The CNC Shop

One thing about building your own CNC machine is the electrical part. You can buy all the electrical parts or you can build them up yourself. By that I mean you build or modify a power supply, make your own boards for the drivers and so forth. Since I'm also interested in electronics I decided to make my own. Besides it's a lot cheaper

Once I had decided on a table size for my machine I was able to guesstimate what size motors I would need. I searched the net for used ones and found some at All Electronics. Since these are surplus you will need to look around. I'll mention the specifics once they are ready to be installed on the machine.

In the mean time I found a guy who had built a small table top CNC router to do circuit boards with. I studied the pictures and decided that this would be nice to have to make the boards for the bigger machine and would also give me a chance to see what goes into building such a machine at home.

So with that in mind I stopped at the local surplus electronics store and procured a couple of smaller stepper motors. These are unipolar motors. They are easy to spot because they have six or more wires coming out of the motor. For further info on bi-polar and uni-polar just do a search on the net. You'll get more info than you can digest.

If your interested in building one of these machines there is a guy on the net that sells plans for the beginner. His machines are very simple and can be built with basic hand tools. Since I have 3 lathes and 2 mills of different sizes I can make a majority of the parts from metal and fabricate some other items that would be hard to make without the use of machine tools. If you are interested check out John C. Kleinbauer. He has a very nice site for building cheap and simple cnc machines. Before you people from over seas surf over to his site I'll warn you that he does not sell his plans outside of the U.S.A. and Canada. That's his policy.

Here are a few more links to some excellent sights with lots of good pictures and info.

Aaron Bowser's CNC Pages Has some great design ideas.

Buildyouridea.com This guy poured his own parts for a machine.

Axxus Technologies This guy built one cnc out of metal and a second one using oak.

While waiting for the first parts to arrive such as the IC driver chips and bigger motors, I started to develop some ideas that I've gleaned for searching the net. I'll present them here.

NOTE: Update; Sept. 29,2008. I've never like to post links on the web site because to many dissapear over time. Such has happened to three of the site I quote above. John Kleinbauer sight is no longer up. I don't know if he still maintains a Yahoo forum. Both Aaron Bowser and Axxus Technologies are no longer functional. Buildyouridea.com is still active as of this writing.

I have been contemplating of removing this page since I haven't touched this project for quite some time. For now I'm leaving it up and will determine it's fate If I ever get around to redesigning the whole site.

	Here is a picture of the smaller stepper motors I picked up for doing the PC router machine. The specs on them are as follows: 5.0 Volts, 200 steps per rev, 1.0 Amp. I don't know what the NEMA size is.
	This picture will give you an idea of the size of these motors
	This picture will give you an idea of what "storefront window channel" looks like. After surfing Dave Kush's site at " buildyouridea.com" and saw the nice machine he built using this material I decided to see if I could get some from a large glass dealer in my area. This is what they gave me.
	Take a close look at the profile and then take a look at the profile of the piece in the next picture. See if you can spot the difference. Also compare this with the material Dave uses on his site.
	Here's the picture of the second piece of channel. Can you spot the difference. If not click here to find out.
	As I did more searching on the net for Home Built CNC machines I can across several different variations of linear bearings made and bought for moving the gantry or table (x-axis) and the Y-axis. The bought ones were quite expensive and some of the ones that were home made were quite large. After some serious head scratching I came up with this design. It's a 7/8" dia. sealed bearing with a 3/8" dia. bore and is .280" thick. The piece of aluminum is milled out to except the bearing and a 3/8" dia. hole is reamed to except a 1/2" long steel rod to support the bearing.
	Here is what the parts look like "un-assembled". Click here for a drawing. This is only a part of what will be needed to make up a whole linear bearing. I'm going to put all of the drawings of all the parts in a file as DXF for downloading when the machine is finished and running. This could be a while. So in the mean time I'll put up JPG drawings to give ideas as to how I'm doing it. It may insipre you to come up with a better design.
	Here I'm drilling out the majority of stock with a 9/32" drill before using a 1/4" end mill to remove the left over stock.
	The blocks have been milled out, the short shafts that hold the bearing in the bearing block have been cut to size. Also note a second hole in the upper left hand or right hand corner of each bearing block. That's a 1/4" dia. reamed hole that will allow the bearing block to pivot. Behind that is the piece that the bearing blocks will fit in to. It's a piece of 1 1/4" sqaure aluminum. Note the penny for size comparison.

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