I would like to build a small CNC router. I found plans and instructions on these web sites:
http://www.instructables.com/id/How-to-Make-a-Three-Axis-CNC-Machine-Cheaply-and-/
http://www.solsylva.com/cnc/1aplansoverview.html
I wish to use ready-to-use drive box and stepper motors like the kit shown on this web site:
http://www.xylotex.com/3DB-116.htm
I also have Vex Robotics set and I tried to build a CNC router using the set but I was not happy with the plastic gears. If I use the set to build a CNC router, and use the drive box and stepper motors, I will have to make parts that fit the stepper motors, bearings, lead screws, and pipes to the frame of the CNC router. The image shows a partly-built CNC router frame. Any suggestions?

You are right the plastic gears would be an issue. How about some more pictures?

Take a look at the Probotics equipment they have one configuration that is very well suited to the new builder.

This particular kit (currently their other kits don't offer this protection) has safeguards against shorts and open circuits that would fry a Xylotex driver board, I know I learned the hard way. The kit is $100 less expensive than Xylotex and has 200 OzIn steppers, but you would need a case.

They also have a RFIsolated breakout board I would suggest using it rather than the one in the kit, they would exchange it and just pay a few dollars more. This would protect your PC from stray voltages going back into it.
Here is the link to the kit.

http://www.probotix.com/3_axis_stepper_motor_driver_kits/3_axis_probostep_stepper_motor_driver_kit/

Good luck and keep the pictures and updates comming.

I have been reading the thread at this link:
http://www.cnczone.com/forums/showthread.php?t=21411&highlight=solsylva
I would like to build the machine that sits on top of wood to be routed.

I have been reading the thread at this link:
http://www.cnczone.com/forums/showthread.php?t=21411&highlight=solsylva
I would like to build the machine that sits on top of wood to be routed.

That design is very flexible in what you can do with it, and where you can take it.

I looked at the 17-inch by 20-inch blue machines on Solsylva's website and my machine that I was building. I think that it's possible for me to turn my machine upside down. What about lead screws, lead screw nuts, bearings, etc?

My CNC machine built so far. I didn't attach the Z-axis carriage to the Y-axis carriage yet. I didn't attach motor and gears to the Z-axis carriage yet. I may use a Dremel motor tool as a spindle.

I use linear sliders sold by the company that makes the Vex Robotics Set in my CNC machine but they're not good enough because they are either too loose or too tight. Which is better?
Round or Square Tubes and ball bearings?
L-shaped metal pieces and ball bearings?
Drawer slides with ball bearings?
Should the tubes or L-shaped metal pieces be made of aluminum or steel?
Link to Vex Robotics website: http://www.vexlabs.com/vex-robotics-all-products.shtml

My CNC machine built so far. I didn't attach the Z-axis carriage to the Y-axis carriage yet. I didn't attach motor and gears to the Z-axis carriage yet. I may use a Dremel motor tool as a spindle.

You are comming right along.
How about a front and side shot.
Thanks

My CNC machine is almost finished but due to its size, the working area is about 6-1/2 inches by 7-1/2 inches and the machine itself is about 18 inches by 21 inches by 19-1/2 inches. Should I scrap this machine and build a new one following plans for one of the CNC machines from Solsylva?

After finding out that a few people built CNC machines using Lego parts, I started building one based on the Solsylva plans for 17X20 CNC machine but I need more small tires. I ordered the tires from an online store.

I got the Solsylva plans in the mail today. The overhead leadscrew machine should be easier to build than the other machines. I assume that all MDF or plywood parts are 3/4" thick. The material list on page 2-2 is a bit confusing. How do I know how many bolts, nuts, screws, bearings, each, in different sizes that I need to buy? I'm not sure if plastic sheets can be used instead of MDF or plywood sheets. I'm not sure if I can get most of the materials from Home Depot or Lowe's stores. Any suggestions?

I finished building a small version of CNC machine using Lego parts. I didn't put motors on it yet. I may start building the 17X20 CNC machine with overhead leadscrew following the Solsylva plans. I will build the wooden parts from 3/4" plywood.

