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Profit Milling

Loui

Plastic
Joined
Jan 23, 2020
Hello, I'm new in this forum (never in a forum before) and i'm a newbie at programming CNCs. I recently program a rough cycle using profit milling and even though the chips are flying and the tool can handle the the feeds and speeds, it seems like the machine shakes violently when doing small steps around the work piece. I know I can slow it down so the machine would not shake. Everything seems to be fine except the shaking of the machine. The shaking concerns me. If I don't slow down my rougher and the machine keeps shaking will the machine, spindle, ball bearings get damage overtime?

Thank you

Loui
 
1 - Make sure that look ahead/shape comp is turned on and set appropriately. Most Esprit posts will require you to manually add a tolerance setting in the custom fields. VERY few people are using look ahead correctly, and it is absolutely required for HSM on most machines.

2 - It's been a while, but I believe Esprit will allow you to add fillets to the toolpaths. Bigger fillets will lead to less "shakey" motion.
 
Thank you all! I am using Esprit. I will make sure my settings are correct.
 
I don't mean this to sound critical although it may come off that way.

How can someone have access to software like Esprit and be asking questions like this?

Here I am stuck with Fusion, Solidworks and HSMWorks. Turning out good parts so there is no way I could justify the cost of something like Esprit, although I would love to have it.

It is my understanding that with Esprit your maintenance agreement includes tech support and training??
 
I don't mean this to sound critical although it may come off that way.

How can someone have access to software like Esprit and be asking questions like this?

Here I am stuck with Fusion, Solidworks and HSMWorks. Turning out good parts so there is no way I could justify the cost of something like Esprit, although I would love to have it.

It is my understanding that with Esprit your maintenance agreement includes tech support and training??

Maybe they figured they would get a quicker answer on here? Who knows.

OP what machine are you doing this on?
What you're describing sounds like it can't handle direction changes at higher feedrates. Some machines can easily compensate for this, others cannot so you would just have to slow it down until the machine likes it.
Also is your program using arcs whenever possible? Or a ton of tiny little moves?
 
I don't mean this to sound critical although it may come off that way.

How can someone have access to software like Esprit and be asking questions like this?

Here I am stuck with Fusion, Solidworks and HSMWorks. Turning out good parts so there is no way I could justify the cost of something like Esprit, although I would love to have it.

It is my understanding that with Esprit your maintenance agreement includes tech support and training??


This could be a dude with a tabletop router and a cracked version of Esprit...

Just saying..
 
How can someone have access to software like Esprit and be asking questions like this?

A lot of things are magically handled in post processing.

Seriously, I will bet that less than half of Esprit users are setting look ahead appropriately. A brand new NHX can feed at over 2000IPM in cut, and it will rattle itself to death doing so unless look ahead is turned on.

Esprit can give you a lot of control over look ahead, but many users don't know it's there. A lot of other CAM systems just do a half-ass job of handling it for you, and basically treat motion comp as either "on" or "off".
 
Using a smaller cutter can help in some cases.

Someone posted here a few years ago about slotting with an endmill just slightly smaller than the slot width. It was traveling just a few 0.010 back and forth, starving the ballnut of lubrication and subsequently destroying it.

Same can happen with the thrust bearings.
 
Someone posted here a few years ago about slotting with an endmill just slightly smaller than the slot width. It was traveling just a few 0.010 back and forth, starving the ballnut of lubrication and subsequently destroying it.

Never thought about that. But, it makes perfect sense now that you say it Eric! Gonna store that away!
(bye-the-way, gonna need a couple vises soon! LOL)
 
Hello, I'm new in this forum (never in a forum before) and i'm a newbie at programming CNCs. I recently program a rough cycle using profit milling and even though the chips are flying and the tool can handle the the feeds and speeds, it seems like the machine shakes violently when doing small steps around the work piece. I know I can slow it down so the machine would not shake. Everything seems to be fine except the shaking of the machine. The shaking concerns me. If I don't slow down my rougher and the machine keeps shaking will the machine, spindle, ball bearings get damage overtime?

