Author Topic: Constant feed MOP  (Read 3132 times)

Offline Garyhlucas

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Constant feed MOP
« on: November 22, 2019, 23:36:58 pm »
It occurs to me it would be really nice if pocket and profile MOPs could change the feed speed on radiuses to recognize that the if the tool has very close to the same radius as an inside radius that the actual feed rate of the cutting edge is far higher than the programmed feed of the tool path. I’ll bet we could cut far faster if you enabled radius feed compensation and avoid jamming a tool right into a tight corner. 
Gary H. Lucas

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Offline Bob La Londe

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Re: Constant feed MOP
« Reply #1 on: November 23, 2019, 02:04:04 am »
I've been complaining about that for years.  I try to plan to avoid it, but its not always practical.  The trochoidal milling plugin does it, but its often a slower tool path than the regular straight line toolpaths.  Its always a trade off.  Takes another level of calculation I guess.
Getting started on CNC?  In or passing through my area?
If I have the time I'll be glad to show you a little in my shop. 

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Offline dave benson

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Re: Constant feed MOP
« Reply #2 on: November 23, 2019, 02:06:52 am »
Hi Garry
This has already been done with the feedrateadjuster, which was mainly started
for the troc mops.
Have a look here: http://www.cambam.co.uk/forum/index.php?topic=7689.0
I abruptly stopped public development of this feature as I was publicly and privately
asked for the .exe code, using the excuse that it was not displaying the decimal points
properly, this was complete BS.

About the same time (can't remember if it was Fly or Pixelmaker) had said that a CB
competitor looked like a poorly implemented version of CB plugin's and all, so I stopped
public development of this feature.

I privately continued development as it turned out to be beneficial in many ways, firstly being able to run much higher feed rates, and increasing the tool life no end.
It's childish I know, but it still puts a cheeky smile on my face to see how well it operates on the mops.
The newer version can run with all of the mops, although it's not sensible to use for some of them.

Give the one here a go, and if you can get it to run and are interested to apply it to the rest of the mops, I'll have a look to see if I can find a way make it run on only the Legit copies of cambam.
It's the way of the world now, that within the first few links, on a search on Google is that
there all about how to crack CB.

Dave

Offline Mark81

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Re: Constant feed MOP
« Reply #3 on: November 23, 2019, 07:05:30 am »
I privately continued development as it turned out to be beneficial in many ways, firstly being able to run much higher feed rates, and increasing the tool life no end.
It's childish I know, but it still puts a cheeky smile on my face to see how well it operates on the mops.
The newer version can run with all of the mops, although it's not sensible to use for some of them.

Give the one here a go, and if you can get it to run and are interested to apply it to the rest of the mops, I'll have a look to see if I can find a way make it run on only the Legit copies of cambam.

In my opinion, CB should buy from you the source code and embed it in a new version.
In this way, you will be payed for the job you've done, CB's developers don't have to write this feature from scratch and CB will gain another great feature! :D

Offline Bubba

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Re: Constant feed MOP
« Reply #4 on: November 23, 2019, 20:53:36 pm »
Give the one here a go, and if you can get it to run and are interested to apply it to the rest of the mops, I'll have a look to see if I can find a way make it run on only the Legit copies of cambam.
It's the way of the world now, that within the first few links, on a search on Google is that
there all about how to crack CB.
***********************
Dave, as always, thanks for those plugins you and others write. There must be a way to distribute to those who are legit
CB owners. You and other script writing guru's probably could write script that looks at forums users and their info like date when one joined the community,how active they are, etc.. David, the forum moderator could set up file depository and some means for authorised access to the plugin? On the other hand, maybe I should just shut up and finish my bottle. ;D ;D 
My 2¢

Win 10 64 bit, CB [1.0} rc 1 64 bit, Mach3, ESS, G540

Offline dave benson

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Re: Constant feed MOP
« Reply #5 on: November 24, 2019, 00:42:37 am »
Hi Mark/Bubba

I'm pretty sure most of the Plugin/script writers that present their work here, do so to help
other CB'ers and are not in it for any financial gain.
The trouble here, is that there is not very much feedback, whether it be I've tried this and it works well or I've tried this and found a bug. (Eddy's Lamented this before in some threads in the past).
I would like to see David's Numerical Move plugin and some of the Drawing related tools
Eddy and Others have developed added to CB as these make a real difference to the ease of use of CB. The one's used only occasionally would still be fine as a Plugin.

I can not look into how to do this right now as I have been working on the electronic chip breaker.
I've got it to a stage where it's working,  by writing the Gcode by hand using sub's ( a bit caveman I know in this day of cam) but it's only way to get the logic right.
I've discovered that Mach3's interpreter doesn't use G50 the way it's implemented in other
type's of lathe's.
What I expected G50 to do was limit the top speed of the spindle to 600 rpm in CSS mode, but it
uses this for scaling instead, this lead to a change of underwear moment as the X axis moved toward the center of the work piece the spindle speed wants to go to infinity (max spindle speed) and for the brief couple of moments it took to register what was happening that monster 160 mm chuck loaded with a 1.2 kg  piece of stock was spinning at 1800 rpm.
Because of its size the chuck is speed limited to 1350 rpm, I realised in that moment  that if my home made Backplate let go the chuck had enough Kinetic energy to some serious damage.

Edit to Add--> For your own safety comment out line 5 if you are going to test the code.
In the image the left hand side is the stringers you get using a normal ID facing wizard in Mach3
on the right of the image is the result of the chip breaking.

