Are their any downsides to Dynamic Milling?

[AMCNitro]

On 5/24/2022 at 6:56 AM, MIL-TFP-41 said:

If there is any downside to dynamic milling is it can create the misconception that it needs to be used everywhere. I have seen guys program a .560 wide slot using a 1/2" endmill. Yes it can make the part, but that short motion is not good on machines & takes longer than just going old school and cutting a slot. I have seen others dynamic mill a keyway in a mild steel shaft.

 

I have that problem with one of my guys.  I taught him dynamic and he uses it on eeeeveeerryyythiiingg, drives me up the wall.  Quarter inch slot, dynamic, when a ramp will do.

[crazy^millman]

Mushroom effect is something a programmer has to also think about. I have a project I am currently working on for a process improvement. I have cut from the TOP and now I am cutting from the sides. There is material removed past a certain point but OPTI-Rough still ignores the air cutting with no stock present taking the largest section of material in area above the area it is cutting and carrying that all the way down through the cut motion. Now I have to break it into more stock models and OPTI-Rough sections to avoid the extra 30 minutes of air cutting per part. It is that or create surfaces to avoid which then create other problems with not arcing in and out like it should. 

[huskermcdoogle]

4 hours ago, crazy^millman said:

Mushroom effect is something a programmer has to also think about. I have a project I am currently working on for a process improvement. I have cut from the TOP and now I am cutting from the sides. There is material removed past a certain point but OPTI-Rough still ignores the air cutting with no stock present taking the largest section of material in area above the area it is cutting and carrying that all the way down through the cut motion. Now I have to break it into more stock models and OPTI-Rough sections to avoid the extra 30 minutes of air cutting per part. It is that or create surfaces to avoid which then create other problems with not arcing in and out like it should. 

This is now fixed going into 2023 apparently.  Haven't tested yet with the public beta.  I doubt it is perfect, but certainly looks better.

 

https://www.youtube.com/watch?v=Gs6XS4Tgmog

[crazy^millman]

16 minutes ago, huskermcdoogle said:

This is now fixed going into 2023 apparently.  Haven't tested yet with the public beta.  I doubt it is perfect, but certainly looks better.

 

https://www.youtube.com/watch?v=Gs6XS4Tgmog

No dice didn't work on my current project I tested it with PC1 and no difference. I have 8 extra stock models and 8 extra operation per part, but it gives me the non wasted motion I need.

[crazy^millman]

I even go as far as making different containment boundaries for each depth of cut since we get those random stragglers running off to cut air. 

[cncappsjames]

I will usually set my back feedrate to something I believe it will actually get to.

[MIL-TFP-41]

13 hours ago, crazy^millman said:

I even go as far as making different containment boundaries for each depth of cut since we get those random stragglers running off to cut air. 

I use that strategy more than stock model. One thing I hate to see is a machine running up & down (or in & out) in the Z axis like a sewing machine.  If I am making a prototype/first article part I don't get that picky. But if I am looking at a production run, I get rid of any wasted motion. Seconds add up....30 seconds per part doesn't seem like much, till you multiply it over 2000 parts.

[JParis]

2 minutes ago, MIL-TFP-41 said:

if I am looking at a production run, I get rid of any wasted motion. Seconds add up....30 seconds per part doesn't seem like much, till you multiply it over 2000 parts.

Yup and that's the big difference between program for a few parts and programming for 50, 60 or 70k+ parts....

Just 5 seconds over 50,000pcs = 69.5 hrs.....you are approaching 2 weeks in saved machine time that is then utilized for something else....so not only are you saving that time & cost on those parts, you are able to load up and run other parts in the remaining window multiplying the time used into profit....

For someone like me who programs for more than 20 high production run HMC's, some parts we'll make over 100/k per year...the time spent bleeding those seconds pays back BIGLY in $$$

So you economize any and everywhere you can.

[Tim Johnson]

7 hours ago, JParis said:

Yup and that's the big difference between program for a few parts and programming for 50, 60 or 70k+ parts....

Just 5 seconds over 50,000pcs = 69.5 hrs.....you are approaching 2 weeks in saved machine time that is then utilized for something else....so not only are you saving that time & cost on those parts, you are able to load up and run other parts in the remaining window multiplying the time used into profit....

For someone like me who programs for more than 20 high production run HMC's, some parts we'll make over 100/k per year...the time spent bleeding those seconds pays back BIGLY in $$$

So you economize any and everywhere you can.

