Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: adprinter on March 08, 2009, 05:59:14 PM
-
Hi folks!
I have just registered my copy of Mach3, LazyCAM Pro, and Mill add-ons. I have been using Mach3 to drive my home made Router table. I am using a Mechatronics 4 axis driver board, and NEMA 34 Vexta PK296-01AA stepper motors 24VDC 2a per phase Bi-polar wired serial. I have been through MANY frustrating hours of attempting to tune the motors in Mach3, and switching the DIP switches on the Mechatronics board between Full, Half, Quarter, and Eighth step and STILL cannot get the motors to drive the machine reliably without losing steps. Can anyone help with DIP switch settings, and Step, Velocity, and Acceleration rates which will yield reliable results? For a look at my machine build, please see the MYCNC.PDF Any help would be greatly appreciated!
-
Just a quick thought.
You say your stepper motors are 24v... at what voltage are you driving them?
Steppers are supposed to be driven at somewhere between 20 and ive heard sometimes 35 times their acutal voltage.
Fernando
-
Nice build and brilliant documentation on the construction.
I think Fernando may be right in that your steppers are not providing enough torque to drive the axis's reliably.
(Just for reference my steppers are 5 Volt, 2 Amp per phase and they are driven at 25 Volts, 1.5 Amp per phase).
Tweakie.
-
Fernado and Tweakie,
The power supply I am using is a 24vdc 6.3a switched system. I know very little about electronics, but received this one along with the Mechatronics 4 axis board as an ebay purchase. The motors were purchased from a different ebay vendor, and the specifications for them I obtained from oriental motors.com 24 volt DC 2amp per phase Bi-polar with 2ohm coils. They are six wire motors, and the wiring diagram (also from Oriental Motors) showed that for Bi-polar funtion to wire one coil to the A+ and A- and the other coil to the B+ and B- outputs of the driver board. (The center taps are NOT to be connected for serial Bi-Polar function) which is the way I wired these motors. I cannot use a power supply higher than 24vdc, as this is the limit that the Mechatronics driver board can handle. Can anyone recommend an economical solution here? The motors are rated at 420 oz in in Bi-polar mode, and I have learned that Oriental Motor offers other models which are rated as high as 1200 oz in. However they required higher amps (which the Mechatronics board can't handle) and have a $308 EACH price tag. This is more than I can afford right now. Any help would be appreciated. And THANKS for the response!
-
Lots of things to cover so will rermark at a high level.
Your voltage should be 4 to 20x motor voltage with enough amperage for all the motors.
Take a look at the motor curve for the motors you have and see where you are on the
torque to speed curve as that will give you an idea of just what kind of torque your getting out of them.
As speed increases the torque will decrease and power which is what your interested in will be max
around 1/2 speed and 1/2 torque approx so that gives you another ballpark on where to run them.
If that dosen't satisfy requirements for your desired speed and power / torque then you need to review
the whole system, which you should have done in the first place, and see what if anything you should do.
The driive train works as a "system", so the weakest link in it can have a big effect. The mechanics of the system
defines system rerquirements. You can analyze your requirements via software from major manufactures
if you so desire, but using practical considerations as compared to similar equipment has great value.
With the above in mind just simply reduce your speed and acceleration and test the axis requiring the most torque
and gradualy work your way up until you start to skip steps. Back off say 30% and see what you have in terms
of speed. If that is not satisfactory then you need to increase the powere supply to the motors within the capabilites of your drives / board / system. 420 in/oz motors got a lot of torque.
So it is difficult to make anymore specific / usefull comments without addiitional info on the mechanics of your system.
