Centroid Community CNC Support Forum

As I may have mentioned, I have no real experience with machining metal, except for the hacking I have done when building a mostly all aluminum 3D printer, and now this CNC router project. However, I am a woodworker, and know a little about working hardwood. Lucky for me, there are a lot of similarities between working very hard wood like Ipe, and aluminum.

Marty, you asked if I cut and then milled the ends of the extruded aluminum for trueness. I wish I could, but I have nothing to mill with. I have a router table, but I would hardly call using a router table on aluminum, milling. First off it is kind of dangerous. You really need to know what you are doing when working aluminum with a woodworking router table. I cut the ends of the extruded aluminum on my table saw. That is where I cut the majority of the aluminum pieces used in constructing the CNC router. Below is a picture of a setup for cutting the connection plates used to attach the linear modules and the gantry.

Thank you for sharing the details of your build with us.
Marty

I am resurrecting this very old thread, because I think it may be nice to tell the rest of the story. I made a lot of progress on the design and build of my CNC router project, but life somehow got in the way. To be honest, maybe I just found an even shinier thing to start playing with, I can't remember . The project got mothballed, put under some plastic, and placed in the corner of the shop. That was in 2019. It's kind of embarrassing to say, but it's now 2024, and over the last week, I got the itch to pull it out of the corner, and try to get it over the finish line. I'll try to bring the story up to date, and continue to document my journey.

First, I think it's time for some pictures (see below). Here is the current state of the project. I completed most of the construction, and got the wiring and software rung out to the point that the three axis were properly moving and homing, and the spindle motor was running via the VCP. I also constructed a spindle water cooling unit, using some of the CPU cooling toys that were available at the time. The cooling unit rides on the back of the gantry. Using an Arduino mini controller, I built and coded some controls for the cooling unit to displays the coolant (water) flow, and fan speed. These parameters are monitored, and if they fall below a threshold, a relay (dry contact) is activated. The relay will eventually be used for an Acorn input to signal an issue, stop the running job, and power down the spindle. I also added a inexpensive tool touch plate, which has been interesting to get working. Instead of all the I/O going directly back to the main controller box, I built a sub unit that also provides some LEDs signals for the axis limit switches. The I/O of course all needs to go back to the Acorn, it's just done with a simple DB9 cable, and the sub unit provides a place to plugin a lot of the external stuff (limit switches, tool touch, spindle cooling unit signals and power, ect.). That's about as far as it got before I mothballed it. the pictures below will tell the visual story, and fill the holes in my description.

The first picture is of the sub-unit for interfacing some of the I/O. The sub unit has two relays in it that can be controlled with two of the Acorn outputs. I should point out that I have a rev 3 Acorn that didn't come with a relay module, so I added some relays in the main controller box and the sub unit. If you look at the main control box pictures, You will see a 4 relay module mounted to a plate above the Acorn.
The controller box is nothing special. I used a contactor and safety relay to work the e-stop. I like not having anything software controlled in the loop of an e-stop. Looking at the front of the unit, you'll see a main disconnect switch, which of course controls power to everything. When that is engaged, only the 24v/5v DC power is enabled, as well as a 240v ac outlet for the PC. The goal being to bring the Acorn up and the CNC PC for CNC12 to connect, but the rest of the power is disabled via the contactor. The switch at the front of the panel (labeled START) is used to get the rest of the system powered up. This allows the e-stop to depower all motion controlling hardware and spindle motor, but leave the Acorn, and PC up and running.
Even with the sub-unit I/O box, there is a lot going to the main box. I decided to mount the VFD for the spindle motor outside the controller box. This eliminated any potential electrical noise, and gave me more room for everything else.
More to come...

Z-Axis Linear Module

I learned a valuable lesson with the Z axis, the more rigid the better. I designed and built the X and Y axis, but for the Z axis, I went with a manufactured linear module. It was an inexpensive unit I found from one of the many Chinese suppliers. See below:
It may not be clear from the picture, but the rails are only supported at the top and bottom. After mounting the spindle motor, it was clear the lack of rigidity was going to be an issue. Looking at some of the more stout linear modules, the rails are either HGR or SBR linear guide. I decided to modify what I got to use two SBR linear guides. It was not a simple mod, but I'm happy with the results. I ended up needing to extend the 2080 aluminum back to a 20120 by using two 2060 extrusions and joining them from the back. That provided the room needed for the SBR linear guides and ballscrew. You can see the results in the pictures below:
Oh, the spindle motor mount was also a modified off the shelf item. the original was all one casting like:
I wanted the mounting area to be longer, providing greater leverage. That is I wanted to make sure to motor was properly supported for the horizontal forces it would see. I ended up cutting it in two on the table saw, and sanding it smooth. Its attached to the linear module mounting plate from behind.

