Messages

291

General Mach Discussion / Re: SpindleRPM

« on: April 20, 2006, 11:45:25 PM »

I am just working on this same thing, I used a PDMX spindle sensor and wired the signal up to the A axis home limit switch input on a Bob Cambell breakout board. The spindle sensor requires 5 volts but the breakout board had a 12 volt power supply for this sensor so I used a couple of resistors soldered in the wire to reduce this down to 5 volts. Set up the input signal for index to pin 15 in the ports and pins, at least that's what the cambell board uses for this input.

292

General Mach Discussion / Re: my Leadwell vmc and Mach3

« on: April 16, 2006, 11:21:05 AM »

Really cool, you can't mistake the scream of steppers...

293

General Mach Discussion / Re: my Leadwell vmc and Mach3

« on: April 15, 2006, 01:23:46 AM »

Could I ask, what pitch the ballscrews are in this machine, so as to compare to what my lathe might be capable of for feeds?

294

General Mach Discussion / Re: Lathe turret toolchanger

« on: April 02, 2006, 12:58:32 AM »

Got the toolchanger design mostly done, got the materials and equipment for it, have to print off the drawings and go machine it all. What I would need for the Basic, sequence possibly should go; Solenoid energises to draw lock pin, lock pin sensor sees pin unlocked, stepper motor accelerates then deaccelerates to stop at called out position, 200 step motor, 8 positions, so 25 steps per tool position, code would be better if it were bidirectional so some logic needed to decide which way to go for shortest change degrees. As lock pin solenoid denergises, stepper "vibrates" maybe one microstep either way until lock pin sensor sees pin fully locked. Pin locked signal determines program resume. I will try to get away with not using a home sensor on the turret and will make sure I set the turret in tool position 1 before shutdown each time, upon machine start it will assume it is in that place. If this is a problem I can add a turret home sensor eventually. The italian toolchanger I used in the Clausing lathe had a DC motor to turn it, and as the lock pin plunged back in it would reverse slightly to assist the pin to seat fully, this system worked well and never gave any trouble in years of operation. Using a stepper to do this is possibly easier to do. Thanks to all.

295

General Mach Discussion / Re: New potential screen ( I just dont know any more)

« on: March 27, 2006, 12:41:16 AM »

Looks very, very nice. Don't forget us touchscreen users for the main buttons, nice to be large enough to use with a fingertip. Very cool.

296

General Mach Discussion / Re: CNC4PC Boards

« on: March 25, 2006, 10:55:59 AM »

So, I'm a little confused here now. Which parallel cable is it that works with MachX and a breakout board? The very old regular cable, a biddirectional cable, a data transfer cable, or...? Never heard of a switch box cable before..

297

General Mach Discussion / Re: Lathe turret toolchanger

« on: March 08, 2006, 11:47:42 PM »

Hmm, don't understand the roller ratchet drawing you have there. My thoughts on moving the turret disc versus moving a lock pin; the turret and tools attached weigh quite a bit more than just a pin, so you need quite a bit larger solenoid or system to get it to move in any reasonable amount of time. Still, the pin must have a slight taper to actually lock, and this can be difficult to withdraw from it's taper. Thinking of using a large automotive starter solenoid for the pin withdrawal, plenty of power, readily available and cheap to boot...

298

General Mach Discussion / Re: Lathe turret toolchanger

« on: March 08, 2006, 12:51:03 PM »

Well, I was sort of copying an italian design we had on our Clausing storm lathe with the lock pin. I have seen the Haas machines, the turret extends a small amount before it rotates, this might be a ratcheting type, not sure if it is bidirectional or not. I had hoped this would be able to be bidirectional so hadn't considered a ratchet, and the Haas type is a bit of a pain to engineer for because the bearing package gets more complex if you want to move the thing in the Z axis direction to unlock at all. Early days though, I'll stare at the solid model for a bit and come up with something as simple as I can yet still be compact and rigid.

299

General Mach Discussion / Re: Lathe turret toolchanger

« on: March 08, 2006, 12:59:44 AM »

Yes, you're right, I'll have to clearance some more above the set screw block area for tapping, I just drew this up late last night in about 15 mins so I didn't do too much thinking.... Got to go find a large solenoid for the lock pin somewhere...

300

General Mach Discussion / Re: Lathe turret toolchanger

« on: March 07, 2006, 04:45:38 PM »

Great to hear, this was kind of the only real stumbling block to go ahead with it. Attached is a screenshot of the turret disc, I went with an eight position one as it all fit on an 8" diameter disc after all. Time to go find some applicable hardware for it then....