Nearly all of the hardware parts for the Solsylva plans are commonly available from Lowes and Home Depot if you build it as the plans show. If you make any design changes of your own you may find the need to make or modify a few parts by hand.

CarveOne

I started building a different CNC machine using Vex Robotics parts. It has rack and pinion gears. From reading the thread at this link: http://www.cnczone.com/forums/showthread.php?t=53489 , what's the best gear ratio? My machine uses 1:3 gear ratio and the Y-axis carriage seems to move fast. The motor's 12-tooth gear turns a 36-tooth gear and on the same shaft as the 36-tooth gear, a 12-tooth gear runs on the rack gear. If the motor's 12-tooth gear turns a 36-tooth gear and on the same shaft as the 36-tooth gear, a 12-tooth gear turns another 36-tooth gear on another shaft. That shaft turns a 12-tooth gear that runs on the rack gear, what's the gear ratio?

I started building the Y-Axis carriage for the 17X20 overhead leadscrew CNC machine using 3/4-inch birch plywood. Which roller blade bearings that go on 5/16-18 bolts should I buy?

When I build the X-Axis chassis for the 17X20 overhead leadscrew CNC machine, should I reinforce the inside corners with aluminum angles? Which trim router should I buy? The trim router should have a button that locks the spindle for changing bits. I may go to Lowe's and buy hardware today.

I think the Bosch is one of the best trim routers available. I don't know about spindle lock.
You can't reinforce too much, unless weight gets out of hand.

I think that the Porter-Cable trim router is better because it has ball bearings on the motor shaft.

Looks like ball bearings to me.

if anyone worked with A4983 Allegro chip
please inform me more details about it

On Sunday, I went to Lowe's and Home Depot stores to get hardware for building the 17X20 overhead leadscrew CNC machine. I had to order some hardware from an online store. Yesterday, I cut aluminum angles and flat bars to correct length. Today, I started drilling holes in aluminum angles and flat bars. I got more 3/4-inch birch/oak plywood. I cut out the parts for the X-Axis chassis and glued up two pieces to make one 1-1/2" thick boards.

When I buy the 3-axis stepper motor and driver kit from Probotics, does the kit come with wires that go between the motors and the driver? If so, are the wires long enough? I will have to buy the E-Stop switch and limit switches. Do I need to buy a cabinet for the driver? Should I buy two E-Stop switches and place one on the CNC machine and one on the computer workstation? I started building the X-Axis chassis.

The X-Axis chassis is almost finished. The steel tubes were cut and were ready to be installed. I got package from VXB but six bearings were missing.

My CNC machine being built in the workshop at the program for mentally handicapped people where I work. I made a few changes such as oak/birch plywood instead of 1X4 and 2X4 wood. The wooden parts of the machine are done. The steel tubes were cut to size. I'm now working on aluminum parts.

I E-Mailed PROBOTIX messages last Thursday and yesterday asking them some questions. I never got any replies from PROBOTIX and I'm afraid to buy anything from them. Any suggestions?

You are right the plastic gears would be an issue. How about some more pictures?

Take a look at the Probotics equipment they have one configuration that is very well suited to the new builder.

This particular kit (currently their other kits don't offer this protection) has safeguards against shorts and open circuits that would fry a Xylotex driver board, I know I learned the hard way. The kit is $100 less expensive than Xylotex and has 200 OzIn steppers, but you would need a case.

They also have a RFIsolated breakout board I would suggest using it rather than the one in the kit, they would exchange it and just pay a few dollars more. This would protect your PC from stray voltages going back into it.
Here is the link to the kit.

http://www.probotix.com/3_axis_stepper_motor_driver_kits/3_axis_probostep_stepper_motor_driver_kit/

Good luck and keep the pictures and updates comming.

Jeff, sorry about that. I found your messages in my spam folder. I admit I haven't checked it in a few days.

