[travis.farmer]

This is an older picture of my machine. i have since bought an ATC spindle for it.

the ATC spindle mounted in place. it is a 4.5KW 3PH spindle.

This is the control cabinet wiring, so far. still have several things to tie in.

the CNC Router is run by LinuxCNC, using a Mesa 7i80HD-16 controller board (seen up top of the cabinet, hidden by the copper-clad ribbon cables.)

I look forward to providing more details as i go

 

[travis.farmer]

Here is a video i did (by no means a pro video maker) of a test run (no material).

 

[Superburban]

Is the computer directly controlling the router? Most 3d printers, and laser cutters just load the file, and run from a micro SD card (well, at least mine do, maybe not most).

How fine of a detail, or resolution can that do?

 

[travis.farmer]

Is the computer directly controlling the router? Most 3d printers, and laser cutters just load the file, and run from a micro SD card (well, at least mine do, maybe not most).

How fine of a detail, or resolution can that do?

the Mesa 7i80HD-16 board is where the real magic happens. it is a FPGA that is programmed (with selectable Mesa firmware) to handle the step generation that drives the stepper drivers and stepper motors. but the computer does play a huge part in controlling the FPGA, and therefore the machine. without both working together, the magic would not happen.
the computer is running Debian Linux 11 (Bullseye), with a real-time kernel (very important), and LinuxCNC 2.9. the reason for the real-time kernel, is microprocessors have a hard time in time based processor management. after the first step, they complete the second step when they get around to it. the real-time kernel allows the microprocessor to act like a microcontroller, similar to a 3d printer controller. in other words, after the first step, the computer does what it needs to do, but when the time comes for the second step, it is near spot on timing.
the real-time kernel is most important if LinuxCNC is doing software stepping. that is when a parallel printer port is used for the machine input and output. so for this setup, one must select the computer motherboard and processor carefully and experiment with it to get the timing settings matched with it's ability. my machine used the Mesa board to handle the step generation, and connects to the computer via a Ethernet connection, directly (no network switch or router in between). because of this, there is much less load on the computer itself for timing, except that it only needs to send the FPGA instructions in time to generate the steps.

hopefully i have explained that part well. i don't know all there is to know, but i can share what i "think" i do know.

as for precision, if i did the math correctly (not my strong point), the steppers have 200 steps per revolution, and 1/8 micro-stepping, so 1600 microsteps per revolution. the ballscrews have a 5mm per revolution pitch, so every microstep, the axis will move about 0.003125 mm. though for routing wood, i am unsure if that level of precision is even necessary. ;-) i mainly run 1/8 microstepping just to make the machine run smoother. there is a lot of mass in the gantry and spindle, so if the Y axis is running a little jumpy, it would shake the whole shop (before i setup the acceleration correctly).

 

[Superburban]

Yes, great description thanks.

 

[travis.farmer]

the previously mentioned ATC (Automatic Tool Changer) spindle that i have on my machine is actually a fairly recent addition. i bought it with my IRS tax return money. i intend to make a living, using my CNC router, so i wanted an ATC spindle to allow faster tool changes, and eventually, fully automatic tool changes. it uses pneumatic power to operate a piston inside the spindle. this piston actuates a little grabber that grabs onto a little knob at the top of the tool-holder, and draws it up tight, so the cone part of the tool-holder is pulled into a matching cone in the nose of the spindle.
because this cone is the entire drive contact of the tool-holder, it must be clean and free of oil, water, and dust. so the air coming in must be clean and filtered, mainly because a charge of air is used to blow dust from the cone before locking it in. so that air charge must be water and oil free. despite having a pneumatic piston, my first thought was that it should have a few drops of air tool oil, but the directions advise strongly against this.

i am relatively new at CNC routers, but i am learning as i build mine up. i originally bought it off of Craigslist, for i think it was $600. just the machine and the original spindle (a Perske 5HP 3PH). i added the stepper motors (NEMA23), stepper drivers (Leadshine DM542E), Mesa board (7i80HD-16), and well... the list goes on. but i have been very slowly building this machine up, and while it still has quite a few temporary installations, like a homing sensor held on with tape, as i fine tune things i can mount things more solid.

