Messages

871

General Mach Discussion / Re: need help step per unit

« on: May 05, 2009, 01:04:26 PM »

mach3 steps per motor revs =200x32 = 6400

You have a 32 microstep drive?

You also have a very low drive ratio which will give you very little torque. You are essentially direct driving a low pitch lead screw.

872

General Mach Discussion / Re: Mach 3 and Geckodrive G540

« on: May 05, 2009, 10:09:51 AM »

If your going to be using MasterCam then you most likely would not benefit from the Mach Add-Ons. The add-ons let you chain together code from the wizards to create a G-code program without needing a CAD/CAM program. It works great for common tasks but not more complicated things.

When you purchase a Mach license it normally only takes a few hours at most to get the license file sent to you, but since it is a person in the loop process it could take up to a day. For instance if you bought one from my website at Midnight it would be a few hours before I was awake and could process the order.

Be sure to go to Gecko's website and download the XML profile for the G540, that will have all your settings needed to make Mach work with the G540 already set.

873

General Mach Discussion / Re: Can two 36v power supplies be used in series to get 72v?

« on: May 04, 2009, 12:31:15 PM »

Speaking frankly, and not to knock anyone, I think the Keling power supplies are MeanWell knock offs. I have tried and tried to get data sheets for the power supplies from them to no avail. I don't think you would have fried a true MeanWell supply that way.

Unregulated supplies are just that, unregulated. The more current they supply the lower the output voltage is. When your servo starts and hogs a bunch of current the voltage is going to drop way down. To prevent sags all you can do is use a bigger supply, add more filter capacitors or not drive the servo as hard.

874

General Mach Discussion / Re: Can two 36v power supplies be used in series to get 72v?

« on: May 02, 2009, 11:48:48 AM »

People considering these supplies from Keling should know that although they are listed as 'overload protected' the fuse blows only after the transitors have fried and shorted out.

That should just NOT happen. I have tried a few times to get a better data sheet for their supplies but have not succeeded.

875

General Mach Discussion / Re: Any one used xylotex boards to upgrade an EMCO lathe?

« on: May 02, 2009, 11:26:15 AM »

The stepper motors, stepper drives, and power supply need to be chosen to work together. Gecko's stepper motor guide (linked to above) is a good read, and will help you understand how to choose the parts. In short you need to start with choosing the steppers to match the job at hand ( 'bigger', more oz-in, are not always better). When you know the motors inductance you can use Geckos rule-of-thumb formula to calculate the supply voltage. Keep in mind that this calculation just gets you in the right ballpark for getting the most out of your motors. Now you'll know what current voltage range of stepper driver to look for.

I've used the Xylotex driver in the past and they work well. When the Gecko G540 came out I was blown away though. The built in optical isolation makes it a lot easier to folks to wire things up and eliminates the need for a separate break-out-board. It also has charge pump integration built right in , oh and a 0-10V output for the spindle. (So it is easier to use and less expensive too!) Here is what one looks like: http://soigeneris.com/products3.aspx, I have been redoing these pages and will get the manuals on there soon.

What I would do is look at the factory steppers and do some googling to find out their specs. Chances are that the engineers spent a lot of time matching those motors to the machine. It will give you a good place to start looking.

876

SmoothStepper USB / Re: Feed hold corrupts coordinates

« on: April 27, 2009, 04:02:36 PM »

If you are using Feed hold and tool offsets you will have problems right now. Brian has explained this has something to do with how/when the tool offsets are applied. I think 4.0 will have completely new code for offsets.

877

SmoothStepper USB / Re: Does the SS have PWM outputs?

« on: April 26, 2009, 09:34:23 PM »

The SmoothStepper will do a PWM spindle output just fine.

878

SmoothStepper USB / Re: Can't override Feedrate

« on: April 26, 2009, 09:32:42 PM »

With the SS you cannot override over 100%. You can go slower though.

So you can just program your feeds properly so there is no need to change it, or set your feed higher than you need so you can slow it down via the override.

879

SmoothStepper USB / Re: Problem getting clean index pulse

« on: April 26, 2009, 07:45:52 PM »

Let me make sure I follow. The inputs into the BOB from your limit switches, etc are isolated but the outputs from the BOB to your relays and drives are not? Some drives have optos built in to the S/D signals (like Geckos). Some do not. If your drives and other outputs are not somehow isolated then having the inputs isolated is useless. What make/model is you BOB?

880

SmoothStepper USB / Re: Problem getting clean index pulse

« on: April 25, 2009, 04:19:26 PM »

Is your BOB opto-isolated?? I would suspect not. I always recommend opto-isolating the I/O to/from your controls. If you don't you will always have problems. With an LPT driven machine the problems will still be there but they show up as 'Mach did something weird today!). With the SmoothStepper the noise problem will jump right out at you and smack you in the nose and say, "This machine is noisy!".

This is one of the reaons I like the new Gecko G540. Opto-isolation is built right in.