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Author Topic: Why does Mach 3 need a tool length?  (Read 13513 times)

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Why does Mach 3 need a tool length?
« on: June 13, 2014, 12:21:01 PM »
Ok I run all sorts of mills at work and we never have to enter the tool length of any cutters . We work off offsets and manually pick up all of our cutters and use the tool changer everyday.
The only time I ever need to get a length is for calibrating my laser on my fidia but the rest of the machines we NEVER need length.


The only reason I ask is I want to pick up my cutters like I do at work and do manual tool changes in my IH cnc ???


Besides I don't have an extra holder for a dedicated indicator nor do I have a height gauge ???
Re: Why does Mach 3 need a tool length?
« Reply #1 on: June 14, 2014, 12:12:01 AM »
Learn,
I am trying to understand what you mean.  Are you using work offsets like G54 for each tool?

The purpose of tool length is to let use a number of tools at every work offset location.  So if you had 5 tools and four vises all holding the same part you'd set 5 tool lengths and four work offests so you could machine at each location using all five tools.

Please explain further.

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Re: Why does Mach 3 need a tool length?
« Reply #2 on: June 14, 2014, 04:53:04 AM »
Ok at work we use the tool changer  religiously and not once have I ever set a length for the cutters.
hass
hurco
YCM
Vison wide
eumach

all of these machines we set the cutter off the work price and run with it . All in the same off set .

we use g90g43h# in all of our paths along with the m6t# .


so basicly we never set lengths of cutters we just scratch them ( pick them up off of a 1,2,3 block) load the program and run it.  

now at home I won't be able to just kick off the program and sit back down and program the next job I will have to tend to the tool changes and do it manual :( lol . I hope this makes sense.

I do understand  lenths as well as the fidia I have a laser and it picks the length off all the cutters sorta like I would have to do in mach 3 then touch off on a work price with a tool that has been lasersd and enter my z offset in .

I just curious why I have to go with the last route with the lengths . The machine should know its position as it has been homed out correct?. I just ordered a couple more holders so I would have cutters and drills
made up I only have 5-6 tools that I use .

thanks in advance

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Re: Why does Mach 3 need a tool length?
« Reply #3 on: June 14, 2014, 04:55:53 AM »
Oh and another thing with the larger machines listed above besides the fidia we do not have to enter what kind of cutter it is. The fidia it has to know diameter and radius as it is a 3+2 machine and everything is to the center of ball for the rtcp.

Offline ger21

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Re: Why does Mach 3 need a tool length?
« Reply #4 on: June 14, 2014, 06:32:05 AM »
Quote
we use g90g43h# in all of our paths along with the m6t# .

G43 is tool length offset, and uses the tool length to offset the tool.

Quote
I do understand  lengths as well as the fidia I have a laser and it picks the length off all the cutters sorta like I would have to do in mach 3

So the laser is measuring the tool length.

I'm pretty sure you're using the length at work, and you just don't realize it. Unless you touch off every tool before you use it, the lengths have to be stored. If you use an ATC without the control knowing the tool lentgh, then you're using an ATC like a manual tool change.

In Mach3, if you zero the tool each time you change it, then Mach3 doesn't need to know the length, UNLESS you use a G43 length offset.
Mach3 also doesn't need to know the diameter, unless you're using G41/G42 comp.

And Mach3 has no idea, and doesn't care what kind of tool it is.
Gerry

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Re: Why does Mach 3 need a tool length?
« Reply #5 on: June 14, 2014, 08:53:21 AM »
Learn,
You are setting tool lengths when you touch off cutters to the top of a part, because in those machines it is done automatically.  Those machines all have a tool table in the control that you can access and see the length offset for each tool.

I worked at a place that did it that way for years.  Once I taught the operators that tools could be touched off anywhere, and any ONE tool could then pick up the top of the part we stopped setting tools to the top of the part. Using a common place, that is not the part, to set tools means that tools can be set at any time, even after the usual reference point on a part has been machined away. This means if a tool wears out you can replace it in the middle of machining a part if needed.

Using a reference tool, typically an edge finder or touch probe kept in a tool holder saves even more time.  I had to laugh that the machinists were installing and removing their personal edge finder at the beginning and end of every shift!  The company purchased an inexpensive edge finder and one more tool holder and it paid for itself by the end of the week!

My home machine uses Tormach holders that are repeatable.  I bought one extra holder for the edge find and never take it out of the holder, its my reference tool. I don't have accurate home switches, so I have to reset my tools only after a reset of Mach3, which typically means once I have set them I work all day without ever setting them again.

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Re: Why does Mach 3 need a tool length?
« Reply #6 on: June 14, 2014, 09:32:38 AM »
we use the 123 block on the table with a known offset  that we key in the offset location

I know the machines have a tool table but it is done automatically .



so basically I need a tools that never changes as a ref tool. and a height gauge << both items I do not have.

I guess I will improvise

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Re: Why does Mach 3 need a tool length?
« Reply #7 on: June 14, 2014, 09:33:31 AM »
Quote
we use g90g43h# in all of our paths along with the m6t# .

G43 is tool length offset, and uses the tool length to offset the tool.

Quote
I do understand  lengths as well as the fidia I have a laser and it picks the length off all the cutters sorta like I would have to do in mach 3

So the laser is measuring the tool length.

I'm pretty sure you're using the length at work, and you just don't realize it. Unless you touch off every tool before you use it, the lengths have to be stored. If you use an ATC without the control knowing the tool lentgh, then you're using an ATC like a manual tool change.

In Mach3, if you zero the tool each time you change it, then Mach3 doesn't need to know the length, UNLESS you use a G43 length offset.
Mach3 also doesn't need to know the diameter, unless you're using G41/G42 comp.

And Mach3 has no idea, and doesn't care what kind of tool it is.

ok cool I will try that out

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Re: Why does Mach 3 need a tool length?
« Reply #8 on: June 14, 2014, 09:43:31 AM »
Ger21 so basically if I home it out when I set each cutter then save the length in the table I won't need to use the g43 correct ?

Offline ger21

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Re: Why does Mach 3 need a tool length?
« Reply #9 on: June 14, 2014, 10:26:55 AM »
I don't know what you mean by "home it out". You only need the length in the table to use G43. If you don't use G43, then you don't need the length.

I don't use G43, but I use an auto zero macro with two plates that automatically measures the tools after a tool change.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html