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Author Topic: Just a Little bit bigger :)  (Read 3013 times)

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Offline dq828

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Just a Little bit bigger :)
« on: December 01, 2017, 02:59:40 AM »
I am still getting use to how this all works but I often seem to be faced with a situation where I make a cut, like a rebate or a hole in a bit of wood, and after the cut is made Id like the rebate /hole to be just a little bit bigger like 0.001"or similar. What I do now is go back upstairs, change the drawing in Fusion, repost it, then back downstairs etc only to find it should have been a just a little bit bigger :)

The tools and tool ofsets are handled by Fusion as far as I can tell. What I was wondering is, is there a way in Mach4 to apply an extra bit of offset and then rerun the cut without wearing myself out going up and down stairs?

David
Re: Just a Little bit bigger :)
« Reply #1 on: December 01, 2017, 06:37:05 AM »
If you have the tool table setup in Mach and are using the tool offsets G41/G42 you can go in and tell Mach that the tool is a little smaller than it actually is and it will cut bigger.
We never have the time or money to do it right the first time, but we somehow manage to do it twice and then spend the money to get it right.

Offline ger21

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Re: Just a Little bit bigger :)
« Reply #2 on: December 01, 2017, 09:06:47 AM »
Why are you concerned about .001"  when cutting wood?

You'r most likely chasing flex in your machine, and a variety of issues can cause size issues greater than .001"
Gerry

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Offline dq828

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Re: Just a Little bit bigger :)
« Reply #3 on: December 01, 2017, 09:37:58 PM »
I'm a mm guy and I put the point in the wrong place should have been 0.01" :) The answer is so things fit in the holes and rebates properly.

Offline dq828

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Re: Just a Little bit bigger :)
« Reply #4 on: December 01, 2017, 09:42:22 PM »
If you have the tool table setup in Mach and are using the tool offsets G41/G42 you can go in and tell Mach that the tool is a little smaller than it actually is and it will cut bigger.

Unfortunately or fortunately as the case may be, the tools stuff is handled by Fusion and as far as I can tell the offsets are in the cde when I post it. I dont think there is a way to do what I want.

Offline Stuart

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Re: Just a Little bit bigger :)
« Reply #5 on: December 02, 2017, 08:32:01 AM »
Then just lie to fusion360
When you set up your tools in f360 say you have 10mm em set the table to the offset you need eg 10.1 or 9.9 regent the cam size changed

Or set the tool comp in f360 to controller and set up the tool wear in mach4
Re: Just a Little bit bigger :)
« Reply #6 on: December 02, 2017, 01:02:44 PM »
Tool diameter offsets are really useful when hand coding as you can write code for actual part size then use radius compensation for whatever tool you want to use. However when using Cam you almost always do the compensation in cam  as part of creating an operation because it is also use for stepover. Tool compensation is really only needed on finish passes so if you make those separate operations in cam then it is fairly easy to add g41/42/g40 to the code for the finish path. It can then be tweaked at run time.

Offline dq828

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Re: Just a Little bit bigger :)
« Reply #7 on: December 03, 2017, 05:31:16 AM »
Tool diameter offsets are really useful when hand coding as you can write code for actual part size then use radius compensation for whatever tool you want to use. However when using Cam you almost always do the compensation in cam  as part of creating an operation because it is also use for stepover. Tool compensation is really only needed on finish passes so if you make those separate operations in cam then it is fairly easy to add g41/42/g40 to the code for the finish path. It can then be tweaked at run time.

Thanks, I'll have to do some study on tweaking, I get nervous every time I touch the code :)

Thanks again

Offline RDR

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Re: Just a Little bit bigger :)
« Reply #8 on: December 03, 2017, 08:07:11 AM »
http://help.autodesk.com/view/fusion360/ENU/?guid=GUID89C78618-20FD-4A82-BFB4-BC66AFE417DD  Here's a link for cutting com in fusion the one I think I would use is the wear that lets you program the size tool you are using and then you can change it if it's not right.  I also think there is a NYC cnc YouTube video on this topic

Offline dq828

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Re: Just a Little bit bigger :)
« Reply #9 on: December 04, 2017, 03:50:32 AM »
http://help.autodesk.com/view/fusion360/ENU/?guid=GUID89C78618-20FD-4A82-BFB4-BC66AFE417DD  Here's a link for cutting com in fusion the one I think I would use is the wear that lets you program the size tool you are using and then you can change it if it's not right.  I also think there is a NYC cnc YouTube video on this topic

I think you are on to something there, by the looks of it if I chose WEAR I might be able to have my cake and eat it too. I'll have to do some testing.

Thanks