bought a used 48" X 48" X 5" used router table

once i shovel a path through the 4 feet of snow beside my CNC camper (not all storm accumulation), perhaps this weekend, i have a stepper with a power-loss brake for my Z axis. trying to establish the best setup for applying and releasing the brake.
my plan is to connect it via a relay to the stepper driver enable signal. that way, as soon as the system disables the steppers, it locks the Z from settling. of course, an E-stop will do the same.
the control computer will be connected to a battery backup (UPS), but the machine power will not. so i will include a relay in the E-stop loop circuit, that connects to the AC supply of the CNC camper to sense a power failure. therefore stopping the machine, and locking the Z axis before the power supply filter caps are even drained down.
is this a good plan, or is there a better way to pull power from the brake to lock it up?

~Travis

[QUOTE=travis_farmer;2259218]once i shovel a path through the 4 feet of snow beside my CNC camper (not all storm accumulation), perhaps this weekend, i have a stepper with a power-loss brake for my Z axis. trying to establish the best setup for applying and releasing the brake.
my plan is to connect it via a relay to the stepper driver enable signal. that way, as soon as the system disables the steppers, it locks the Z from settling. of course, an E-stop will do the same.
the control computer will be connected to a battery backup (UPS), but the machine power will not. so i will include a relay in the E-stop loop circuit, that connects to the AC supply of the CNC camper to sense a power failure. therefore stopping the machine, and locking the Z axis before the power supply filter caps are even drained down.
is this a good plan, or is there a better way to pull power from the brake to lock it up?

~Travis[/QUOTE]

The easiest way I know is to set up a relay that shorts the Z axis stepper when power is off which will essentially "lock" themotor enough to prevent the axis from dropping...

hmm, that would have been simpler, and cheaper than the stepper with a brake i already bought. ;) (not that i ever had a problem with impulse buying)
same general principal as what i had in mind, though the relay would drop power from the brake, rather than shorting the motor.

~Travis

i finally made a (very) short video showing my CNC router.
[url]https://www.youtube.com/watch?v=WCr2X_-9Kjw[/url]
the control box wiring is a mess, as i quickly threw it together to get it working. the temporary Z home switch may not have any close accuracy, but it worked for just testing the machine. the new home/limit switched can be seen in the white plastic tray to the left on the router table.
at some point i plan on making some fixtures to hold the new limit/home switches. i will also swap out the Z stepper for the one i have with a power-fail brake on it.
i have some 120Vac to 36Vdc power supplies on order. when they arrive, i will swap them out for the current setup (120Vac to 12Vdc PSU, plus 12Vdc to 36Vdc boost converters). originally i intended to use a large lead-acid 12Vdc battery to power and provide power backup for the drivers. that was before i had the stepper with a brake. when i swap out the PSUs, i can take the time to clean up the wiring in the control box.
i really need to clean up the wiring in my CNC camper so i can have proper lighting, and such. i also need some heat in the camper, and to finish the roof so i can get rid of the tarp covering it.
a lot of work needs to be done, and finances are tight at the moment due to a recent back injury. but i will eventually get it working properly. i have big plans for it, as far as work-related tasks, so it is a fairly high priority (just below bills that need paying).

~Travis

Just a bit of an update...
due to having to use my Makita RF1101 router off the CNC, more than on the CNC, i am going to put the 3-phase 5HP Perske spindle. i have ordered a VFD (HY04D023B), hopefully it will work with my spindle. i have read that i should have gone with a bigger one, but as it is [U]stated [/U]as being rated for 18FLA, and my spindle is... i don't remember (but it is less than that).
I still have to mount the Z-axis stepper (with brake)... though i am waiting for either warmer weather, or i need some sort of heat in my CNC camper.
also, i was afraid the 12Vdc switching PSU, driving three 12 to 36Vdc DC-to-DC converters, would present a weakness, so i have three 36Vdc 11A switching PSUs to install. this should also make it easier if i need to troubleshoot the power.

now, as my Perske spindle has only one collet size (1/4 inch), i may have to order at least a 1/2 inch and an 1/8 inch collet, though i am unsure of what and where to get them. my little bit of research told me that Perske uses their own collets, but i think there are different taper sizes. if i provide measurements (i will get them a little later today), is there somebody that can help me identify what i need? i can probably make due with what i have now, for testing, but in the future...

