Hello all,
I encounter a strange thing: when milling goes “upwards/climbing” the surface is quite uneven, rough somehow. On the “downwards/falling” side of the model it is very even and smooth as expected. Any ideas on that? It is not part of the wood.
Bit is a 1 mm ball-nose, speed is 500 mm/min with stepover 0,2 mm in Luban
Thanks for your ideas!
Tobias
The problem is in a combination of the nature of ball end cutters and the Luban software.
Ball ends don’t cut on the bottom. They cut on the sides. So when making a tool path you want the finishing pass to go from down to up. With Luban you have no control over this and it doesn’t account for this. You need a CAM program like Fusion 360 that gives you more control over your toolpaths.
You might be able to compensate in Luban by increasing density/and or decreasing step down. But then your work times might increase unacceptably.
I found a video tutorial explaining this on youtube a while back. I can do a search for this later if you’re interested.
-S
Thanks, that sounds reasonable. Unfortunately I am not into Fusion 360, and I haven’t found a simple tutorial that shows me the necessary things for Snapmaker-usage 
However there is a German CAM called Estlcam which I am using and which should be capable of doing as you’ve suggested, I’ll give it a try. I can set finishing-options to parallel-X, parallel-Y or contour-parallel.
I also think that 1 mm is still quite “big” for finishing, however the original Snapmaker V-bit with 0.3 mm takes ages… Maybe there is a tool in-between?
Best regards
You’re able to fully controll the Snapmaker with Estlcam?
I’m looking for a better CAM-Program because in the free version of Fusion 360 you’re not able to manipulate the Path after generating (e.g. set the point where to go in and out of the material - or at least you can’t set it specifically)
I also think that 1 mm is still quite “big” for finishing, however the original Snapmaker V-bit with 0.3 mm takes ages… Maybe there is a tool in-between?
You could use a grinding toll for the finishing process, since there is less force involved you should be able to go with a decent feed rate. But i haven’t tried it myself.
(just a random google pick to show you what i mean: PFERD - STEEL Schleifstift Kugel Ø 20x20mm Schaft-Ø 6 mm A30 für Stahl- und Stahlguss | Toolineo, guess a grain size of 30 should be finde for wood working but they are produced in different grain sizes and diameter)
BUT since you going straight down you have to make a small hole in the center to a void a (theoretically) zero cutting speed in the center when grinding flat surfaces
Well, I have overwritten the built-in CNC-programm “Marlin” with the parameters Snapmaker wants. Then I can export the .cnc file and put it on a USB-stick for the Snapmaker. Works perfect so far. Estlcam can not export x-max and x-min which would be needed for Snapmaker’s boundary, and you have no picture. But that’s all!
Start-code in Estlcam:
;Header Start
;header_type: cnc
;estimated_time(s):
;is_rotate: false
;max_x(mm): 5
;max_y(mm): 5
;min_x(mm): -1
;min_y(mm): -1
;work_speed(mm/minute):
;jog_speed(mm/minute): 2500
;Header End
G90
G21
M3 P100
G1 F
G0 F2500
End-code in Estlcam:
M5
G0 Z10.00
G0 X0.00 Y0.00
There’s standard terminology for this. “Conventional milling” vs. “climb milling”. I believe you’re using the word “climb” contrary to the standard way people talk about this.
Wood does not machine the same way metal does. Climb milling shears the top surface and yields a different surface finish from conventional milling, which can pull up fibers from the wood.
Yes, it is quite likely that I am using the words falsely in this context as my mother tongue is not English. However I think that it is clear what I mean with “going upwards / climbing”
So let’s see if there is any difference in milling parallel-Y or contour-parallel