To answer your question: The motors have leads that are maybe 10 inches long. You will find shielded motor wire here: http://www.probotix.com/cable_and_wire/. It is sold by the foot. This 5-conductor wire can be used with the 6-wire motors by tying the two center tap wires together at the motor side.

FYI to others: the contact form on the site is set to always pass through the spam filter.

Thanks,

>Len

I painted the wooden parts primer white and worked on metal parts. I don't know what color to paint the wooden parts.
Len, should a jumper wire be connected to two middle terminals on the driver board?

Nope - they are already connected. When you get your boards, you'll see this by looking at the bottom.

5-wire motors are basically the same in that they connect the center taps inside of the motor.

>Len

I had a few problems building the Z-axis carriage/router plate. Instead of fuel hose and clamps, I tried flexible spider shaft couplings but they're too long at about 1-3/4". I didn't get the stepper motors yet. Are the 200 oz. in. stepper motors about 3 inches long, not including the shafts? I need to know the motor for the Z-axis clears the overhead leadscrew for the X-axis if I have to raise the motor mount 3/4". I didn't drill holes in aluminum at the exact locations. Any suggestions? Should I get more aluminum and use the CNC machine to drill small holes? Did anyone build CNC machine using metal instead of wood while following the plans from Solsylva?

I got the stepper motor driver kit from PROBOTIX this morning. After measuring the boards and power supply unit, and making a drawing of where the parts are supposed to be mounted, I checked Radio Shack's website to see if the have large project boxes but they don't have any. I had to open up an old VCR and take the parts out so that I can put the kit inside the VCR case. How do I test the kit to make sure that it works?

I got the stepper motor driver kit from PROBOTIX this morning. After measuring the boards and power supply unit, and making a drawing of where the parts are supposed to be mounted, I checked Radio Shack's website to see if the have large project boxes but they don't have any. I had to open up an old VCR and take the parts out so that I can put the kit inside the VCR case. How do I test the kit to make sure that it works?

You will need a dedicated PC, some software such as Mach 3, you can download a demo version. Get this part up and running then start adding the hardware.

Which kit did you buy?
Did you get a straight thru parallel cable from them too?
Any other acessories from them?
Go to PROBOTIX and print out the manual and wiring diag for that kit.

When the above is known we can go further.

I bought the kit shown on this link but with PBX-RF breakout board, an E-Stop switch, some limit switches, a cooling fan, fuses, and some cables. I printed out the manuals and wiring diagrams. The manual for the 4.2A power supply is wrong.

http://www.probotix.com/3_axis_stepper_motor_driver_kits/3_axis_probostep_stepper_motor_driver_kit/

I bought the kit shown on this link but with PBX-RF breakout board, an E-Stop switch, some limit switches, a cooling fan, fuses, and some cables. I printed out the manuals and wiring diagrams. The manual for the 4.2A power supply is wrong.

http://www.probotix.com/3_axis_stepper_motor_driver_kits/3_axis_probostep_stepper_motor_driver_kit/

I baught that RF breakout board too. Will you be using a USB cable to supply the 5V on the computer side of the BOB, that was the easiest for me? If so don't forget to remove the jumper on JP6 as described in the manual.

I would get your PC and software running first as you will ned it to test your hardware.

You could wire and lay everything out on a nonconductive surface if you wanted to make sure everything ran before mounting it in your control box.

Make up your cables that are between your stepper motors and control box. Check all connections with VOM meter to insure you do not have any shorts or opens before connecting the cables.

Good luck

I saw the USB port but I didn't know what it's for. There's no manual for the PBX-RF BOB. Should I connect the USB port on the PBX-RF BOB to the USB port on the back of the computer case or can I use a powered USB hub? The terminals on the PTrans IM101C24-1M power supply are marked from left to right: L-AC, N-AC, G-AC, COM, COM, +V, and +V. There is a white object for adjusting +V and a green LED. The word "PTrans" has an image of the world between "P" and "T". I already installed the Mach3 software on my computer running Windows XP. I may need to buy a new computer just for running the Mach3 software.

