be stationary like mine, or are you going with a moving table with a stationary up right?

[E-Stop]

The table will be stationary and the gantry style head will travel. Making the table move would require about twice the floor space of the stationary design. With a 4' x 8' work envelope, it's going to take up a good chunck of real estate anyway.

I forgot to mention it but the Z axis unit is on 18" rails.

One thing I found interesting in your drawing is the placement of the Y axis rails. I have been trying to decide which way to mount the rails. The two choices were mounting them parallel to the table or perpendicular to the table. In your design I see the two rails are not in either of these orientations but kind of one each way. What factors influenced your decision to mount them this way? Is there an advantage of one way over the others? I like the looks of yours and I am considering changing mine but first I want to weigh all the details.

[HomeCNC]

The main reason I placed the Y rails in the postion shown was because if the rails were side by side on the vertical plane the all the balls at the top of the bearings would be taking the wear.

Also after I started to look at this design more, I also liked the fact that I can adjust the top rail to help square up the spindle to the table in the X direction. I will use the spindle mounting screws to square it up in the Y direction.

[HomeCNC]

I managed to finish my Servo controller box this weekend. It worked great! I used a torid for the transformer this time. Wow do I like them.

[HomeCNC]

I got a little carried away with the front grill. I painted it black and engraved the lettering in with my CNC mill.

[CNCadmin]

Nice work keep the pics coming...