Komputer Numerically Kontrolled (KNK) Router
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
WARNING: working with electricity is dangerous and it can result in sudden death. Hire a certified electrician for any work involving electricity!
Here are the details for the fun part: the control/drive electronics. Shown is the main box which contains all of the vital components to control my CNC router. Again, I designed my router with two DC servo motors to drive the x-axis (long axis), one servo for the y-axis, and one servo for the z direction. I chose two Gecko 340 servo drivers to run the two x-axis motors and the 320 model for the y and z. The control board that talks to the computer and communicates with the Gecko drives is the CNC4PC C11T multifunction board. There are tons of other similar boards that will work just fine, for example the one designed by Bob Campbell. I made a 35 VDC power supply using a 500 VA toroidal transformer (from Parts-Express.com). The motors' nominal voltage was 38 V, so 35 was good enough. After rectifying the transformer's output (25 VAC), I used a 47,000 uF cap. to smooth out the humps (WARNING- these things are dangerous when charged!!), then added several other smaller sized caps to minimize the ripple. The 35 VDC supply powered the Gecko drives. A separate wall-wart power supply powered the control board. To get +5 VDC for the control board, I used the common LM7805 voltage regulator. Again, a couple by-pass caps were used to minimize spikes. I wanted to separate the power supplies between the Gecko and control board to avoid any noise or coupling problems. The motor encoders were powered by the Gecko drives directly. For safety, I installed two fuses, one at the AC input and one on the DC side. An emergency stop switch was installed just in case. Since the control board and the Gecko drives had their own power supplies, I used two light indicators, one for the main AC power and one for the control board power. That way if one of the supplies goes bad, I'll know which one. The box that houses all the electronics I bought from Home Depot and I wired the metal case to the return (ground). A parallel port cable runs from the box to a nearby computer.
I didn't spend much time on www.cnczone.com, but you may find more info and details related to cnc machines if you're patient enough to read the forum.
Approximate cost for the box of goodies:
Box and misc parts $100
Parts for main power supply $130
4 Gecko drives $530
Control board $125
Wall-wart AC-DC transformer $free
Here are the details for the fun part: the control/drive electronics. Shown is the main box which contains all of the vital components to control my CNC router. Again, I designed my router with two DC servo motors to drive the x-axis (long axis), one servo for the y-axis, and one servo for the z direction. I chose two Gecko 340 servo drivers to run the two x-axis motors and the 320 model for the y and z. The control board that talks to the computer and communicates with the Gecko drives is the CNC4PC C11T multifunction board. There are tons of other similar boards that will work just fine, for example the one designed by Bob Campbell. I made a 35 VDC power supply using a 500 VA toroidal transformer (from Parts-Express.com). The motors' nominal voltage was 38 V, so 35 was good enough. After rectifying the transformer's output (25 VAC), I used a 47,000 uF cap. to smooth out the humps (WARNING- these things are dangerous when charged!!), then added several other smaller sized caps to minimize the ripple. The 35 VDC supply powered the Gecko drives. A separate wall-wart power supply powered the control board. To get +5 VDC for the control board, I used the common LM7805 voltage regulator. Again, a couple by-pass caps were used to minimize spikes. I wanted to separate the power supplies between the Gecko and control board to avoid any noise or coupling problems. The motor encoders were powered by the Gecko drives directly. For safety, I installed two fuses, one at the AC input and one on the DC side. An emergency stop switch was installed just in case. Since the control board and the Gecko drives had their own power supplies, I used two light indicators, one for the main AC power and one for the control board power. That way if one of the supplies goes bad, I'll know which one. The box that houses all the electronics I bought from Home Depot and I wired the metal case to the return (ground). A parallel port cable runs from the box to a nearby computer.
I didn't spend much time on www.cnczone.com, but you may find more info and details related to cnc machines if you're patient enough to read the forum.
Approximate cost for the box of goodies:
Box and misc parts $100
Parts for main power supply $130
4 Gecko drives $530
Control board $125
Wall-wart AC-DC transformer $free
Last edited by bigKam on Tue Mar 31, 2009 12:49 am, edited 2 times in total.
Hey Kam,
Super slick work, as usual. Lots of great functions on the C11T. Are you getting any significant heat build-up inside of the enclosure without a cooling fan/vents? I'm guessing your wall-wart had an output of 9 vdc. Just for fun, I tried to spot the LM7805 and caps... upper right of the big cap?.. with the white wire to the fuse, then white continuing to the indicator light/BOB? Okay, so I need to get a life.
Glad to see your machine living and breathing. What driver and CAM software are you using?