Dave
« Last Edit: November 24, 2019, 01:08:28 am by dave benson »

Offline Bob La Londe

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Re: Constant feed MOP
« Reply #6 on: November 24, 2019, 02:02:30 am »
Dave,

I don't understand.  I have used JK's trochoidal milling plugin and it does a good job of eliminating unexpected tool load in corners.  I do not have yours installed that I am aware of.  Is his plugin based off yours or is there something else I am not seeing? 

My only issue with JK's plugin was that its really not as fast as just using the regular pocket MOP most of the time.  Even given the tool load issue in corners. 
Getting started on CNC?  In or passing through my area?
If I have the time I'll be glad to show you a little in my shop. 

Some Stuff I Make with CamBam
http://www.CNCMOLDS.com

Offline dave benson

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Re: Constant feed MOP
« Reply #7 on: November 24, 2019, 03:30:10 am »
Here's a shot of a real job that I do using the troc mops.
I made a copy of the first mop that uses the feed rate adjuster and pasted it at the bottom
of the part and generated the code.
together both mops take 32 m 3 seconds. 1923 seconds all up.
The first mop with the feedrateadjuster takes 554 seconds.
The second mop takes without the feed rate adjuster takes 1369 seconds.
CB says it's 63% faster, the sim says it's 70% faster. but these are only calculated
values and only a guide, in reality on the mill it worked out 56% faster.
This is using the new feedrateadjuster not the one I've posted here, the old one was fast but not as easy to use and requires some tweaking of the variables inherited from the Style to be effective.
The new one that I have not posted can be applied to all the mop's not just the Troc's.

Dave

Offline kvom

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Re: Constant feed MOP
« Reply #8 on: November 24, 2019, 13:08:11 pm »
I wonder if this would also work for thread mill code.  Normally here one calculate a linear feedrate based on desired SFM, then adjusts feedrate according to external (higher) or internal (lower) threading.

Offline Bob La Londe

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Re: Constant feed MOP
« Reply #9 on: November 24, 2019, 17:36:30 pm »
I guess I missed it.  Does your plugin modify JKs plugin? 
Getting started on CNC?  In or passing through my area?
If I have the time I'll be glad to show you a little in my shop. 

Some Stuff I Make with CamBam
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Offline dave benson

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Re: Constant feed MOP
« Reply #10 on: November 24, 2019, 21:54:49 pm »
Quote
I wonder if this would also work for thread mill code.  Normally here one calculate a linear feedrate based on desired SFM, then adjusts feedrate according to external (higher) or internal (lower) threading.

Yes it would adjust the feedrate depending on the radius of the internal and external
threads, I haven't tried this as I don't have a thread mill, I think that if you had for example
a 19 mm stud to make and in the same job had a 12 mm stud and used the same tool
then the 12 mm stud feedrate would be less than the 19 mm one which can be tuned with the variables.

It in no way modifies the tool paths, It gives you dynamic feedrate adjustment  in real time on the mill depending
on the cutter load on each line of Gcode. It's not a plugin, it can be selectively turned on and of per mop.

Dave

Offline Bob La Londe

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Re: Constant feed MOP
« Reply #11 on: November 24, 2019, 23:28:40 pm »
I notice there are two in the thread where you first discussed it.  Which one should I download if I want to play with it?  

Do I understand correctly that the version available only works with the trochoidal MOPs? 
Getting started on CNC?  In or passing through my area?
If I have the time I'll be glad to show you a little in my shop. 

Some Stuff I Make with CamBam
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Offline dave benson

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Re: Constant feed MOP
« Reply #12 on: November 25, 2019, 11:56:49 am »
Download the last one.
Yes the troc mop's, the smoothing variable controls the rate of change between the low and high feedrates.
in other words the accel or rate of change leave it at 1 and generate the code and use CB's in build editor to look at it.

once you get it going ok then make a part with identical mops all pointed at the one piece of geometry and change the variable between 0.5 and 2 in each of those mops to see how it affects the acceleration rate into and out of the corners (this is also dependent on the radius of the corner) for example if you have a 6 mm endmill and the corner radius is 3.1 mm then it will drop down to the min feedrate say 50 mm\m if the corner radius is 6 mm then it may only drop down to 100 mm\m in other words the chip load on the tool dictates the values.
Dave
« Last Edit: November 25, 2019, 11:59:31 am by dave benson »

Online dh42

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Re: Constant feed MOP
« Reply #13 on: November 25, 2019, 15:39:28 pm »
Hello

Quote
Have a look here: http://www.cambam.co.uk/forum/index.php?topic=7689.0

Oh !, I never seen this plugin before !

I'll move the thread in the plugin section and add it to the plugin web site when time permit ... (and when I understand what is it exactly ;))

++
David
« Last Edit: November 25, 2019, 15:43:41 pm by dh42 »

Offline Bob La Londe

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Re: Constant feed MOP
« Reply #14 on: November 25, 2019, 16:29:35 pm »
I would consider it before adding it to the plugins page.  The version available to most of us users does not appear to be complete and has limited application.  I actually quit using the trochoidal milling plugins (which this one appear to work on) some time back except for the hardest materials to machine, because generally I found the long linear moves of the regular MOPs took less time. 
Getting started on CNC?  In or passing through my area?
If I have the time I'll be glad to show you a little in my shop. 

Some Stuff I Make with CamBam
http://www.CNCMOLDS.com