Need recommendation on new build

[garymiller397]

I am about to start my DIY CNC router. Have looked at at a lot of DIY builds and have designed my own based on features from several other builds. I will be using 1605 Ball screws and round, fully supported linear rails. However, I have a couple of questions.

What number of microsteps do you experienced builders recommend for the stepper motors?

Is there a right or wrong way to lubricate the linear bearings? What type of lubricant?

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[wizard]

When it comes to stepper motors, they come in fixed step size with 1.8 degree being very common. It is the electronic drives that achieve microstepping. You are free to couple different drives to a stepper to get the performance uou want. Drives have to be properly sized for the stepper if course. Generally you dont want to rely upon microstepping fir precise postioning at least not beyound 8 micro steps. The reason some drives have high micro step counts is to smooth and quiet a stepper motor. There is more to it but this gets you started.

There are many ways to go about machine lubrication. Some are better than others, id avoid the trickier and more expensive solution for simple. You can get good results with plain old #2 grease. Or uou can go the wiped on oil for an even lower tech solution. Avoid heavy or thick lubricatants.

[ger21]

Most people run 8-10 microsteps.

As for lubrication, are you using round linear rails, or profile rails?

1605 is a poor choice of screws, btw. 10mm pitch is much better for a router.

[garymiller397]

Thanks for the info. Unfortunately the price on the 1605's was just too good to pass up.

I now have another problem. The build is going fine and I am now wiring and testing the electronics. I could not find an old computer with a parallel port so added an expansion card. Mach3 seems to be communicating fine with the parallel port because when I use the arrow keys, the X, Y and Z values in Mach3 change on the screen. But I don't seem to be getting the correct outputs from the parallel port. All pins seem to have about 4.6 volts as an output and the arrow keys will not change the voltage. I have tried two different parallel port cards (1 PCI and 1PCIe) with no difference. What am I doing wrong?

[ger21]

The DROs counting doesn't mean anything. They'll show movement even with no port at all.

The most important thing to get right is the port address.

Start with just a single motor, and make sure you have the port and pin numbers correct.
Jog back and forth, and measure the voltage on the direction pin. Another test would be to assign a piin for M7 or M8, and measure the voltage on the pin while toggling it on and off.

[garymiller397]

Checked that port 1 is 1x378. Set the pins for step and direction in Mach3 and made sure they were on port 1. I have one motor connected and when I energize everything, I hear the motor power up. I checked the output on the breakout board and it is at a constant 2 volts and will not change with the arrow keys. I also checked the output directly on the pin of the parallel port card and it will not change with the arrow keys either. As I said, I have tried 2 parallel port cards with the same results.

[ger21]

Are you using a 32 bit version of Windows?
And do you have a 5V parallel port card?

[garymiller397]

Sorry, I meant 0x378. I checked the device manager and I get 2 parallel ports showing. The ECP printer port is set to LPT1 and is using I/O range of 0378 to 037F. The
PCI printer port is on LPT3 with an address range of 0778 to077F

[garymiller397]

Yes - 32 bit windows 7. I assume it is a 5 volt card because when I measure the voltage directly at the parallel port on the card I get 4.6 volts

[ger21]

Then you shouldn't be getting 2V at the breakout board.

[garymiller397]

I agree, but the bigger problem is that the pins on the parallel port card should behave the same as the outputs on the breakout board. The only difference is the optical isolation. I have measured the voltages directly at the parallel port on the card and they will not change when the direction keys are used, and they should. All of the software and drivers appear to be properly installed and I made sure that I ran the memory override for Window 7 before installing. Could this be a windows 7 issue. Should I go back to XP?

[ger21]

No, the breakout board pins should behave the same as the parallel port.

Run drivertest.exe in the Mach3 folder, and see what the results are.

Where are you getting the port address from?
378 is usually the motherboard port. PCI cards typically have different addresses.

[garymiller397]

So I need to verify or eliminate the breakout board as the problems. All the breakout board does is take the signal from the parallel port and put it through optical isolation. In theory, the system should work without the breakout board directly from the parallel port. I ran drivertest and everything looks good.

As I said before, the root of the problem is that I am not getting the right outputs from the parallel port. When I go into the device manager for the ECP printer port (LPT1) and look under the resources tab, it indicates that the port range is 378 to 37F. Should I be using the ECP printer port or the PCIe to multimode Parallel port (LPT2)? I think that the problem may be that the OS is using 0378 but the card is changing the port for the PCIe card

[ger21]

Sounds like you may be using the wrong port, or wrong address. Can you post a screen shot of Device Manager?

[garymiller397]

I think I have figured it out. The OS is using the correct port, but the card is using a different port and it cannot be changed. But there is good news. My motherboard has built in parallel port configured in the BIOS to the correct port. All I need to get is the cable to extend it to the rear of the computer - about $15.

Thanks for all of your help with this. it is greatly appreciated.

[ger21]

You just need to find the correct address for the add in card.

[louieatienza]

Thanks for the info. Unfortunately the price on the 1605's was just too good to pass up.

I now have another problem. The build is going fine and I am now wiring and testing the electronics. I could not find an old computer with a parallel port so added an expansion card. Mach3 seems to be communicating fine with the parallel port because when I use the arrow keys, the X, Y and Z values in Mach3 change on the screen. But I don't seem to be getting the correct outputs from the parallel port. All pins seem to have about 4.6 volts as an output and the arrow keys will not change the voltage. I have tried two different parallel port cards (1 PCI and 1PCIe) with no difference. What am I doing wrong?

You can get a buffered breakout board which will output 5V. I believe you need to set the port to EPP...

[garymiller397]

Ok! everything is workings properly.Motors are moving, everything going in the right direction. About to wire the limit switches before installing the table and setting up the motors and screws. Have a question about the probe settings in Mach3. Do they work that same as home switches in that they make contact and then back off or is a simple make connection.

[ger21]

Probing is done with a G31 move. The probe will move towards the commanded position. If the probe is tripped during the move, Mach3 will decelerate to a stop, and the move is finished.

Not the same as homing at all.