G-man
Super slick work, as usual. Lots of great functions on the C11T. Are you getting any significant heat build-up inside of the enclosure without a cooling fan/vents? I'm guessing your wall-wart had an output of 9 vdc. Just for fun, I tried to spot the LM7805 and caps... upper right of the big cap?.. with the white wire to the fuse, then white continuing to the indicator light/BOB? Okay, so I need to get a life.
Glad to see your machine living and breathing. What driver and CAM software are you using?
G-man
Hi G-man!
OK, I'm kidding.
.
I'm actually using Mach3 to control the machine. Running LazyCam and some other cam software (depending on what mood I'm in) to process my *.dxf and graphics files to produce the gcode. Playing around also with CNC Simulator. Overall the software is pretty easy to set up and run, about 3 hours from learning to implementing. There's so much info over the Net on this stuff as you know.
Will get some photos up soon of the finished machine once I install the cable carriers I found on ebay. Currently using homemade plastic thingies -- they work, but not pretty. I want it to be pretty.
Put two cold hotdogs into the box, ran the machine for about an hour hoping to get a hot meal, but was dissapointed. Not much heat generated, but will continue to monitor this as I suspect the cold temps in the garage helps to keep the metal box at a favorable temp. I will probably add a fan, and maybe some sort of thermal sensor just in case.G-man wrote:...Are you getting any significant heat build-up inside of the enclosure without a cooling fan/vents?
Nope. 12 vdc @ 500 mA from the wall-wart and the 7805 is located just above the top motor output port (black one). The 7805 is bolted upside down to a small metal tab on the inside edge of the box. The tab functions as a heat sink as it tends to get a little warm.I'm guessing your wall-wart had an output of 9 vdc. Just for fun, I tried to spot the LM7805 and caps... upper right of the big cap?.. with the white wire to the fuse, then white continuing to the indicator light/BOB? Okay, so I need to get a life.
Wrote the control software using low-level assembly mixed with C, then the kernel for the gcode translator using a variant of Pearl. The program to convert the *.dxf or any graphics file to gcode was written in Java. Finally, picked up an old Atari joystick and interfaced it with the PC's sound card to control the jog in x, y, and z......What driver and CAM software are you using?
OK, I'm kidding.
. I'm actually using Mach3 to control the machine. Running LazyCam and some other cam software (depending on what mood I'm in) to process my *.dxf and graphics files to produce the gcode. Playing around also with CNC Simulator. Overall the software is pretty easy to set up and run, about 3 hours from learning to implementing. There's so much info over the Net on this stuff as you know.
Will get some photos up soon of the finished machine once I install the cable carriers I found on ebay. Currently using homemade plastic thingies -- they work, but not pretty. I want it to be pretty.
Ha, ha... my eyes were getting bigger and bigger as I was reading that.Wrote the control software using low-level assembly mixed with C, then the kernel for the gcode translator using a variant of Pearl. The program to convert the *.dxf or any graphics file to gcode was written in Java. Finally, picked up an old Atari joystick and interfaced it with the PC's sound card to control the jog in x, y, and z......
Have you messed around with CamBam yet? The trial version lets you create 40 different files without a time limit. Super user friendly and includes some really usable CAD functions. There's lots of tutorial stuff on-line and a good on-line support forum. CamBam integrates nicely with Mach3. And it's something that even I can get to work.
Okay, now I see the regulator. I checked out the data sheet on the LM78xx series. Pretty neat little gizmos.
G-man
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Head Monkey
- Posts: 310
- Joined: Sun Jul 17, 2005 4:53 pm
- Location: Carnation, WA
- Contact:
Nice work man, congrats on the machine. Your box looks great, too! (Hmmm… not sure I’ve ever said that to a guy before…) Looks like you’ll be machining cores in no time.
I also use Gecko drives and I do find that after a long session that they put out quite a lot of heat. I mounted them to an aluminum heat sink through the side of the box and that seems to have been all I needed. No fans or anything, which keeps the box sealed and dust free. I made the heat sink out of 3/4" aluminum on an old table saw, believe it or not. You can kinda see it in this picture, on the right side of the box: http://www.happymonkeysnowboards.com/bl ... hop_40.jpg
I also use Gecko drives and I do find that after a long session that they put out quite a lot of heat. I mounted them to an aluminum heat sink through the side of the box and that seems to have been all I needed. No fans or anything, which keeps the box sealed and dust free. I made the heat sink out of 3/4" aluminum on an old table saw, believe it or not. You can kinda see it in this picture, on the right side of the box: http://www.happymonkeysnowboards.com/bl ... hop_40.jpg
Everything I know about snowboard building, almost: MonkeyWiki, a guide to snowboard construction
Free open source ski and snowboard CADCAM: MonkeyCAM, snoCAD-X
Free open source ski and snowboard CADCAM: MonkeyCAM, snoCAD-X
Hi Mike,
Whew... that must have been a bit of a tense experience running that block of aluminum through the table saw that many times. Pretty effective heat sink you ended up with.