RICH
-
I have not weighed the Gantry assembly of my system which includes on it the Y axis drive, as well as the Z axis drive systems, but I estimate it to weigh around 180 lbs. Obviously, the main axis I am having problems with, is the X axis. (Since it carries the load of EVERYTHING else!). I am using ACME lead screws 1/2" diameter 10 TPI with Lovejoy motor couplings on the X and Y axis, and a .375" diameter 5TPI ballscrew on the Z axis. (This was a pre-assembled purchase which included a NEMA 23 stepper motor from ebay). All 3 axis are wired Bi-polar series. The spindle I am using is a Porter Cable 690LR which I mounted on the Z using two 2" thick x8"x8" blocks of 6061-T6 aluminum which I bored the required 3.4" hole on my southbend lathe in order to clamp the PC Router onto the Z axis slide plate. Following problems with the Z losing steps, I eliminated the top clamp block to reduce weight. The Gantry assembly is constructed of 2"x2"x3/16" angle steel (see the MYCNC.PDF file posted at the beginning of this thread). I Guess that it is just NOT possible with the motors/driver/power supply system that I am currently using, as I said before. I have spent many frustrating hours trying different step rates, velocities, and acceleration rates trying to find a satisfactory "sweet spot" in which the motors could drive the machine without losing steps. It appears that I will have to wait until funds are available to invest in higher torque motors and drive system. Also, I have noticed that temperature seems to play a major role in the problems I am experiencing. When it is below freezing in my shop, is when the greatest failure rates occur. Now that the weather has warmed up, it seems to have improved somewhat. But the lost steps still continue. I have successfully managed to carve out my name in a block of plywood, and rewound the Gcode (which I wrote by hand for the first test, after mapping the lines which form the letters of my name on a piece of graph paper, and assigning x, and y coordinates- think BASIC geometry and writing a text file from this map to import into Mach3). The repeatability was perfect! But that was at a time when everything seemed to be functioning perfectly (it was a warm day at the time). Sorry for the long post, but just wanted to give as much relavent info as I could. Thanks for your help!
-
well from what i can say, the power supply and drives are limited for those stepper motors,
10TPI is a lot of gearing reduction and still you are not able to move reliably.
Although 10tpi qould require high rpm from the stepper to produce acceptable speed rates. You would need 500rpm to get 50ipm which i doubt you can get with noticable torque at those voltages.
-
HELLO!!
I WANT TO ESTABLISH THAT THE POWER OF A MOTOR STEP BY STEP? AS THE CALCULATION? WHAT
THE DATE REQUERED?
-
By using a 6 wire motor in 4 wire mode you are putting the motor windings in series. This will make the inductance more than twice as high and the top speed will be way less than 1/2 a bipolar wiring.
With a 24V supply and 10 TPI you will have a vary slow machine.
I have a Metronics board and it works OK but the 2A 32V max is a real performance killer.
The lowest cost cure might to be to get a unipolar driver board They are around $100.00. It will give you twice the speed and more amps at the low end.
I you have the money you should look at the GeckoDrives. The new G251 is a nice small driver that will run at 3.5A at 50V.
New 4 wire steppers will run twice as fast as your current 6 wire and will make more power. This stepper should give god speed and will run at 2.5A OK.
http://www.kelinginc.net/KL23H276-28-4B.pdf
-
I have since purchased a Gecko G540 driver board which supports up to 3.5a and 50vdc. This driver did produce an improvement in performance using the 24vdc 6.3a power supply. (But is STILL stalling/losing steps at times). I am considering a higher voltage power supply, to use with the VEXTA PK296-01AA motors. I looked at the KL23H276-28-4B motors you recommended at Keling, but they are NEMA 23 motors, and my machine is built using NEMA 34 motors. I have read on this forum that 1200 oz in motors present performance problems, so I am considering the 960 oz in motors instead. However, having made the investment in the new Gecko drive (over $300) I am limited to 3.5a 50v motors. Can you recommend a power supply/NEMA 34 motor combination which will work well with the Gecko G540 driver?
-
You could try using the center tap and one end of each coil to gain some speed.
