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yet another STUPID video from practical machinist youtube page

empower

Titanium
Joined
Sep 8, 2018
Location
Novi, MI

i'll be honest, this triggers me...
first off, how the fuck can you not program a roughing path that doesnt risk plowing the tool into the stock? you're an awful programmer if you cant do that.
second, comparing time with a toolpath that spends at least a minute just cutting air before it even gets to the stock, to one where it ramps in directly? GTFO!
third, there is NO FUCKING CHANCE IN HELL a haas is reaching anywhere near 200IPM in that narrow slot, 50 if you're lucky.

this comparison is 100% flawed, and this guy is passing it off as gospel, SHAME ON YOU!
 
I might have almost crashed a tool before. Maybe- almost. I got a mill with exactly 0 experience cnc milling, and negative experience on manual mill.
I am unclear where 200 ipm is in any of those. Maybe the rapids?

Seeing side by side use of different cutters is useful.
 
I might have almost crashed a tool before. Maybe- almost. I got a mill with exactly 0 experience cnc milling, and negative experience on manual mill.
I am unclear where 200 ipm is in any of those. Maybe the rapids?

Seeing side by side use of different cutters is useful.
he said one of the adaptive toolpaths was 200ipm and the non adaptive was like 80. but yeah its not getting anywhere near that.

let me be clear, i'm not saying there's no use for non dynamic/adaptive roughing paths, there is. this was just probably the worst way to compare them. dude is absolutely clueless about programming/machining, and is only doing this retarded shit for clicks. i hope people dont take this clown seriously.
 
Yeah I saw that the other day, tough to watch. Definitely not 200ipm.
He's very green when it comes to running and programming a cnc that's obvious. I wonder if he's used to DIY desktop mills because....damn. That's not a good video.
 
Yeah I saw that the other day, tough to watch. Definitely not 200ipm.
He's very green when it comes to running and programming a cnc that's obvious. I wonder if he's used to DIY desktop mills because....damn. That's not a good video.
i'm all for people learning, pushing and improving themselves! but maybe dont pass yourself off as an expert when you clearly arent! this just screams desperation for clicks on his video, i cant think of any other reasonable explanation.
 
I think it’s a bit odd he doesn’t participate in the forums, perhaps he would learn a bit. I’ve certainly picked up quite a bit from the forum in 15 years. I cannot make it through an entire video, not a good representative for the cross section of forum participants.
The painful thing about YouTube is most experts are simply figuring things out just for the camera.
 
I think it’s a bit odd he doesn’t participate in the forums, perhaps he would learn a bit. I’ve certainly picked up quite a bit from the forum in 15 years. I cannot make it through an entire video, not a good representative for the cross section of forum participants.
The painful thing about YouTube is most experts are simply figuring things out just for the camera.
He made a username and posted once...

There are alot of actual experts on youtube, it doesn't take long to figure out who does and doesn't know what they are doing. Just ignore the ones who don't.
 
He made a username and posted once...

There are alot of actual experts on youtube, it doesn't take long to figure out who does and doesn't know what they are doing. Just ignore the ones who don't.
the damn algorithm keeps shoving it in my feed because of other machining related videos/channels i watch, lol
 
third, there is NO FUCKING CHANCE IN HELL a haas is reaching anywhere near 200IPM in that narrow slot, 50 if you're lucky.
We've all got our schtick on here and I know this is yours but, Mastercam backplot calculates the cutting time. While I agree the various Haas machines don't accelerate like higher-end brands, my experience has been that the cycle times are pretty close to calculated.

The VF-2 loses some due to an umbrella tool changer and not having the instant toolchanges of a side-mount. The VF-5XT has a huge table to control and much further to travel for tool change. Other than those, if it said a cutter path was going to be 3:27 and a single tool, I'd expect it to be within 10-20 seconds. The math must be mathin'
 
We've all got our schtick on here and I know this is yours but, Mastercam backplot calculates the cutting time. While I agree the various Haas machines don't accelerate like higher-end brands, my experience has been that the cycle times are pretty close to calculated.

The VF-2 loses some due to an umbrella tool changer and not having the instant toolchanges of a side-mount. The VF-5XT has a huge table to control and much further to travel for tool change. Other than those, if it said a cutter path was going to be 3:27 and a single tool, I'd expect it to be within 10-20 seconds. The math must be mathin'
no cam will accurately calculate cutting time, all it does is take the distance of the toolpath divided by the feedrate. and it ASSUMES the machine is capable of keeping that feedrate constant 100% of the time. it does NOT take into consideration accel/decel capabilities of every machine, which plays a MAJOR role. you can play with fudge factors to bring it in a bit closer, but it'll never be accurate.
you can take a lets say 1" square pocket and set the parameters to have the exact same toolpath length as a 5" square pocket, at the same feedrate - your cam calculated time will be the same, but run both in the same machine and compare the times. they'll be DRASTICALLY different.
 
no cam will accurately calculate cutting time, all it does is take the distance of the toolpath divided by the feedrate. and it ASSUMES the machine is capable of keeping that feedrate constant 100% of the time. it does NOT take into consideration accel/decel capabilities of every machine, which plays a MAJOR role. you can play with fudge factors to bring it in a bit closer, but it'll never be accurate.
you can take a lets say 1" square pocket and set the parameters to have the exact same toolpath length as a 5" square pocket, at the same feedrate - your cam calculated time will be the same, but run both in the same machine and compare the times. they'll be DRASTICALLY different.
That's not true, but your being wrong supports your own argument.

IDK about mastercam specifically, but Featurecam specifically includes acceleration in it's simulations, and I'd honestly be surprised if MC doesn't as well, even if they're hardcoded. in FC I can make the cycle time be anything I want by adjusting the machine simulation parameters.

Comparing a real machine to a CAM simulation is pretty meaningless unless you know exactly what the CAM is simulating.
 
no cam will accurately calculate cutting time, all it does is take the distance of the toolpath divided by the feedrate. and it ASSUMES the machine is capable of keeping that feedrate constant 100% of the time. it does NOT take into consideration accel/decel capabilities of every machine, which plays a MAJOR role. you can play with fudge factors to bring it in a bit closer, but it'll never be accurate.
That's exactly my point: it is pretty close. I can't even remember where the settings are but, you can adjust the machine's rapid speed and I think tool change time and it does the rest.

Yes, I get it: A inches of rapids times rapid speed, plus B tool changes times seconds, plus C inches at programmed feed = cycle time. I get that it doesn't calculate the acceleration times. The backplot number has always been close enough. They aren't drastically different. That suggests that despite all the changes of direction, the machine must be doing a pretty good job at keeping up.
 








 
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