I went back and checked out your photo gallery again. Man, what a nice work space you keep. Love that dual intake dust collection you have.
G-man
Whew... that must have been a bit of a tense experience running that block of aluminum through the table saw that many times. Pretty effective heat sink you ended up with.
I went back and checked out your photo gallery again. Man, what a nice work space you keep. Love that dual intake dust collection you have.
G-man
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doughboyshredder
- Posts: 1354
- Joined: Mon Sep 17, 2007 7:37 pm
I had the priviledge of checkin out Head Monkeys shop a little bit ago, and it really is impressive. Cleaner than I could even imagine my shop being. Overall an incredibly impressive setup.
Big Kam, this is just amazing.
I now have two more machines I want to build. A KNK (ha, I like that), and a sublimation press.
and you had me going witht he control software. Nice work!
Big Kam, this is just amazing.
I now have two more machines I want to build. A KNK (ha, I like that), and a sublimation press.
and you had me going witht he control software. Nice work!
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Head Monkey
- Posts: 310
- Joined: Sun Jul 17, 2005 4:53 pm
- Location: Carnation, WA
- Contact:
Thanks for the props guys. Yea, I’m kinda anal about keeping the shop clean 
G-Man, yea, running a plate of 3/4" alu on a tablesaw was not something I would have thought was a good idea, but it turned out okay. Lots of WD40 as a lubricant, and IIRC a blade with as many teeth as I could find. Made a mess of the machine, which wasn’t really all that bad to clean up, and spread super-fine flakes of alu all over the shop which took longer to finally cleanup, but it worked. I also cut 3/4" and 1/4" plate to size on the same setup. Alu is just so damn soft…
G-Man, yea, running a plate of 3/4" alu on a tablesaw was not something I would have thought was a good idea, but it turned out okay. Lots of WD40 as a lubricant, and IIRC a blade with as many teeth as I could find. Made a mess of the machine, which wasn’t really all that bad to clean up, and spread super-fine flakes of alu all over the shop which took longer to finally cleanup, but it worked. I also cut 3/4" and 1/4" plate to size on the same setup. Alu is just so damn soft…
Everything I know about snowboard building, almost: MonkeyWiki, a guide to snowboard construction
Free open source ski and snowboard CADCAM: MonkeyCAM, snoCAD-X
Free open source ski and snowboard CADCAM: MonkeyCAM, snoCAD-X
Mike,
I do quite a lot of metal lathe work using aluminum, and I'm always seeing shiny, fine aluminum particles floating around in the beam of my work lamp. So, I've gotten to the point where I wear my respirator when I'm machining aluminum. I'm not sure how bad aluminum particles are on the lungs, but my lungs have suffered enough over the years already, and I need for them to carry me along a bit longer. Seems like I have a respirator hanging around my neck, for one reason or another, for a few hours almost everyday.
Regarding CNC (KNK), I'm already finding that I'd like to have a forth and fifth axis machine (for cutting waxless bases for one thing), so I'm working on some design stuff in that regard. Do you sometimes find you'd like more than 3 axes? Now that I have the 3 axis machine, I can use it to make all of the parts (in a day rather than the 6 months the first machine took) for subsequent machines. CNC is so much fun.
Cheers,
G-man
I do quite a lot of metal lathe work using aluminum, and I'm always seeing shiny, fine aluminum particles floating around in the beam of my work lamp. So, I've gotten to the point where I wear my respirator when I'm machining aluminum. I'm not sure how bad aluminum particles are on the lungs, but my lungs have suffered enough over the years already, and I need for them to carry me along a bit longer. Seems like I have a respirator hanging around my neck, for one reason or another, for a few hours almost everyday.
Regarding CNC (KNK), I'm already finding that I'd like to have a forth and fifth axis machine (for cutting waxless bases for one thing), so I'm working on some design stuff in that regard. Do you sometimes find you'd like more than 3 axes? Now that I have the 3 axis machine, I can use it to make all of the parts (in a day rather than the 6 months the first machine took) for subsequent machines. CNC is so much fun.
Cheers,
G-man
doughboyshredder: I agree --- Mike's shop is incredibly clean! When I visited I couldn't find one spec of dust!