Thank you

Loui

.
1) yes sudden tool failure can easily damage part and the machine costing easily over $10,000. worth of damage if not careful
.
2) the most important factor usually is length tool sticks out of tool holder, length of tool holder from spindle face, dia of cutter. cutter and tool holder vibration limits there are usually certain hp and cutting force limits
.
3) part and holding fixture vibration. obviously when hp used and cutting forces are high enough severe pounding vibration can loosen things up like a impact wrench can tighten or loosen a bolt even when turning force is not as high as it would seem. pounding vibration effects things
.
4) machine limits both hp at spindle and the ability of machine to withstand cutting forces. obviously some machines might be limited to 1hp, 10hp, 20hp being used. obviously many parts and working holding methods and machines might not be able to hold over 2000 lbs of pounding cutting forces. everything has limits. you dont normally put 2 tons in a 1/2 ton pickup truck for example
.
5) yes often cutting parameters are adjusted so you get less than 1% sudden tool failure rate. 1% failure is like driving a car and every 100 days you crash the car. 1% can be way way too high a failure rate. of course things are usually adjusted for high reliability. crashing a car makes the travel time longer not shorter usually. going too fast often makes things take longer when failures are taken in to account. if driving a old car at 100mph makes the car shake badly where you feel it might fall apart suddenly most people slow down even if car could go 100mph or faster. obviously machine you use effects things or limits
 
.
1) yes sudden tool failure can easily damage part and the machine costing easily over $10,000. worth of damage if not careful
.
2) the most important factor usually is length tool sticks out of tool holder, length of tool holder from spindle face, dia of cutter. cutter and tool holder vibration limits there are usually certain hp and cutting force limits
.
3) part and holding fixture vibration. obviously when hp used and cutting forces are high enough severe pounding vibration can loosen things up like a impact wrench can tighten or loosen a bolt even when turning force is not as high as it would seem. pounding vibration effects things
.
4) machine limits both hp at spindle and the ability of machine to withstand cutting forces. obviously some machines might be limited to 1hp, 10hp, 20hp being used. obviously many parts and working holding methods and machines might not be able to hold over 2000 lbs of pounding cutting forces. everything has limits. you dont normally put 2 tons in a 1/2 ton pickup truck for example
.
5) yes often cutting parameters are adjusted so you get less than 1% sudden tool failure rate. 1% failure is like driving a car and every 100 days you crash the car. 1% can be way way too high a failure rate. of course things are usually adjusted for high reliability. crashing a car makes the travel time longer not shorter usually. going too fast often makes things take longer when failures are taken in to account. if driving a old car at 100mph makes the car shake badly where you feel it might fall apart suddenly most people slow down even if car could go 100mph or faster. obviously machine you use effects things or limits

What in the fuck does your reply have to do with this guys question? You post the same shit every time and 99% of the time it's not helpful.
 
What in the fuck does your reply have to do with this guys question? You post the same shit every time and 99% of the time it's not helpful.

If you read thru his posts (between the lines) it seems he is always trying to justify going slower. Whether it is tool length stickout too long, or "sudden tool failure", or bad clamping blah blah. Everything circles back to him doing everything the slow and *safe* (:rolleyes5:) way.

I am pretty sure Tom has never heard, or doesn't understand, the phrase "you have to break a few eggs to make omelets"
 
If you read thru his posts (between the lines) it seems he is always trying to justify going slower. Whether it is tool length stickout too long, or "sudden tool failure", or bad clamping blah blah. Everything circles back to him doing everything the slow and *safe* (:rolleyes5:) way.

I am pretty sure Tom has never heard, or doesn't understand, the phrase "you have to break a few eggs to make omelets"



Maybe this will get it through to him. Capture.jpg
 








 
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