I saw the USB port but I didn't know what it's for. There's no manual for the PBX-RF BOB. Should I connect the USB port on the PBX-RF BOB to the USB port on the back of the computer case or can I use a powered USB hub? The terminals on the PTrans IM101C24-1M power supply are marked from left to right: L-AC, N-AC, G-AC, COM, COM, +V, and +V. There is a white object for adjusting +V and a green LED. The word "PTrans" has an image of the world between "P" and "T". I already installed the Mach3 software on my computer running Windows XP. I may need to buy a new computer just for running the Mach3 software.

I used the USB port on the back of my PC. By using the USB power source you do not need the "PC Side Power of 12-40 VDC.

Sorry I can’t answer the question on the power supply, the one I bought from them is no longer available, it simply consisted of a large transformer, Capacitor and a Bridge Rectifier. I see each PS has a manual listed you might find your answer there. You can see a photo of my inprogress control box build below, to get an idea how I did it. I used an old PC case.

I found the manual for power supply at this link: http://www.metapo.com/products/New%20ips/IM101C12-1M.pdf

To connect the power supply:
* Whack the female end off of the power cable.
* Strip back 2" of the outer jacket. Separate the 3 wires. You should have a Black (L-AC) and a White (N-AC) and a Green ground (G-AC).
* Clip back the string that runs through the insulation.
* Strip off 1/2" of insulation from each of the exposed wires.
* Trim down some screw eyes so they will fit into the slots in the power supply connectors.
* Remove the screws on the power supply connectors.
* Crimp on the connectors and screw them down.
* Plug in the power cable and verify that you have 24 Volts across V+ and Com
* Then, Disconnect the power cable.
* Crimp connectors in the same way as above to your power wires that lead to your fuse blocks and screw them down.


Here is a picture: http://www.probotix.com/cnc_images/SideStepAssembly/power_supply_3.jpg

The PBX-RF is functionally identical to the PBX-2, except that it is isolated from the PC through radio frequency. It is easiest to power the PC side of the board with the USB port, however a powered hub should also work. You could also power it with a 6 volt or higher DC wall-wart type power supply.

How do I set up the E-STOP on the PBX-RF BOB? Do I need cooling fan over the stepper motor driver boards? Are the stepper motors and the stepper motor driver boards not supposed to be hot?

How do I set up the E-STOP on the PBX-RF BOB? Do I need cooling fan over the stepper motor driver boards? Are the stepper motors and the stepper motor driver boards not supposed to be hot?

The photo below shows the wiring of my E Stop. You use the GND and the top position as shown.

I have a fan in my control box but not hooked up because I don't have the right voltages for it. But the boards runn cool. mine measure 95 F with a room temp of 70 F.

Hager

How do I set up E-STOP on Mach3 software. I think that it's "on" unless I hit it then it's "off". When it's "on", the needle on the ohms meter moves from left to right. When it's "off", the needle on the ohms meter doesn't move.

Here is the way I would wire an e-stop to the PBX-RF. Many people will tell you that you also need a circuit to lockout the motor & spindle power while in e-stop.

Legally I can only say be sure to use a proper emergency stop circuit. I do not wish to be liable for missing fingers. Search the forums, there are some very good emergency stop circuit diagrams floating around.

>Len

I'm afraid to solder wires to the PBX-RF board. What I need is normally-open E-Stop switch or create some kind of circuit for the E-Stop switch. I think that I need some relays.

Well, there is a way to do it without soldering. You could grab the ground and 5V by hacking apart a USB cable. You could do this by splitting apart the cable that supplies the breakout board, or you could use another USB cable straight from the PC.

You could also wire it to one of the limit switch inputs, if you have any that aren't being used.

Or you could even wire it in series with the limit switches, which should be wired normally closed as well. It would not show up as an e-stop, but it would stop the software when tripped, which is what you are trying to accomplish anyhow.

Also, know that the escape key works as a software e-stop in most programs.

