Messages

71

General Mach Discussion / Re: Physical buttons for plasma

« on: May 16, 2016, 03:30:55 PM »

Thanks for the photos. Certainly satisfied my curiosity!

72

General Mach Discussion / Re: Odd behaviour?

« on: May 14, 2016, 03:27:34 PM »

I had it randomly on my lathe. I also had it once where it turned the spindle off instead of reducing speed. That one wouldn't of been so bad, but it knocked both the turret and spindle out of alignment, as well as shattering a relatively new drill 

I've got to admit, I definitely don't miss Mach on my lathe!

73

General Mach Discussion / Re: Multimeter info

« on: May 14, 2016, 03:19:26 PM »

Even a cheap meter will do most things. The big issue with cheap meters though, is they're not usually the most accurate, however in terms of machine conversion, you don't usually need much accuracy. You're typically more interested in if there is power and it's at roughly the correct voltage, or if you have continuity. You rarely need to know with certainty an exact voltage or resistance.

74

General Mach Discussion / Re: Physical buttons for plasma

« on: May 14, 2016, 03:14:13 PM »

OK, I'm going to have to ask. How does the magnetic breakaway for the torch get aligned?

I've been wondering about it since I seen the video, but it's not clear in the video. I'm guessing there's some kind of tapered locating tabs, that allow it to locate positively, yet still breakaway if hit from the side?

75

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: May 12, 2016, 07:08:20 PM »

You do seem to have the same problem as me. Workshop size and power supply are limiting factors.
If I had a high enough roof, and a proper 3 phase supply, I'd have a VMC.

I mostly agree with what others have said about it not being worth converting a manual machine. It's a lot of work, and as has been highlighted over on mycnc, there are knee style CNC machines about for reasonable money.
If I hadn't bought the Matchmaker aka a Shizouka ST-N knee mill that was built from new as a CNC, I would of probably converted something SX3 size, although I did buy a Denford Novamill as an interim machine, which is partly why the Matchmaker retro is still not complete. However I did get the last of the relay holders for the toolchanger pneumatics wired up last week, inbetween trying to get caught up with orders after losing two days getting my lathe turret fixed 

76

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: May 12, 2016, 01:43:13 PM »

Gary, servo torque is near constant over its speed range, whereas a steppers torque quickly drops of as the speed increases.
The major advantage is the servo performance should be reasonably constant at all speeds, whereas stepper performance will decrease as speed increases.
A well designed stepper system can be as good as a servo system, however it's still an open loop system, unless you use closed loop steppers, but then you're into a similar price range as servos. I priced both options for my knee mill, and from what I remember, a closed loop stepper system was about 80% the price of similar torque servos, and would limit rapid speeds.

Dave, if you were to convert the bridgeport to be capable of those speeds, I'd be factoring in some form of auto lube system while the machine was apart. I wouldn't be wanting to risk slides running dry at those speeds, and even a manual auto lube system will make it far easier to keep things lubed. Arc Euro sell the needed bits at reasonable prices, although I'm sure there are other sources.

77

General Mach Discussion / Re: Haas VF1 Conversion

« on: May 08, 2016, 06:36:12 AM »

I'll echo Hood's comment about using a higher end controller that can handle 24V.

CS-Labs CS-M__/_, Dynomotion KFlop+Konnect (Konnect is a 24V IO expansion boards, if you've got analog servo drives, you'd want a Kanalog board as well), Vital DSP or HiCon, and Galil controllers can all handle 24V.
They also remove the need for parallel ports.

By the looks of it, that tool change sequence would be better handled in a single place, which would vary depending on what controller you use.
It could all be handled within Mach with enough IO. My only concern would be how quickly Mach would be able to stop the spindle on detecting the pin alignment, as Mach3 only has 10Hz update rate for Macros (Mach 4 is faster, but I've not been aware of any specific figures).

My personal preference would be a KFlop, as you can program it directly to handle whatever you want. Once it's programmed, it can control everything on the machine and respond near instantly to input changes, so things like tool changes, you just need to tell the KFlop what tool you want, and it does it and tells you once it's finished.
With something that relies on Mach Macros to tell it what to do, there is usually a delay in responding to input changes.


Regardless of controller choice, the first thing I'd suggest you do, is go through the machine, and make a list of all the Inputs and Outputs you'll need. Once you have that list, it'll give you a far better idea of what you need to get the machine working.

78

General Mach Discussion / Re: CSS - in meteres or milimeters

« on: April 27, 2016, 07:06:49 PM »

There was some discussion about Mach 4 turn over on the yahoo group last week.
IIRC Brian said the only major thing left was to sort out the default screens, but he did offer to make it available to anybody who was willing to test it.

79

General Mach Discussion / Re: CSS - in meteres or milimeters

« on: April 27, 2016, 04:44:30 AM »

And just to clarify Hood's typo, CSS is specified in M/min or Ft/min depending on if you're in mm (G21) or inch(G20) mode.

80

General Mach Discussion / Re: CSS - in meteres or milimeters

« on: April 27, 2016, 04:31:16 AM »

Without seeing the part, would it be possible to break the taper moves into segments, then alter the spindle speed and federate for each segment?

As long as you've not got exact stop mode active, I'd think the segments should get blended into a reasonably continuous movement.