-
Could you elaborate? "Center tap and one end of each coil" is not possible with six motor wires and only four Gecko connections. Oriental motors instructs that the center tap is not used for Bipolar serial connection of the motors. (And since they are six wire motors, parallel connection is not possible). I am confused about the center tap. Is this in essence energizing only HALF the coil?
-
You will never have a fast machine with steppers and a 10TPI lead screw.
I am running 5 TPI lead screw's and a 60V supply and low inductance 400 OZ NEMA 34 steppers and I can get well over 1,000 RPM, but if you watch the little 1/2" lead screws go 1200 RPM you know that this is not a vary good idea for a 34" long screw.
Go to a 50 V supply first, it goes with your stepper driver.
I would think with your current 420 OZ steppers at 1.2A that they will start to loose power at about 125 RPM. 50V will make that 250 RPM. Your max speed should be around 12 IPM.
Faster steppers will help but you might want to think first if you ever will want to cut at 80 IPM or so. To do that you will need faster screws.
As for new steppers you might look at the KL34H280=45-8A 640 OZ stepper or the KL34H280-45-4A
The 4A runs at 4.5A so you will have to give away about 25% of 640 OZ of torque but it has a little higher voltage that will let you run it in parallel to get better speed. The inductance is 6.8mH. I would think you could get 750 RPM.
The KL34H280-45-8A is a 8 wire motor and for a series hookup will give you a 8.8mH of inductance at 3.1A. You will get the full 640 OZ of torque but gain two mH of inductance so you will lose some speed. The 8A would work nice with some faster screws like the 4 TPI ACMI or even the faster 2 TPI.
You current steppers should perform fine If you go to a faster screw. With 250 RPM from the stepper and a 2 TPI screw you would have around 125 IPM cutting speed. You have a lathe so turning the screws should be no problem.
-
You will never have a fast machine with steppers and a 10TPI lead screw.
I am running 5 TPI lead screw's and a 60V supply and low inductance 400 OZ NEMA 34 steppers and I can get well over 1,000 RPM, but if you watch the little 1/2" lead screws go 1200 RPM you know that this is not a vary good idea for a 34" long screw.
Go to a 50 V supply first, it goes with your stepper driver.
I would think with your current 420 OZ steppers at 1.2A that they will start to loose power at about 125 RPM. 50V will make that 250 RPM. Your max speed should be around 12 IPM.
Faster steppers will help but you might want to think first if you ever will want to cut at 80 IPM or so. To do that you will need faster screws.
As for new steppers you might look at the KL34H280=45-8A 640 OZ stepper or the KL34H280-45-4A
The 4A runs at 4.5A so you will have to give away about 25% of 640 OZ of torque but it has a little higher voltage that will let you run it in parallel to get better speed. The inductance is 6.8mH. I would think you could get 750 RPM.
The KL34H280-45-8A is a 8 wire motor and for a series hookup will give you a 8.8mH of inductance at 3.1A. You will get the full 640 OZ of torque but gain two mH of inductance so you will lose some speed. The 8A would work nice with some faster screws like the 4 TPI ACMI or even the faster 2 TPI.
You current steppers should perform fine If you go to a faster screw. With 250 RPM from the stepper and a 2 TPI screw you would have around 125 IPM cutting speed. You have a lathe so turning the screws should be no problem.
Could you elaborate? "Center tap and one end of each coil" is not possible with six motor wires and only four Gecko connections. Oriental motors instructs that the center tap is not used for Bipolar serial connection of the motors. (And since they are six wire motors, parallel connection is not possible). I am confused about the center tap. Is this in essence energizing only HALF the coil?
By center tapping you will lose half your torque but double your speed(more than double). The current will be the same but you might be able to bump it up some and still have the motor stay cool. You will have a lot more power at 250 to 500 RPM. With a 10 TPI screw I would think 200 OZ might be OK but you will need to find out by testing.
They say not to use the center tap for bipolar but you can if you are willing to give away some power.