>Len

I found an AC/DC wall pack that outputs 5VDC at 2.4A. I would like to use it instead of the USB cable from computer. If I get a 5VDC relay with contacts rated for 120VAC at 15A, how should I wire the relay to the E-Stop switch so that when I hit the E-Stop button, the relay cuts power being supplied to a power strip where I'll plug my trim router in. Should the relay cut power to the bottom half of the isolation plane of the PBX-RF board? I disconnected the stepper motors from the driver boards and packed them so that I take them to the workshop where I work to be installed on the CNC machine. Should I apply power to boards so that I can connect and test the E-Stop circuit?

I have been working on the Y-Axis leadscrew and coupling nut, and ran into few problems. The leadscrew was little bit too low and the aluminum angle for the coupling nut won't fit. I may be using steel tubes that are too big. In fact, I had to change the bottom steel tube on the Y-Axis gantry to a smaller one. I had to use another piece of aluminum angle similar to the way aluminum angles were made for the Z-Axis coupling nut. The skate bearings were too small for the 7/8-inch bearing retainers. I may have to warp some tape around the bearings. The biggest problem would be the X-Axis leadscrew - it's too low and will hit the upper shaft on the stepper motor for the Z-Axis leadscrew and the aluminum angles for the Y-Axis coupling nut. The plans from Solsylva didn't say that I need stepper motors with shafts on one ends. The stepper motors that I bought from Probotix have shafts on both ends. I wanted to take pictures of the CNC machine that I have built so far but the batteries in my digital camera were weak. Any suggestions?

I have been working on the Y-Axis leadscrew and coupling nut, and ran into few problems. The leadscrew was little bit too low and the aluminum angle for the coupling nut won't fit. I may be using steel tubes that are too big. In fact, I had to change the bottom steel tube on the Y-Axis gantry to a smaller one. I had to use another piece of aluminum angle similar to the way aluminum angles were made for the Z-Axis coupling nut. The skate bearings were too small for the 7/8-inch bearing retainers. I may have to warp some tape around the bearings. The biggest problem would be the X-Axis leadscrew - it's too low and will hit the upper shaft on the stepper motor for the Z-Axis leadscrew and the aluminum angles for the Y-Axis coupling nut. The plans from Solsylva didn't say that I need stepper motors with shafts on one ends. The stepper motors that I bought from Probotix have shafts on both ends. I wanted to take pictures of the CNC machine that I have built so far but the batteries in my digital camera were weak. Any suggestions?

Suggestion, Yep charge the camera batteries. He He

I am not familiar with the Solsylva plans so I don't really understand your issues.
Generally it is a good thing to have shafts on both ends in case you want to put a crank handle there. My motors aren't double shafted and I have to turn the acme thread and that is not easy to do. Naturrally the power to the steppers is turned off.
As soon as you get pictures let's see your problem. Although a Solsylva builder might understand and reply.

Good luck
Hager

The plans from Solsylva called for gas pipes that have 3/4" inside diameter and about 1" outside diameter. The steel tubes that I used have about 1-1/8" outside diameter. The steel tubes are usually used for electrical wiring. I got the largest enclosure from Mouser and started putting the electronics in it.

I had to raise the X-Axis leadscrew half inch to clear the aluminum angles for the Y-Axis and the shaft on the Z-Axis stepper motor. The machine is almost finished. Stepper motors for the X-Axis and Y-Axis are not yet installed.

I had to get new batteries for my camera.

Hi Jeff,

Thats a nice looking control box.

I need to replace mine with a larger one some time.

Keep pleanty of batteries on hand, pretty soon you will need to take a lot of pictures.

I finished building the CNC machine and tried to get the 3-Axis ProboStep Stepper Motor Driver Kit working using a notebook computer. I tried a desktop computer and found out that one of the stepper motors got very hot and that one of the driver boards smoked. I had to e-mail Probotix and ask them about replacing the motor and board.

I finished building the CNC machine and tried to get the 3-Axis ProboStep Stepper Motor Driver Kit working using a notebook computer. I tried a desktop computer and found out that one of the stepper motors got very hot and that one of the driver boards smoked. I had to e-mail Probotix and ask them about replacing the motor and board.

