So I had my first successful cut.
I’m making four of these as spacers for my rails. these will be set between the stationary x and moving x rails to ensure they are in the proper place when powering the cnc.
First - I didn’t measure correctly (I think my calipers is on the fritz) and so I made these too small in CAD and don’t fit the machine.
Second, and this is where I could use some advice - I think I’m using the wrong end mill. I used a ramp to get the cut started (maybe that was the first mistake, not sure) and the speed for that was really slow and I started getting some burning wood dust. nothing serious but could have been if I was not watching. Once I got past the ramp and was cutting with a speed of 2000mm/m it was fine.
The reason I think it is the wrong one is that it is a 4 flute mill.
I would recommend some of the bits from the V1 store.
They’re less expensive than the one you linked, and they’re of good quality. (The ones you linked may be as well…I just don’t know). Also, you support Ryan that way.
Also, have you seen the Milling Basics page? Ryan recommends much lower feed speeds to start. Granted, more flutes generally implies higher feeds, but 2000mm/min is probably a bit fast for the first cuts.
I use upcut spirals almost all the time. They clear chips better than down cut. They leave some fuzz on the top surface, but I’m usually going to sand a little anyway, so don’t worry about it.
I do like the down cut for a few things…melamine, cabinet grade plywood with very thin face veneers that I’m afraid of sanding through etc.
Ramping should be ok as long as the angle is appropriate for your endmill. If you’re running that in the 660 at full tilt with no speed control, you’re probably on the hairy edge of rubbing, i think. Might be half a thou per tooth if guesstimation is correct, once you got going. A, slower ramp would probably make some heat. Not sure what you’re using for CAM, but I think you should be able to set the ramp speed higher if you think your machine can handle it.
That said, I agree 100% with Pete. The endmills at V1 are high quality, and fewer flutes let’s you take the same chipload at a lower feed rate, or a bigger chipload at the same feed rate.
Yeah, I saw those after I posted. I will probably pick some of those up.
I did, a while ago and didn’t think to look at it before hand.
I noticed Ryan’s recomended feed rate is 8mm/s. That seems a bit slow? (I know he has test it already so should be fine). My ramp rate was 1000mm/min and started to burn, but again I’m using 4 flutes. maybe with 2 flutes it will be better at slower feeds.
I do have the 660 and was at full speed. but I also have a speed control. Its a baisc one form amazon. Amazon.com.
I"m using Fusion 360 with Guffy’s post processor.
I’ve been watching some videos, for 1/4" plywood, would I even need the ramp or could I just plunge into it and cut?
I’ll slow things down a bit and use Ryan’s recommended starting speed unless either of you have a better place to start for feed rates and spindle speed using the speed controller.
Depends on the mill. Some can plunge, some can’t. If the flute goes all the way to the center when you look at the tip, it should be fine.
Plywood is generally pretty hard, what with all the glues and such, so it could take some twiddling to figure out. Nothing wrong with starting slow and adjusting the speed down with your controller until you get chips. Pretty sure you’ll lose a bit of power, too, so tweak is the name of the game. Honestly, that’s my favorite thing about the 611…speed control.
As far as advice goes, there is a reason those numbers are on the basics page. That’s where I started, anyway. Now I like to calculate my own by considering chipload, step overs, and surface speed.
I should note that the distance between the two x rails is different than the two y rails
Don’t cut 4 of the same size. Check your rail spacing you might also need two different length spacers
