cutting in 4th axis

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RPMMachine
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cutting in 4th axis

Post by RPMMachine »

If I rough a spur in the 4th axis from the top, works perfect, when it goes to do the tooth shave it acts like it is using the saw.
In Gearotic 2.0 the tool paths all look perfect, When loaded into the Tormach mill, the tool paths looks like some really wierd stuff.

I must be missing a step or doing something wrong. Any insight would be greatly apreciated thank you.

The spur I need to make is for a bull dozer final drive it is over 3-1/2" wide. 13 tooth 3.812 dia, 4DP and pressure angle of 14.

Thank you
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ArtF
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Re: cutting in 4th axis

Post by ArtF »

Hi:

  Can you post a photo of the toolpath displayed? I know the 4th axis is a bit confusing in GT, and its being
rewritten for the fall. I intend to write a simulator for it so we can verify on any job what the end result should
look like.

  The routine though is mostly the same, though in GM the equation for an involute was used in the calculations,
while in G2 the actual tooth shape is used from its graphic in order to derive the positioning, the logic being this
allows for not only involutes but other shapes. So the shaving shoudl simply be the Y axis ( in conventional placement)
moving forward and back in concert with a rotation to place the side of a bit so it just touches the tooth involved. 

  If you tun off rooting, just turn on shaving the toolpath usually looks pretty clear on the tooth flanks so one can see
what its cutting. The display is quite different as it shows the potion of the tool taking into account the rotation, while
in GM, the toolpath was never actually shown, making it difficult to imagine what it was doing.. But the paths should
look very similar ... unless the tooth shape is screwy for some reason..

Post the project and Ill have a look and post what I think is the best shot showing the shaving path.. Ill endeavor to
make this much better and easier to imagine in the rewrite of the 4th axis. Im separating the 4th and 3 axis modules
in order to separate the controls and setting and to lower confusion. 4th axis is a hard thing to display or code as its
complexity in setup and control is high, so Im trying to dumb it down to human levels. :)

Thanks,
Art
RPMMachine
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Re: cutting in 4th axis

Post by RPMMachine »

Hi Art here is the tap file.

Joe
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RPMMachine
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Re: cutting in 4th axis

Post by RPMMachine »

Here is the tool path that is shown on the Tormach.
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GEAR 003.JPG
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ArtF
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Re: cutting in 4th axis

Post by ArtF »

Yes, lol.. something definitely wrong there. Im thinking depth per pass or some setting is negative when it should be positive or something.
Can you pose the project file.. the gth file so I can test that file. Let me know the tool size and such..

Art
RPMMachine
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Re: cutting in 4th axis

Post by RPMMachine »

Hi Art,

I think this is the file you want. It is a .250 end mill. 13 tooth spur, 3.812 dia. 4DP and 14 pressure angle.

I use wood to do the test cuts when trying new programs and such, so it is all kinda fun to try.

If everything worked perfect I would not be learning anything, so it is fun in a way.

Living in farm country there always has been a need to cut gears and sprockets though, so there will be no
lack of work for Gearotic 2.0 and the Tormach, thats why I have 2 of them.

The program does work great for gears for my other projects that I do. Like gears for my "Wood" Metal lathe that I make.

Joe

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lathe.png

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ArtF
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Re: cutting in 4th axis

Post by ArtF »

Awesome. :)

  Love the lathe.

Ill analyse and get back to you.

Art
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Re: cutting in 4th axis

Post by ArtF »

Joe:

  Not sure what setting you have out of tolerance, but heres a snapshot of my screen on the same gear. I include the numbers
section so you can compare to what you have set. Your toolpath should look more liek this one.. Let me know what was off
if you can, Ill make sure I limit it in the new module this fall...

Art
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joesgear.png
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