my cheap cnc plasma cutter (650.00) works great

[vdoug]

i made a cnc plasma cutter with the cheapest stuff i could find.motors/driver/power supply/metal/chain.bearings included.if you want to see it work my video is on youtube under d9electro1. http://www.youtube.com/results?searc...9electro1&aq=f

[driberif85]

Looks good. How did you do it so cheep? I thought that every thing cost allot more.

[zeed]

Nice work,could you please post some details on your chain and sprocket drive?

[vdoug]

Originally Posted by driberif85 Looks good. How did you do it so cheep? I thought that every thing cost allot more.

the computer i had.remember im still a newb compaired to the guys on here. but i will tell ya how i did it to the best of my memory.
went to the steel store(not lowes,home depot ect...)we have two of them here where i live.bought 1 1/2" thin wall squar tubing and a 20' stick of 3" flat bar 1/8" thick. and then 1/8" angle for the legs and slats.(about 65 bucks in metal).
i used #35 chain(i measured it to have 3/8 pitch per link). i got it off ebay(usabearings) 2 ten foot boxs.have a lot still left.
found 2 idler sprockets on ebay.they were cheaper than i could find anywhere else.probably 1/3.but hes not a store so i got what he had. 25 tooth i believe.drive sprockets (usabearings) , 9 teeth. they had 5/8 bore so i had to put collars on my motor shafts. might have gotten them from usabearings to,cant remember.
i bought hardware from tractor supply.use 2 grade. 1.99 a pound.
and a 4 axis kit(motors,power supply,driver board,printer cable etc..) from wantiamotor on ebay.and v groove bearing i got from that guy that does mycnc/the black toe guy.and got alot of ideas from him as well.i think the bearings are a buck or 2 cheaper then when i bought them.(16 bearings)think i had 140.bucks in them. oh that guy is way cool too, check his web site out.
the rest is drilling, welding, cutting, fussing, ect...

things i would change? well i mounted my z axis high and when the table moves rapidly i get some vibration because the wieght of the motor is on top(leverage).
i dont have limit switch's or nothing fancy the y axis to be 6 or 8 inchs wide to suport the z axis better.and at the end of th x axis i have the square tubing on the top of it.(have to lift metal above them, then go under the gantry. or slide gently between slats and that tubing. if it was under the x axis or even with it.then you could just sit a piece of metal on the table.) live and learn.
to get even cheaper you could just have a fixed z axis(i dont have thc) so it pretty much stays at the same height(1/16 off piece,1/2 rapids) and maybe get by with a 3 axis system. i used 2 motors on my x axis.

to sum up:it cuts pretty good.way better than i can cut by hand and i do ok with cad so iam faster than drawing on metal.i also cheaped out beacuse i question my ability so i didnt want to sink a bunch into something i couldnt get to work.but now i will go farther with the next machine.

one more thing. i bought my software(course you can use the demo ver. 500 lines of g code) got mine from sheet cam. bought the combo pack with mach 3 there. i think you save a little that way.

i will take more close up videos if you want to see them and post them just let me know.
i hope this helps or someone dont make the same mistakes i have.

[driberif85]

Thank You for the quick reply. I work as a welder so the gantry/table portion shouldn't be too hard. However the the computer/ black box stuff worries me. I have not wanted to spend a pile of money and not be able to get it to work. I have basic CAD skills. Not much in the 3D area but I don't need 3D for cutting. I hate to ask this but do you have any links? I did use Google. I was able to find usabearings on Ebay I how ever could not find wantiamotor. Is this the right web site for mycnc/the black toe guy Build Your Own CNC Router Machine ? Are you pretty happy with how the V guide rollers roll on the 1/8 Flat Bar. I know that they are supposed to have the special V guide track to run on. I know that right there would make a huge difference in cost. I like how you bolted the Flat Bar to the tubes. I know that if it was welded that it would of warped. Bolting it is a simple solution to that problem. Last question did you use eccentrics to adjust the V rollers? Thanks again.

[vdoug]

Originally Posted by driberif85 Thank You for the quick reply. I work as a welder so the gantry/table portion shouldn't be too hard. However the the computer/ black box stuff worries me. I have not wanted to spend a pile of money and not be able to get it to work. I have basic CAD skills. Not much in the 3D area but I don't need 3D for cutting. I hate to ask this but do you have any links? I did use Google. I was able to find usabearings on Ebay I how ever could not find wantiamotor. Is this the right web site for mycnc/the black toe guy Build Your Own CNC Router Machine ? Are you pretty happy with how the V guide rollers roll on the 1/8 Flat Bar. I know that they are supposed to have the special V guide track to run on. I know that right there would make a huge difference in cost. I like how you bolted the Flat Bar to the tubes. I know that if it was welded that it would of warped. Bolting it is a simple solution to that problem. Last question did you use eccentrics to adjust the V rollers? Thanks again.

eccentrics?you may be well beyond me in the brains department.not even sure what that means. ok start with the easy stuff.
yes build your own cnc is the guy.

wantiamotor i could not find with search this time either so i looked up under my old buys and found wantaimotor items - Get great deals on items on eBay Stores! didnt see the 354 ozin ones that i used, but seen some 270 ones for 186.90 and 88.99 to ship. i took a shot in the dark that the 354's would work so i cant really tell you that the 270 ones will.like i said low in the brains department. someone on the site should be able to or you could go above the 354 oz in. and they arent the only sellers of the kit on ebay as well. you might find a better deal.
the disk has mach on it, but i had down loaded mach before i bought the kit and when it came in i tested the kit and got it to work on machmill not machplasma. 4 axis i suspect.
(when i moved it to the shop"dads garage" i loaded the one off the disks and i couldnt get them to work untill i loaded a better one off mach site. then was fine.) but you can still use machmill to turn on your plasma cutter. you have to watch your settings to. with sheet cam, if i generate g code under just "mach",the torch stays on. but if i generate under "mach plasma" the torch works right. i wanted micro stepping cause i read that it was better. and the motors do hit harder with full amps. oh and if you find a kit on ebay i wanted 1/16 step. seen on some that they only went down to 1/8 step.for testing or running without limit/stop switchs. be sure to turn them off in the software too.

