Tip Calibration Procedure (looking to compare methods)

[SuperCrash]

Gentlemen-
I originally posted in the old forum, because I wasn't aware of this newer, shiny-er forum. The original link is here. I'm reposting in this forum as people may not check the old one.

The basic upshot of the post is thus: I am using a 2x20mm tip on a TP20 to find the datum sphere, and then not using that tip for anything else. The CMM exists out in the shop, runs many programs, etc., so the tips that are out there do exhibit wear over time. By using a "virgin" tip and probe, I'm minimizing the error in finding the datum sphere. I was just curious if anyone else is using this method.

SC

Relevant stats:
CMM: B&S ONE
PC-DMIS 3.7 MR3
Probe Head: MH8
TP20 probe system
Probe Rack: MCR20
Extension(s): 50mm carbon fiber (PECF1)
Datum ball: straight fixed, 0,0,1
OS: MS Windows XP Pro Version 5.1.2600 SP2 Build 2600
Total Physical Memory: 512.50 MB
Graphics: Mobo integrated

[craiger_ny]

No I don't use that method, I don't believe it is necessary but I'll keep an open mind as posts come in.

BTW that is not the "old" board it is just the non-alcoholic one.

Craig

[SuperCrash]

No I don't use that method, I don't believe it is necessary but I'll keep an open mind as posts come in.

BTW that is not the "old" board it is just the non-alcoholic one.

Craig

[email protected]#[email protected]# Blasphemy! How did I fall into that board then?

Glad to know I'm in the right place now.

Yeah, we'll see. Most of the comments on the other board indicated that no one else does what I do; however, I did argue that I saw some of the stranger qual problems disappear when I switched to this method. Whatever works, right?

SC

[#2#]

I do not do this. If I understand correctly you load the 2x20 and then cal. A0B0. When you do this you answer that the sphere has moved and take your manual hit. Then you let it run dcc for the rest. Then, when you want to cal. your other rubys you will answer no to "has the sphere moved".

Is this correct?

I assume the reason you do this is to help ensure the vectors of your cal hits are as close to perfect as possible. I believe (note this is what I have learned/been told by no reputable source) that when you run a cal. pcdmis will calculate the actual position of the sphere and save that for reference next time you answer "no". Otherwise how would answering "no" work? If this is the case you can run whatever tip you want for the first run. I would calibrate just A0B0 and answer "yes" the sphere has moved. Then, when it is finished run again answering "no".

In reality, what does it matter as long as your std. dev. is good shouldn't the error for the vectors being off be negligable or compensated for?

[Gregl]

If you have a tip changer or use mulipule tips, you need a master probe.

I have 8 different tips that I use, Up to 6 different ones in a program, and have 1 Qual program that I use that quals all the tips and positions that they are used in all the programs that we use, takes about 35 mins to run. and move the speare to 3 differrnt locations, but the master probe is one that we also use the most. a 4X50mm .

[layout tech]

I have a probe changer and I have no Master Probe.

When I open a program to run it I calibrate any and all tips used in that program but Master Probe I have never hear of that.

I would not even consider running a program that I have not calibrated tips before it is run.

On the shopfloor we have operator run CMM's that I have written a program calibrating all tips used in any of the programs. That program is run at the beginning of each shift. Still no Master Probe. ??????

P.S. Super crash, After running the probe to finetune sphere location you are calibrating all other tips used aren't you???

[John Kingston]

No I don't use that method, I don't believe it is necessary but I'll keep an open mind as posts come in.

BTW that is not the "old" board it is just the non-alcoholic one.

Craig

Matt, Paul and I post in the other board. Therefore, it is not non-alcoholic.

[craiger_ny]

Matt, Paul and I post in the other board. Therefore, it is not non-alcoholic.

I too posted in the other forum and mentioned beer when I did. That thread got pulled so I am inclined to say it is non-alcoholic.

[John Kingston]

http://i58.photobucket.com/albums/g2...gersAvatar.gif




I too posted in the other forum and mentioned beer when I did. That thread got pulled so I am inclined to say it is non-alcoholic.

By other forum, do you mean pc-dmis.com? never had a problem.

Oh, on subject. I use the PC-DMIS calibration method with no modifications.

[cmmguy]

I searched for "Beer" and only found one thread dating back in February. That at least constitutes very DRY.

[Gregl]

After re-reading what I wrote, I correct myself

The reason I need the master probe(tip)
is because I move the Qual Sphere during my tip qual, and the master tip is used for the cmm to know the relationship between a tips qual'ed on position #1 or position #2 or 3.

[John Kingston]

I searched for "Beer" and only found one thread dating back in February. That at least constitutes very DRY.

That is about the time this board came into existence as a replacement for the old B&S board. All the bells and whistles got a lot of us visiting here more than the other.

[Ravenmaniac]

Do you move the positions around due to usable space being consumed by the part to be measured? I'm unfamilaiar with this master "probe tip" uasge. I am however a devout follower of the "alcoholic webstrata members guild" forthwhich our website constitution was founded. But..back to your query, I, like probably alot of others setup their rack accordingly and follow a strict routine of tip calibration for a program as or before it is employed. You would not believe how many times I've found a tip that I calibrated at say, 9am for one program, showing up chipped, dirty, or just plain damaged at 10. Let's see what else turns up over this..............B

[John Kugler]

I was informed by some VERY smart Brown and Sharpe folks that the correct way to calibrate is with a REFERENCE probe. That probe should be as short as possible with the biggest ball possible. As I understand it, that is to ensure that the cal. sphere is found and measured as acurrately as possible so all the rest of the probes find that nice and accurate sphere.






"...he's got big balls, she's got big balls...." - AC/DC

Sorry, couldn't resist.

[craiger_ny]

I was informed by.......Brown and Sharpe folks that the....probe should be as short as possible with the biggest ball possible. As I understand it.......all the rest....find that nice.......

Figures B&S goes and tells us something contrary to what us guys have been told all of our lives. It is nice of them to try to make me feel better about my manhood but my complex has been developed through years of ridicule that B&S will never be able to console.

Craig