So, I Ordered a new Onefinity CNC a couple weeks ago awaiting it’s shipment, and In the meantime I have been playing with the Vectric Software building a couple projects and trying to get a firm grasp on that aspect. I have spent numerous hours studying and watching videos and managed to clear up most of my questions but one in particular I am a tad confused with.
I get the theory of Conventional & Climb cutting in respects to a router, and that in most cases with the grain and nothing out of the Ordinary Conventional (Counter Clockwise) is the preferred (and safer) method. This is the way I have always made my cuts with my hand router.
When setting up a toolpath, Vectric Defaults to Climb, so I always change that, and with a profile cut watching the simulation I see the bit moving in a counter clockwise fashion (even the little diagram shows this) Though when discussing a pocket this appears to be the exact opposite, and even the diagram indicates this if you, select “conventional” the bit moves “clockwise”. Please disregard my ignorance as I am new to this and have never even used one of these machines, but is this what is expected for a “pocket” cut? Is there something behind the theory I am failing to understand with this? Which do you prefer for pocket cuts on typical Baltic birch plywood for a cleaner cut?
Thanks for your time and consideration.
I use climbcut for almost everything, coming from an industrial machine shop environment we used climb cutting on all machines with ball screws, the chip loads differently and the result is usually a better finish for me anyway.
Throwing in my 1.73 cents worth:
Climb cuts are difficult, if not impossible, to perform by hand because it wants to take off on you like a spider monkey. But the robot has no problem resisting those forces.
Switching from one direction to another can do things like improve the finish, preventing tear-out and will affect things like the chip loading on the bit.
Example is when I cut foam (kaizen), there is a world of improvement in quality when doing climb cuts (and going as fast as the steppers will run). And IMO a climb cut “should” leave a cleaner finish as the bit is not trying to “dig in” but “fly out” of the cut.
Other considerations include:
- Up, down, or compression cut bit being used
- 1, 2, 3 or more flutes
- Hardwood or aluminum
- RPM and feed rate
I myself tend to use conventional first, then switch if there’s any issues including chatter.
Thanks for the Replies. So it seems Like people just roll with the defaults provided. You both make great points on the Machine the router mounted it has no ability to run away from you as if it were in your hands. Though with the additional resistance, does that cause unnecessary heat or stress on the bit? The reason I ask is I will be using an 1/8 extended downcut end mill bit for alot of my work and I don’t want to break them or wear them out quicker than necessary.
I greatly appreciate you taking the time to respond to my initial question
Well, for the most part, it should be all relative to whatever RPM, feed rate, depth of cut and stepover being used.
From what I’ve learned (could be wrong), in general, a climb cut is thought of as causing less heat. However, if you are going too deep per cut and have a large stepover along with high RPM and slow feed rate, all of these factors will likely negate the benefits of the climb direction, cause the sides of the bit flutes (parts that don’t do any cutting) to “rub” against the material more, which causes more heat leading to dulling and breaking.
The things I pay attention to are:
- Size of the chips; should not be too large or small
- Sound of the cut; is it chattering, screeching or sounding like the aforementioned spider monkey trying to sing Dixie
- Overall finish of the material; smooth or rough
Since I can’t override the RPM or feed rate per the web interface, I decided to use my VFD/Spindle in manual mode so I can at least tweak the RPM on the fly which can usually solve things most of the time. Otherwise, I have to stop, update the parameters in Vcarve and restart.
Yes, it is too bad that Masso doesn’t have a way to change the spindle speed and the feed rate on the fly during a cut. Some other systems have that feature.
You can change both while running a program, i do it all the time
Care to share how it is done?
On the F2 Tab there is a window labeled G code and Overrides, touch the overrides button and up pops the sliders for feed and RPM, too bad the feed only goes to 100% so you would want to program for say 150% of desired feed and then adjust accordingly.
Hope this helps
That makes. I’m using Extended 1/8 & 1/4 bits and the pass depth appears to be set to their diameter so shallow cuts with allot of bit not even in the wood.
Though It still makes me wonder why a Pocket cut is listed as a “climb” going in a conventional direction as the conventional direction is listed as a climb.
I will be sure to keep your 3 points in mind when making my first Cut, A Spider Monkey whistling Dixie will be quite hard to miss
My first cuts will be in 3/4 or 1/2 in plywood depending. (cabinet grade finish not necessarily Baltic) I figure that should be a pretty easy cut opposed to starting out with purple heart or maple or better yet a rock.
It looks like most everything got answered sufficiently. I didnt see this part though.
You said you want to use baltic birch, BB, a lot. For any type of plywood the grain is alternated on each layer. This makes it more stable. It also negates any conventional or climb cut setting. The grain is going all kinds of ways all at once. The climb/conv is really only relevant when cutting non plywood. Your bit is rotating clockwise(normally). Take that into account and you should be fine.
As for the 1/8" bit. Use a compression bit, cut a few thousandths into the spoil board, make sure your bit is long enough to cut what you are cutting and go. You should be fine to cut plywood in one pass. Start at slower speeds and work your way up. That speed sweet spot may change. Even between 2 sheets of BB. All wood is different.
Thanks for the additional Input @dmayne. Good points in Regards to the Plywood and it’s grain, and I see even less cares when it comes to cutting MDF.
In regards to my original Question being answered, yes & no; I feel more confident in making my first cut and no concerns or hang-ups on the tool path selection I had prior to asking. Though what hasn’t been answered is why is the tool path for pocket when selected “climb” or “conventional” opposite of what the cut actually is? Surely Vectric didn’t make a simple mistake and mislabel it, the router is moving in the opposite direction than what we label it. Regardless if mounted in the z-slider or in your hand the router only spins in 1 direction, so it’s not being changed. That’s what I Was trying to understand, as maybe there’s more to the theory or explanation in relation to the Pocket cuts.
I do love compression bits i have a couple of very expensive whiteside ones I use for template routing, but as I have never used one of these machines before and I know I’m in store for a learning curve filled with mistakes, and I don’t want my initial mistakes to be done on pricier bits, but rather wait till i get a better handle on it’s operations and slowly start upgrading my bits to the better quality ones. In the meantime I ordered a 1/8 and 1/4 extended end mill thats cutting length is longer than the thickness of the materials being used, as well as a roughing bit to hog out the initial layers before making the finer cuts, a 30 degree V-bit (Based on several read suggestions) and lastly a 1" surfacing bit. I think that will serve me well for the initial take off.
Any chance that conventional theory of Climb vs Conventional directions are based on cutting the outside of a vector/piece of material, where when you are do a pocket you are theoretically cutting on the inside of the moving to the inside of the vector, hence it is seen as being “backwards” or opposite of what you are thinking… Just a thought…
@Dustoff00 I have been thinking about this for a bit and I think you may have hit this on the head. I had to use some scratch paper and a pen to visualize it, but it makes perfect sense. The Bit spins clockwise on the edge of your material when doing a profile cut from the outer edge from left to right and that is conventional. Though in pocket cuts the bit is moving in an outward fashion, and for the clockwise bit to spin into the material that is now crudely labeled as behind the bit the router would have to move in the opposite direction.
Great thought, making me feel a bit stupid for not conceptualizing that earlier! Thanks for Sharing!