Author Topic: Leadin & Max Crossover Distance help ??  (Read 19644 times)

Offline twocik

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Leadin & Max Crossover Distance help ??
« on: February 02, 2011, 17:25:14 pm »
Sorry if this has been asked a million times, but I can't really find what I'm looking for.  I have a couple of questions on 2 features in Cambam and if someone can help explain how these work that would be great. 





- Max Crossover Distance

(Maximum distance as a % of the tooldiameter to be cut in horizontal transitions.  If distance to next toolpath exceeds this then a rapid to next position via the clearance plane is inserted.)


I can see how this would be used for a pocket, but for a profile is what I'm trying to figure out ?  If I understand this correctly this feature will add a G00 from the path that was just cut to the next to speed things up...   Could this leave stair steps marks/ridges on the sides of a part if setup in a profile mop ?





- Lead In Move

I kind understand that a leadin move is used to help with ease on entrance, but don't really know how to use this feature.  Say if I'm cutting a inner profile of a square and wanted to ramp into the square hole, how would I set this up ?  Basically cutting out time loss on the stop, plunge, then cut feedrate.


LeadInMove

LeadInFeedrate -      (if set to 0 then Cut Feedrate will be used)
LeadInType -
SpiralAngle -           (I'm guessing this is used for circle shapes only)
TangentRadius -



If you need more info. just let me know.

Thanks

Offline dh42

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Re: Leadin & Max Crossover Distance help ??
« Reply #1 on: February 02, 2011, 19:22:32 pm »
Hello,

Quote
If I understand this correctly this feature will add a G00 from the path that was just cut to the next to speed things up...

On a profil MOP, the MaxCrossOverDistance parameter is used ONLY if you have defined the CutWidth parameter bigger than the tool diameter. That mean that you have // toolpath to cut the width defined in CutWidth

In this case, it works as a pocket, if the distance between the // toolpaths is minus that MaxCrossOverDistance x ToolDiameter, the mill will cut in a horizontal movement to the next // toolpath (in G1). If the distance is bigger, the mill go to the clearance plane (in G0) then moves to the new toolpath and plunge verticaly in the stock. This second way is more longer.

Quote
Say if I'm cutting a inner profile of a square and wanted to ramp into the square hole, how would I set this up ?

pict1: a leadin used to cut the external profile of a square, with lateral movement of the mill

leadintype: the kind of leadind used, Tangent or Spiral (ramp)
LeadInFeedrate: the feedrate used when the mill is on the leadin path, if 0 it's the value defined in cutfeedrate is used, but if you want to enter gently in the stock you can define a smaller value here for the leadin

for the spiral angle and tangent radius see pict 2

tangentradius: the radius of the toolpath (XY plane) that as been added to do the leadin (only for tangent mode)

spiralangle: the toolpath can, in addition down with a spiral movement, it's the angle of the spiral with tangent mode and the angle of the ramp in spiral mode (maybe a little confusing this designation)

pict3
a leadin for intenal cut of your rectangle, you must eventually move the start point (red circle) if you want that mill down in the hole of the rectangle (that's better! ;) )

++
David


Offline twocik

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Re: Leadin & Max Crossover Distance help ??
« Reply #2 on: February 02, 2011, 22:12:15 pm »
On my default Profile mop it's set to 0.7 MaxCrossoverDistance, CutWidth 0, should this be set to 0 or it has no effect if the CutWidth is set to 0 ?     Last month I was adjusting the backlash out of my axis because I noticed stair stepping on the side of my parts, curious if this might have been the case....  





"In this case, it works as a pocket, if the distance between the // toolpaths is minus that MaxCrossOverDistance x ToolDiameter, the mill will cut in a horizontal movement to the next // toolpath (in G1). If the distance is bigger, the mill go to the clearance plane (in G0) then moves to the new toolpath and plunge verticaly in the stock. This second way is more longer."



Wouldn't it be easier to use pocket, or am I only seeing a 1/5 of what's it truly used for ?






"tangentradius: the radius of the toolpath (XY plane) that as been added to do the leadin (only for tangent mode)

spiralangle: the toolpath can, in addition down with a spiral movement, it's the angle of the spiral with tangent mode and the angle of the ramp in spiral mode (maybe a little confusing this designation)"



Yes these two are what confuse me.  I guess I was picturing more of a straight line ramping toolpath down into my stock/square.   I cut mostly 2.5D, and my Gcode is usually setup to where it positions the cutter right over top of the starting point of the toolpath.  Say it's a 1" x 1" square, it will pick the start point (or I can) and move at the plungerate Z into the stock then X & Y move.  By adding a leadin move will the starting position of the toolpath be change to fit that move ?    