~Travis

today, as the weather was warmer (39*F), i was able to work on my CNC router.
I installed the 3PH 5HP Perske spindle back on, having already testing that my spindle and the VFD i ordered work well together. i also installed a brake stepper i ordered a while back for my Z-axis. later today i will move the components from my LinuxCNC control computer into a better looking 4U server case. this way i can use the rack mount tabs to secure it under my desk.

i am thinking of doing something a little different with my desk. i saw online a desk that the computer was built into the desk, with a glass top, showing the computer bits. it is my plan to mount the stepper drivers, breakout boards, power supplies, and so on, int the desk, under a 1/4inch piece of glass. the compartment will be vented from underneath, but it will make it easier to work on the control bits, as i will simply have to lift the glass, and there it is. could be a neat idea, or it could be a flop. in any case, i think it will look interesting.
the other side of my desk, i will try building in a tool chest in. just some space for cutting bits, spare parts, and other tools.

at least progress is slowly making way, again. hit a little turbulence, but my excitement for the machine has returned. :D

~Travis

[QUOTE=travis_farmer;2271280]
now, as my Perske spindle has only one collet size (1/4 inch), i may have to order at least a 1/2 inch and an 1/8 inch collet, though i am unsure of what and where to get them. my little bit of research told me that Perske uses their own collets, but i think there are different taper sizes. if i provide measurements (i will get them a little later today), is there somebody that can help me identify what i need? i can probably make due with what i have now, for testing, but in the future...

~Travis[/QUOTE]

Looks like they use either SYOZ20 or SYOZ25 collets. You can get them from several sources.

[url]https://www.vortextool.com/machine-tool-accessories/collets/perske-series-precision-collets.html[/url]

[url]https://www.techniksusa.com/wood/din6388.htm[/url]

This page has some dimensions of the collets.
[url]https://www.techniksusa.com/metal/special_order_collets.htm[/url]

Excellent!! thank you very much, Gerry!

~Travis

i spent a little time doing a slight re-wire of the PSUs, drivers, BoB, and so forth. my VFD has power supply terminals for 24Vdc, and 5Vdc, so i am going to use those to power the BoB, and the Z-axis brake-release. i contacted the VFD seller, and they assured me it would handle the small loads, as i described. the manual unfortunately gives no specs for those terminals. so i rely on the sellers word that i won't release the magic blue smoke.
i must say though, the machine looks a mess, with the temporary wires for the spindle, and the Z-axis brake. i will clean it up when i am sure it all works as it should.

diving into a re-wire, and making changes to the desk, and such, is becoming overwhelming, but i just take it a little at a time. hopefully, i will have it back usable again in a few weekends.
the biggest thing holding me back is trying to find money enough to get my own house, so i can have a permanent install of the CNC. so everything i do will be temporary, and modular. but if i can get it going, there is the chance i can use it for money making projects to supplement my income.

but anyway, enough about the personal crap. i just wanted to post a quick update, in case anybody is following this machine build.

~Travis

quick update...
I wired up everything, according to the new wiring plan (using the VFD power supplies to power the BoBs), tested and adjusted the stepper power supplies. however, i went to login to the LinuxCNC computer, and apparently used the wrong password many times, before realizing the password was right, but the username was wrong. when i figured it out, i wrote it down, for future reference. today, i will do a full test, before re-mounting the control bits.

~Travis

bit of a snag... after changing the wiring plan, the machine no longer homes. i suspect a wiring fault somewhere, but there is the chance of something more drastic, like a failed BoB, or both (i have connected a second BOB for more I/O if needed in the future). interestingly, the steppers all perform correctly. it is just the BoB input channels. they are opto-isolated on the BoB, so i don't think the computer LPT ports were affected.
i just came in for lunch, so afterward i will double check my wiring, and confirm correct voltage levels. i hope the BOBs are ok, as i really don't want to have to wait for shipping for replacements. but, in any case everything else i have changed seems to be working. so far, anyway...

~Travis

i got my new wiring plan prototype wired up, and it works great. i also reduced the micro-stepping to half-steps, as i realized i didn't need that much precision (i think it was 1/32 before). when i really get going with the machine, i will know better how much precision i need. on the plus side, i went from 30mm/sec, to 90mm/sec. no video yet, as the board i mounted the controls to, are a mess. i will clean it up some other time, when i get to it. and when i say mess, i mean it is a shameful mess of wires.
i also have the spindle VFD semi-configured, though i still have to connect the serial communication to the control computer.

I love when things come together. :D
seeing the machine come back to life, and working better than before, it's like giving birth to a creature, and watching it grow up. :)

~Travis

i finally got around to trying to connect my spindle VFD via RS485 (Modbus). had it all planned out, and it was going to be perfect... but then it wasn't. i followed the tutorial i found on YouTube ( [url]https://youtu.be/1NF8EFoPlrk[/url] ), and when turning on the spindle from LinuxCNC, nothing. tried several different settings, and nothing. at one point i was able to turn the VFD on, and the spindle ramped up, but kept going up, and up. tried to stop it via LinuxCNC, and no response. my best guess is that i should swap the piece of twisted-pair CAT5 (one pair only), for a piece of some shielded CAT5e i have kicking around. perhaps it is getting noise. my second guess is that i may need to insert a termination resistor.

in any case, i haven't crashed and burned. just working with the folks on the LinuxCNC forum to get it figured out.

