Messages

301

General Mach Discussion / Re: Where are tool length offsets referenced from?

« on: July 03, 2016, 09:21:28 AM »

Tool legth offset is just a number, where it is referenced from is up to you. People have a tough time getting there mind around this. I simply pick a reference tool. My preference is a common edge finder permanently installed in a toolholder. It needs a tool number to be assigned. A dab of paint at the joint shows that it has not been moved. This edge finder can be used to pick up the sides or the top of a part.  I like to use a 0.500" pin that is rolled back and forth under the edge finder. I do this because an oops like being in continuous or a large jog step when approaching the part doesn't result in a crash.

So using my reference tool with the correct tool number I can pick up the top of a part, or the table, or top of the vise and zero the Z axis. Then set other tools on that same surface.  So the offset number will simply be plus or minus the length difference between my reference tool and this tool. To test you got it right. Move the reference tool with the correct tool number well clear of table or part and zero the Z axis. Call a tool change for a new tool with the correct tool number. Make a feed move to Z zero. The end of this tool should now be at the same Z level that you set the reference tool at.

Hope this helps, it takes a little practice.

302

General Mach Discussion / Re: Top right on the screen, says Mill->G15 G80 G17...... Help Please!

« on: July 01, 2016, 04:07:00 PM »

Those codes are common prep codes that show you that the XY plane is active, all drill cycles are canceled etc. g0,g1,g2,g3 are motion codes that would be kind of useless to see this way as normally the machine could be ripping through them way faster than you could read. By the time you read it, it be too late anyway. So put your machine in single block mode and look at the G-code to see what it will do on the NEXT press of the start button.

303

General Mach Discussion / Re: Winding springs using Mach control

« on: July 01, 2016, 12:07:38 PM »

Joe,
Yes, feed rate just determines how fast the spring gets wound. you can use manual override on feed rate to adjust how fast it works as it is working.

304

General Mach Discussion / Re: Winding springs using Mach control

« on: June 30, 2016, 09:17:13 PM »

I'd use 2 axis control with the spindle as one axis. I'd leave the tool post as X and make the Spindle Y. So a simple drawing of X vs Y gives you a profile for Mach to follow. I'd set up Y as Steps per degree. So a line of Y = 3600 and X = 50 would wind a spring with 10 turns that is 50mm long, center of first coil to center of last. Programming a curved line would produce a spring with variable pitch. Program a very short X move at both ends and you'd have a spring with closed coils at both ends.  Does this make sense?

305

General Mach Discussion / Re: M3 - pick up on a part for remachining

« on: June 21, 2016, 06:17:14 PM »

Robert,
I know you weren't looking for a fix, however when you have a Cad model that you can manipulate it is nearly always easier to do the manipulations there as opposed to doing it on the actual part.

I once repaired a cast iron wheel hub for an old fork truck that had 3 out of  5 lugs broken off and one was missing. They were all tapped holes too.  I clamped it down on the CNC, picked up the center hole and one of the still good bolt holes.  I transfered those numbers into my cad program.  This gave me the bolt hole circle and location of all five bolt holes. Then I rotated the drawing of the hub to the coordinates I actually measured and did the CNC program from that.  I brazed all the pieces back on and spiral milled the tap size hole for each bolt. Came out great. No one believed it could be repaired.

306

General Mach Discussion / Re: M3 - pick up on a part for remachining

« on: June 21, 2016, 04:33:00 PM »

Since you have a Cam program I'd fix the problem there. Pickup center of one hole by sweeping with dial indicator. Zero X and Y axis.  Move to a second hole and again pick up center. In Cam move the center of the first bolt hole to 0,0. Rotate part to move second bolt hole to X and Y you got from finding center of second hole. Repost the program and you can continue on from there.

307

General Mach Discussion / Re: Side mount tool changer controlled by Mach3? Has anybody done it?

« on: June 16, 2016, 09:26:54 AM »

I see that it does put tools back in different pockets. Not impressed with the indexing cam mechanism! Starting rotation and stopping at every pocket is such a waste. A servo driving it with continuous smooth motion to the required pocket seems like it would be so much better.

308

FAQs / Re: Sample gcode need larger scale

« on: June 15, 2016, 09:24:07 PM »

You say miniature, like maybe the G code was written in inch units and your machine is set up in mm? There is a g-code to select units, look it up in g-code list.  Is it only a little bit smaller?  Check whether your stepper drivers are set for micro stepping and that steps per unit of travel matches in Mach 3

309

General Mach Discussion / Re: Side mount tool changer controlled by Mach3? Has anybody done it?

« on: June 15, 2016, 07:04:13 PM »

I have never seen a tool changer that puts a tool back any place than from where it came from. The really fast machines preload a tool into the changer arm. It grabs the tool in spindle and rotates the arm to the new tool and loads it. Then while the machining going on it puts the removed tool back in the pocket it came from.

310

General Mach Discussion / Re: Continuous jog stays on

« on: June 11, 2016, 09:38:20 PM »

Yes I reported this a couple of years ago and a lot of other people verified that it happens with motion cards of all kinds including smoothstepper.