CNC Toolpath Strategies for smaller machines

Nice Find! I'm a fan of 28584 from them. Really does a nice job in aluminum.
 
It's a great discussion and will help everyone to learn new things and strategies. Well, there are different components that contribute to an effective machining process in high-speed for mold and die makers. As we have learned a lot on the impact of HSM on CNC machine and cutting tools, spindles, and more importantly controls. We also ignore the fact that high-speed machining impact on tool path and programming techniques. Now machining technologies are evolving and meet the specific needs of new tool path strategies designed to suit the HSM environment.

In HSM environment we can use higher spindle speeds and feed rates for removing materials faster without compromising the part quality. This strategy applied to finish dies and mil modes to net shape and improve the surface finish and for achieving geometric accuracy.

So, if we want to facilitate high-speed machining, a CAM system should be the following:
  • reduce the feed rate loss
  • Achieving a sustainable chip load
  • Increasing the processing speed of program/software
 
Yup, Fusion360 is a very good CAM tool. It can be a little quirky at times.

I'm not in love with the CAD side, but I've been doing integrated circuit layout for over 20 years so I'm kind of set in my ways. ;^)
 
Yep, I use Fusion 360 at home even though I have a mastercam seat (for work).

Lars Christensen has a great YouTube channel showing how to use it, although I think he stopped posting new videos recently. Still, plenty of content there.
 
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Thanks for the suggestion! I'm just starting out in Fusion myself, and plan to glom onto these videos.

www.youtube.com

Lars Christensen

Best place to learn more: https://www.larschristensen.org/about-me
www.youtube.com www.youtube.com
 
Take a look at https://academy.titansofcnc.com/ It's a free online course in CAD, CAM, and machining. The best laid out self paced course I have ever seen, takes you from zero to machining parts in a very short time. Uses Fusion 360, I'm working my way through it to learn the CAD end. Very easy to follow, and understand.
 
ChrisAttebery said:
I also posted this on cnczone but I'll repost here for those that don't participate there.



I have a G0704 with a 1100W motor on it. I ran it at 4500 rpm for a few years and then bumped it up to 6750 rpm last year. I generally shoot for a MRR of 1.3in/min. I use high quality HSS end mills because they are cheap and these machines don't have the rigidity to use carbide efficiently.

My go to parameters are:
3/8" 2 flute YG-1 aluminum end mill
Speed: 6000 rpm
DOC: .500"
WOC: .05"
Feed: 54 IPM

My general rules for HSM in aluminum are to use full depth, 10-20% WOC, 1-2% feed per tooth. If I need to reduce DOC I increase WOC up to 20%, then I start adding feed. I wish someone made a 3/8" 3 flute in HSS. That would be my next step.

All of this assumes that you have a coolant system of some sort. I use a home brew mist system.

I have used 3/8" 3F carbide end mills in the past. They worked great but cost about 3X what the 3/8" 2F HSS end mills do. I decided that for my needs it wasn't worth the extra expense.

Good luck,


Chris
Click to expand...
I appriciate your stance on the cost of carbide, but......
At 3x the cost I'm getting 9x the life. Typically my carbide failes because I failed my carbide. I get aggressive some times. Poor application of coolant causing thermal shock. But I have to say, that 3rd flute is a game changer and as long as your not bone heading it like I do sometimes, they'll last for a VERY long time in aluminum. For me, I like to operate at 80% of adjusted hp. So for a 2hp spindle motor, you'll have 1.8hp at the tool with a belt drive, +/-. So for me, I like to see 1.4ish hp utilization from a 2hp motor. I don't get spindle bog and finish stay nice. It leaves you with enough room to speed up through chatter sometimes, if needed. Gives some maneuvering room with s&f recipe. BTW, I'm running a light machine too. It a Tormach 1100M with ATC and 4th axis. With this small envelope, I use the 4th axis as a horizontal tombstone for more parts per sqr in. I'll try to remember to pull up some of my setting and share them here later. I might be presumptuous in understanding the rigidity of those grizzlies as PM machines, I've not used one. For your smaller tooling(under 3/8") make sure runout is well under .001" . That cost me a few endmill before my head fell out of my 3rd point of contact. Assuming tool holders for these machines are like Mari's.....big mistake.
 
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