i currently have it sitting in the back of a gutted out camper trailer, as it was what i had. i am building a new shed that will serve as my shop. it is a 13' X 20' platform, that i will move a tent/garage onto, and build some better end-walls. i have the platform built, but time got away from me and winter hit, so the platform is covered by a tarp, waiting for summer.

today, i was adding the air-lines that wind around my machine to get to the spindle, and once all was connected, i turned the regulators down, and added air from an air compressor. then i turned the pressure up for the lock/unlock piston to around 95psi, according to the gauge, and noted it would not quite actuate the piston enough to allow a tool-holder to be inserted. i carefully turned the regulator up to 100psi, and it just operates the piston. i suspect the gauge may be off, as 95psi is the max for the spindle. either that or the air passages may have a blockage from some packing Styrofoam. i hope not, as i am unsure how to clean them out...
my first order of troubleshooting is to replace the gauge on the regulator. there is also the potential that the solenoid air valve is not opening all the way, and therefore not letting the full charge of air through. a few things to check tomorrow.

it is my intention to be able to make some basic signs for people to pay for the upgrades, like the full ATC setup so i don't have to manually change tools. my biggest hold-back is the space the machine is in only allows access to one side (yeah, it is that tight a fit in the old camper). so i cannot even attach the spoilboard yet. i just can't reach across the table, and i don't want to lean on the table because the slides for the gantry are mounted under the table. i can't risk bending the table.
so i just putter along on the machine, and get as much done as i can before i can move it to the new shop.

 

[travis.farmer]

Yesterday, i was able to add a rack tool changer code to my LinuxCNC configuration. i didn't write that code, entirely, as it was grabbed from another LinuxCNC member's configs. i did modify it to suit my machine, though. i had to temporarily disable some safety checks to run it though, as the rack and sensors is not there, yet. once the rack and sensors are there, i can re-enable them.
Still, it was nice to see the machine going through the motions. i hope to do a quick YouTube video at some point, showing the machine going through the motions. pretty fascinating to watch. i may even turn on the Air, so the spindle tool lock/unlock can be heard to function.

i see the schematic in David's CNC thread.. i am digging the colored wire traces. i use the electronics design part of Fusion360 (free hobbyist/non-commercial license), and to my knowledge, coloring the traces is not an option. i have attached my current, work-in-progress, schematic of my machine. it is not as detailed as David's, but i understand what it means, and can find the connections as needed. color traces would be a real improvement though.

 

[difalkner]

i see the schematic in David's CNC thread.. i am digging the colored wire traces.

CorelDraw all the way!

Your schematic is neat, organized, and I can see why you understand what it means; it's logical.

 

[travis.farmer]

other than tying up some loose ends, like proper homeing sensor mounting (the tape method keeps coming undone), and cleaning up the on machine wires, the machine is basically ready to mount a spoilboard, and start using for basic signs and other carvings.
though, there is the issue of finding T-nuts and T-bolts for the aluminum table, and other mounting locations. the table T-tracks i have measured to be 3/8" inner tracks. all the T-nuts and T-bolts i have are 1/2" wide. so to mount the spoilboard, i either have to grind some T-bolts down to 3/8" wide, or find some other way to mount the spoilboard.
I can't drill into the aluminum table top, as the Y-axis slides mount under the table, and i am hesitant to weaken the table support ability.

if i can find enough T-nuts and T-bolts that fit without grinding, i could do away with one large spoilboard, and just place scraps of wood under anything i need to cut through the material, and otherwise just mount the material directly to the table.

 

[difalkner]

i could do away with one large spoilboard

I'm not certain that is a good thing. Having a single spoilboard that can be surfaced for a known level and coplanar surface is a good thing. You can mount your workpiece anywhere and know that it is on a reference surface.

