Vertical Feed rates in partially-vertical cuts

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cahlfors
Posts: 66
Joined: Tue Jan 24, 2012 8:27 pm
Location: Sweden

Re: Vertical Feed rates in partially-vertical cuts

Postby cahlfors » Tue Nov 28, 2017 9:16 pm

roivai wrote:
Tue Nov 28, 2017 5:47 pm
For example, if there are Tags added with another dressup, the ramps on the tags will get the same ramp feedrate as well. I suppose that is not too much of a problem?
I was thinking about this, too, and I think it might actually be an issue. Typical ramps and helixes are in the order of 5-10 deg steep (full horizontal speed milling as you have suggested), whereas a tag is typically 45 or more and must be done much more carefully. Better yet would be to use ramping on the tags as well. That way, they could be 90 deg steep. The reason to go lower, in my thinking, is that mill tools don't plunge well. However, 10 deg steep tags would come out much too wide. Maybe we have a chance to end up with a much better tag dressup here?

/Chris
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herbk
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Location: Windsbach, Bavarya (Germany)

Re: Vertical Feed rates in partially-vertical cuts

Postby herbk » Tue Nov 28, 2017 9:33 pm

Hi cahlfors,
i dont see that as a problem...: the ramp speed can be adjusted by the user and if the pre-selection is set o the "save side" it will be save.
Gruß Herbert
roivai
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Location: Oulu, Finland

Re: Vertical Feed rates in partially-vertical cuts

Postby roivai » Wed Nov 29, 2017 7:40 am

cahlfors wrote:
Tue Nov 28, 2017 9:16 pm


I was thinking about this, too, and I think it might actually be an issue. Typical ramps and helixes are in the order of 5-10 deg steep (full horizontal speed milling as you have suggested), whereas a tag is typically 45 or more and must be done much more carefully. Better yet would be to use ramping on the tags as well. That way, they could be 90 deg steep. The reason to go lower, in my thinking, is that mill tools don't plunge well. However, 10 deg steep tags would come out much too wide. Maybe we have a chance to end up with a much better tag dressup here?

/Chris
This might be a valid concern. The tags feed rate seem to be exactly the same as the ramps used to be - vertical feed rate always. So now they can get machined much faster. And user will not know until checking the G-Code output or running the the code.. :/

I came up with a solution where I can keep track of the path segments which were modified during ramp insertion and apply the ramp feed rate only to those segments. I try that tonight and report how it goes.
chrisb
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Re: Vertical Feed rates in partially-vertical cuts

Postby chrisb » Wed Nov 29, 2017 9:16 am

I think ramping the tags is the wrong approach. it is more the same problem as with pockets touching the outside of the object where an overlap is desired. The tags come from the outside as well. So a possible movement if gcoded by hand is to go up, go over the tag and outside the object, move down - still outside, and move in again.
herbk
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Location: Windsbach, Bavarya (Germany)

Re: Vertical Feed rates in partially-vertical cuts

Postby herbk » Wed Nov 29, 2017 2:36 pm

Hi Chris,
chrisb wrote:
Wed Nov 29, 2017 9:16 am
I think ramping the tags is the wrong approach. it is more the same problem as with pockets touching the outside of the object where an overlap is desired. The tags come from the outside as well. So a possible movement if gcoded by hand is to go up, go over the tag and outside the object, move down - still outside, and move in again.
here i don't understand what you are in mind?
If i want a holding tag, the tool goes up don't mill the area where the tag shoult be, after that it goes down in the material which have to be removed...
Gruß Herbert
chrisb
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Re: Vertical Feed rates in partially-vertical cuts

Postby chrisb » Wed Nov 29, 2017 5:01 pm

My common usecase with holding tags is shown in the attached image, the red line shows the mill path (sorry for not having a green pencil but children are too big now to use them).
- At point 1 I go up
- I move to point 2, which is outside the object
- I move down at point 2
- I enter the material from the side

This is much more friendly to the mill than going vertically down and I can go faster as well. The path from 1 to 2 can of course be composed of straight lines as well.
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herbk
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Location: Windsbach, Bavarya (Germany)

Re: Vertical Feed rates in partially-vertical cuts

Postby herbk » Wed Nov 29, 2017 6:08 pm

Hi Chris,
there seams to be the same name for two different things (again...). :)

On working with routers its mostly a big peace of material on the machine table und you mill out more then one part ar once. I know you know. ;)
To keep that parts on its place till the whole work is finished we don't cut the whole slot to 0 On a few places we keep a litte contact to the base material which we call "haltestege" , which i translated with "holding tags" or short "tags"...

But in the manner the tag dressup works, i'm in mind the dressup means this holding tags i'm talking about and not just a jump over a barrier. In particular for the reason, that the shape of the tags is changable, it could be a triangle or runded, - there is no need for, if you just want to make a jump.
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Gruß Herbert
roivai
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Location: Oulu, Finland

Re: Vertical Feed rates in partially-vertical cuts

Postby roivai » Wed Nov 29, 2017 7:56 pm

I think I found a way to apply the ramp feedrate to the ramp/helix edges only. For now it is at
at my own branch, but I create a pull request if nothing new comes up..

Regarding the tags.. Like I wrote earlier, the rampentry dressup will turn every straight vertical plunge into a ramp.. So if the tags are configured to have 90deg angle on them, the downward movements will turn into ramps. I don't have any solution for that, except for making the tag angle something else than 90. I just tried and if I set it to 89deg, the rampentry ignored them, but the tags will be almost vertical in practice..
chrisb wrote:
Wed Nov 29, 2017 5:01 pm
My common usecase with holding tags is shown in the attached image, the red line shows the mill path (sorry for not having a green pencil but children are too big now to use them).
- At point 1 I go up
- I move to point 2, which is outside the object
- I move down at point 2
- I enter the material from the side

This is much more friendly to the mill than going vertically down and I can go faster as well. The path from 1 to 2 can of course be composed of straight lines as well.
Hmm, this is interesting! Is it possible to generate such tags with the DressupHoldingTags?
chrisb
Posts: 25681
Joined: Tue Mar 17, 2015 9:14 am

Re: Vertical Feed rates in partially-vertical cuts

Postby chrisb » Wed Nov 29, 2017 8:21 pm

herbk wrote:
Wed Nov 29, 2017 6:08 pm
Hi Chris,
there seams to be the same name for two different things (again...). :)
I see, it might have been a misunderstanding due to my limited English.
cahlfors
Posts: 66
Joined: Tue Jan 24, 2012 8:27 pm
Location: Sweden

Re: Vertical Feed rates in partially-vertical cuts

Postby cahlfors » Thu Nov 30, 2017 8:20 pm

roivai wrote:
Wed Nov 29, 2017 7:56 pm
So if the tags are configured to have 90deg angle on them, the downward movements will turn into ramps.
Perfect in my thinking - no more need to angle the tags! That will keep them as narrow and strong as possible. :D

/Chris
FreeCAD-daily/Ubuntu or Mint
Mendel 3d-printer/pronterface
HeeksCAM
LinuxCNC
Optimum BF20L mill