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proper way to set z height for face milling rough cut parts

Yeah when I had to machine a B Side Mold plate, I would have to
load the carousel full of drills, unload the whole thing,
load it up again with reamers, unload it
load it up again with all the roughing end mills,unload
and then FINALLY load it full of finishers.
sometimes there was even too many for a 20 tool carousel, and the above process had to be broken down further. :D
 
I touch off every tool as soon as it goes in the carousel...no loading a bunch of tools and then touching them all off...too easy for me to miss one if I get distracted by the phone or something.

Do you have a Renishaw probe?
I use a macro on my Brother to touch off all tools with 1 push of cycle start.
 
Hi Mtndew:
You wrote:
"Do you have a Renishaw probe?"

Nope it's a 1991 Minimill...no tool probe and no part probe.
It might be possible to put one on, but I'd expect a major headache to do so, and I can do what I need to do without them and still be profitable, so I've never even bothered to look into it.

The shop I'm setting up for a customer of mine has a DT-2 with probes, and yeah, it's nice, but for the kind of work I do, it doesn't improve my bottom line enough to matter.

Don't forget I'm retired...I still do this because it's fun for me and keeps me out of my Lovely Wife's hair.
I like the pin money too.
But my shop stopped being a real business several years ago.

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com
 
I don't use control comp, but that's just currently in my shop, not that I think its the best way, nonono.
Well, without it, and name-brand, high quality endmills obviously coming in under their nominal dimension, somebody needs to be compensating for the undercut sizes somewhere, whether that's in the CAM or at the control. No fat fingers allowed doing precision work. But then, we never ever used 'operators.' It was the antithesis of what we were doing: a staff of engineers, doing the design, manufacturing, inspection and testing with all the middleman steps removed.

But there is another thing, most if not all machinists I know will tell you that a drill chuck, even though they come in holder types for CNC's, should not be used in CNC's, I agree
but people starting out in their garage don't have the money to buy a sweaty fist full of collets, so they buy drill chucks.
You keep writing like I'm inexperienced and somehow you're educating me from my "YouTube ways". I deliberately stocked the lab with two full sets of ER16 and ER32 collets and an assortment of long and short holders, after everything was accounted for and loaded in the machines. That meant never needing to go looking for the collet that happened to be holding the 1/4" endmill right now and needing it for something else. The tool changer was fully kitted and then the tool box was filled.

And that's exactly how my personal machine is setup as well. I went to drill chucks from ER collets as an educated decision after doing the collet route. I have too many ER holders. I just counted 12 ER 16 and 32 holders on the back of the machine and the carousel is ready to go. The drawer has two full sets of ER collet in 16 and 32 and some extras of common sizes.

I heard all the excuses for not using drill chucks. They exist because they're fast to setup. I started with two and bought two more to arrive at this configuration. In reality, they run plenty true enough for most holes. If pull-out, high RPM and super precision were critical, I could load an ER tool. That's what the extra pockets are for. But having them in order means I can run the carousel until it's roughly pointing at me, install all four drills and run the sequential Renishaw touch-off in one MDI step. Four offsets can load while I do something else.

One year, we did a tour of maybe forty college engineering interns. It was a 30-40 minute introduction to manufacturing methods and rapid development. The tour started with one of the engineers designing a part in Catia. It was mostly done but, to prove the point, he did the last few steps while they watched on a big screen TV.

He saved the part and pulled it into Mastercam and did an introduction to what that does and how it worked. The tour moved on to the machines while he continued programming real-time. We moved to round parts, showed the SL-20 lathe, explained how that worked, showed some parts, moved to our VF-5XT, did the same there, moved to our gantry router, did the same. By this point the engineer had programmed the part in Mastercam and walked it over, live and cut the part they saw being worked on 20 minutes ago.

Manufacturing time includes all the programming and setup. Rapid setup and getting the part into your hands is often the goal.

Yes, if you've used every pocket for drills and then again for that many reamers, you had a unique, outlier of a situation. We could have done the same if that were necessary. For the other 99% of the work, a pre-loaded carousel and tool library was king.
 
I deliberately stocked the lab with two full sets of ER16 and ER32 collets and an assortment of long and short holders, after everything was accounted for and loaded in the machines. That meant never needing to go looking for the collet that happened to be holding the 1/4" endmill right now and needing it for something else.
Yeah I usually recommend to new guys instead of ER16 and ER32, not dividing your funds,
just get all holders ER20 and buy 2 sets of standard collets, 2 sets of metric collets, and 5 of each standard fractional size for end mills.
so .5, .375, .25, .1875, .125 5 of each.
This setup gets a lot done. If you need a larger than 1/2" tool then buy those couple ER32 holders with the collet just for that tool size.

2 Cents:cheers:
 
Well, without it, and name-brand, high quality endmills obviously coming in under their nominal dimension, somebody needs to be compensating for the undercut sizes somewhere, whether that's in the CAM or at the control. No fat fingers allowed doing precision work. But then, we never ever used 'operators.' It was the antithesis of what we were doing: a staff of engineers, doing the design, manufacturing, inspection and testing with all the middleman steps removed.
You do know that you can output with computer comp, but control wear functionality correct?
This is also what the other poster stated (computer comp with control wear)
In this way you have to use the correct size end mill, but you can dial it in with wear,
So no fat fingering diameters in the control.
 
You do know that you can output with computer comp, but control wear functionality correct?
This is also what the other poster stated (computer comp with control wear)
In this way you have to use the correct size end mill, but you can dial it in with wear,
So no fat fingering diameters in the control.
The Renishaw software measures and loads the diameter into the diameter field. No way that I'm aware of to change that, short of editing all the macros.