 

[travis.farmer]

I'm not certain that is a good thing. Having a single spoilboard that can be surfaced for a known level and coplanar surface is a good thing. You can mount your workpiece anywhere and know that it is on a reference surface.

i was under the impression that where the gantry slides were attached to the underside of the table, that the gantry rode parallel with the table. i had assumed that the table was a reference surface, but perhaps you are correct, that machining a reference surface is best. as soon as i find something for a spoilboard, i will mount it in place.

i have been doing some thinking on my rack tool changer (for ATC), and due to my machines setup, rather than the usual back mounted rack, i will do a front mounted one. i will have to reach over it, but i will build it on slides, so it slides out of the way, forward, when not in use. i could even use a spare stepper and screw and some crap slides i have on a mini CNC that i no longer use. all it needs to do is move forward and back to allow the CNC to work down to Y-zero, when not changing tools. all i would have to do is tie it into LinuxCNC as a forth axis, and set it up with the limits and homing, like a regular axis. it will need slide and screw protection from wood chips, as will the tool rack. that can simply be a cover that flips open as the rack slides forward.
each tool pocket on the rack will need a inductive proximity sensor, so before it grabs a tool, it knows if the pocket has one in it. and likewise, if returning a tool, so it knows if the pocket is full already (shouldn't be, but for human error).
it is fortunate that the LinuxCNC + Mesa board system has ways to expand the number of digital I/O, with fair ease.

It is all so simple in my head... ;-)

i remember the old days of parallel printer port driven logic, or self-contained GRBL systems. not nearly as easy to add more I/O ;-) (trying hard not to sound like i am selling LinuxCNC and Mesa... but i do like the system a lot )

 

[difalkner]

i had assumed that the table was a reference surface, but perhaps you are correct, that machining a reference surface is best.

Trust me; I'm correct. Even a new sheet of MDF isn't really flat. When I change out my spoilboard, which I've only done twice in 6 years, the first thing I do is surface it.

It's always interesting to see that even on a very light skim cut there are peaks and valleys on what appeared to be a flat surface. I surface the spoilboard every few months and I'm in a climate controlled environment. If you're not then you may have to surface the spoilboard every other week, it just depends on how much the humidity swings in your CNC area.

 

[travis.farmer]

it just depends on how much the humidity swings in your CNC area.

it swings a LOT. Maine is very humid, and neither the current nor the future (in process of building) shed is very close to climate controlled. the future shed will just be a large garage tent that i will build end-walls for, and insulate when i can afford to.

kinda why i was hesitant at first on using a spoilboard when not cutting through. kinda has me questioning how to keep it flat with wild humidity swings. seems like i should have quite a bit of spoilboard material around, ready to go when the previous one gets too thin. ;-) MDF at my local lumber yard has to be ordered, as it is rarely used in these parts. i think Home-Depot or Lowes may carry it (located 20 - 30 miles away).

 

[travis.farmer]

minor setback... bought some hardware to upgrade my machine... and didn't realize it would require such an extensive re-wire.
i bought some Mesa boards to expand the number of inputs (for my rack tool changer), and a board for an on-machine control panel. but to use the boards, i have to change the firmware on the main Mesa board, and that will move the wiring around to different pins. like, all the wiring.
it is a hassle, but needs to be done to protect my investment in the new boards.

 

[MadMark]

Inside every small problem is a larger problem struggling to get out ...

 

[travis.farmer]

Inside every small problem is a larger problem struggling to get out ...

probably likely, though i am unsure exactly what you mean. i have many larger problems, so it is difficult to know to what one you refer.

 

[travis.farmer]

the hardware i bought to upgrade my machine is a circuit board that handles most of the inputs from the machine. or at least, all the PNP sensors (PNP sensors pull to the logic-high when active, where NPN pulls to logic-low when active). my homing sensors and apparently my tool-length probe are NPN, so those are still handled by the main board.
the reason for the add-on board, is it works with machine voltage (24V) rather than the low voltage (5v) the main board needs, so no need for voltage level converters. this cleans up my control cabinet just a bit, with the exception of the spaghetti-wiring everywhere.