If so I can see how this would help with the starting point line that some parts seem to get when cutting like this.  Please feel free to add anything else to this subject that might help me understand it a little better.

Thanks




Offline dh42

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Re: Leadin & Max Crossover Distance help ??
« Reply #3 on: February 02, 2011, 23:02:42 pm »
Hello,

In most case, profile MOP are used to cut a part in a plate of material, and use only one toolpath in width, but it can be used to do a groove of a predetermined width, for example for insert a gasket. and you don't necessary have the mill with the same diameter as the groove. MaxCrossoverDistance as no effect if they are no // toolpath, you can let in to 0.7.

I suppose that leadin and leadout have many different way of use,but basically I think that Spiral is designed for a penetration in Z movement and Tangent for penetration by the side.

With the Spirale mode, you can let all parameter to 0, and you get a spirale that begin from the top of the part to the depht of cut in a regular ramp (angle of the ramp is calculated automatically) see file: rampe_auto.cb

in the second file, I set SpiralAngle to 20 (degrees), in this case, CB use a ramp of 20°, and when the mill reaches the level defined by DephtIncrement he cut flat (without ramp) the rest of the material. see file: rampe_20deg.cb

I have little difficulty to explain that in English (it's not my language)

I make 3D video simulation of this 2 file here

http://www.youtube.com/watch?v=qUckNpsbNrM

++
David

Offline twocik

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Re: Leadin & Max Crossover Distance help ??
« Reply #4 on: February 02, 2011, 23:14:16 pm »
David this is exactly what I want to do in my part, and didn't know spiral / tangent were define by degrees.  Now it's starting to make sense !     So a spiral leadin move is very similar to a spiral drill mop (no stepping), consistent movement along the toolpath without stopping until final depth.


What I'm trying to achieve is a better finish that way I don't have to wait so long near the tumbler and faster run time... :)  I'm also playing with speeds and feeds to help as well.  




David thanks a lot of the video, really helped me out !!  Would be cool if we had a 5 - 15 sec video for every feature in CB, but Andy would probably go nuts.. :)

Offline pixelmaker

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Re: Leadin & Max Crossover Distance help ??
« Reply #5 on: February 02, 2011, 23:17:08 pm »
Hello together,

always if you cut a profil, there, where the z-axis move down and up you get a marking in the material. When you cut hard materials with more depth increments the z-axis move up and down on the same coordinate and the marking get bigger and bigger. To prevent for this you use a leading in and out. It is in first not for going more easy into the material, then you do with a tangent LeadInMove the same depth increments then without.
Tangent LeadIn and TangentLeadOut you see on screenshot 1.
A spiral leadInMove you can use at first, when you i.e. between 2 Kopies have not enough place for a tangent LeadInMove. Spiral cutting is harder for the bit then going straight on the depth increment.
I use the spiral LeadInMove also to cut a sideprofil in a spiral way. For this you have to set the spiral angle to zero.
Then you have no z moving who can leave a marking. The cut begins on top of the workpiece and cuts one spiral for every DepthIncrement. So you don´t have a z move at standing machine. Screenshot 2
For pocket you also can use the LeadInMove and LeadOutMove to prevent the marking, but it works only with the RegionFill InsideOutsideOffset. Don´t use it with horizontal- or vertical hatch.
There are a lot more what you can do with LeadIn- LeadOutMove.
Start with this.


ralf

Offline dh42

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Re: Leadin & Max Crossover Distance help ??
« Reply #6 on: February 02, 2011, 23:23:28 pm »
David thanks a lot of the video, really helped me out !!  Would be cool if we had a 5 - 15 sec video for every feature in CB, but Andy would probably go nuts.. :)

It's what I'm doing for the French doc, maybe Andy can use the same links for English doc when finished.

++
David

Offline twocik

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Re: Leadin & Max Crossover Distance help ??
« Reply #7 on: February 02, 2011, 23:31:52 pm »
Thanks Ralf for explaining that, I get what you're saying but had to actually play with CB to understand that one.


David I understand very little french, english would work perfect for me.  However pictures/videos kind of explain themselves even thought words do help.  So if it's in french no problem I'll still check it out.  Again thanks for all of the help, I'm going to keep playing with this until I get ! 

Offline twocik

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Re: Leadin & Max Crossover Distance help ??
« Reply #8 on: February 03, 2011, 20:29:29 pm »
Ok playing with it only in CB before I test this on one of my cutters :)   One thing I can't see in CB and reading the produced gcode it looks like my cutter will be brought back up and down into the stock for every pass.  I was wanting to cut my profile just like a spiral drill mop (continues move, without any stopping), is this possible ?  One pic is set to tangent the other to spiral, also added a top shot.