To center tap means to use the center tap and only one of the other two wires.
-
I am going to try your suggestion of using the center tap, and one end of each coil. Just to see.... you said this is possible, if I am willing to give away some power. I don't think that this is going to help the situation because LACK of power seems to be the problem (Insufficient torque). But one thing I have learned, that trial and error sometimes yields desired results. I will try your suggestion, and alternate coil end connections until I (hopefully) achieve improved performance. Gecko recommends motors with a 2.5 to 3.0 mH coils. I researched this, and according to Oriental Motors, the PK296-01AA motors have 26 mH when wired Bipolar serial. So (if I comprehend correctly) what you are saying, by using the center taps and one end of each coil, I should realize a REDUCTION in mH of inductance (which SHOULD bring these motors closer to the Gecko recommended inductance ratings)?
-
In the electronics world inductors are called "chokes". They are often used to stop high frequency's from passing through a circuit. For steppers with slow screws we don't want high inductance. You motors have a vary high inductance and voltage rating. This will allow them to work with a low current driver like the Mectronics but the price is speed.
28mH is a huge value. Your inductance if you use a single coil should be around 7mH so the speed will be close to what the the 45-8A stepper would give.
A 50V supply and a 7mH coil should give you over 500 RPM and still hold 200 inch of torque. You might be able to get 50 IPM before the torque starts to fall off with that setup.
Your motors would be happier with a 100V supply or a unipolar driver or faster screws. In the long run I would look at getting the much faster screws. They are more efficient and will let you use your existing motors just fine.
You might take a look at the Roton #60986 lead screws, 4 start and 2 TPI with the dumpster nuts.
You want to use the lathe anyhow!
-
THANKS Arizonavideo for the tip on using the center tap to reduce the mH of the coils. I am now getting 100 IPM on the X axis, and (so far) I have been able to get 24 IPM on the Y (I plan to switch the Y connection to the opposite end of the coil to see if I can get an improvement there are well). These speeds are according to the Motor Tuning function of Mach 3. I have not yet changed the resistors, so I have no idea how much current I am feeding these motors. According to Gecko, I am supposed to use 1K resistors per desired amp of current. I currently have it wired with 2.5K resistors inline. Anyway, I tested the accuracy (looking for lost steps) by outputting gcode generated by the Write wizard, and rewound to the beginning, and repeated 5 times! The toolpath was repeated with absolute precision. Finally, after 8 months of work, I am able to get down to some "play" time! Again, THANKS for your input! I plan to eventually modify the machine design, and hope to be able to afford ballscrew drives, and linear rails for an improvement in rigidity, and accuracy (for machining purposes). But for now at least, I am able to do some nice wood carvings. Any suggestions as to WHICH surface to mount a heat sink on the Gecko G540? It is designed for surface mounting of the face plate itself, but I suspect that the heat sink will need to be mounted onto the rear surface of the unit. I have a large aluminum finned heat sink I plan to use, and mount a 12v cooling fan directly onto the ends of the (1.5" tall) fins. Now that I have the machine working with good results, I am now down to making some organization of the "Rat's Nest" of wires, and junction blocks within an old PC Case as the housing for the power supply, and driver. Again, THANKS for your help!
-
If you use heat sink paste and remove any coating from the PC case where you mount the Gecko, you can mount the Gecko inside and the heat sink on the outside.
-
It was not my idea to only use one half of the two coil but MachineMaster. I have not tried the idea myself but it should help and the price is right.
I think the Gecko current drive resistor is the same as the current made, so a 2.2k= 2.2A which should be over driving the steppers some.
I have over driven some steppers and they did not improve the power much and got really hot. I have not read anything about coil saturation effect on steppers so I don't know what gains might be had by overdriving a single coil. The motor will run cooler with a single coil being used so heat should not be a problem. If you can run 2.4A and the performance is fine and they don't get too hot you might be OK just leaving them set that way.