And no, you can't use wear to control cutter compensation unless you use control comp in the first place. Either way, you're using control comp. It's just a question of whether the diameter is actual or zero.
 
The Renishaw software measures and loads the diameter into the diameter field. No way that I'm aware of to change that, short of editing all the macros.

And no, you can't use wear to control cutter compensation unless you use control comp in the first place. Either way, you're using control comp. It's just a question of whether the diameter is actual or zero.
Been so long since I've used it, But video says you can, must be fake news, thatd be different.
 
Been so long since I've used it, But video says you can, must be fake news, thatd be different.
The Renishaw software measures and loads the diameter into the diameter field. No way that I'm aware of to change that, short of editing all the macros.

And no, you can't use wear to control cutter compensation unless you use control comp in the first place. Either way, you're using control comp. It's just a question of whether the diameter is actual or zero.
 
That reminds me, love this response.
He's a job shop with automation. Yes, for him, he would set up to run many hundreds or thousands of parts. Yes, it would take a long time to set up a bucket wheel excavator to dig a swimming pool. He's tuning seconds out of the process and needs a cutter to not wear or break prematurely.

Everything I've ever needed to do has been in batches of less than a hundred parts but, very high mix. Set up time is king. Cycle time is secondary or often nearly irrelevant. What matters is precision and consistency. If the 1/2" endmill is tuned to hit the numbers on this part, the next three, totally different parts will also likely hit the numbers on the first try.
 
Been so long since I've used it, But video says you can, must be fake news, thatd be different.
You're focusing on Mastercam. Yes, Mastercam can do that. Renishaw wrote all the macros on the Haas and I assume the packages they sell for other brands to be similar.

Renishaw's macros write the cutter diameter to the diameter offset field. It does not do a wear comp number. Yeah, it's just macros and could be changed but, there's no reason except for the length of cutter comp on and off ramps.
 
And no, you can't use wear to control cutter compensation unless you use control comp in the first place. Either way, you're using control comp. It's just a question of whether the diameter is actual or zero.
You're arguing semantics. To me, "wear comp" means only the deviation from nominal is in the control's D value, which means it's safe to run with all zeros in the control's D fields. This is far simpler, safer, and faster for setup, and you only need to probe the length. Then only tools making critical features need to be dialed in. "Control comp" means the full size of the tool is in the D value, which means you must have a value, and a correct value, in each D field, or you crash. This takes more time, and invites user error. It also means that when you look at your offset table, it's a big pile o' numbers (slower for the eye), rather than a clean column of zeros with a number here and there for your critical tools. KISS principle says use wear offset on tools that need offset.
 
You're focusing on Mastercam. Yes, Mastercam can do that. Renishaw wrote all the macros on the Haas and I assume the packages they sell for other brands to be similar.

Renishaw's macros write the cutter diameter to the diameter offset field. It does not do a wear comp number. Yeah, it's just macros and could be changed but, there's no reason except for the length of cutter comp on and off ramps.
I don't bother probing diameters, just lengths. Reason being, for one, it takes more time to probe the diameter, and two, it won't get your part dead nuts anyway. It'll get close, and I can see for some people it may be close enough, but probing the tool can't account for deflection, so I need to adjust from there anyway.
 
Just messn with yah Donkey,
Reminds me I haven't went around the back of a machine for a while and spun a cordless drill chuck against the cabinet while someones running a machine :eek:haha
Teaches new guys not to be afraid to hit the e-stop. :bawling::D

Or tie a zip tie to a tool holder while they're at lunch. :D
 
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I have to ask on tool diameter comps.
Feed rates.
1 inch hole, 1/16 diameter end mill and 5/8 diameter end mill. We all know this feed different to hold a chip load. The same thing on outside corners.
If I am the control and do not know the radius out here I go by centerline and hope you did the math or the go slow or go fast.
Some controls handle this change based on what is in as tool diameter and some do not. Same with all CAM systems.
If you have the best CNC stuff and lie to it about tool diameters it will make dumb and stupid decisions.
 
I have to ask on tool diameter comps.
Feed rates.
1 inch hole, 1/16 diameter end mill and 5/8 diameter end mill. We all know this feed different to hold a chip load. The same thing on outside corners.
If I am the control and do not know the radius out here I go by centerline and hope you did the math or the go slow or go fast.
Some controls handle this change based on what is in as tool diameter and some do not. Same with all CAM systems.
If you have the best CNC stuff and lie to it about tool diameters it will make dumb and stupid decisions.
Interesting, So your saying the feed rate, is optimized based on chip load, modified by the cutter diameter parameter, totally legit.
But I don't remember a control modifying the feed rate when I did cutter comp, been a while though, It only comped the tool, didn't change any feed rates?
 
I have to ask on tool diameter comps.
Feed rates.
1 inch hole, 1/16 diameter end mill and 5/8 diameter end mill. We all know this feed different to hold a chip load. The same thing on outside corners.
If I am the control and do not know the radius out here I go by centerline and hope you did the math or the go slow or go fast.
Some controls handle this change based on what is in as tool diameter and some do not. Same with all CAM systems.
If you have the best CNC stuff and lie to it about tool diameters it will make dumb and stupid decisions.
This shit usually make my brain hurt, but if I remember correct, it is the same, you comp at control on a rad vs dia to get feed.
or you comp in the CAM vs rad to get feed,
and if your using CAM comp+wear for tight tolerances your only changing the dia param very little at control so the feed rates actually are the almost the same.

I don't know, Its late, someone don't start showing the sin of cutter engagement for a given diameter compared to another, or I'm out, haha
and I'm not getting paid for it, teaching cutter comp was one of my pet peeves, people have a hard time wrapping their head around it,
especially the pierce before point, and pierce after comp, for left right orientation from back in nam. :D
 








 
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