For 50,000+ parts why wouldn't you use a rotary transfer machine?

[JParis]

Just now, Tim Johnson said:

For 50,000+ parts why wouldn't you use a rotary transfer machine?

We don't have any...

As programmers we have about 0% say in what the company buys...so, we use what they put on the floor.

All I know at the moment, is where have 21 HMC's....2 more standalone HMC's are due to be dropped in the middle of July and an order that looks to be coming will put 4 more HMC's in play..plus 4 new lathes

[Bill Craven]

9 hours ago, MIL-TFP-41 said:

If I am making a prototype/first article part I don't get that picky. But if I am looking at a production run, I get rid of any wasted motion. Seconds add up....30 seconds per part doesn't seem like much, till you multiply it over 2000 parts.

I totally agree with this.  

It needs to become ingrained as a mindset.  "how can I save a few seconds?"  

I used to be a .1 rapid plane guy when I was doing prototype programming.  Now I am a .05 Rapid plane guy.  lol

When I was teaching programming, I used to explain to the students that our job was not to make parts.  Our job is to remove material.  The faster we remove material, the shorter the cycle time is for the part and the more profitable the shop is and the more secure my job is as a programmer.

 

[crazy^millman]

2 hours ago, JParis said:

We don't have any...

As programmers we have about 0% say in what the company buys...so, we use what they put on the floor.

All I know at the moment, is where have 21 HMC's....2 more standalone HMC's are due to be dropped in the middle of July and an order that looks to be coming will put 4 more HMC's in play..plus 4 new lathes

Yes sir that is my job then yes sir I will do it to the best of my ability with what I got to get it done.

[cncappsjames]

19 hours ago, JParis said:

We don't have any...

As programmers we have about 0% say in what the company buys...so, we use what they put on the floor.

All I know at the moment, is where have 21 HMC's....2 more standalone HMC's are due to be dropped in the middle of July and an order that looks to be coming will put 4 more HMC's in play..plus 4 new lathes

Management thinking is SO short sighted. You are WELL beyond the point where alternative manufacturing methods should be examined.

JM2CFWIW

[JParis]

44 minutes ago, cncappsjames said:

Management thinking is SO short sighted. You are WELL beyond the point where alternative manufacturing methods should be examined.

JM2CFWIW

Oh, they explored a Rotary Transfer machine....several factors kept them from going that route...cost being one but a larger factor......getting up and keeping it running...it so different that we don't currently have the people to staff it....

Hell, at this point in time we're down at least 6 operators and a couple of setup guys...

Automation I have gotten quickly up on their radar and that is getting some very good traction...

But no, we have no real say in Machines, hell, we're just getting traction on getting some options that would be helpful, though we can get anything we want so long as it's a Mazak....

When you're doing $XXX,XXX,XXX+ in business they feel pretty good about how they got here.

[cncappsjames]

I wasn't necessarily alluding to RTM's. Those are unique beasts suited to certain types of parts AND require a certain type of staff to own and maintain... automotive, connectors, fasteners, fittings, etc... are the industries that can better support RTM's.

Limiting things to Mazak is what I had in mind because I know you guys are a strict Mazak house. We went into a Mazak house and just xxxxing cleaned their clocks on turning center improvements with Eurotechs. Slashed cycle times by double digits in every single case without too much program modification.

[JFK_LC_MFG]

I use the old style toolpaths while the other programmer in our mold shop uses all the new high speed routines. I routinely whup him for speed. I got over burning up cutters long ago. Run 'em hard, change 'em out, then send 'em out to resharp. Turning all of your rapid moves into feed moves and retracting dangerously close to your workpieces hasn't been a winner in our shop. Someday I'm going to put more effort into trying them myself and I'd wager I'll whup him some more. Really more about you and how you use these strategies than the strategies themselves.

[neurosis]

3 minutes ago, JFK_LC_MFG said:

Turning all of your rapid moves into feed moves and retracting dangerously close to your workpieces hasn't been a winner in our shop.

We have a couple of older machines that the paths just don't work as well on.  Once in a while we can hit a sweet spot on them but more often than not, I have to use older machining methods.  Or sometimes I'll still use the dynamic paths but with more conventional speeds, feeds, step overs, etc.  I still get better tool life this way. 

Most of our newer equipment does very well. 

I've figured out over the years, and this could just be me putting limitations on myself, that they don't work in every scenario.