Did you up the voltage?
The little Geckos don't need much heatsinking and at 2.2A almost any heatsink will cool them enough. A slice of 5" x 1 1/2 AL angle stock should work fine and bolt it to the box. You could go all out and get a 10" piece. ;D
-
THANKS MachineMaster, (I stand corrected, Arizonavideo). YES, this wiring scheme has yielded amazing results. And I now understand your meaning about the little 1/2" acme screws turning at high RPM! (My X axis screw is 49" long). I just tried cutting a rectangular pocket 4"x7" with the feed rate set at 22 IPM. While cutting, I used the MDI screen and set the manual overide to 250% the machine just took off! However, about half way through the second pass, it lost some steps, and ruined the part before I could react. I tried jogging manually back to where it went haywire, and hit Cyclestart. That's when it REALLY lost it's mind, and went about destroying the part. I have not yet tried a different power supply- still using the 24vdc 6.3a unit. But after seeing the results of using half-coils, I am anxious to upgrade to at least a 48vdc unit. The Gecko drive supports up to 4 axis. I am currently using only 3 axis, but plan to add a horizontal/vertical rotary table with a tailstock setup as the 4th axis (once funds will permit). The heatsink I mentioned, I think will work just fine even without a cooling fan. After running the machine for over 2 hours, the Case of the Gecko was only slightly warm to the touch, and the stepper motors felt even cooler than the drive. There are trim adjustments on each axis of the Gecko G540- between the Motor Tuning function of Mach 3, and these trim adjustments, I am left confused as to exactly what the trim adjustments do. After swapping to the opposite end of the coil on the Y axis, I am now getting 48 IPM (according to Mach 3 Motor Tuning screen). Even after many hours of tweaking the acceleration rate, and velocity rate, this was as fast as I could set the Y axis motor to run (without stalling/losing steps). I don't understand why this is happening, since the Y axis is only carrying the load of the Z axis, and router, while the X axis is carrying the load of EVERYTHING on the Gantry (and I am getting 100 IPM on that motor).
-
I can get 300 IPM with the 400Oz steppers and 60V and 5TPI but I will lose steps if you let it run long enough. I have only just started cutting parts but I have slowed things down to 150 IPM for rapids and have not lost any steps.
The 48V supply will give you a 50% speed increase so it is worth doing. To make sure you don't drop stepps you will need to slow thing down more than you think. I would be happy if you got a good strong 60 IPM cutting.
I am still curious about how a single coil behaves with lower or higher current. Can you use twice the current and still get 400OZ out of it? Your motor was a 1.2A for a series connection? Correct. If you run it at 2.4A then you still should make close to 400OZ of torque. Does this happen?
The adjustment on the Gecko drive is to get ride of the inductive ring from the motor. It should happen around 900PPS. Set the motor to 900 PPS and adjust the pot until the motor makes the lowest amount of noise. You will only need to do this once.
