CNC Mill as a poor mans CMM?

[kunfuzed]

So management wont pony up the cash for a shop floor cmm, and checking stuff into Quality is a pain at times, and frequently we have parts on a machine that get machined undersized, taken off, checked, and finished.

 

My question is, roughly what would it cost to outfit a (HAAS) 3x machine to perform cmm functions? (and enhance use of the machine itself...)

 

What I think we need..

 

1. Probe

2. Macro Options installed

3. Verisurf plug in for Mcam

4. Beer

5.Training

 

Thoughts?

 

Thanks!

[The Cathedral]

Not sure about the Haas, but we've outfitted at least five Fanuc machines with Renishaw OMP-60 probes with full macros, and that install runs around $10k each. We also use Productivity Plus for offline programming of the probe; we have the stand alone package, but the plug in for Mastercam costs around $2k (which is about half the standalone price [depending on your reseller, of course.]) If your Haas is older and uses RS232, you'll need a separate software program on your DNC computer to read what the Renishaw macros output using DPRINT. (You don't need this at all to run the probes or anything, but it sorts and collects all the information into a nice excel spreadsheet.) So the whole software suite is around $12k including training and install.

 

So for your first install, I'd say you're looking at around $22k; after that, if you want to outfit more machines, all you need is more hardware and macros and those are $10k.

 

 

Of course, then you run into the problem of checking a part on the same machine it was made on... Any error in the machine will be an error in the probe.

[GPC_CNC]

You also have to consider your quality needs. Like any gage a CMM needs to be qualified that it is measuring accurately. All articles I've read regarding this type of thing point to ball bar testing, laser auto columnating, etc, etc when using the machine tool for measuring purposes. This also needs to be done after any crashes occur.

 

Our CMM's are pretty much the final word where I am at though. Aerospace/Defense all require certification for anything used for measuring. If you're making your own thing, it probably will be good enough for all but the tightest of tolerances. Another thing to consider is that the software isn't designed to make a 3D plane like a CMM would. You can't measure an angled plane (something you would probably have to surface in a 3X machine) and make an alignment to that plane to measure from. Like you said, it would be a pretty poor mans CMM.

 

However, like Cathedral said. Your measurements will only be as good as the machine.

 

Greg

[Gorn@GT]

You want to give your Haas dealer a call. They sell a package. You may need the software update in your machine to run the newest renishaw macros. Renishaw also sells a standalone program system but if you are just starting out with basic stuff you can just use their existing Macros and fill in the variables. Our local dealer offers training in using the standard macros. I combined that with the software update and the install so we got everything for 8 hours of service call.

 

If you are going to use this for inspection I would suggest the Reishaw Ball Bar tester to keep an eye on the machine. It is not as good as laser calibration but if someone bumps something and tweaks the machine it will tell you. I still do not think it would pass an aerospace audit as acceptable inspection method even with a gage R&R but at least you have a much better feel for what you are sending into QA.

[The Cathedral]

You can't measure an angled plane (something you would probably have to surface in a 3X machine) and make an alignment to that plane to measure from. Like you said, it would be a pretty poor mans CMM.

 

 

Greg

 

The Prod + software is actually pretty powerful, and you can measure angled planes, do alignments, pull data, etc. from some really complicated geometric shapes. I use it all the time to set my alignment from intersecting, 3D planes on our 3+2 mills. However, organic, non-geometric features are beyond it's capabilities. 

 

You wouldn't be able to do that using just the built-in macros, however. You either need the stand alone software or the Mastercam plug in and a 3D model.

[EX-wccprogrammer]

If you're really strapped for cash, all you really need is the machine-side probe and macro capability.  You will need software like Verisurf if you are trying to check 3D features.  But if you are checking dimensional features, macro programming can be done by hand, without all of the add-ons and licenses mentioned above.

 

Granted, all of the above make life easier, but it can be done without.

[THEE THAINZ™]

RENISHAW's Regional sales manager for the west coat (he used to do mid west) area is Dave Grey. Office phone out of MI is 810-629-2874. Call your HAAS reseller also if your HAAS is new enough it might have what you need in it macro wise then to buy the probe and activate the software it might run you around $15000.00 total.

[scooke4073]

I wouldn't even consider doing it unless you have scales on each axis...and a machine that is straight (laser verified). In addition I would only use a string gauge probe (OMP600 or equivlant) and never cut another chip on the machine.

 

I've done testing and shown better repeatability on the machine (Mazak Variaxis) than an offline Zeiss CMM (using gage R&R study). It is possible to do....the hardest part is convincing a customer that it is an accurate inspection method.

[The Cathedral]

I wouldn't even consider doing it unless you have scales on each axis...and a machine that is straight (laser verified). In addition I would only use a string gauge probe (OMP600 or equivlant) and never cut another chip on the machine.

 

I've done testing and shown better repeatability on the machine (Mazak Variaxis) than an offline Zeiss CMM (using gage R&R study). It is possible to do....the hardest part is convincing a customer that it is an accurate inspection method.

 

Unless he's running tight tolerance medical or aerospace, I'm going to have to respectfully disagree. If the parts he's making fall into the general +/- .005" tolerance the machine is more than capable of keeping it in there and running (as long as the machine runs true, no backlash, etc.) We use our probes day in and day out and they can keep a part within one or two thousands repeatability, verified by offline CMM.

 

I guess it all depends on the type of work, that's really the defining factor.

 

I do agree that the strain gauge probe is definitely more precise than the mechanical trigger probe, but that also adds a few k onto the price tag.

[kunfuzed]

To clarify, we would not be buying off parts, but mostly checking difficult dimensions, and if a reasonable calibration method was possible, just make sure parts were good before going to Quality. Also, make sure parts are good before comming off the machine.

[kunfuzed]

I would say our tightest tolerances would be say .001 true position on hole patterns, or +/_ .0005 on a large bore. Lots of others stuff is .005, .010, and .030 tolerances. Big thing is we want a good idea that it's coming off the machine good as well.

 

The situation we have today is checking a surface profile to provided cad geometry. Not tight, just complex. And it a a pain havving it CMM'D in Quality.

[EX-wccprogrammer]

Macros in the machine are not going to be able to analyze a profile, with the exception of a very slick, custom written macro.

 

Without one, you will need to collect data for the profile points, and upload that data to your CAD.  Then, using software like Verisurf, the data can be analyzed.

 

This is still better than taking the part off the machine to check it, IMHO. 

[kunfuzed]

Thanks for the responses guys!  Is Verisurf the software that would be able to write a probing path on the machine?

[EX-wccprogrammer]

Verisurf checks the data.  Renishaw Probing Plus might write what you need.  Or you may have to write by hand.

[Sticky]

If you have a tight and square machine, and your parts tolerances aren't too tight its very doable, an the return is worthwhile.

 

One thing not mentioned here beyond inspection capabilities are the reduced setup times you can gain.

[The Cathedral]

If you get Renishaw, you'll probably end up using this to write the paths:

 

[dstryr]

lol no way you are going to check TP of .001 on your HAAS with a renishaw probe....

 

Run the inspection program 5 times in a row and tell me if the results change due to thermal growth.

[dstryr]

You can get a Zeiss Duramax for the shop floor for like 50k last time I quoted one.

[CADCAM3D5AXIS]

Hows the garlic down there ???   ^^^^^^

[EX-wccprogrammer]

dstryr, on 17 Jul 2014 - 12:45 PM, said:

lol no way you are going to check TP of .001 on your HAAS with a renishaw probe....

 

Run the inspection program 5 times in a row and tell me if the results change due to thermal growth.

We run probing on a Haas VF6/50 and get repeatability within .0004