Sprutcam 8 2D Contouring Question

Hello all,

I have a quick (hopefully simple) question regarding Sprutcam 8 and 2D Contouring. I have a part with a .25" gap (slot) (.13" deep) that I would like to mill using a .25" end mill. When i assign the slot to a Sprutcam 2D Contouring operation it will not cut the slot unless i tell Sprutcam the dimension of my cutter is .249 or change the dimensions of my slot.

Is there any way to get Sprutcam to mill a slot that is the exact width of a end mill?

I have searched for a means to adjust the tolerance in Sprutcam to allow the program to cut the slot ignoring the fact that there will essentially be 0 stock remaining when the cut is complete but it does not generate a tool path regardless of tolerance setting. Now i understand that due to runout and various other facts the slot will ultimately be somewhat larger than .25" wide once the cut is complete but that is acceptable for the part i am trying to create. If i tell Sprutcam that the End mill is .249 it seems to do extra passes in an attempt to mill away the extra .001 stock that essentially is not there. The extra milling type drags the machining process out to 4X the amount of time required to simple mill a slot. Any assistance would be appreciated and thank you all in advance for your help.

~Maurice

Been down this path before and basically a I see it you either have to manipulate reality or settle for the program being a little fat in term of run time. I've been taking post processor Sprut code and doing a lot of hand editing these days. Basically I know what I want, Sprut does it's thing that's pretty close and I just close the gap manually. Some Sprut operations are simply full of wasted motion. Waterline roughing can be efficient at times, but flat land finishing or a drive can get you real close on many operations. Using the combine and complex finishing protocols can work well too. I love using Sprut for generating chamfer code though...works great. Wish I had more to offer you.

Have you tried making the end mill diameter something like 0.249999999 in your tool library? That might be small enough to let SprutCAM make the cut and large enough that it thinks there is no need to do additional passes.

Mike

Crono

2d contour is what you want to use for total control.
First add 2d contour to your list of operations
Then select your tool .25 mill to mill a .25" slot
Next I would set depth of cut and other parameters expected for this operation
Now with 2d countour highlighted select job assignment tab at bottom
Next select the bottom face of the slot you want to mill
With bottom face of slot selected goto job assignment and select pocket button
Sprut will show 2d contour tool paths for the slot with yellow line.
You will need to adjust the 2d operation to mill down center of slot by clicking on the little icon at right in the job assignment tab. "this sets left, right, center, compensation"
all important info highlighted yellow and red
Attachment 247726


When it shows tool 2d contour down center . your set! change depth of cut and whatever for fit and finish :)
No messing around it will do it in 1 pass if you want and set it for that depth!
Run and generate g-code

hope this helps
md

Thanks for the tip MD, I use that function for engraving text, I never thought of it for a slotting op??! I use Sprut 7 but I think the op is the same.

Md,
Your recommendation works so long as there is a bottom layer to select as shown in your picture. Do you have a method for when the hole in the part you are making is a through hole? (The end mill cuts all the way through the part). Some of the slots I have work as you have described. Others that go through the part do not. :/

Mike,
I have tried adding trailing 9's to the end mills size (.2499 and more) to the point where Sprutcam 8 just rounds it up to .25 when i return to the tool page. If i zoom in on the tool path generated it retains a slight offset even still. The resulting offset causes the tool to do 4 passes vice just the required 2. Most of the parts I am making have several cuts in it (tracks essentially completely through the part) and the extra time spent air milling is what i am trying to avoid.

Pickled,
So far the only thing that has worked on cuts entirely through the part was your suggestion of slightly altering the part geometry to a .26" size hole and then only cutting .25" into it. Slightly tricky ensuring the part geometry remains the same despite larger holes but it does work with a bit of patience. I am surprised at the level of difficulty in using Sprutcam 8 to do something that I would have considered simple. .25 hole + .25EM = .25" hole.

Thank you all for your recommendations. The search for greater efficiency continues.

Crono
If no bottom to select then the next thing to do is give it a path to follow in 2d contour
Go to 2d geometry snap a line in the middle of the slot.
Then return to machine tab and 2d contour operation
Select the line that was drawn down center of slot
Go to job assignment and add with the curve button
Sprut will follow the line drawn to any depth desired
Attachment 247768
And if its a slot all the way thru with closed ends
Do the same as above with line down center then adjust the 2d tool path length to be short of closed ends by radius of tool.


This is complex software and at times it helps to draw your own tool paths for your needs
I add all kinds of extra lines to my models for just such reasons. I add these in cad software most the time. "call them construction lines"
Look for my thread on going cagey here in sprut forum!
Still I have no problem adding lines and entities in sprut also, just takes some practice.
And the lines can always be used as tool paths!
I can kind of stress if 2d contour cant do it its going to be hard to do in sprut :)

Additional uses of added lines are tool paths for surface prep or finish with say a fly cutter.
Draw lines in the pattern you want the fly cutter to follow on the surface.
Use 2d contour with a fly cutter as tool and add lines as tool path curves and let it follow your predefined pattern.
works great and I can control chip swarf so it fly's to back not out front of mill.

md

also I would like to add, do not forget that if you have "check workpiece" and check part selected, then software will not always machine or give you what you want. For roughing and finishing auto tool paths thats fine, 90% time. BUT for contouring, this can lead to no tool path or partial tool path, if you check these off, then you have more control of the operation.

Those usually end up checked by default BTW

Crono - you should be able to set the top and bottom levels manually for a 2D contour operation. You'd do this from the Parameters dialog box for the operation and it lets you select any depth you want. If you select an edge of the slot as the "Curve" in Job Assignment, you can select whether or not the cutter path is centered over the edge or uses the edge as a bounding side for the cut, as MD suggested in his first reply.

If you are still having trouble, why not upload your project and one of us can program it so you can see the details and watch the simulation. If the part is proprietary, upload a dummy part with the same desired feature and restriction.

Mike

MD,
Thank you so much. This is exactly what i was looking for. A simple solution and time saved on the mill.

Quote:

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Originally Posted by Crono1124

Do you have a method for when the hole in the part you are making is a through hole?

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Sprut 8 may be different but in Sprut 7 I would simply select either the lower edge of the slot or flip the part and select the bottom face and press the "Bottom Level" button in the Job assignment tab. This automatically sets the bottom level that Mike is referring to.
When milling right through a part I normally use this as a starting value and manually set the value just a touch deeper.
Step