-
Arizonavideo, I am not sure how to go about measuring torque output and am operating on blind faith alone that the 2.5K resistors are limiting the current to 2.5 amps. I plan to order a 48vdc power supply today, and with connect it as soon as I receive it. I will report the results once that is done. If I am interpreting correctly what is being accomplished by using the center taps and one coil end only, is that only HALF the coil length is being energized. This did result in an amazing increase in speed, with fewer lost steps. Before trying this, the motors could not be relied upon to turn the screws for even a minute without stalling. The actual rating of these motors is 2a per coil. (So, I am pushing these about .5a above their rated current). I played last night until about 3:00am with the OPEN test file included with Vectric's V Carve Pro software, trying to carve a pocket. About halfway through the process, I lost steps, (and of course ruined the part). Thus my decision to go ahead and try your suggestion of the higher voltage supply. Still monitoring the temperature of the driver, and motors. Still only slightly warm to the touch. (Like a kid, I could'nt wait to play, so I still haven't mounted the Gecko to the heat sink). I currently have Mach 3 setup with the default 2500Mhtz. What changes will I need to make, to set the motors to 900 PPS? (My processor is a Pentium IV running at 1.8 Ghtz). The parallel port is set to EPP mode thru the BIOS (per Gecko's instructions). Are you referring to the pulse rate in Mach 3's Motor Tuning screen? What SHOULD the "inductive ring" sound like? Should the motors be free wheeling, or under load when this test is performed? The pocket cut I mentioned above was set up with a feed rate of 20 IPM. However, I set the Manual Overide to 60% from the MDI screen of Mach before starting the code running. (For an effective feed rate of about 12 IPM). And even at this snail's pace, it managed to lose steps halfway through the code. I do not have an automatic tool changer on my machine, so I stripped out all macros which were generated by the Postprocessor of V Carve Pro. I also do not yet have a touch sensor for setting the tool height, so I manually jogged the tool to the work, recorded this measurement with a back up device (pencil), and manually coded the Z movements to accommodate for the cut depths, and rapids (using notepad's search and replace function). This yielded EXCELLENT results up until the machine lost steps. I am very hopeful that the higher voltage supply will cure this problem. Thanks for all your help, I will be waiting for further instructions on the Gecko adjustments.
-
I'm fairly new to a lot of this stuff so I'm not sure if you should wait for instructions but I will give my 2 cents worth.
When driving a stepper, Current = low speed torque. Voltage = speed.
For your steppers any power made past about 1000 PPS and higher is determined by the voltage. The current could be set 20A and the motor would make no more power.
Below around 900PPS the power and current is set by the driver.
If you are loosing steps at a low speed then you need more power from the steppers or driver. If you are losing steps over about 1000 PPS then the power supply voltage will help.
It sounds like all will be fine when you go to a 48V supply. The drive will die with a 67V input so you can't over volt much.
The motor tuning is described in the Gecko instructions but I think they use the term low speed and don't give a exact PPS # because it is different for every type of motor.
In Mach3 I have been tuning the motors using the servo motor function. Go to Diagnostics tab then click the Servo Freq Gen button. You can set any PPS rate from there. There is no ramp up or slow down when changing direction so you will lose steps at higher frequencies using this function.
Enter a # of PPS in the Hz box, some will be much louder than others. Try 700 to 1500 in 100PPS steps and you will be able to hear the "ring" Leave the setting there and adjust the Gecko trim pot so the motors makes the least amount of noise.
-
Arizona,
Well.... I got the 48 volt supply, and also changed out the motors for Keling's 906 oz in motors. Wired them up in Bipolar series (even though the specs state 13.3 mH inductance). Now the machine FLYS! I used the Write wizard, to engrave some text in Times Roman Font, and then used the MDI screen to return to X0 Y0 and repeated 100 times with absolute precision! I was able to tune both motors to 76 IPM, and considering that the old motor/power supply setup could not be relied upon for more than about 6 IPM feed rate, I am simply amazed at the results! I have not yet tried wiring these motors half-coil (don't see the need, since all seems to be well now). Thanks for all your help!
-
You still might try hooking up the steppers in parallel.
You will only make around 500 OZ of torque but your top speed will be more than double. I would think of 150IPS rapids and cutting at 80 or 100IPS.
With less torque the motor tunning will need to be changed to allow more time for the motor to change direction. There is always a price to pay, faster cutting, faster rapids but slower change of direction.
Glad things worked out.
