OX Build of Sorts

[cncnewguy]

I wanted to post a bit about my machine. As you will see in the photos, I have C-Channel for the rails and Z axis. If I move the X axis rails further apart, I will have a 44" x 44" table with a 10" Z axis travel. However, the Z axis is not very stable at -8". I just retrofitted the Z axis with a longer plate to move the wheels further apart. That has stiffened the Z axis up tremendously. I also added 4 wheels to the outside of the C-Channel for the Z axis. Now it has four inside the channel and four pinching the outside towards the gantry. I am using nema 23 for the Z axis and nema 34s for the X and Y. I have 2 34s running opposite directions for the X axis. It all rides on wheels and timing belts. It is on a temporary mobile base due to real-estate constraints. I will eventually build a fixed base either from more extruded aluminum or perhaps angle iron. When I do build the base, I will add the appropriate drag chain. But the boards I am currently using seem to do the trick. They just limit my access to the side of the machine. I have a 1.5kw 24000 RPM 115V water cooled spindle with the associated VFD. Of course, all of this is run via the ACORN board. I do not have the extra relay board. I added a two-relay board (10A 115vac) and I have 1 30A 220V waiting for my 220V to be hooked up to a larger dust collector. I manually jog it to zero. I have hard stops and will likely be adding limit switches in time.

I built a box to enclose the electronics. You will see that the entire back folds down on a piano hinge so I can easily access the components. Once complete there is little reason to get to all of the components. I did put my acorn board on a piece of 1/8'' hardy board and it slides in and out like a drawer. I also have a piece of hardy board across the top of the ACORN board to keep the wires above from contacting the board. Now, I can just disconnect the wires from the outside and feel comfortable that the connections to the stepper drivers and ACRON board will not be stressed. I will add a plexi glass door with filtered vent holes near the bottom and I have a 24VDC fan at the top of the box. Each stepper driver, the fan, VFD, and the ACORN board have independent switches. This way I can tune off a stepper motor if I need to physically move the axis.

I have been building stuff from wood for 25 years, but only recently decided to build a CNC. I look at it as another tool to augment my current skills and not a replacement for any one tool. So far all I have done is cut out a few names, circles, squares (for accuracy purposes) etc. Once I finally had everything moving in the correct direction and then calibrated, I quickly realized that the CAD/CAM was a whole new world. I turned to Inkscape and Fusion 360 for everything so far.


Pros: for ACORN - Cost, support forum

Cons: not much. There does seem to be a lot of MACH3 stuff on You Tube, but fortunately most of that info translates to all machines.

Thanks to Keith and Marty for getting me through my trying times.

Advice to someone getting started: Do not get ahead of yourself. Do the bench test of the motors. Then add a feature and test it - i.e. limit switch, zeroing block etc. Take snap shots of your settings before you modify them. Initially I would do this several times per day until I had something that worked. You do not need to run the machine at max RPM and max feed-rate. I am going to add a buzzer to go on for 3 seconds prior to the machine staring to move to warn the kids and me that it is about to move. I can see someone getting their hands caught if they are unfamiliar with the machine. Finally, look at the Z axis pic - you will see some extra t-nuts waiting for me to add something - anything. I will be adding a dust collection hose support to the front and perhaps a laser in the future. I added them when I rebuild my Z axis. They are too cheap not to have some hanging out within your rails.

I hope this helps someone. Let me know if you have any questions about my build.

[cnckeith]

thanks for posting! what axis motors and drives are you using?

[cncnewguy]

I am using 3 Dual Shaft Nema 34 CNC Stepper Motor 8.5Nm (34HS46-5004D) 5A 86x114mm with the MA860H-N stepper Drives (Leadshine equivalent) and a NEMA 23 motor that came with my open builds prebuilt z axis. That is using a smaller version of the leadshine type driver.

[chaznatr]

I really like your enclosure, I have been trying to decide how to do mine. I have 3D printed small enclosures for the Acorn and the relay boards but I still want to put everything together. So I might have to "borrow" some of your ideas.

[cncnewguy]

Chaznatr,

The best advice I can provide it whatever you make for an enclosure, make room for expansion. Also, do not try and go too compact. I found that a little biot of wasted sapce is acutally not wasted. You will use it. Also, mine is made from 3/4 plywood. This makes it easy to attach almost anything and nothing shorts out like it might in a metal box. I have since made a larger enclosure from the one depiceted. I will have that on casters and will include a worksurface on top for the coputer screen and keyboard.