Messages

431

General Mach Discussion / Re: Spindle orientation on a Bridgeport...

« on: February 21, 2018, 08:09:14 AM »

Ok, before i go too deep on mechanical indexing etc - all of this is a way off yet, lets have a re-visit to my setup..

I have a Bridgeport Knee mill with CNC everything It has recently been tagged as a KMVMC (knee mill vmc)

It has a 3Hp AC motor running sensorless vector drive with VFD at a 1:1 ratio, max speed is wound up to 125Hz to give me 4000rpm.

Is there a way to calculate a size of AC servo motor that would slot in and give me the same (or better) performance??

It seems most common ones only go to 2500rpm so would need to run at 1:1.6 ratio.

Just as a cost effectiveness exercise.

432

General Mach Discussion / Re: Spindle orientation on a Bridgeport...

« on: February 21, 2018, 07:52:45 AM »

Hmm, ok a shot-pin or bolt seems it may be the only way then with my motor/drive setup.

I'll need to get the jog function programmed and working off a push-button in the drive first to do some tests it seems.

I knew i should have gone for a servo drive when i rebuilt

433

General Mach Discussion / Re: Spindle orientation on a Bridgeport...

« on: February 21, 2018, 06:53:45 AM »

Yep, this point could be a major go/no-go point as changing controllers etc is out for the present due to funds and the fact that its all new anyway

I have see mechanical methods but i dislike those so far - cams, shoot-bolts etc.

There are also many mentions that on a BT30 size spindle the dogs are not needed anyway as the drive is taken by the taper, no idea if that is so or a good idea but it would certainly fix the issue cheaply !

434

General Mach Discussion / Spindle orientation on a Bridgeport...

« on: February 21, 2018, 06:31:46 AM »

I'm slowly making my way to an ATC project only BP conversion, got tool length on the knee, will be fitting a BT30 spindle this weekend, got new tooling etc,

Have read many great threads on here about ATC's but can find nothing on spindle orientation - seems with the BT30 having dogs, without this in place the ATC is a non-starter??

Now, I have an encoder on my spindle as it does rigid tapping, my first thought was can Mach read the Index pulse on this? Maybe that would be a way forwards, i just have no idea, the spindle drive is a standard 3Hp VFD driven AC motor the VFD has an "Inching" input option IIRC.

Whats the way forwards here?

435

General Mach Discussion / Re: MACH3PLASMA LIMIT SWITCHES FOR G540/PROMA

« on: February 21, 2018, 02:12:22 AM »

Yep, thats it,

the switch is nOT connected to z-min etc it is a separate switch connected direct to the "Probe" input on mach3.

436

General Mach Discussion / Re: MACH3PLASMA LIMIT SWITCHES FOR G540/PROMA

« on: February 20, 2018, 04:55:28 PM »

IIRC - If i recall correctly

Its not too difficult, I've had a few different setups on mine but they use the G28.1 or G31 reference codes, you will also need to add your pierce height setting into the mixture so it will probe the surface, set Z zero, then move to your pierce height and set z zero again then start cutting.

437

General Mach Discussion / Re: MACH3PLASMA LIMIT SWITCHES FOR G540/PROMA

« on: February 20, 2018, 04:12:27 PM »

Not sure, as i understand it, your z axis is not remembering where you set it before starting cutting i.e. you maybe set z zero with a gap of say 3mm between torch and work - it then cuts ok, moves up and down with THC but when finished, Z Zero is no longer 3mm form work??

Its hard to tell as my table has material height sense at the start of each cut so if it did lose position, it would reset it every time.

If you have a floating head, all you should need is a switch fitted in the right place, an input to the Probe input on Mach and some probing code, its pretty simple, oh and you need to alter your post processor IIRC to call the probe cycle before each pierce.

438

General Mach Discussion / Re: MACH3PLASMA LIMIT SWITCHES FOR G540/PROMA

« on: February 20, 2018, 03:19:16 PM »

Have you got a floating head?

This is a slide assembly and switch on the torch mount that is used for probing the height before every pierce or every few pierces.

439

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: February 20, 2018, 01:26:23 PM »

A box full of very nice tool holders turned up yesterday, on special from my tool supplier

Also made the drawbar for the new spindle.

Now i just have to make a gap to pull the head apart....

440

General Mach Discussion / Re: Scripter Compile Error bites again :(

« on: February 19, 2018, 02:46:40 PM »

Hmmm.....