Spindle Motor Cooling Unit

As described earlier, the spindle motor cooling unit is mounted to the back of the gantry. This enabled a closed loop water cooling system for the motor. I will eventually build a removable cover for the pump, reservoir and control board.
Next up, tool touch off and laser guide.

mikes wrote: ↑Fri Nov 22, 2024 11:21 pm I learned a valuable lesson with the Z axis, the more rigid the better. I designed and built the X and Y axis, but for the Z axis, I went with a manufactured liner module. It was an inexpensive unit I found from one of the many Chinese suppliers.

That goes for ANY axis, not just the Z axis.

Extruded aluminum machines aren't going to be anywhere near as rigid as a welded, steel frame but that's just the nature of extruded aluminum frames.

ShawnM wrote: ↑Sat Nov 23, 2024 7:05 pm

mikes wrote: ↑Fri Nov 22, 2024 11:21 pm I learned a valuable lesson with the Z axis, the more rigid the better. I designed and built the X and Y axis, but for the Z axis, I went with a manufactured linear module. It was an inexpensive unit I found from one of the many Chinese suppliers.

That goes for ANY axis, not just the Z axis.

Extruded aluminum machines aren't going to be anywhere near as rigid as a welded, steel frame but that's just the nature of extruded aluminum frames.

Shawn, I'm not going to disagree with you. Although this was not about the material used to build the Z axis linear module, but its design. I just made a bad choice when I selected that unit. I'm currently very impressed with what I've been able to achieve with the aluminum extrusions for all three axes. I will not be machining anything more then aluminum and hardwood with this router. However, I have yet to but the machine through any torture testing. I suggest, the only metric that matters is the amount of flex before the stepper motors slip. An equivalent setup in steel, would be interesting to see.

Yes I see the design from your pic. I don't think I've seen a Z axis with floating linear rails but I see your concern for sure. The ball screw will add slightly more strength to that but your upgrade will certainly make a huge difference. One of my routers is a small 3x5 that I machine only aluminum aircraft instrument panels on and the Z axis looks almost identical to the one you built. Only difference is I have a square body, 5HP, air cooled spindle that bolts right to the Z axis back plate. You should have no issues with your upgrades, very nice work.

So, the previous post kind of brings us up to date with what I had complete on the project before mothballing her (I'm old enough to call inanimate objects a her, so no flack please). Here is some of the new work I have done since resurrecting the project.

laser pointer/aligner

Installing a laser pointer/aligner, for part setup, was a fun and easy add to the CNC router. I purchased one of the inexpensive 100mW cross hair laser pointers from one of the many local Chinese suppliers. I think it cost all of $10 USD, and included a mount. It operates on 5vdc, and came with a USB connector. I'm running with a mill licence, but Centroid was nice enough to include an example VCP for a router in one of the example VCP directories. Adding that to the correct directory and starting the Wizard, it was simple to select that VCP. I mention all this as the OOTB mill setup does not have a laser ON/OFF or Laser Set XY button. With the alternet VCP, they are presented (and with a very nice looking brushed aluminum background ).

As stated earlier, there is a 2 relay module in the sub-unit/panel I build. That box already had 5vdc coming in on the DB9 cable, as well as two of the Acorn's outputs which are connected to the relay unit. So, turning on the laser form the VCP was not much work. Here is a picture of the end result:
Ok, I'm going to be honest with you, I also wanted the laser to make squaring the gantry easier. I had resisting trying to dial that in with just the spindle as a reference. The laser made that easy peasy. The mounting block is just a piece of scrap aluminum I had. Tapped some holes in the spindle mount, and Bob's your Uncle.

Next up my adventures with tool touch off...

mikes wrote: ↑Mon Nov 25, 2024 4:38 pm
with a very nice looking brushed aluminum background ).

great! i was wondering if someone was going to try that and think that was cool, i like it too.

post fresh report.zips as you go so we have a snap shot of your current setup.

also read this doc before setting up the TT.

https://www.centroidcnc.com/centroid_di ... rement.pdf

and do you have a link to the laser you bought?

The laser used for the project was gotten from Amazon: Focusable 638nm 650nm 515nm 450nm Red Green Blue RGB Laser Diode Module Line/Cross/Dot Head With USB Adapter 12mm Cooling Heatsink (515nm Cross 515MC-10)