Helix machining for circular holes

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herbk
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Re: Helix machining for circular holes

Postby herbk » Thu Jan 05, 2017 8:04 am

cox wrote:
lorenz wrote:please, do not call it drilling, that is a completely different operation.
+1
+1 to

In "real live" drilling is a total differnt operation as every kind of milling!


Hi sliptonic,
Is there ever an advantage of one over the other?
yes, this way gives more space for the chips and it's more easy to remove it by air/vakuum.
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quick61
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Re: Helix machining for circular holes

Postby quick61 » Thu Jan 05, 2017 9:28 am

sliptonic wrote:I did get this working and it produces very nice paths! I sent you a pm about specific implementation issues.

When clearing a circular hole, it does a helical descent, then rapids out, moves over the step width and repeats with progressively larger helices.

I'm curious if users would also like to see the alternative strategy where it spirals down a step, then spirals out to the full width, rapids back and repeats.

Is there ever an advantage of one over the other?
Wouldn't an even better alternative strategy be to have the tool spiral down to depth first, then work it's way out, using all of the tools available side to do the cutting. If I'm not mistaken, that is how the big boys do it, but maybe that's getting into the realm of adaptive clearing? The only thing I know of out there that comes close would be libactp, but I would think that's a long way off yet, if ever.

BTW, thank's for those last 2 vids. Helped me. :)

Mark
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herbk
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Re: Helix machining for circular holes

Postby herbk » Thu Jan 05, 2017 9:52 am

quick61 wrote:Wouldn't an even better alternative strategy be to have the tool spiral down to depth first,
Hi Mark,
depends on the material you are working with and how deep it goes down.
You got, may be, probs with removing the trash and getting coolant to the tool is more diffikult.
Gruß Herbert
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sliptonic
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Re: Helix machining for circular holes

Postby sliptonic » Thu Jan 05, 2017 1:34 pm

wmayer has merged the PR but I think this needs some additional work.

My biggest concern is that it adds a dependency to scipy which is pretty heavy. If it's not present, the operation will throw an error and not work at all. If the same functionality can't be done with occ, we should be looking for scipy and disabling the command if it's not available..
cox
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Re: Helix machining for circular holes

Postby cox » Thu Jan 05, 2017 3:46 pm

sliptonic wrote:I did get this working and it produces very nice paths! I sent you a pm about specific implementation issues.

When clearing a circular hole, it does a helical descent, then rapids out, moves over the step width and repeats with progressively larger helices.

I'm curious if users would also like to see the alternative strategy where it spirals down a step, then spirals out to the full width, rapids back and repeats.

Is there ever an advantage of one over the other?
My guess:
End-mills generally is not made to plunge and might wear out quicker with the helical decent, so I would guess that for certain tool material combinations, the alternative strategy could be preferable.

So speed vs tool-preservation I guess.
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lorenz
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Re: Helix machining for circular holes

Postby lorenz » Thu Jan 05, 2017 10:10 pm

sliptonic wrote: wmayer has merged the PR but I think this needs some additional work.

My biggest concern is that it adds a dependency to scipy which is pretty heavy. If it's not present, the operation will throw an error and not work at all. If the same functionality can't be done with occ, we should be looking for scipy and disabling the command if it's not available..
I agree, if scipy is not already a requirement for FreeCAD it is a bit much to introduce it just for this command. I will try to rewrite it without the k-d tree module.
sliptonic wrote: I'm curious if users would also like to see the alternative strategy where it spirals down a step, then spirals out to the full width, rapids back and repeats.
This is a very nice idea, I will definitely implement this as an option!

sliptonic also gave me some feedback in a PM, I will try to incorporate all your feedback and present you with a refined version.

Thanks for the feedback and enthusiasm so far,
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sgrogan
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Re: Helix machining for circular holes

Postby sgrogan » Thu Jan 05, 2017 10:50 pm

lorenz wrote:I agree, if scipy is not already a requirement for FreeCAD it is a bit much to introduce it just for this command. I will try to rewrite it without the k-d tree module.
Hello lorenz,
Thank-you for this! On Win scipy is a real show stopper. With no opensource or even free Fortran compiler we have no good way to support this requirement. We do support numpy if this helps.
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Re: Helix machining for circular holes

Postby sliptonic » Thu Jan 05, 2017 10:53 pm

sgrogan wrote: On Win scipy is a real show stopper. With no opensource or even free Fortran compiler we have no good way to support this requirement. We do support numpy if this helps.
I didn't realize that. Since it won't work on win, even with user taking on admin burden, should we revert the commit until it's fixed?
lorenz
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Re: Helix machining for circular holes

Postby lorenz » Thu Jan 05, 2017 10:57 pm

sgrogan wrote:Hello lorenz,
Thank-you for this! On Win scipy is a real show stopper. With no opensource or even free Fortran compiler we have no good way to support this requirement. We do support numpy if this helps.
If numpy is OK as a dependency (it seems, numerous FreeCAD scripts require it) I could probably just copy over the kdtree.py module from scipy. At first glance, it seems to be a pure python implementation with only very little dependency on other scipy functionality. As scipy is available under a BSD license it should be possible to distribute a modified kdtree.py within FreeCAD.

Would that be OK, also for the main developers?
Last edited by lorenz on Thu Jan 05, 2017 11:32 pm, edited 1 time in total.
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sgrogan
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Re: Helix machining for circular holes

Postby sgrogan » Thu Jan 05, 2017 11:06 pm

lorenz wrote:If numpy is OK as a dependency (it seems, numerous FreeCAD scripts require it) I could probably just copy over the kdtree.py module from scipy. At first glance, it seems to be a pure python implementation with only very little dependency on other scipy functionality. As scipy is available under a BSD license it should be possible to distribute a modified kdtee.py within FreeCAD.
On the Ubuntu PPA, OSX, and Win builds we already support numpy by default (it's used in FEM, as well as the drawing_dimensioning and assembly2 add-on WB's)
Hopefully after the Python3 port this will be improved, the FEM guys feel restricted as well.
lorenz wrote:Would that be OK, also for the main developers?
This is as you said up to the main dev's.
Thanks for the attention to the problem again, from the Win users, Thank-You :)