Bit/Router Retraction during Carve - Why?

Hey 1F Nation! Still a newb, but curious when carving projects, why does my router/z-axis continually retract, then restart in another area of the piece, before completing the object it was starting to carve?

An example would be when carving letters, the cnc will make a letter “E” by placing like three identical holes at the ends of the letter, retracting each time. Then will move to the vertical side of the letter “E”, then carve…why doesn’t the program just start and finish the letter from top to bottom, why all the retractions and repositions? Maybe the number of Nodes in the program has something to do with this phenomenon, I just dont know.

At the end of the carve, it’s all there and carved, but seems highly inefficient to continue to stop and start all over the piece. Is there a way to limit these constant “retractions” during a carve? BTW, I have so far been using just Carbide Create-free to create projects. TIA

It is the nodes in the program. You can edit these nodes and delete and move some of them to make more efficient cuts all though this takes time in editing. Some times its not worth the extra time to make it efficient unless you are going to be reusing the same pattern for many cuts.

Aha moment for sure JDog! I used to make signs by hand, so I’m just used to starting and finishing, LOL…will just have to be more patient, as mentioned, it always gets the job done beautifully. I did reduce my retract height recently on some of thes projects, so maybe that can cut down on some time…thanks for the feedback!

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I have to watch the CAM program I use (Estlcam). Great program, but I always process the job “as created”, with respect to the machining order. If I were to mow my lawn in the same manner Estlcam processes jobs on its own, I’d mow 2 strips in the front yard, go to the back yard and mow around a tree, catch a strip on the side yard, mow a dot on the other side yard, then go back to the front yard for a couple more passes. :rofl:

Jdog is right about the nodes. If the individual letters are made up of thousands of nodes, it’s probably not worthwhile to mess with it. Just let the machine do it’s thing and trust that it will come out ok, regardless of how retarded it seems to be processing it. :sunglasses:

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Haha, Love the lawn analogy Bill!!! I always learn something new every day. My wife says the same thing about her robot vacuum…it drives her mad to watch it cover a room in an hour, while that same room would take her 10 minutes. Her advice to me was set it and forget it, it will get the job done, and you didn’t have to do it :rofl:


Smart woman! :sunglasses:
But yeah, I definitely get your point/frustration! Let’s see how quick we can wear out the machine with non-contiguous moves! :rofl:

Correct me if I’m wrong one of the ways to eliminate a lot of those individual nodes is to convert to smooth curves or bezier curves. The less nodes the less the router will retract

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There are entry and exit nodes and then there are position nodes. Only the entry and exit nodes do the spindle retract and move to a different position. These are usually represented by a different color in the cam software. The other nodes just represent a new line position or a middle reference position. You can decrease the safe z height to just above the surface as long as you dont have clamps that it might hit and the speeds between retractions will be faster. I have my safe z at .01

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All good input fellas! I did reduce the retraction height…no concerns with clamps on most of my jobs, they are all flush with workpiece typically. Thanks again for your input!