~Travis

[QUOTE]i also reduced the micro-stepping to half-steps, as i realized i didn't need that much precision (i think it was 1/32 before).
[/QUOTE]

Microstepping doesn't actually increase precision. It's more important for smoothness. You should always use 8x or 10x, for smoother running motors.

alright, thanks for clarifying that. goes to show how much i still need to learn. :)
I will make that change next time i work on it. and here i was so proud of the fast speeds. as big as the machine is, it does seem to shake the earth a bit when taking single steps. ;)

~Travis

solved my RS485/VFD communication issue. i did insert the 120Ohm termination resistors (i assumed the VFD and the USB/RS485 adapter had them already, but i was wrong), and i also swapped out the piece of CAT5 UTP cable for a piece of CAT5e FTP cable, and i intend on grounding the FTP shield to PC ground. with the exception of a few VFD parameter changes that i had set wrong (motor rated RPM and number of poles, so RPM reports wrong), it now functions.

i still really need to install a proper Z-axis home switch, as the testing switch leaves way too much unusable travel. i also have to readjust the spindle mount on the Z-axis box, up to a higher point. it currently extends too far down, and leaves little usable travel.

perhaps a task for after lunch.

~Travis

it occurred to me while i was running some testing G-code, that i haven't been touching off incorrectly (paper method), and just running from there.
so i have decided i need to build a touch plate. i have some blank copper-clad PCB, so i can use that as the probe plate, and connect it to the probe input, and then have a ground clip to clip to the cutting tool. beyond that, i am going into unknown territory.

i must say though, watching the machine carve away, i was so enamored, i forgot to change the microstepping above 1/2. as large as the spindle is, it was pure joy to see the machine wield it like a surgeon's blade.

so, now that i have fallen back in love with my CNC, i should also focus on the safety aspects. i still don't have an E-stop button wired in. i need to pick up a braking resistor for my spindle/VFD, and wire a hard-wire E-stop from the CNC controller, to the VFD. in an emergency, i don't want to have to wait for the spindle to spin down so i can remove my limb from it. (yes, i know enough to keep away from a running machine spindle) lets see, what else... the wires are still a mess, and a bit of a trip hazard. but having a working machine, i can concentrate on these issues.

i had a dust collection shoe for when i was using a Makita RF1101 router, but i hope i can convert it to work with my 5HP spindle.

oh, one thought, anybody know how to lube the spindle? it is a Perske VS 60.11-2. it just sounds a little dry. i haven't found anything on the crpperske.com website.

~Travis

made a dumb plaque today, just to try carving something other than the word "test". somehow i botched the tolerances somewhere, as on the face run, it left thin strips of plywood beside the cutting bit. could be from the fact i still need to fix the microstepping from being too course. i thought i had the feed rates too high for the spindle RPM, but i didn't break a bit. had me hiding behind a chair a few times though. just got to get used to the machine and what it can do. mainly i just wanted a chance to "play", before i cleaned up the wiring and settings, and the rest of the TODO list. at some point, i want to try milling some very basic aluminum. just to make some fixtures to mount the new HOME switches.

i seem to be running into an issue with lubing the slides and screw for the X-axis. it is fully enclosed, with small slots for the Z-axis mounts to protrude. the Y-axis, i can crawl under and get real good. the Z-axis, initially was easy, but not so much, now, for some reason. i was thinking of either drilling access holes that can be plugged after lubing, or drilling and tapping for some grease fittings. neither sound great, as i don't want to compromise the strength. i may just tape a tube to my small cheap endoscope camera, and pump grease in, with the camera to direct it. in any case, it needs to be done frequent enough that i need to figure something out.

something i need to do, too, is get a infrared tachometer, and clock the spindle, so i can calibrate the VFD a little better. the rpm reported to LinuxCNC is not the same as reported on the VFD display.

with the extra pins available on my second LPT port, i intend to configure control for the dust-collection to turn on (aka, shop vac, at the moment). i also need inputs for E-stop loop.

i originally planned on having a divider wall between the machine and the "control room", to protect the computer, and myself (should a bit go flying). but i think instead that i will just mount some lexan panels on the side of the router table. if the vac system works as i want it to, the piles of dust flying everywhere should be minimal (in a perfect world).

there is a bunch of stuff on my TODO list, but i am slowly working through it. though i think i add to it as fast as i check off items. ;)

~Travis

quick question, what would be a good, simple, and cheap Z tool length probe plate material?

at first i was thinking of buying a plate of stainless steel for it's hardness and not likely to tarnish. then i thought maybe aluminum would forgive just enough to not harm the tool. eventualy, i will probably make something better, but for now, just something to get me by.
my other thought on aluminum is that i could mill it with my router if it needs re-surfacing. i am assuming i can mill aluminum without coolant...

~Travis

[QUOTE=travis_farmer;2283904]quick question, what would be a good, simple, and cheap Z tool length probe plate material?

at first i was thinking of buying a plate of stainless steel for it's hardness and not likely to tarnish. then i thought maybe aluminum would forgive just enough to not harm the tool. eventualy, i will probably make something better, but for now, just something to get me by.
my other thought on aluminum is that i could mill it with my router if it needs re-surfacing. i am assuming i can mill aluminum without coolant...

~Travis[/QUOTE]

Aluminum or copper.