-
Arizona,
Can't wire in parallel- 6.1a draw in parallel mode, and the Gecko G540 is limited to 3.5a Yesterday I added a relay to control the router power on/off from the computer. NICE not having to get up and climb over everything to turn the router on or off. However, there is an issue with the Y axis. I discovered that one end of the lead screw is .035" out of line with the drive end. More tweaking with shims is needed to prevent lost steps on the Y (as this misalignment is causing some binding issues on the lead screw). Concerning the parallel wiring scheme: with the set resistors in place on the G540, will this be sufficient to limit the current draw to 3.5a? I ask this question, because the last thing I want to do is burn out the Gecko drive. I don't know enough about electronic theory to comprehend exactly how the set resistors limit the current draw to the motors. Gecko recommends 1K per desired amp to be used as the set resistors. (I have 3.5K resistors in line at the moment). Keling specs states that the rated current in Bipolar Series mode is 3.05a for these motors, and 6.1a in Bipolar Parallel mode. Do you think that it would be "safe" to attempt the Parallel wiring without risk of damage to the G540? Should I wire 3.5a fuses in each of the motor supply conductors to prevent damage to the Gecko? Sorry for the long post, but am trying to grasp how best to try the parallel scheme.
-
First, no fuse!
If the fuse were to blow the back EMF wave from the motor might kill the drive. Dont use a fuse. They say this in the instructions.
The driver will never make more than 3.5A. It would be nice if you could get 4A from them somehow but you just cant. Set the resistor to 3.5A and you are done.
Most steppers are wired in parallel. You will gain top end speed but loose about 30 to 40% of your low speed power. If you are cutting soft material then you may want speed more than just 12 IPM power.
You did not say if your dropping steps all the time and if it is at high speed or low speed.
With an parallel connection you will have more power above about 800 PPS or 400 RPM than you do now but almost half the power at 200 PPS. There is no danger to this hookup, the only question is if it is a better way or not for your use.
Do you need to cut at 80 or 100 IPM?
-
Arizona,
YES - I would like to cut wood at 100 IPM! Wired serial, I am only able to tune the motors to about 76 IPM (without losing steps- by "losing steps" I mean the motors whine without turning if I try to tune them above about Velocity of 76 IPM and Accelaration at about 18 IPS). I will try the parallel scheme tomorrow, and report back with the results.
-
Hi, I am a beginer, i want to make cnc hot wire cutter, what should we do, what sould we buy. Tq
-
I am not familiar with Hot Wire Cutters, and cannot offer any information regarding the wiring for such a tool. However, as I comprehend it, CNC can be used to drive your "tool of choice". Mine happens to be a Porter Cable LN690 wood router. Please see the MYCNC.PDF file (attached at the beginning of this post thread) for a drawing of the table design I built to drive the router (tool of choice). Perhaps others on this forum could help you with the wiring of the tool itself. But as far as what I have actually built, the PDF lists most of the components. I am using an old Dell Optiplex computer with 2 GB of memory & Mach3 software. For the driver I have a Gecko G540 driver board. And I upgraded the stepper motors to 900 oz/in from Keling Technologies. I am using 1/2" diameter 10 threads per inch ACME lead screws to drive the X and Y axis, and a 3/8" diameter 5 threads per inch ball screw to drive the Z axis on my table. Having said all of this, I am sure that it probably conflicts with some of the items I listed in the MYCNC.PDF file. The items listed in the file were acurate at the time I wrote the file. However, I have since "upgraded" to the items listed here, because the used motors, and driver board, and power supply I originally started with were a source of major frustrations trying to learn how to use the Mach3 software with unreliable components which would not function consistently. After upgrading to the components listed above, I have created many beautiful pieces on my router table. I am still evaluating various design software packages, and have so far been most impressed with Vectric's V Carve Pro. Lack of funding prevents me from any new purchases for now, but plan to later. Hope this helps to point you in the right direction to get started. I will say this, (repeating the advice of others on this forum) Buy RIGHT, Buy ONCE! If you cannot afford to buy new QUALITY components, then Don't Buy until you CAN afford to! This will save you a lot of un-necessary frustration, and money! Do as much research as you possible can, in designing your machine, and the best components needed for your use before buying anything. Unfortunately, it is the "school of hard knocks" that will be your best teacher in all of this. But you will learn along the way.