Messages

361

Third party software and hardware support forums. / Re: MicroKinetics to Mach3 Conversion

« on: December 09, 2015, 06:32:29 PM »

Okay,
It sounds like you have very legit reasons to change, and I can tell you my home built CNC preforms WAY better than that under Mach 3!  So the changeover shouldn't be such a big deal if you keep the current drivers and power supplies and change out the USB motion card and the software on the PC. Let us know what you do and how it works for you.

362

General Mach Discussion / Re: Bridgeport 2J Vari-Speed Head, Sensorless Vector Drive, Mach3, cheap tachometers

« on: December 07, 2015, 07:24:06 PM »

NO, that would be real bad!  Your motor is probably rated 1750 rpms at 60 cycles. So the gear reduction is reducing that down to 1000 rpms with proportionally greater torque at the spindle.  Setting the VFD for 300 Hz would make your motor run at 8,750 rpm, and it would likely self-destruct at that speed in a very short time. Also the torque would fall off badly as well.  Now if your motor is a 1750 rpm motor the maximum safe speed would likely be 3450 rpm like a standard 2 pole motor would give you.  The bearings and all would be fine. So you could set your drive to give 120 Hz for 3450 rpm and then adjust your gear reduction to produce 5,000 rpm, and that would be okay, assuming your spindle is okay with that speed.  The torque of course will be lowered proportionally  as well.  So no free lunch with a VFD.  People who really like them simply do work where full motor horsepower is seldom needed.  If you need the most power at the spindle gearing is always better.

363

Third party software and hardware support forums. / Re: MicroKinetics to Mach3 Conversion

« on: December 07, 2015, 07:13:15 PM »

My first question is what is it you are unhappy with?  It looks like a fairly nice machine on their website.

Yes Mach 3 can handle 4 axis simutaneous motion. I looked at your drivers and they would work with Mach 3.  I have a Xulifeng USB 4 axis drive card and it seems to work fine with Mach 3 but I doubt anyone would say it is the best. I doubt the MN400 card would work with Mach 3.

I don't know what AC servos would do for you. It won't improve the position accuracy, unless you are missing steps. However if that is happening then there are other issues because my machine never misses a step ever, unless I actually crash it.  It might make the machine faster, but only if the ball screws and ways can handle that and you may get the same results simply by using larger stepper motors as it appears the motors you have are not the largest the drives can handle.

364

Show"N"Tell ( What you have made with your CNC machine.) / Re: cutting MDF and Plywood

« on: December 07, 2015, 06:17:22 PM »

Stewart,
In wood I wouldn't worry too much about the feed rate being half of what it should.  You'll only see the full feed rate on relatively long moves because you have to slow down for every corner and if they are close together you won't ever get near the highest possible feed rate. I don't know where you are but these guys seem to have pretty good pricing:

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_solid.html

365

Show"N"Tell ( What you have made with your CNC machine.) / Re: cutting MDF and Plywood

« on: December 07, 2015, 03:08:12 PM »

Better yet get a single flute Onsrud router bit and really fly through that stuff. Consider a down spiral cutter so that thin material isn't picked up by the cutter.

366

General Mach Discussion / Re: Bridgeport 2J Vari-Speed Head, Sensorless Vector Drive, Mach3, cheap tachometers

« on: December 07, 2015, 03:02:17 PM »

The cheap tachs work well they only have to count over a fixed time span which is easy. Your VFD puts out a steady frequency in hz which is what your input is telling it to do. However an induction motor must have some slip to magnetize the armature which appears to be what you see. That drive has a tach input I believe so you could close the loop within the drive. I can't see any benifit to that, repeatabilty of setting is always more important. If you want higher speeds though you can program a higher top frequency in the drive. Be careful though, top frequency is 400 hz or higher.

367

General Mach Discussion / Re: limit switch set up

« on: December 07, 2015, 02:53:40 PM »

Sounds like you missed a setting. How are you telling mach 3 that the input is the limit for x, y, and z? If your input is pulled to ground with the switches all closed then the input should be active high because that is what happens when a switch opens. Hope this helps.

368

General Mach Discussion / Re: Need help. Motors dont work properly.

« on: December 04, 2015, 04:54:50 PM »

If your drive output amps match the motor rating you do not want to reduce the amps setting as that directly reduces output torque and the motors will not burn out from the higher voltage. Higher voltage allows the drive to continue supplying the full amperage as the back emf builds up with increasing motor speed.

369

Mach4 General Discussion / Re: Help with Tool Change Script for Large VMC with Umbrella Style Tool Changer.

« on: December 03, 2015, 08:02:58 PM »

The Z axis on that machine is used to remove the tool in unison with the drawbar solenoid, by rising off the tool after the carousel grabs it. Then the carousel rotates to the new tool and the z axis drops down on it. So the machine must be homed to properly position the z.  Fadal did this really simple. You always parked the z between the marks on the column before shutting down. Then the machine would rotate the z motor to find the index mark on its encoder. So you will need to do something similar I believe. Hope this helps.

370

Mach4 General Discussion / Re: Help with Tool Change Script for Large VMC with Umbrella Style Tool Changer.

« on: December 02, 2015, 05:21:19 PM »

I use to the programming for one of those back when they were new!  It was tough loading large tools because the distance from the tool load button to the spindle was just about both arms stretched out straight. Hope you fix that issue.