Offline pixelmaker

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Re: Leadin & Max Crossover Distance help ??
« Reply #9 on: February 03, 2011, 20:36:33 pm »
Quote
I was wanting to cut my profile just like a spiral drill mop, is this possible ? 
Hello twocik,
yes, it is possible, please look on the second screenshot in my post befor. You see, I use a spiral LeadInMove with a 0 angle. This makes a cut in form of a spiral without any stop. The spiral will be control about the DepthIncrement Value.
And I wrote:I use the spiral LeadInMove also to cut a sideprofil in a spiral way. For this you have to set the spiral angle to zero.
Then you have no z moving who can leave a marking. The cut begins on top of the workpiece and cuts one spiral for every DepthIncrement. So you don´t have a z move at standing machine. Screenshot 2


ralf
« Last Edit: February 03, 2011, 20:38:24 pm by pixelmaker »

Offline twocik

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Re: Leadin & Max Crossover Distance help ??
« Reply #10 on: February 03, 2011, 21:01:29 pm »
Ralf I did try it set to zero and seeing the G0 Z0.2 up moves.  You're showing me a circle, will it work on a square ?


Here's the code with the spiral set to zero



G0 Z0.2
G0 X1.1622 Y1.3643
G1 F8.0 Z0.0
G2 F18.3 X1.3425 Y1.15 Z-0.133 I-0.0372 J-0.2143
G1 Y-1.15
G2 X1.125 Y-1.3675 I-0.2175 J0.0
G1 X-1.125
G2 X-1.3425 Y-1.15 I0.0 J0.2175
G1 Y1.15
G2 X-1.125 Y1.3675 I0.2175 J0.0
G1 X1.125
G2 X1.3425 Y1.15 I0.0 J-0.2175
G0 Z0.2
G0 X1.1622 Y1.3643
G1 F8.0 Z-0.133
G2 F18.3 X1.3425 Y1.15 Z-0.266 I-0.0372 J-0.2143
G1 Y-1.15
G2 X1.125 Y-1.3675 I-0.2175 J0.0
G1 X-1.125
G2 X-1.3425 Y-1.15 I0.0 J0.2175
G1 Y1.15
G2 X-1.125 Y1.3675 I0.2175 J0.0
G1 X1.125
G2 X1.3425 Y1.15 I0.0 J-0.2175
G0 Z0.2
G0 X1.16 Y1.3647
G1 F8.0 Z-0.266
G2 F18.3 X1.3425 Y1.15 Z-0.4 I-0.035 J-0.2147
G1 Y-1.15
G2 X1.125 Y-1.3675 I-0.2175 J0.0
G1 X-1.125
G2 X-1.3425 Y-1.15 I0.0 J0.2175
G1 Y1.15
G2 X-1.125 Y1.3675 I0.2175 J0.0
G1 X1.125
G2 X1.3425 Y1.15 I0.0 J-0.2175

Offline dh42

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Re: Leadin & Max Crossover Distance help ??
« Reply #11 on: February 03, 2011, 21:23:55 pm »
Hello twocik,

Yes spiral leadin with 0 angle works also with a square or any shape.

If you want, you can attach your .cb file (not the Gcode) in a thread, and I can simulate it in 3D for you.
(if you can read DivX, I can directly attach the video in a thread, otherwise I stores it on Youtube)

Today, I use the spiral leadin with 0 angle for the first time in real with a profil MOP to cut 15mm of oak with 2mm of dephtincrement, and that solves a problem that I have with wood. With multiple level of cut, I have traces like strata on the sides of the part (horizontal lines at each DepthIncrement level). The spiral leaves no traces  :D

++
David

Offline pixelmaker

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Re: Leadin & Max Crossover Distance help ??
« Reply #12 on: February 03, 2011, 21:26:18 pm »
Yes, David says it all.

Offline twocik

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Re: Leadin & Max Crossover Distance help ??
« Reply #13 on: February 04, 2011, 03:34:17 am »
Ok guys tell me what you think....  To me it looks like it's going up and down, but I could be reading the toolpath wrong.

This product I can't display publicly because I'm most likely going to patent it, but would be glad to email it to you as long as you promise to delete afterwards...  




