Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: David_Web on July 27, 2007, 01:18:52 PM

Title: Automatic touching
Post by: David_Web on July 27, 2007, 01:18:52 PM
I was just reading the manual and came to the bit about touching.
It seems timeconsuming and hazardus at best so why not figure out something less prone to breaking a tool than a steel plate.

So I came up with the idea of modifying the digitizing probe.
The same ide but instead of using a shaft with a ball at the end there would be a flat surface cloase to the base. And obviously upside down. This has the benefit over a simple switch that it reacts with off center tools and is more accurate. I have a few other simple ideas for switches as well.

The idea is to mount the sensor at a fixed position on the table so that Mach can be asked move there to compensate for the tool all by itself.

I have not heard of anyone that does this so I thought it would be a nice feature. I would certanly want it.
However I don't even have a CNC mill or router yet to I can't test the idea.
Title: Re: Automatic touching
Post by: vmax549 on July 27, 2007, 01:31:22 PM
Something like this maybe:
http://www.artsoftcontrols.com/forum/index.php?topic=3483.0
(;-) TP
Title: Re: Automatic touching
Post by: David_Web on July 27, 2007, 01:36:42 PM
Sorry I didn't see that. It is a brilliant Idea.
Maybe we shoud migrate to that thread.
Title: Re: Automatic touching
Post by: vmax549 on July 27, 2007, 01:41:08 PM
David there are many different version of the same approach floating around do a search on tool setting , tool touch off. The one i showed you auto sets the tool table data. There are ones that reset the Z to zero at each tool change , etc.
Just depends on what you want to do. (;-) TP

Also you can buy a combo touch probe/ tool touch probe from IM services. It converts from one to the other when needed. Model TP100
Title: Re: Automatic touching
Post by: pointcloud on July 28, 2007, 07:32:20 AM
You can also use an auto touch off for plasma or torch cutting with thin material. It mounts differently, like on the torch.. It will allow you to keep a Z0 everytime you start a new cut... I use it with a thc 300... I love it...
Title: Re: Automatic touching
Post by: spl888 on December 11, 2009, 01:05:43 PM
If I do not have additional pin to integrate the tool sensor in Mach3. Can I use the same pin (said pin 15) for the emergency stop to integrate the tool sensor. The tool sensor is a contact sensor. The two wire become short when it contact the tool (to locate the z height when changing the tool). This is equivalent to push the stop button. If I use this pin to connect the tool sensor, what is the best G code to locate the tool position in the program.

Thanks
Title: Re: Automatic touching
Post by: Hood on December 11, 2009, 02:09:13 PM
If you use the E-Stop input all that will happen is you will have an instant stop and the likely-hood that the axis will move a bit more than Mach knows, so I would say its not a good idea.Why not add a second parallel port to get extra inputs?
Hood
Title: Re: Automatic touching
Post by: spl888 on December 11, 2009, 02:40:14 PM
Thanks
Please correct me if I understand wrong. In Mach 3 port & pin setting screen for the input signal, there is noted "Pin 10-13 and pin 15 are inputs. only these 5 pin number may be used on the screen. Does this mean we only have 5 input pin available. If we have 4 axis and each axis has one home sensor and plus one pin for Estop then we do not have input pin for the tool sensor. Is it correct ?
If we need to use another port (normally PC only have 1 parallel port), how it can integrate with Mach3 ?
Peter   
Title: Re: Automatic touching
Post by: Hood on December 11, 2009, 02:45:31 PM
Mach can utilise a second parallel port, so if you get a PCI parallel port you install it, look at the address it is installed to then enter that into the box for the second port on the Ports and Pins main page. You can  also choose to have pins 2-9 set as inputs on the second port thus giving you adiitional inputs above the normal inputs.

Hood
Title: Re: Automatic touching
Post by: Hood on December 11, 2009, 02:49:54 PM
Also please note you can have home and limit switches on each axis and if they are normally closed switches you can series wire them and then just use up one Input pin.
Hood
Title: Re: Automatic touching
Post by: spl888 on December 11, 2009, 03:20:09 PM
Yes, the limit switch is shared the same pin with the home switch. But for the tool sensor, do we have to use a new pin, for which there is no additional pin in Mach3 if we have 4 axes plus a pin for Estop. Is it correct ?
Peter
Title: Re: Automatic touching
Post by: Hood on December 11, 2009, 03:22:27 PM
You can have ALL limits and home switches sharing a single input thuis you would have plenty spare.

Hood
Title: Re: Automatic touching
Post by: spl888 on December 11, 2009, 04:45:27 PM
Thanks
How can we share the single pin for all 4 axes switches ? Can we share the same pin (pin 15) for the tool sensor and the Estop ? If yes, it will solve the problem.
Thanks again for your help.
Peter
Title: Re: Automatic touching
Post by: Hood on December 11, 2009, 04:53:43 PM
You can connect ALL of your home and limit switches in series and then you will only need to connect to one pin. You set all these limits and home switches up as the same pin in Machs Ports and Pins.

You could set the tool sensor up to the same pin as the E-Stop but that would just be trouble as when the sensor was hit Mach would instantly stop the pulses and the axis would likely travel further than Mach thinks it has. You should never use the Stop  button when an axis is in motion or you will loose position and need to re-reference.External  E-Stop and the Stop  button in Mach are meant for Emergency only.

Hood
Title: Re: Automatic touching
Post by: spl888 on December 11, 2009, 05:57:10 PM
So I can use any pin other than Estop pin to share the tool sensor inputs, just connect in series and set the same pin # in Machs ports and Pin.
Thanks very much
Title: Re: Automatic touching
Post by: Hood on December 11, 2009, 06:13:33 PM
If you use another pin that is already being used then it will be seen as that function as well as the sensor and vice versa. This may or may not be a problem, that will depend on what function you share the pin with and what you do with the input.
 As mentioned previously, if you are needing extra Inputs either get a second port or share All of your home and limit switches and then you will have spare inputs.
Sharing limit and home switches will not affect anything else as Mach does not care which switch is hit when it is seeing them as limits and when it is homing it is only moving one axis at a time so again it doesnt matter that they are all shared.

Hood