Tangetntial Shaving - Top to Bottom

[Dan]

Hi Art,

When using tangential shaving the tool first dives to full tooth depth and then moves up by the "z down-step amount" with each pass. Can you allow the user to select if it would start from top and go to bottom or the other way? Just like rooting works - starts from the top and goes down with each pass.

Thanks,
Dan

[ArtF]

Dan:

  Hmm, hadnt thought of it.. but I see no reason why it couldnt be done that way. Please bring it up again in the
fall. Im deep in controller code at the moment, but Ill consider adding that as an option in the fall.

Art

[Dan]

Thanks Art. I will remind you in a month or so.

Dan

[Dan]

Hi Art,

Just to remind you this ;)

Dan

[ArtF]

Hi Dan:

  kk, Looking into the possibility leads to a question..

Now in tangental, the cutter doesnt really move from bottom upwards, its just that the
Y axis has moved the tool away from center, so the distance to the rooth is larger, the tool
actually doesnt move. ( well, in "maintain depth" anyway, if not there is slight motion ).

    Now , when at zero degrees, the tool should take the least material if rooting has been run,
and each segment will take a slight cut depending on # of segments. Im worried if that is reversed,
(starting at max Y outwards and moving back to 0), the tool load will be on the lowest portion of the bit
on each pass. On each pass, particularly on thinner bits, youd be cutting on both sides of the cutter
in some cases. It doesnt seem feasable.. ). Can I ask what the purpose is of reversing the shave? 
Perhaps theres a better way to solve an issue?

Art

[Dan]

Hi Art,

I do not understand what you're trying to say. Why is it a problem?

The reason I want it the opposite way twofold:

First, I always like to cut with my end-mills using 10-20% of their their length from the bottom. This way only the bottom of the tool gets dull and it can then be resharpened without affecting the tool diameter. Of course, it's only true for larger end mills that can be practically resharpened.

Second, they way it is now is not safe for the tool bit as it exerts large forces on the tool having contact along a large area and causes its breakage. If the tool started from the top of the tooth, I could adjust the down step to be very fine and thus reduce the load on the tool, which I cannot do with the current way it's done.

Hmm.. Does it make sense...?

Dan

[ArtF]

Makes sense. Im not saying it cant be done, just saw it was a rather large job due to the complexity of
the algorithm so I wanted to ensure it was worthwhile to dig deeper.. ( I tend to torture myself with recursive algorithms..). Ill see what I can do..

Art

[Dan]

Thanks :)

Dan

[Dan]

By the way, Art, another reason in favour of reversing the way it currently does the shaving, is that the current method won't work with slitting saws, while if started from the top of the tooth moving ti the root, it could also be used with a slitting saw.

Dan

[ArtF]

Dan:

I think it works with saws now, Ive see a few examples of cut gear using slit saws.. but I think
it may be better from top to bottom... Ill let you know soon, I plan on attempting it on Monday..

Art

[Dan]

Thanks.

Dan

[ArtF]

Hi Dan:

Seems to work ok, Ill try to get it out on monday..

Art