Missing work direction and cutter placement on pocket

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herbk
Posts: 354
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Location: Windsbach, Bavarya (Germany)

Missing work direction and cutter placement on pocket

Postby herbk » Mon Mar 06, 2017 5:42 pm

Hi,
i'm missing the possibility to select the work direction (cw / ccw) and the cutter placement (left, right, on) on the pocket operation.

If i remember right, it was includet sometimes before, why did you remove it?
Gruß Herbert
sliptonic
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Joined: Tue Oct 25, 2011 10:46 pm

Re: Missing work direction and cutter placement on pocket

Postby sliptonic » Mon Mar 06, 2017 5:53 pm

That option was never included with pocket. Only with profile. Since pocketing is clearing a region, I don't really know how to interpret those options.

I suppose a CW/CCW would imply a general direction of travel to clear but what would happen if you encountered an island inside a pocket that you're clearing CW? You would then be traveling CCW around the island. :?
herbk
Posts: 354
Joined: Mon Nov 03, 2014 3:45 pm
Location: Windsbach, Bavarya (Germany)

Re: Missing work direction and cutter placement on pocket

Postby herbk » Mon Mar 06, 2017 6:21 pm

Hi sliptonic,
if you cut a pocket only the first round is allways a "full diameter cut". If you use a step over less 100% then you have a "cutting side" on each other round.

Maybe it's not important to have a direction and a cuttung side left or right for pocket operations, but the setting "on" for the cutting side is needed for creating a path without tool compensation.
Gruß Herbert
sliptonic
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Joined: Tue Oct 25, 2011 10:46 pm

Re: Missing work direction and cutter placement on pocket

Postby sliptonic » Mon Mar 06, 2017 8:38 pm

herbk wrote:Hi sliptonic,
if you cut a pocket only the first round is allways a "full diameter cut". If you use a step over less 100% then you have a "cutting side" on each other round.

Maybe it's not important to have a direction and a cuttung side left or right for pocket operations, but the setting "on" for the cutting side is needed for creating a path without tool compensation.


Cutting side and direction only make sense if your path is built from the base object edges ie Profile. In the case of pocket, those edges only determine the bounds of the space, not the actual path. I can see the need for a setting to 'use compensation' where turning it off be the same as using a tool with a 0 diameter.

FWIW, you can achieve the same thing now by setting the material compensation setting equal to negative 1/2 the tool diameter. You can't do this in the task panel because the control doesn't allow negative numbers (this is a bug) but you can do it in the property pane.
sliptonic
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Joined: Tue Oct 25, 2011 10:46 pm

Re: Missing work direction and cutter placement on pocket

Postby sliptonic » Mon Mar 06, 2017 9:30 pm

Actually, the 'use compensation' setting can't work. The entire point of the pocketing op is to fill the space with movements to clear the material. We MUST know what the tool diameter is in order to do that. The StepOver %, the tool diameter, and the material allowance are all used to calculate the position of the cutter as the boundary is offset in or out.

'Use compensation' would only have an effect on the final pass against the boundary wire. If you want control of that, you should do a regular pocket and leave some material with the 'material allowance' Then do a profile to remove the final material. The profile, of course, can use compensation or not as you see fit.
chrisb
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Re: Missing work direction and cutter placement on pocket

Postby chrisb » Mon Mar 06, 2017 11:53 pm

From the view of a cutting machine operator it is sensible to decide on which side to mill because the quality of the cut is different. And most mills, drills, etc. are turning right.
mlampert
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Re: Missing work direction and cutter placement on pocket

Postby mlampert » Tue Mar 07, 2017 12:13 am

chrisb wrote:From the view of a cutting machine operator it is sensible to decide on which side to mill because the quality of the cut is different. And most mills, drills, etc. are turning right.

If I got my terminology right you are talking about "climbing" and "conventional" milling - for which only the outer most pass on a pocket matters.

Personally, if I care about the surface of a pocket, I would always mill the pocket smaller and then do a final Profile pass on it to remove the rest of the material. But I can see that someone would want to control the direction during the initial pocketing as well.
chrisb
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Re: Missing work direction and cutter placement on pocket

Postby chrisb » Tue Mar 07, 2017 12:23 am

mlampert wrote:
chrisb wrote:From the view of a cutting machine operator it is sensible to decide on which side to mill because the quality of the cut is different. And most mills, drills, etc. are turning right.

If I got my terminology right you are talking about "climbing" and "conventional" milling - for which only the outer most pass on a pocket matters.

Personally, if I care about the surface of a pocket, I would always mill the pocket smaller and then do a final Profile pass on it to remove the rest of the material. But I can see that someone would want to control the direction during the initial pocketing as well.
I had to look it up, but yes, we are talking about climbing vs. conventional milling. (To look it up with these terms was easy, the other way - impossible). And yes, that is exactly how I would mill a good surface, but I am not a professional who considers maximizing output while minimizing time. I want maximum quality, that's all.
GeneFC
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Location: Punta Gorda, FL

Re: Missing work direction and cutter placement on pocket

Postby GeneFC » Tue Mar 07, 2017 1:15 am

mlampert wrote:If I got my terminology right you are talking about "climbing" and "conventional" milling - for which only the outer most pass on a pocket matters.


Actually, climb milling is usually preferred for any operation if the cut width is less than the mill diameter. This is not only for the surface finish but because it is easier on the tool. Climb milling allows for each tooth to take a full chip at the start of the cut, while conventional milling causes each tooth to rub for a while until it eventually bites into the material. Dulls the cutter quicker.

I always use the pocketing function with about 50% tool engagement and climb milling. I am not sure why choosing CW or CCW would offer any additional capability over climb and conventional. I have not tried islands in pockets, so perhaps there is a difference in that case.

Gene
mlampert
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Re: Missing work direction and cutter placement on pocket

Postby mlampert » Tue Mar 07, 2017 2:17 am

chrisb wrote:I had to look it up, but yes, we are talking about climbing vs. conventional milling. (To look it up with these terms was easy, the other way - impossible)

I hear ya ;) - sliptonic educated me a while back when we were talking about general features and common preferences of Path operations - see old dogs can learn new tricks :)