Struggling With Speeds and Feeds for Bas Relief Engraving
DISCLAIMER: I'm new to cnc wood carving and cnc in general. Please put any answers in terms a newbie would understand.
I've created a 150mm x 197mm (ish) relief that is only 2.475mm in relief depth. That's really not all that big.
I'm trying to carve this on a Sainsmart 3018 Prover with the stock motor. I used the 3mm endmill for the roughing (unmodified from the TDB) and got a reasonable time guess-timate out of Carveco. It calculated 2 hours 12 minutes and it actually finished in 1 hour and 40 minutes.
Here's where I nearly fainted. Either Carveco isn't calculating correctly or I'm simply not setting things up right when it came to the finishing. I chose the 1mm ballnose (unmodified from the TDB) and it calculated over 623 hours!!!! I went back and compared the speeds and feeds for that size ballnose using data about my 3018 Prover in GWizard calculator and the recommendation was more conservative from it than what is in the Carveco TDB.
Any advise would be greatly appreciated!
Comments
Are you sure you didn't put a dot in front of that 1mm cutter? Just a question, my fingers are sort of fat so I miss things at time and have to recheck, and fyi I never look at the time from carveco, I always use the time the control software gives me, if you are concerned about times and the like there are feeds and speeds charts out there that you can look at https://www.the-carbide-end-mill-store.com/Feeds-and-Speeds.html for one.
mike
LOL. I did double check that because I just could not in my wildest imagination visualize 623 hours. I did figure out what was happening though. I had defined a step-down of 0.2mm and the software was trying to cut the outside perimeter of the piece with a 1mm ball nose at 0.2mm at a time in the finish cut. That's something I would do with my saw.
I tricked it though and defined the inside portion as a rough cut but using the same speeds, feeds, and bit. The time estimate came down substantially. Even so, I thought it was too long, so I made 2 aggressive rough cuts and 1 "finish" cut defined as a rough cut. It dropped all three operations to a sum total of 13 actual hours (even though Carveco estimated around 55 hours). Much more reasonable!
I'm trying to entering two new tools into my Carveco tool data base, (Radius Engraving Toolpath) they are both Tapered Ballnose bits form Rennie Tools.
I'm intending to do a 3D carve using oak. I would really appreciate advice so I can carve my project as accurately as possible. My machine is Ooznest 1500 x1000 with a Mafell 1000 spindle.
Tool 1 : R05 * 20* 1/4" 60L *2F
Tool Diameter 6.35 mm
Half Radius 0.50 mm
Stepdown 3.0mm
Flute Length 43.91mm
Final Tool Offset 3.175mm
Stepover 0.061mm
Spindle Seed 18k
Feed Rate 1450 mm/min
Plunge Rate 635.0mm
Tool 2 : R1 * 20* 1/4" 60L *2F
Tool Diameter 6.35 mm
Half Radius 0.50 mm
Stepdown 3.0 mm
Flute Length 43.91mm
Final Tool Offset 3.175mm
Stepover 0.061mm
Spindle Seed 18k
Feed Rate 1450 mm/min
Plunge Rate 635.0mm
Many thanks
Alex Mann
Alexander,
I use the tip of the bit on all of my tapered ball's.
It's not necessary to worry about too much of the other stuff, the software adjusts the feed and speed, though length would be good to put in.
When using the tapered balls (tapered anything really) it's always best to make sure you don't unintentionally cut something you didn't want too. If you don't you might not be happy.
mike
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