Update - Here's the produce gcode, it's definitely going up and down for that MOP


( .375 OS Rough )
S3056
M08
G0 Z0.2
G0 X1.1622 Y1.3643
G1 F8.0 Z0.0
G2 F18.3 X1.3425 Y1.15 Z-0.133 I-0.0372 J-0.2143
G1 Y-1.15
G2 X1.125 Y-1.3675 I-0.2175 J0.0
G1 X-1.125
G2 X-1.3425 Y-1.15 I0.0 J0.2175
G1 Y1.15
G2 X-1.125 Y1.3675 I0.2175 J0.0
G1 X1.125
G2 X1.3425 Y1.15 I0.0 J-0.2175
G0 Z0.2
G0 X1.1622 Y1.3643
G1 F8.0 Z-0.133
G2 F18.3 X1.3425 Y1.15 Z-0.266 I-0.0372 J-0.2143
G1 Y-1.15
G2 X1.125 Y-1.3675 I-0.2175 J0.0
G1 X-1.125
G2 X-1.3425 Y-1.15 I0.0 J0.2175
G1 Y1.15
G2 X-1.125 Y1.3675 I0.2175 J0.0
G1 X1.125
G2 X1.3425 Y1.15 I0.0 J-0.2175
G0 Z0.2
G0 X1.16 Y1.3647
G1 F8.0 Z-0.266
G2 F18.3 X1.3425 Y1.15 Z-0.4 I-0.035 J-0.2147
G1 Y-1.15
G2 X1.125 Y-1.3675 I-0.2175 J0.0
G1 X-1.125
G2 X-1.3425 Y-1.15 I0.0 J0.2175
G1 Y1.15
G2 X-1.125 Y1.3675 I0.2175 J0.0
G1 X1.125
G2 X1.3425 Y1.15 I0.0 J-0.2175
« Last Edit: February 04, 2011, 03:38:37 am by twocik »

Offline twocik

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Re: Leadin & Max Crossover Distance help ??
« Reply #14 on: February 04, 2011, 05:49:39 am »
GOT IT !!!  ;D


Well after playing with just about every little feature I found that the Max Crossover Distance was what did the trick....  I had it at a value of 0 and put it back to 0.7 with a depthinc of .1" and now it looks to be one continuos path.  However if I change the depthinc to say 0.15" the Max Crossover Distance needs to be adjusted too (I put it at 0.9 and continuos path again).  So again back to square one, why is it that the Max Crossover Distance fix the problem/bridged the gap ? 


Sorry for all of the questions and puzzles.  I always use the same features to cut out my parts (I cut 2.5D, but soon 3D) and  figured it's time to learn new strategies in CB to speed things up and well in this case for better finish without the overnight tumbler shift. :)   






( .375 OS Rough )
S3056
M08
G0 Z0.2
G0 X1.2329 Y1.3389
G1 F8.0 Z0.0
G2 F18.3 X1.3425 Y1.15 Z-0.1 I-0.1079 J-0.1889
G1 Y-1.15
G2 X1.125 Y-1.3675 I-0.2175 J0.0
G1 X-1.125
G2 X-1.3425 Y-1.15 I0.0 J0.2175
G1 Y1.15
G2 X-1.125 Y1.3675 I0.2175 J0.0
G1 X1.125
G2 X1.3425 Y1.15 I0.0 J-0.2175
G1 F8.0 X1.2329 Y1.3389
G2 F18.3 X1.3425 Y1.15 Z-0.2 I-0.1079 J-0.1889
G1 Y-1.15
G2 X1.125 Y-1.3675 I-0.2175 J0.0
G1 X-1.125
G2 X-1.3425 Y-1.15 I0.0 J0.2175
G1 Y1.15
G2 X-1.125 Y1.3675 I0.2175 J0.0
G1 X1.125
G2 X1.3425 Y1.15 I0.0 J-0.2175
G1 F8.0 X1.2329 Y1.3389
G2 F18.3 X1.3425 Y1.15 Z-0.3 I-0.1079 J-0.1889
G1 Y-1.15
G2 X1.125 Y-1.3675 I-0.2175 J0.0
G1 X-1.125
G2 X-1.3425 Y-1.15 I0.0 J0.2175
G1 Y1.15
G2 X-1.125 Y1.3675 I0.2175 J0.0
G1 X1.125
G2 X1.3425 Y1.15 I0.0 J-0.2175
G1 F8.0 X1.2329 Y1.3389
G2 F18.3 X1.3425 Y1.15 Z-0.4 I-0.1079 J-0.1889
G1 Y-1.15
G2 X1.125 Y-1.3675 I-0.2175 J0.0
G1 X-1.125
G2 X-1.3425 Y-1.15 I0.0 J0.2175
G1 Y1.15
G2 X-1.125 Y1.3675 I0.2175 J0.0
G1 X1.125
G2 X1.3425 Y1.15 I0.0 J-0.2175