FAST CHIP BREAKER PECKING USING G73

[Bob La Londe]

FAST CHIP BREAKER PECKING USING G73

I think you could do this:

Enter this line of data in the Custom Script field
G73 Z$z X$x Y$y Q$q F$f R$r

Select Custom Script as the drilling method. 

So you do not have to remember it in the future.
Copy the MOP.
Go to your styles menu in the system tab and create a new style in the correct style library. 
Right Click the Style and paste format.
Name the Style something easy to remember like "Chip Breaker Drilling" or "Fast Pecking."
Use that style when you want to fast peck drill.   

Please test before running, but a quick simulation on my desktop in a sandbox installation of Mach 3 shows it performing about how I would expect. 

The line of code using this method looks about like this:  G73 Z-1 X0 Y0 Q0.125 F10 R0.01

[Garyhlucas]

Bob,
Thanks, I'll give this a try.

[Bob La Londe]

Just a quick demo that shows this simple method built into CamBam works without any external processor or script. 

This test was on PathPilot, but a sandbox test shows similar operation on Mach3

https://www.youtube.com/watch?v=9tnxENjuA4w

[dh42]

Hello

Whoo ! ... very fast !  seems to drill easy !

++
David

[Bob La Londe]

As I delved into trying to make things go faster I realized the main reason for pecking is to break the chips.  As long as you are not deep drilling this technique works just as well as regular pecking and takes much less time.  It backs up just enough to break the chip. 

For deep drilling you still have to fully retract so the flutes do not pack up with chips.  I think if you have less than a drill diameter length of flute exposed at the deepest you need to fully retract. 

[lloydsp]

"I think if you have less than a drill diameter length of flute exposed at the deepest you need to fully retract."
--------------------

Yeah... I go for three diameters, and even then, with 'gummy' materials, I have to increase it.

Lloyd

[Bob La Londe]

So I was making some molds yesterday and it occurred to me that the G73 would be useful on every single hole I was drilling for every size drill except the spotting drill.  Rather than modify them on the fly while doing CAM I went back and inserted the G73 line above to the script field in every one of my drilling styles except my tapping styles.  (They already have a G84 in them)  I left them all to default to "canned cycle," but now any time I can use the fast pecking cycle I just have to "flip a switch" by selecting "custom script."  

Then it occurred to me why not add that line to my default style.  It won't affect my tapping styles.  When I create a new tapping style I copy an old one and adjust for the pitch.  By adding the G73 line to the default style's custom script field it will always be a quick easy selection option when I create a new drill operation even if it doesn't use a saved style.  It won't prevent me from just using a canned cycle or a spiral operation.  Its just one more quick easy selection.  

[Garyhlucas]

I need to look into styles and other features.  I had an old Bandit controller on a knee mill and I used G73 for just about every drilled hole to control chips from winding up around the drill. I don't drill much because I hate changing tools so it hasn't been a big deal.  That control had the best mill/bore cycle I have ever used.  It would plunge at the center and spiral outward at a constant stepover finishing with a full orbit and and then spiral back to center.  Really smooth and with no sudden stepover changes you could really push the feed up with out breaking anything.  By contrast the Fadals I ran would step straight out for the next pass so you had to carefully set the plunge feed to not snap the tool off.

I have used the custom MOP to program a really deep hole operation using a 1" Forstner bit in PVC to a depth of 4-1/2" which was tricky because I had to be aggressive so it didn't melt but also needed to get the chip out before it balled up.

[Bob La Londe]

Now that I have quick change spindles and have started using the tool tables on the high speed mills I am going to have to look at drilling with a high speed spindle again.  Takes mere seconds to change tools, and if drill works at such high RPM it will be a lot faster than all of the spiral interpolation drill MOPs I use on those machines now.

YES!!! Styles can save you an unimaginable amount of time.  Standardize your tool library for each machine, and then have a style library for each (different) machine.  

For setting an alignment pin press fit hole I click the point, then I click drill twice.  In the first drill I select one style for the first one and a second style for the second one.  Standard depth, interference, tool, rpm, all other parameters, and lead or start clearance are all setup automatically.  It drills a .251 clearance from 0 to -.125 and a 2.48 interference from -.25 to -.45.  Took me ten times longer to write this paragraph than to do it.  

In the simplest form a style is just a preconfigured set of settings for a MOP.  You select the style for the MOP and all the parameters (except ones you have changed) are set from the style.  You can still change settings, and if you want you can right click and reset to all the defaults for that style.  Its pretty cool.  Learning to use my tool libraries and style libraries has saved me thousands of hours.  I also have synchronized my tool tables on my machines with the tool libraries for each machine in CamBam.  

[Garyhlucas]

The FIRST robotics team build season started yesterday and I will again be the manufacturer of every part not purchased so making it less work will be nice.  Got the tapping heads working with the new drill press, and now I can just spiral drill location holes and finish on the drill press if the material is thick.  I put holes in lots of 1"x2" rectangular tubing and this will allow me to mill one side with a small mill and then finish the other side on the drill press.  Lots of parts are too long for my machine travel so doing part of a part and moving it really adds a lot of work so this will help a lot with that.

[Bob La Londe]

I tested it with Mach 3 today.  It works, but the retract amount is different.  I guess I'll have to find that DRO in Mach3 David was talking about.  

Best part is the high speed spindle seems to handle drilling just fine.  The spot drill was at 40 IPM, and the peck drilling was at 80 or 90 IPM.  

https://www.youtube.com/watch?v=Nn-egUsoE0w

The first G73 video showed it being tested under Path Pilot (LinuxCNC derivative).  This video shows G83 peck drilling vs G73 rapid peck drilling under Mach3.   Its still clearly faster, and it does work in Mach3 also.  It could stand a little tweaking, but it works.

[dh42]

Hello

I guess I'll have to find that DRO in Mach3 David was talking about. 

This is the OEM DRO 91 ; if it is not present in your screenset, you can add it with MachScreen.

++
David