when i drilled my holes for the v groove bearings. i alotted some play for adjustmentand wear(used bigger drill bit).the my cnc guy does his with slots. his was better but i had no good way to cut slots in my 1/4" plate. tighten the top bearings first then pull the bottom bearings to a nice fit. not a binding fit.(will produce more drag if to tite), but you dont want the rail to be able to pull up.forgot to mention my 3 (guess you could call them heads)that my v grooves are attach to. i got from work.didnt want to buy a full piece.that helped on cost too. they are 6" by 6"

i played with design cad years and years ago 2d. and would have bought that but i found turbocad deluxe 15 2d/3d for 20 bucks on ebay.it came with tutorals. it has snap with magnetic modes that are way cool. and no more than i can do its easy and fun. some of them cats out there do art with it. way way above me. someday i want to get a scanner and they these days scan to pdf files so i will have to get corel draw to convert the files plus you can draw and edit and get a pile of clip art too. someday
that way i believe i can scan parts then cut them out.

overview of the plasma cutter.learning as i go.i have a hypertherm powermax 1000 (60 amp)you will need to have the thin cut tips or even 40 amp tips for the thiner stuff.so if you were going to do 1/16" or less you could get by with a less amp machine.
the reason i mention that is because i said in the other post a fixed z axis. thin stuff moves or warps while cutting so a fixed z i dont think will work.

i will take some more video and the guy from my cnc has tutorals on how to figure steps per turn. (if you need more help on steps per turn i will do some figuring to help.) when i was building i imagine 700 inchs per min for thin plasma cutting. my machine does 700 easy but havent had to. most stuff i have ran is 150 or less.course im still playing with speeds. with that said.
unless you are going to do paper thin stuff.you dont have to have 9 tooth to bump up the speeds (9 tooth was the smallest i could find) you could do screws or what ever. 9 tooth= 9 x.375 per pitch = 3.375 inches per turn of the motor.which takes more torq 354 ozin goes down. but was still plenty for me. i know the guys on this sight might correct me (please do) so i dont send anyone in the wrong path. i want to help not hurt.
i only used a drive sprocket and an idler in a slight s pattern.

the z axis i found a 8" screw with teflon coating and a plastic backlash type nut for less then 20 bucks on ebay.it had a aluminum gear which was pressed on and a small bearing.i took it apart and put the bearing on the shorter milled side and drilled a hole in my metal for the bearing(3/8")

once again in a day or two i will post more video on my site at youtube
and if by chance the guy from buildyourowncnc is reading. you have a great wife. in one of his videos he's routing mdf in the bathroom. if you ever routed mdf you know how messy/dusty that stuff is. and thanks for the videos.

[driberif85]

Thanks for all the info. It seems that I have just been over thinking allot of this. I did quite a bit of reading on build your own cnc last night. There is allot of info there. I will most likely start with Oxy/Acet because I all ready have a torch. In my opinion you made the right choice with the Hypertherm. The last place I worked we had a Thermal Dynamics but it seemed to spend all of its time in the shop. I downloaded the trial of sheet cam last night. I will have to see if what I know from Auto Cad will cross over. How big did you end up making your actual cut area? I can not make up my mind on that. Bigger is better but I don't have the room to go as big as I would like to. Have a good one.

[vdoug]

Originally Posted by driberif85 Thanks for all the info. It seems that I have just been over thinking allot of this. I did quite a bit of reading on build your own cnc last night. There is allot of info there. I will most likely start with Oxy/Acet because I all ready have a torch. In my opinion you made the right choice with the Hypertherm. The last place I worked we had a Thermal Dynamics but it seemed to spend all of its time in the shop. I downloaded the trial of sheet cam last night. I will have to see if what I know from Auto Cad will cross over. How big did you end up making your actual cut area? I can not make up my mind on that. Bigger is better but I don't have the room to go as big as I would like to. Have a good one.

i got a good video for you on my youtube. close ups
YouTube - cnc plasma $650 for driberif85 and cnczone good luck i over think a bunch. sometimes i have to walk away from it and then it hits me. bam pow thats how i can do it.
i think it ended up like a 32 by 42 or so. never measured the actual.but could have gone bigger with the chain. i cut mostly small parts so far(it hasnt stoped me yet) i would sugest a 4 foot cutting area plus. i have to cut the metal down before i put it in the machine.
i went for cheap on this one to see if i could and now something better to build the next one with, i will try timeing belts this time. so far mcmaster is where im going to buy the belt and spur gear.(xl belts) going for 1/2" unless someone on the site can suggest better pricing or size. hint hint (notice the parts that arent painted and the msha tape? kinda gives it away that im a coal miner.)
almost forgot to mention. oxy is real slow(from what i hear) but with the right speed you can cut thicker than the cheaper plasma's. and the sheet cam is for generating g code from your cad program.

[coldrain]

Hello, i'm new to the site, great machine. i'm thinking of building something similar for my own use and would appreciate a few pointers. i see you use 2 motors on the x axis do you drive them from 1 controller or do they have separate ones, how do you sync them to make sure the gantry runs true? and finaly how is the torch turned on and off. as i have said i'm a complete novice to cnc and any info will be much appreciated.

[vdoug]

yes i use one control board. it has a relay on it and i hooked it to my plasma's triger switch. also in mach3 i made the second drive motor a slave to that axis.