Messages

1751

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: May 12, 2016, 04:38:48 PM »

Thanks, still far from sure what to do really.

Lots have suggested getting a donor, seems there are a few to choose from especially Bridgeport BOSS' and Interacts in various models plus loads of others.

Chances of finding a good mechanics/duff controls donor probably slim though, that still leaves transport and rebuild space etc.

I can see ballscrews setting me back £1500 so getting a donor built with them fitted seems a good idea if less money.

Tough nut to crack i think.

1752

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: May 12, 2016, 01:49:41 PM »

Yep, its got a lube system already but it would get a total overhaul if i did go ahead.

I'm getting plenty telling me to get an old VMV etc, but my main worries are that they all seem to have small beds, all seem to need too much power and all seem heavy.

While some these may be good traits for a machine, for me they make it hard to use, expensive to run and impossible to move

1753

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: May 12, 2016, 10:30:50 AM »

Hmm, just had a thought  ...

Instead of my recently dropping around £2k on building a mini-mill/router, what I should have done is use that cash to convert the Bridgeport and fit an adaptor mount that enables me to hold the 24k water-cooled spindle - best of both worlds??

I could even mount a complete custom Z-axis on the rear of the ram where the slotting head should fit!

The BP has a lovely 48" bed, ok maybe it only has 9" of Y axis but that's still not too shabby I think, certainly I've done a hell of a lot of big jobs on the old girl.

So, what would the drawbacks be here?

The new spindle has the speed I need, I think a BP conversion can reach 4-5000 mm/min rapids which is where the mini-mill is set so thats no issue, ballscrews would provide the same accuracy as the mini-mill has presumably.

Hmmm......stupid or not.....?

1754

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: May 12, 2016, 09:07:41 AM »

something like this...
http://www.aliexpress.com/store/product/New-Servo-motor-and-driver-set-2-4N-M-0-75KW-3000RPM-90ST-AC-Servo-Motor/314742_760999511.html

No details on the drive though.

The hardest part is the Z axis on a BP, no perfect solution just lots of workable ideas it seems.

1755

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: May 12, 2016, 08:30:22 AM »

Similar power on servos?

Just looking at stuff to price up  research etc.


Thanks

1756

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: May 12, 2016, 07:44:31 AM »

I was thinking something like the Centroid Conversion where you can still twiddle the table axis handles and Mach3 shows the position change as a DRO.

I guess its not critical, maybe best just to pull the handles off completely and go CNC only, no need to worry about DRO stuff then.

Having seen the ridiculous torque available from the little screws on my mini mill, would steppers with maybe 2-1 or 3-1 reduction be a viable option for a Bridgeport?

Just thinking out loud and looking at pennies etc.

1757

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: May 12, 2016, 06:35:19 AM »

Am i right in my belief that if i want real-time display of position in Mach3, I would need to use servo's and encoders?

1758

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: May 12, 2016, 06:12:11 AM »

Good points there, I have made many large holes - the only way i could do them was to buy a boring head or two and drill with the largest bit i had then slowly cut myself outwards to the finish dia - a fair while when you only have a 1" drill and need a 4-1/2" hole! That would have been a doddle with even basic CNC.

I have a small job i run little batches of - cutting squares on the end of 1/2" rod, currently use a collet block and rotate 4 times - basic CNC would be only one rotation step as it could cut opposing sides easily at one setting.

Looking back, there isn't really much I do that is hand positioned - its all DRO work from zeroes - basically manual CNC stuff, if i want to throw some holes in something I use the pillar drill

I think i will dig deeper into this and get some prices for a ballscrew kit.

1759

General Mach Discussion / Re: digitize light

« on: May 11, 2016, 03:35:06 PM »

Thats the one

Nice one.

1760

General Mach Discussion / Re: digitize light

« on: May 11, 2016, 03:14:31 PM »

Yes off normally

Is the probe input configured in ports&pins?