Hi Jeff,

That's a bummer.
I never noticed any of my motors running hot, did you find out what the problem was?
As far as the notebooks I understand some of them have poor parallel outputs. But I don't have any first hand experience with that.

Am interested to find out what happened.
Good luck
Hager

Lee told me to send the boards back so I sent them back on Thursday. When I get the boards back, should I check the current limit on the driver boards with or without the stepper motors? What should the current limit be? I wish that I bought a Romaxx CNC router instead of building a CNC router.

Lee told me to send the boards back so I sent them back on Thursday. When I get the boards back, should I check the current limit on the driver boards with or without the stepper motors? What should the current limit be? I wish that I bought a Romaxx CNC router instead of building a CNC router.

Hi Jeff,

Yes I know it is frustration, but you will have a more versitile machine when you are done. Check the manual on the one you baught. I'm pretty sure the adjustment procedure is in it.

Hager

I'm a little bit confused about checking and adjusting the current limit on ProboStep boards. I think that it should be done without the stepper motors being connected to the boards. I think that the stepper motors use 1.5 amps per phase at 12-24VDC. The stepper motors are HT23-200-6 200 oz. in. hybrid. The motors are connected to the boards using all 6 wires with the yellow and white wires connected together.

I'm a little bit confused about checking and adjusting the current limit on ProboStep boards. I think that it should be done without the stepper motors being connected to the boards. I think that the stepper motors use 1.5 amps per phase at 12-24VDC. The stepper motors are HT23-200-6 200 oz. in. hybrid. The motors are connected to the boards using all 6 wires with the yellow and white wires connected together.

You are correct, this is taken from the Probotix instructions:

"WARNING: If the motor is connected during VREF adjustment, excessive heating may occur. Most motors can NOT experience temperatures above 100°C. At these temperatures internal melting and seizure may occur. Short-term current overdrive will, in general, not harm most motors".

When I first set up my ProboStep boards I did it with the steppers disconnected. If you power up some driver cards without a stepper attached it would fry the board, but the ProboStep boards are safegarded against that. These boards are protected against shorts and opens at the stepper, this is a real plus for protection especially for the beginner.

I felt it strange that your steppers got very hot, my 116 oz/in get warm but not hot to the touch. I think you said you tried to run from a laptop, I don't know for sure but seems I have red that not all laptops put out a full signal on the parallel port. I'm running a dedicated PC to mine, no internet connection at all on it, want to stay as far away from a virus as possible. It's tough enough figuring out Mach3 with a virus showing up.

Good luck and let us know when you get running.

I felt it strange that your steppers got very hot, my 116 oz/in get warm but not hot to the touch. I think you said you tried to run from a laptop, I don't know for sure but seems I have red that not all laptops put out a full signal on the parallel port. I'm running a dedicated PC to mine, no internet connection at all on it, want to stay as far away from a virus as possible. It's tough enough figuring out Mach3 with a virus showing up.The strength of the parallel port signal shouldn't be affecting anything. As long as it hits the turn on voltage, which is surprisingly low, the bits will be registering. All it has to do is interpret the low voltage as a 0 and the highs as a 1, with plenty of wiggle room for the high voltage.

Just thought I'd help limit that out for you : )

I finally got new boards from Probotix yesterday. I got confused after installing the new boards. There's no manual for the PBX-RF BOB so I didn't know how the jumpers are supposed to be set. A print-out of the wiring diagram for the BOB shows all jumpers in "off" positions. I checked the wiring a million times until I found out that JP6 jumper needs to be in "on" position when using an AC/DC 5V adapter instead of the USB cable to power the PC side of the BOB. I thought that two of three ProboStep Stepper Motor Drivers were bad until I checked the voltages on the power input and found out that the boards weren't getting 24V. I changed the wires and the boards still weren't getting 24V. I checked the fuses and found out that two fuses from Radio Shack were blown. I replaced the fuses and got all three stepper motors working but I had to set the steps per revolution to 450 so that the stepper motors run smoothly after setting the step resolution to Full step (Mode 8) on the driver boards. How do I set set up Mach3 program so that the an axis moves exactly an inch? The leadscrews are 5/16-18.

