So in testing today on pine, I used fswizard and ended up with breakouts. I was testing the v1 logo, the top of the logo broke out. Exceptionally sharp carbide bit. So any guesses on what would cause this? What should i adjust speed or feed or both? I did adjust speed, this is on new kobalt in mpcnc. I am starting to think i should use something other than pine, but cost and availability i like pine. Maybe i just need to keep experimenting, but getting frustrated…
So in researching, i think i was going too deep. I will try and report back.
Upcut? Downcut? Straight flutes? Compression? How many flutes? RPM?
Some context: Upcut will clear chips easily, but give you more tear-out. Downcut will give you a better surface finish, but won’t clear chips as well. Straight flutes split the difference. And compression bits are usually for when you have a dual-laminated sheet good that you are cutting through, and need two clean surfaces.
Pine can also be really tough because it can also be so soft. It’s easy to end up tearing as much as cutting, and the density can vary greatly across the grain, especially if there are knots.
This is assuming American soft pine (i.e., big box construction-grade lumber).
Straight and upcut. I do not have downcut. Tried between 1 and 2.5 (So 10k to 18k). Cannot remember my feed rate but it came from fswizard. I did however try both 5mm and 10mm cut. 10 did not work out (chips did not evacuate, so it jammed up). 5 was good, but still had beakout.
Everything Cummins said is what I know. The only thing I’d add is sometimes do a first very shallow pass (like 0.5-1mm) is supposed to help, also down cut can help too. This is at least advice from some other cnc friends, have not tried it myself.
Yeah i am looking over the drag race category right now. Seeing the changes etc. Going from dw660 ( no speed changes, just fast) to the kobalt and i really never learned to use this thing! It is all a lil overwhelming. I have mdf i will try that and see how i do.
I’m sure you know more than you think. But it’s all so different. I’m pretty sure if I build a second LR3 or a MPCNC I’d have to learn most of it over again just cause of different build quality
I do. I have made some nice things with this. I just thought i would have had an easier time, lol
If all my life experience has taught me anything. It’s that it is never easy. Every 30 minute job can just as easily take hours. Every thing you’ve learned can just as easily need to be relearned. And sometimes the worst thing you can do is go into something thinking I know everything, even if you do.
Ok so i think my problem is fswizard and me. I cannot seem to get the same values 2 times in a row. I need to find a way to do speed feed without it. Also all my bits are mostly free from work. (we have a regrind shop and he gave me some things). So I really do not have all the values, just calipers and guesses, lol.
Those can be more accurate than tool descriptions.
I do test cuts to determine speed. I cut a fairly small random shape at a few different speeds and see which one works the best in some scrap wood.
Most species of wood will be the same from board to board, so once you figure out the feed rate, write it down.
I don’t see this mentioned, but on soft woods you can also do a finishing pass at a different speed, usually faster. This can help clean up the edge.
Anyone following along. I just found this video. I found it very informative. I will summarize, his videos are good but also sales, idc!
I got to the middle. He had a roughing bit. Set router to 3 (looks like makita that some use here) started at 80 ipm. ( then says he turned up to 160%) but his cut was much shallower than i was trying. So my router was slower and my cut was too deep. 11:15 tonight here in michigan, so hopefully tomorrow I can have success!
Research shows rt0700 should be 17k at 3. Kobalt (via Aza’s research shows 18k. So plan for now. Speed 3. Feed (80 * 1.6 = 128 ipm. Converted is 3251 mpm. Not sure i will try that fast. If i do a simple box, maybe i can try a laddder of 1000 to 3000). Depth i think will be 5mm.
Night everyone. This will serve as my pen and paprr for when i can test, lol.
O.k. so I just found some of my problem. My feed was WAY off. I think I had 2000 mm/min, so 120k mm/s I just took it down to 200 mm/min z plunge 150mm 3 mm z and ran the router at 3, then messed with it all the way down to one.
While running i fussed a lil with the router speed as I was getting a lil chatter at times. I was able to run these speeds at router settings to one and all cut well. I did find 2 to be a sweet spot. I am currently trying to upload a video to my youtube, but my usb c cable is not working for me on this pc right now.
If I get it I will add link here.
That’s roughly ~33mm/sec the formula is just divide by 60
Glad you got it working
Crap, sorry, usually very good with math, LOL.
Changing to 3 flute with same settings to see how it does now.