Messages

1211

General Mach Discussion / Re: gecko servo drive

« on: April 26, 2009, 09:30:05 AM »

Gecko has no warning about that in their extensive instructions.

I have turned my steppers many times and lit up the power indicators on my Gecko203V with no apparent ill effects. But that doesn't mean it's OK.

That would be useful info to ask Gecko and then post back their answer. I just got my first 320 so I'm interested also.

1212

General Mach Discussion / Re: how to go to z without traveling dagonally

« on: April 26, 2009, 09:19:01 AM »

1) Suppose I wanted to have the X and Y moving and the mill spindle spinning an endmill cutting a workpiece held and slowly rotated by the A axis?


2) the A axis is driven by a servo motor. How is that going to resond to being treated as a spindle by mach? That is sot of the whole problem to start with: Mach inability to spin a servo continuously via a single command.


3) The question was how to do what I want to do,  not if I  should want to do it in the first place. 

1213

General Mach Discussion / Re: Help with spindle speed control for Mini Lathe

« on: April 26, 2009, 08:51:15 AM »

If you are referring to the up and down buttons in the Spindle Speed panel on the program run page, then no they did not have any effect for me but then that was several versions ago and I was having trouble with the whole speed control issue anyway. The spindle speed wavered all over the place, and it was anyone's guess what programmed changes were going to do.

I'll give it a try again now that I have the speed comtrol working. It sure would be handy to manually tweak the speed (and/or feedrate) of a running program..

Right now I'm down waiting for a new power supply, so I'll post back when I'm running again.

Thanks for the help!

1214

General Mach Discussion / Re: how to go to z without traveling dagonally

« on: April 26, 2009, 08:43:08 AM »

I don't know where this iidea comes from that no other axis can  move while A moves.

G1 X1 A3600 cuts dandy 10tpi threads

G1 X1 X72000 turns at .005 feed

I run the A 'continuously' now by calcing the number of turns I want, feeding that in with a G command and then clearing the A.

Unfortunately, my little power supply kicked the bucket before I could get video on the nifty face off and then thread program I had working.

This already works fine, I'm just looking for a better way. Swapping axis won't work for me becuase I still need the X,Y, and Z active.

The grand scheme here is to make a mini-machining  center . . of sorts. I have it working, it's just down to refinement.

What I would like is

1) simply a way to reset A to machine 0 rather than just work offset 0. SO far this has not been a practical limitation for what I am doing becuse I've gotten machine A into the 10s of millions, so there is enouh headroom for my simply programs.

2) a simple script or brain that would use the stored feedrate variable and use it to convert the A travel to whatever number of degrees reqwuired for rotations to accomplish the feed for the distance commanded and pass that to the G command as an A number.

Example: Mach has stored somewhere the feed per rev of say .004. I want to turn .020 off a workpiece for a distance of .6 inches. All of the data is availble for Mach to calculate the number of turns (in degrees) the A axis needs to move accomplish the cut. It is just going to have to wait until I have time to dig into the scripting and/or brains of Mach unless I can find a willing guru in the mean time to help out. 

1215

General Mach Discussion / Re: Help with spindle speed control for Mini Lathe

« on: April 26, 2009, 04:04:50 AM »

Hood,

I have not had success changing speed in Mach once a program is running. I have not tried in a while as I gave up getting my spindle to work with Mach until recently when Homann came out with a new board that works beautifully. So this is goint to be a priority again.


What is the correct proceedure to change spindle speed while a program is running?

1216

General Mach Discussion / Re: how to go to z without traveling dagonally

« on: April 26, 2009, 04:01:29 AM »

Good point, Hood!


How difficult would it be to make a button (or command useable in a program) that would cause the A axis to run continuously?

1217

General Mach Discussion / Re: how to go to z without traveling dagonally

« on: April 26, 2009, 03:19:22 AM »

Thats what I was thinking, too.

G1 X10 Y5     moves diagonally

G1 X10
     Y5           moves first in the X and then in the Y

1218

General Mach Discussion / Re: Help with spindle speed control for Mini Lathe

« on: April 26, 2009, 03:11:21 AM »

I've had trouble with a couple different boards and recently tried out Homann Design's new stuff.

The new PWM version puts out a rock steady control votage from Mach3, something I was unable to get with the other boards. I finally have a nice steady Mach3 controlled spindle speed on my X2. HIGHLY recommended.

CAUTION CAUTION CAUTION!!!   Make absolutely sure to use an ISOLATED speed controller. If you connect non-isolated speed controllers to the variable speed controls in these import machine tools, you get a pop and expensive smoke.

That goes for replacement variable speed drives also like those from Minarik and KB. I fried two Minarik controllers connecting them to CNC4PC boards. And that takes out a lot of other stuff with it when if goes. That is the expensive way to learn about 'isolation'.

Suggestion: leave yourself a way to switch back to manual control while a program is runing. Sometimes you may need to vary the speed during a cut to clear up chattering, etc.

1219

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

« on: April 26, 2009, 02:54:43 AM »

Thanks to everyone for the education. Here is what I learned primarily:

It is a lot more complicated that I imagined. There is no agreement at all on how to go about this.

I'm an engineer who spent many years building prototypes of all kinds and doing fault analysis on machines and packaging lines and I had a machine shop with my own heat treating furnace. I cut all kinds of exotic high strength materials including H7 H11, Inconel, Ampco Bronze, etc. I'm a newbee at building my own CNC, but I'm not inexperienced at machining or mechanical design.

While I am definately not up to speed on electronics, I've done work at a Chlorine plant where the cell rows run at hundreds of KV. When you walk the 'tunnel' which has fiberglass grating, your skin tingles and your hair stands up. Needless to say, I know enough to not blow myself up. I think "don't touch the wires that are making that crackly sound" is a good rule . .LOL!


Anyway, this issue is now moot as my solution was to buy a NEMA 34 72V servo motor from www.homeshopcnc.com   

I also have on order replacment power transistors that *might* fix my existing 36V supply (yes, I'm handy with a soldering iron, as well as a desoldering iron). If so, then maybe I'll get another Gecko and use the little 36V servo on my troublesome Y axis, otherwise, I'll just pitch the PS and sell off the little servo and move forward. 

1220

General Mach Discussion / Re: Looking for assistant LPT printer card

« on: April 26, 2009, 02:29:32 AM »

I just posted a specific card, the source to get it and instructions on how to set it up with Mach.

Don't know how to link to other threads on this forum, but the title of the thread is:

Parallel port for PCI bus that works with Mach3 - just passing along info

Just find it and you'll get what you need.