Mach3 has a really nice Utility that aids you in setting this up no matter what thread screw you have.

I made a fixture to hold a ball point pen and measured the lines that it made to verify if the figure was correct.

You may need to click on the examples and view them at full screen to read them easily.

I'm new to this too but I think this is correct but if it isn't someone will jump right in.

Go to the “Settings Alt 6” Tab.
1. On the lower left of that screen click on:
“AXIS CALIBRATION – SET STEPS PER UNIT”

2. The AXIS SELECTION Utility pops up
Select the axis you want to setup,
Then click OK

3. How far would you like to move?
In the example I deleted the “0” (you always have to do this cannot type over) and input 2 as I am set up in inches. Then click OK. And it will move in the + direction.

4. The next screen, “How far did the X axis move.
Measure how far it went and input that figure and then hit OK. (2.25 In my example)

5. X axis will be set to XX.XXXX Then click YES. ( I am running Mach 3 on my home PC that is not connected to my CNC that is why it came up with a funny figure.

The last step is to click "YES" if the results look correct.
You may need to run this a few times to get it right on the money, at least I had to.

Good Luck

I tried to use a desktop computer with a 500MHZ CPU to run the machine but the stepper motors can't run faster than 450 steps per revolution (I think) without losing steps. I tried to find out if I can set up the machine so that it "draws" 8 inches instead of one inch but I can't find anything out in the manual for Mach3 software. Any suggestions besides bringing one of my desktop computers to the workshop at the program for mentally handicapped people?

Jeff,

I am not sure what you mean by "can't run faster than 450 steps per revolution". Those stepper motors are 200 steps per revolution. They can be electrically divided through microstepping to have a higher resolution than that, but that is not related to speed.

The maximum speed that any (2-phase) stepper will run is a little more than 2000 RPMs UNDER NO LOAD. The usuable RPMs depends on the amount of torque they have compared to the resistance of the load they are driving. Looking at the torque curves for the motors will show you how much torque is available over the range of RPMs.

At eight-step microstepping, 2000 RPMs would only be a 53.5Khz pulse stream. If your torque to load ratio collapses at 50% of that then you would only need 27Khz. You may want to ask ArtSoft if their software could do that on a 500Mhz PC, but I would think it should.

I've laid out some of the calculations and relations here: http://www.probotix.com/stepper_motor_calculations/


If you are truly losing steps while trying to run the motors within their 2000 RPMs threshold, then it is likely that the load is too great for the motors.

Can you post some pictures of your machine so that we can have a better idea of what we are talking about?

>Len

I found out that the desktop computer that I was using at the program had 128MB of memory and a Pentium 3 548MHZ CPU! In the "Motor Tuning and Setup" dialog box, I tried to set "Steps Per" at 14400 but the motor made a lot of noise and ran very roughly and stopped several times. If I set it at 1800, the motor ran good but made some noises when starting and stopping but one inch equals 1/8th of an inch on my machine. I will have to bring one of my desktop computers to the program tomorrow because it has 2.4GMZ Pentium 4 CPU and 2GB of system memory.

Jeff,

The "Steps per" metric in Mach3 is the number of steps it takes to move the machine one "unit." The unit can be either inch or centimeter. With all due respect, I think you may be missing some of the fundamentals. This steps per unit value is determined by the motor's step angle, the microstep setting of the driver, any gear or belt reduction between the motor and leadscrew, and the pitch of the leadscrew itself.

It looks like you are using directly driven 1/4-20 threaded rod. If that is true, then it takes 20 revolutions of that rod to move the machine one inch. If you have set the drivers to full-step, then it takes 200 steps to turn the motor one of those revolutions. So then 20 x 200, or 4000 is the value you'd put in the steps per unit, assuming that you are running Mach3 in inches.

If you are micro-stepping, you will just multiply that number times the number of micro-steps.

Once you have this set, THEN you can gradually increase the velocity slider to find out just how fast the machine will run. The acceleration slider should be set most of the way to the right.

