Build Thread- Building a CNC Router; by someone who can't build a CNC Router

[Womble]

I really admire the work being done by people on this site, many of the machines are obviously the work of true craftspeople. I desperately want a CNC router to make patterns for Aluminium metal casting but lack the skill and fancy equipment to build a really good one. Luckly my required specs are really low however as it only has to cut MDF and Plastic with about 100mm of clearance and will only be holding a small trimmer as not a lot of power is needed and the cutting speed is not important.

WOMBLE 1
My goal is to build something as well as I can (really badly) and then use this inferior machine to cut patterns that I can use to cast better parts for a slightly more robust incarnation.

I have gutted an A0 printer that was being thrown out by a local council and used the chasis for the X axis. The council was throwing out 2 and I wish that I had taken both of them.

When used as a printer the chrome rails only had brass bushings on them so I bought a set of 4 linear bearing blocks of Ebay. They are not the best quality blocks around but where so cheap that I can replace them if needed. When the X axis is moved left and right the Dial gauge only registers a few tenths of a mm change maximum which is the great thing about using scavanged parts as the alignment is taken care of for you!

The black z axis was bought of Ebay for $80 and works really well. It is not really going to be sitting that high I just have to work out how to cut the plate that it is on down to size with hand tools and still get a really neat finish.

I have used cheap linear rails for the Y axis and had a scavanged machine cut steel plate that I used to line them up before bolting the rails to the MDF sheet.

I have now puchased or scavanged everything that I need including the ball screws and the total cost for parts is around $550 USD.

To do list.
Seal and paint the MDF
Bolt Steel tubing to the MDF underside to make it more ridged.
Mount the Pillow block bearings for the ball screws
Bolt brackets between MDF board and main Chassie
Fit stepper motor brackets
Attach a table to the Y axis
Cut the Z axis plate to size
Mount the Z axis
Attach a trimmer

101 other tasks I will get to at this point.

[ynneb]

Of course you'll do well. You are way past where many get to and stop, the drawing stage.
Keep in mind, you must do something on it every day, even if its just drilling one hole. Before you know it it will be finished and you'll be sooo proud.

[Womble]

Thanks for the supporting comment Ynneb!

I finally got back on to the CNC router build after some time and constructed all of the brackets for the X and Z axis using plywood. It looks really ugly but is very rigid and will be more then strong enough to cut the patterns needed to cast the final parts for the real machine.

I hooked up the computer to the "will remain nameless" brand of stepper driver and my machine. To my great excitement everything worked perfectly and whired away exactly as it should. I loaded up several GCode files and tested them out and they all ran perfectly. As I was dancing around the shed with glee however there was a loud pop and everything came to a sudden stop. The stepper driver blew and there seemed to be smoke escaping from one of the capacitors on the board

I am not going to even bother sending the board back to the supplier as it seems from reading through the posts that this happens a lot with this particular product so instead I decided to bite the bullet and ordered 3 G203V's from Gecko which is what I should have done in the first place if I wasn't trying to cut so many corners cost wise. I have also decided to buy a Milwaukee Die Grinder rather then go for the cheap router/trimmer that I was going to get.