I'm trying to get my cave up to Mike's standards, so this week I emptied my wallet on a cyclone dust collection system. I wanted the Oneida Gorilla, but couldn't afford it so went with the Grizzly 2HP model instead. They shipped it for free, so that was nice. Will lay some ductwork over the next few weeks. System should suck enough to keep those micron-sized particles to a minimum...
A die-sub press is also one of my next projects! Another project is a KNK planer. Idris before he left for Europe was kind enough to donate his planer and a few other items to SB -- thanks again Idris!!! I'll put everything to good use.
Just putting the final touches on the KNK. Found a killer deal on a cable carrier on ebay -- $50 for a 17' section! I'll do a photo shoot when I feel the KNK is ready for show and tell, but for now here are a few random photos:
I'm trying to get my cave up to Mike's standards, so this week I emptied my wallet on a cyclone dust collection system. I wanted the Oneida Gorilla, but couldn't afford it so went with the Grizzly 2HP model instead. They shipped it for free, so that was nice. Will lay some ductwork over the next few weeks. System should suck enough to keep those micron-sized particles to a minimum...
A die-sub press is also one of my next projects! Another project is a KNK planer. Idris before he left for Europe was kind enough to donate his planer and a few other items to SB -- thanks again Idris!!! I'll put everything to good use.
Just putting the final touches on the KNK. Found a killer deal on a cable carrier on ebay -- $50 for a 17' section! I'll do a photo shoot when I feel the KNK is ready for show and tell, but for now here are a few random photos:
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Head Monkey
- Posts: 310
- Joined: Sun Jul 17, 2005 4:53 pm
- Location: Carnation, WA
- Contact:
G-Man, I’ve thought a couple of times that having a 4th axis would be nice, but for other projects not for snowboards I’ve seen some bad-ass homebuilt 5 axis machines out there, though… cool stuff.
bigKam, good move on the cyclone. The dust these machines can generate is pretty amazing sometimes and the cyclone is perfect for it. Mine is also a 2hp and I find it’s plenty powerful. Good find on the cable carrier, too… heh… I got most of mine on ebay, too. Oh, and I’m totally jealous of your ball screws. Every summer I say I’m gonna take the time to switch out the rack and pinion’s for ball screws, but I just never get around to it…
I’ve seen some bad-ass homebuilt 5 axis machines out there, though… cool stuff.bigKam, good move on the cyclone. The dust these machines can generate is pretty amazing sometimes and the cyclone is perfect for it. Mine is also a 2hp and I find it’s plenty powerful. Good find on the cable carrier, too… heh… I got most of mine on ebay, too. Oh, and I’m totally jealous of your ball screws. Every summer I say I’m gonna take the time to switch out the rack and pinion’s for ball screws, but I just never get around to it…
Everything I know about snowboard building, almost: MonkeyWiki, a guide to snowboard construction
Free open source ski and snowboard CADCAM: MonkeyCAM, snoCAD-X
Free open source ski and snowboard CADCAM: MonkeyCAM, snoCAD-X
Ball screws are incredibly efficient and smooth. I'm using 102" long (dia=1.0") ones for the x-axis (2 of them for a dual-drive setup) and a 50" one for the y-axis (dia = 0.75"). Bought the 102 inchers from http://www.automation4less.com/, just had them cut to length with no machined ends. It was quite expensive to have them machine the ends for supports, so I did that elsewhere when they arrived. Likewise for the y-axis, but I purchased the screw from http://www.roton.com/ instead. Good service and very good quality screw and nut.
As for end-supports (w/ bearing), I bought mine from the UK (http://www.worldofcnc.com/products.asp? ... ort+Blocks). One support is shown in the above photo for the y-axis -- note this is the free end and not the driven end. The support for the driven end is much beefer with special bearings for radial as well as axial loads. The supports I found from the above link were the best in terms of quality and price, but I have to say that I was not happy with the service. It took over 1.5 months for my order to finally arrive, but only after I emailed about 30 times and called about 5 times trying to track my order. The owner said the first order must have been 'lost...ooops'... Funny how I never got any tracking info or order confirmation. They just charged my credit card and left me hanging, so I finally after several follow-ups, 1.5 months later a box appeared on my doorstep and it looked like the package was shipped from Taiwan. Anyway, shop with care.
Backlash is minimal. I'll do some measurements after I get the system set up the way I like it. I started using preloaded ballnuts for the x-axis to eliminate the backlash, but got some rattling noise and decided to ditch them. Could be the nut quality is not that great. Without the preload the system is much quieter.
