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Author Topic: MACH as a CMM machine  (Read 7225 times)

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Re: MACH as a CMM machine
« Reply #10 on: November 12, 2007, 08:18:03 AM »
Chip this is a little off topic but can you use a waterjet to cut an automobile windshield?  If so there is an untapped market for the kit car builders. Many of them need custom glass and have to settle for existing glass due to cost. The existing glass always has to be cut somewhere.

Mike

vmax549

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Re: MACH as a CMM machine
« Reply #11 on: November 12, 2007, 07:50:25 PM »
Chip remember that you cannot attach it to the up and down part of the head the sliding rehostat has to be able to mount rigid to the frame in order to able to move up and down as it follows the contour. That way it can send the voltage signal for height corrections.

(;-) TP
Re: MACH as a CMM machine
« Reply #12 on: August 12, 2011, 02:20:38 PM »
I have been working up ideas and code for a CMM page for mach. I need to know if you have any special things you would like to see MACH do as a CMM type machine.( Coordinate measurement machine).

It could do things like probe a hole and set center of circle and give you the diameter.

G68 CR based on the use of a probe to set a vise, or between the COC of two holes, or from any axis plane ,etc

Length between two points and a return to center . 

Just need some more input.(;-) TP

I have been working up ideas and code for a CMM page for mach. I need to know if you have any special things you would like to see MACH do as a CMM type machine.( Coordinate measurement machine).

It could do things like probe a hole and set center of circle and give you the diameter.

G68 CR based on the use of a probe to set a vise, or between the COC of two holes, or from any axis plane ,etc

Length between two points and a return to center . 

Just need some more input.(;-) TP



OK I just found this thread on the artsoft forum..  what ever happened to the  'Mach3 as a CMM'  effort  (NOW FIVE YEARS LATER)...???

This is EXACTLY what I need to do...
Is it finished...  did you guys give up...?

PLS ADVISE 
Re: MACH as a CMM machine
« Reply #13 on: August 12, 2011, 05:36:22 PM »
OK so use the plasma height controll setup and instead of monitoring the arc voltage level use a sliding reohstat mounted at the head to follow the contour height and generate a variable voltage based on the voltage level as a height input then MACH can adjust it similar to the way it does with plasma. ON THE FLY.

Just a thought, (;-) TP

I will soon be putting together the same thing for my router, as the sheets of material I use aren't always flat! I was going to use compressed air to blow the chip away and help cool the bit, and an ultrasonic sensor to measure the height without touching it. Works an transparent material because it uses sound. Let me know if you would like some info on the ultrasonic sensors we order to use in our products. This along with a Torch Height Controller and it shouldn't be too hard!

Any recommendations on a THC for this application would be great.

Chris
Re: MACH as a CMM machine
« Reply #14 on: August 12, 2011, 10:15:02 PM »
Chip this is a little off topic but can you use a waterjet to cut an automobile windshield?

Yes, you can. I've seen a local shop do it on a 5 axis FlowJet.  The cost to have it done might send them right back to using existing glass though.  The guy running the machine thought it was around $800.
Re: MACH as a CMM machine
« Reply #15 on: August 12, 2011, 10:23:28 PM »
OK so use the plasma height controll setup and instead of monitoring the arc voltage level use a sliding reohstat mounted at the head to follow the contour height and generate a variable voltage based on the voltage level as a height input then MACH can adjust it similar to the way it does with plasma. ON THE FLY.

Just a thought, (;-) TP

I will soon be putting together the same thing for my router, as the sheets of material I use aren't always flat! I was going to use compressed air to blow the chip away and help cool the bit, and an ultrasonic sensor to measure the height without touching it. Works an transparent material because it uses sound. Let me know if you would like some info on the ultrasonic sensors we order to use in our products. This along with a Torch Height Controller and it shouldn't be too hard!

Any recommendations on a THC for this application would be great.

Chris

You won't need to buy a THC.  You'll have to build your own using the ultrasonic sensor.  All the THC does is compare tip voltage to a set voltage.  If the tip voltage is lower than the set voltage, the THC sends a THC UP command.  If it's higher, it sends a THC DOWN command.  You'll need to build some electronics to read the ultrasonic sensor, compare it's output to a set constant and output to a second PP on the Mach3 PC.

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Re: MACH as a CMM machine
« Reply #16 on: August 12, 2011, 10:34:12 PM »
You will also have to create a PID loop to stabilise the function OR you will be chasing it all day. Most THC have the built in pid loop to filter the results and tune out the oscillations.

For the most part it cannot be done without using the THC functions in mach. Only the THC functions can interact with the already  buffered moves for Z.

Depends on the output of the sensor ???  Do you have the specs?

(;-) TP
Re: MACH as a CMM machine
« Reply #17 on: August 13, 2011, 07:09:23 AM »
You won't need to buy a THC.  You'll have to build your own using the ultrasonic sensor.  All the THC does is compare tip voltage to a set voltage.  If the tip voltage is lower than the set voltage, the THC sends a THC UP command.  If it's higher, it sends a THC DOWN command.  You'll need to build some electronics to read the ultrasonic sensor, compare it's output to a set constant and output to a second PP on the Mach3 PC.

You will also have to create a PID loop to stabilise the function OR you will be chasing it all day. Most THC have the built in pid loop to filter the results and tune out the oscillations.

For the most part it cannot be done without using the THC functions in mach. Only the THC functions can interact with the already  buffered moves for Z.

Depends on the output of the sensor ???  Do you have the specs?

(;-) TP

The sensors are capable of providing a current or voltage signal, and I believe the voltage range is 0-5V, but will confirm when I go in today. It is trivial to condition the signal IF it doesn't match the THC voltage range. An extremely simple Op-Amp circuit would suit the purpose. Set the gain and you're done. Designing a PID controller on the other hand is not quite so trivial. Not extremely hard or anything, but it would take time that I don't have. Even if I design and/or build a PID, I will have to tune it to get it to work as desired. PID in THC controllers are already tuned for the application. I would much rather just use an existing, proven design then reinvent the wheel. I'll check the specs on those sensors.

A THC seems to fit the bill, unless anyone knows of a simpler, proven solution?

That being said, what THC would people recommend?
Re: MACH as a CMM machine
« Reply #18 on: August 13, 2011, 07:11:02 AM »
Sorry for hijacking the topic   ;)

Moderators, can we move these messages to a new thread?