My First 3 Axis CNC Router Build

[hammajamma]

After lurking for some time, absorbing as much information as I can, I have begun a 24"x24"x6" 3 axis CNC router. As this is my first build I am going to buy a 3 axis controller/stepper complete kit for the electronics. I'm not sure which one at this time, but that is my intent. It will have a moving gantry and stationary table. The X+Y will be skate bearing and the Z will be a linear bearing removed from an old color printer. (Which also had a decent stepper that might be used on the Z).

I am an artist and this machine will just be the first of several. I am hoping to eventually build a 4'x8'x4' 5 or 6 axis machine to take my virtual 3d work and create actual physical objects. This small first one is mostly about teaching myself how to build and use one. I'm not worried too much about resolution, though i still want it to be decent.

The frame/table/gantry will all be square tubular steel and a steel plate top for the table. (All of the steel is essentially free, leftover from a previous project).The frame will also act as the guideway/rails for the x+y.

This being my first machine I am VERY open to advice, especially regarding the electronics. I have an old laptop that I am probably going to use and several dremels. Is there any reason not to use these for my first machine? I am trying to keep the cost pretty low.

So let's see. I am currently on the market looking for:
2-3 stepper motors
3 axis controller boards
1 driver
1 power supply for steppers
(Or a complete 3 axis electronics kit)
And about 60 skate bearings

Anything I am missing?

Anything else I am missing?

[hammajamma]

Anyone used one of these kits?
Probotix

[thegimpster]

Well for an easy router I would check out www.buildyourcnc.com I was going to build one based off of that, but I got a welder. I have some motors if you are interested, i could cut you a deal.

[hammajamma]

thegimpster PM me with info on the motors including price, as I am interested.

[hammajamma]

As for my router plan, I've got a bunch of sketches done, but will have the base table welded up by sunday and photos to follow.

I just bought 40 skate bearings off ebay for $23 shipped. I already have 16 of the same bearings so I hope to have enough.

Let's see what else... Trying to decide if I should start the Z axis or the Y axis after I weld the table together.

My design is based on this machine, with a few modifications.

[thegimpster]

pm sent.

A tip on the skate bearings, if you need a little more clearance you can grind the point of the angle off. You can grind it a good bit and still have plenty of metal left for stregnth. Also make sure that you get the bearings the same distance out from the center or they will be slanted in some.

[hammajamma]

I didn't take any photos, but the table base and rails are ready and awaiting my bearings so I can make the "shuttles?" for the gantry. Motors are enroute as well.

[hammajamma]

I recieved my steppers in the mail from "thegimpster" Thanks, very much. I have another 70oz stepper as well. Between the four I bought and the little guy I am planning this machine as initialy a 3axis that i will use to build the 4th and 5th axis bits with.

The bearings also arrived.
The table top and frame rails are within 1mm of being "flat". I have heard mention of self leveling epoxy, anyone use this? how effective is it? In all honestly this is an acceptable deviation for my use for this machine, but if it is reasonably easy and cheap I'd like to increase it's precision.

On welding the top to the top rails we clamped the bejebus out of it, and spot welded first and moved about the perimeter rather than following the edge. Anyways I'll be posting a drawing here shortly.

[hammajamma]

So this is all I am doing for the base table and the gantry. It is welded square steel tubing.

[thegimpster]

looks good. I got my tax refund today and plan on buying my new ones. keep up the good work.

[awerby]

especially since it's so high. Think about putting walls on the sides of the table to run the horizontal part of the gantry on without having to move those big vertical members. The Mechmate design works that way, and it seems like a good idea to me...

Andrew Werby
www.computersculpture.com

Originally Posted by hammajamma So this is all I am doing for the base table and the gantry. It is welded square steel tubing.

[cpcapace]

I've worked a bunch with epoxy on MDF. If you want to seal your mdf it's not a bad idea so moisture does not warp you machine.

But if you want to coat the top with a thin layer if may not be level enough.

I would simply seal it. Let the epoxy wet out. It will also strengthen the mdf