And as you know, the critical rotation speed where the first dominate mode of vibration starts to kick in is important to consider. I did the calcs for the boundary conditions I was using to size up my screws.
As for end-supports (w/ bearing), I bought mine from the UK (http://www.worldofcnc.com/products.asp? ... ort+Blocks). One support is shown in the above photo for the y-axis -- note this is the free end and not the driven end. The support for the driven end is much beefer with special bearings for radial as well as axial loads. The supports I found from the above link were the best in terms of quality and price, but I have to say that I was not happy with the service. It took over 1.5 months for my order to finally arrive, but only after I emailed about 30 times and called about 5 times trying to track my order. The owner said the first order must have been 'lost...ooops'... Funny how I never got any tracking info or order confirmation. They just charged my credit card and left me hanging, so I finally after several follow-ups, 1.5 months later a box appeared on my doorstep and it looked like the package was shipped from Taiwan. Anyway, shop with care.
Backlash is minimal. I'll do some measurements after I get the system set up the way I like it. I started using preloaded ballnuts for the x-axis to eliminate the backlash, but got some rattling noise and decided to ditch them. Could be the nut quality is not that great. Without the preload the system is much quieter.
And as you know, the critical rotation speed where the first dominate mode of vibration starts to kick in is important to consider. I did the calcs for the boundary conditions I was using to size up my screws.
Hi Kam,
Great new batch of pics... and what a score on the cable carrier.
I, too, have given quite a bit of thought to a CNC planer. I even started a thread at cnczone a few months ago. Ended up that there were a couple of design issues that I never could get worked out to my satisfaction, so I shelved the idea for awhile. I mostly couldn't come with a good way to get the on-board feed system to float with the contours of the core profile. It seemed best just to start from scratch and build the machine, rather than try to adapt an existing machine... of course, using the cutter head, raising/lowering system, bearings, motor, etc. from an existing planer would be a be a good place to start. It'll be interesting to see what you come up with.
Those look like ground, rather than rolled, ball screws. Wow, what a machine you have. It'll be interesting to see how your servos handle any rapid changes of direction, considering the mass of your ball screws. Rather than lose steps, like my machine would, I guess that your machine might just slow down a bit (probably imperceptively) during the direction change, then just get on with it's business. I also get a lot of stuff from Roton.
I'm just using ACME screws, but I made a tap from a length of screw and I use the tap to make my drive nuts from delrin. I then quarter-split about half the length of the nut (overall length is about 1 1/4") with a hack-saw blade, and put a small hose clamp around the split section. By tightening/loosening the clamp, I can finely tune out any backlash. The delrin doesn't seem to wear much (like not at all) over time. I just mention this because you could probably make a tap out of a length of ball screw and make your own drive nuts... for about 5 bucks apiece in material... and they're real quiet.
I'm cutting out new tip and tail block pieces on my machine today. I don't have a video camera at the moment... maybe I can find a neighbor who has one I can borrow. It'd be fun to post a video of my MDF beast at work.
G-man
Great new batch of pics... and what a score on the cable carrier.
I, too, have given quite a bit of thought to a CNC planer. I even started a thread at cnczone a few months ago. Ended up that there were a couple of design issues that I never could get worked out to my satisfaction, so I shelved the idea for awhile. I mostly couldn't come with a good way to get the on-board feed system to float with the contours of the core profile. It seemed best just to start from scratch and build the machine, rather than try to adapt an existing machine... of course, using the cutter head, raising/lowering system, bearings, motor, etc. from an existing planer would be a be a good place to start. It'll be interesting to see what you come up with.
Those look like ground, rather than rolled, ball screws. Wow, what a machine you have. It'll be interesting to see how your servos handle any rapid changes of direction, considering the mass of your ball screws. Rather than lose steps, like my machine would, I guess that your machine might just slow down a bit (probably imperceptively) during the direction change, then just get on with it's business. I also get a lot of stuff from Roton.
I'm just using ACME screws, but I made a tap from a length of screw and I use the tap to make my drive nuts from delrin. I then quarter-split about half the length of the nut (overall length is about 1 1/4") with a hack-saw blade, and put a small hose clamp around the split section. By tightening/loosening the clamp, I can finely tune out any backlash. The delrin doesn't seem to wear much (like not at all) over time. I just mention this because you could probably make a tap out of a length of ball screw and make your own drive nuts... for about 5 bucks apiece in material... and they're real quiet.
I'm cutting out new tip and tail block pieces on my machine today. I don't have a video camera at the moment... maybe I can find a neighbor who has one I can borrow. It'd be fun to post a video of my MDF beast at work.
G-man