I’m sure this has been discussed before but I can’t find it in a search. When making a Profile Cut out of a circle or anything really that requires several passes, I have this indentation from where the End Mill plunges. It’s not deep, maybe 1/64" and It can be sanded out but then what I’m cutting isn’t precise anymore. What do I need to adjust and make sure of to eliminate those types of markings?
I believe this is due to deflection of the bit, try it at a slower feed rate and see if this reduces the effect.
Ok, but my feed rate was already at 40"min. and it has to make 26 passes to get through 1.25" of Pine. If I go much slower, It will take too long to even consider using the CNC machine.
in Vectric software there is an option for lead in and lead out which eliminates this as the z movement is outside of the geometry. Alternatively there is ramp in which keeps within the same x and y paths.
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I will look into that. Thank you
What type of bit are you using? That has a lot to do with tool deflection as well.
There is also the last pass option when profiling in Vectric, I usually put the allowance at .001 and reverse direction. It seemed to work for me.
Thanks everyone. I will look into those things and make some test profile cuts when I get back from my trip. Heading out for an Off the Grid camping trip to the Adirondack mountains in Upper NY State. No Electricity, No Cell Phones, No Water hookups. Just Batteries and Solar Panels. Should be fun and a way to clear out the noggin.
Bruce it’s a 1/4" 2 flute upcut End Mill. The one that came with the Xcarve back in 2015 when I bought it. Not sure what comes with them now but back then, there was the 1/4" End Mill, and a couple of other bits that they sent as part of the package that was offered.
I usually use a down cut bit when cutting plywood or really about any kine of soft wood. I find the upcut bits tend to tear out and cause the bit to walk around a bit. Also, be sure the bit is still sharp; possibility just need to hone the tips a bit and clean the wood residue off.
I learned while doing another project that this occurs while doing pocket cuts as well.
Jeff, It seems that using the Last Pass option in Vcarve helps. I tried using the same tolerance as you do but it didn’t quite take care of all of my problem. I’m going to increase it slightly and do more test cutting until I have success.
Bruce, unfortunately, I don’t have any down cut end mills. If I did, I would try one to see if there’s any difference. I will buy a couple down cut end mills when I make my next purchase.
Those marks come from the lack of lead-in/out of the bit. You can defeat this by allowing some material left for a finishing pass @ full depth.
Or use lead/in/out if available.
Lead in/out is a nice work around when making profile carves but I can’t use those for pocket carves. I’ll have to use the “Last Pass” or finishing pass to fix my issue but as I said in my last post, I have to dial that in too. The .001 that works for Jeff, isn’t enough for my machine. I’ll have to use a larger number. What that will be will have to be adjusted through test carves.
Thanks for that info Phil. I’ll try a carve with the .005 allowance with the Last Pass in Reverse option and see if that works for me.