>Len

Multiply your steps per unit by 8, then retune your motors. The velocity and accel will need to be reset once you change the # of steps. Also a good idea to close and restart after changing the step/unit.

I had to reduce the velocity so that the machine can run properly. I think that I set it at 15. Now, I ran into problems setting up the limit switches. The E-Stop and home switches work but I can't get limit switches to work without getting messages related to limit switches in Mach3 software and I can't reset the hardware. The wiring diagram at this link http://www.probotix.com/diagrams/3-axis_ProboStep_wiring_dia.jpg is for the PBX-2 board. I can't find similar wiring diagram for the PBX-RF board. The wiring diagram for the PBX-RF board at this link http://www.probotix.com/diagrams/PBX-RF_diagram.gif isn't the same kind as the wiring diagram for the PBX-2 board.

I tried to make a sign but the motors got hot after half-hour. After using Cut2D program to create code, how do I "customize" the code for my machine such as setting feed rate at 15, limiting the distance of Z-axis, and setting the 0,0,0 coordinates to the corner or center of the wood to be routed? If I have to stop my machine for any reason, how do I resume the routing?

It's not abnormal for steppers to get hot. Most can handle up to around 175°F or even more.

Assuming Cut2D works like V Carve, you set the feedrates using the edit tool button in the operations window. The feedrates are assigned to the tools.

Not sure what you mean by limiting the Z axis distance.

To set the 0,0 point, just jog to where you want 0,0 to be and zero the axis in Mach3.

And without home switches, which will give you a repeatable reference position, you'll have a hard time restarting a stopped job.

If the motors are too hot for me to touch, does that mean that they're too hot? I don't want to burn out the motor drives. The way that my CNC machine was built following the plans from Solsylva, the travel of the Z-Axis is limited to about 1-1/2 inches and the Z-Axis carriage can travel up to about 4 inches. When I generate code in Cut2D which works like V-Carve, I don't know how to limit the Z-Axis travel in Cut2D.

If you can keep your hand on them for a few seconds, they should be OK.There's no way to actually "limit" your Z travel. You set the depth with the cutting operation. You can set the rapid (clearance) height using material setup. It shouldn't cut any higher than that. If you really want to limit your travel, use Mach3's softlimits.

How can I check for binding on the carriages? On the Y-Axis, it binds as the Z-Axis carriage moves towards the home position (I think). I think that the Z-Axis router holder binds as it moves up/down. I think that the leadscrews are not perfectly straight. I got the leadscrews from Lowe's. Should I get better leadscrews?

I think that if the CNC machine was built following the plans from Solsylva, it was built to sit on door, floor, etc, and rout on door, floor, etc. Do I have to raise the CNC machine 1-1/2 inches so that I rout wood that's placed on its base?

I think that if the CNC machine was built following the plans from Solsylva, it was built to sit on door, floor, etc, and rout on door, floor, etc. Do I have to raise the CNC machine 1-1/2 inches so that I rout wood that's placed on its base?

How about putting something under each leg to raise the entire machine?

I'm going to raise the entire machine using some pieces of wood.

I raised the entire machine 2-1/2 inches so that the Z-Axis can have full travel. I used pieces of plywood glued together and pieces of steel bed mattress frame. I still have problems with limit switches. I checked wires and limit switches a million times and I can't get the limit switches to work correctly.

I made two signs today. First one was good. Second sign was not good because the CNC machine didn't work properly or there's bugs in the G-Code program that was generated by Cut2D program. How do I test G-Code programs before I run the CNC machine? I know that I can put Mach3 program in off-line mode to test G-Code programs but what if something's wrong with the machine? I'm not sure if I can use computer cables between the enclosure containing the electronics and the home/limit switches. Computer cables are usually shielded. I already have shielded cables between enclosure and stepper motors. On another thread on this forum, someone was having problems with the home/limit switches and someone else suggested that he set the debounce parameters in Mach3 program. Link to thread: http://www.cnczone.com/forums/showthread.php?t=56869