another board i bought is a remote pendant/control panel board. this will allow me to have on-machine controls for various task. the machine is large, and when i get in the new shop, the computer will not be located directly at the machine, as it would be in the way of getting around the machine. this control panel board allows me to have up to 4 MPG hand-wheels (encoder wheels), so i can jog the axis around during the setup process.
it also will have a 20 X 4 character display that can be used as a DRO, or for other status info.
there is inputs for a 8 X 8 key/button matrix, that i can just wire up to 64 buttons to.
there is also some general purpose inputs i can attach an E-Stop button on, and 2 outputs that i can use for status indication, like when the machine is turned on, and when it is actively running a program (maybe). really they could be for anything...

i have not yet bought anything to make the tool changer rack yet, simply because i can not get to that side of the machine to attach and adjust the rack. that will have to wait until i get the machine in the new shed. i may buy the basic hardware for it at some point, but i do not need it just laying around right now.

 

[MadMark]

What is your spoil board made of? Are you thinking of cutting 6061 aluminum? It mills quite easily with cardbide bits, slow feed, and coolant/lube mist.
Its the coolant mist that causes issues with common MDF spoilboards. We overlaid the MDF with HDPE, which didn't mind coolant spray.
Another thing we did was to drill & tap the spoilboard for jigs. This allowed repeat parts without loss of zero. Very handy.

 

[travis.farmer]

What is your spoil board made of?

at present, i have not attached a spoilboard, as i can not get around the machine in the current location to attach it properly. it will be MDF, i believe.

Are you thinking of cutting 6061 aluminum?

i would like to be able to do aluminum, but i believe this machine will be strictly for woodworking. i have been told that aluminum can be milled dry with carbide bits, providing that chip clearing is very good (either air blowing, or good vacuum suction). i may try it some day, with a carbide bit i don't care about experimenting with.
the HDPE spoilboard may be an idea too. though i can envision a mess on the floor if i can't contain the spray.

 

[MadMark]

at present, i have not attached a spoilboard, as i can not get around the machine in the current location to attach it properly. it will be MDF, i believe.



i would like to be able to do aluminum, but i believe this machine will be strictly for woodworking. i have been told that aluminum can be milled dry with carbide bits, providing that chip clearing is very good (either air blowing, or good vacuum suction). i may try it some day, with a carbide bit i don't care about experimenting with.
the HDPE spoilboard may be an idea too. though i can envision a mess on the floor if i can't contain the spray.

The mister acts as a chip clearing spray, coolant, and cutting lube. We'd mix up a quart of fluid from concentrate. It looked like Mt. Dew and was bio-safe.
We attached the spray tube to the cutting head with zip ties. The tank was strapped to the leg of the table that the machine rested on. The tank had an air line with a pressure regulator, to set the mist volume. You could cut for hours on a quart of coolant. The line to the cutting head was 1/8" ID aquarium air line. Cheap and flexible, the gantry never noticed the weight of the line or the brass spray nozzle.
Yes, it made a bit of a mess, but was easily cleaned with a shop rag (you know, the ones in a dispenser box.) Never had much flow spill onto the floor. Oh we had a drip here & there but nothing thst needed a mop. Normally we'd air spray the spoilboard and most of the cutting fluid would evaporate, then we'd wipe it dry and chip free, before mounting the next blank.
The chips got everywhere in the work cell, but we just brushed off the machine and swept the floor. The partition caught some chips but nothing to worry about cleaing up
One cool thing was, that the projected end time from the Mach3, was accurate to the second. If you noted the start time, you could walk in just as the machine was homing at the end of the run.
Parts do need to be rinsed and wiped to remove any chips, and the slightly sticky, coolant residue. It was water soluble, so it rinsed right off, even if dried on.
We bought three of those 5' tall free standing office partitions, the ones with fabric. We got them cheap from the used office supply place because stains were ok. We put them around the machine to form a work cell. This localized the noise and mess. The control computer and drive electronics were located on an adjacrnt table on the other side of the partition. The operator could reach the keyboard and the CNC from their chair. The operator usually didn't babysit during a long run, once the given cut file was verified.
Oh! Speaking of noise, WEAR EAR PROTECTION! We had an earplug dispenser for the operator and a pair of monkey ears for guests.