Got Bugs? (Trouble with my SP600)

[MrComment]

Heres the deal.
Im trying to measure the ID and location of simple hole approximately 17mm in Dia. I want to scan it though.

1st: I created and auto feature of the circle by clicking on the CAD model.
The circle is perfect at this point. Exactly what I would expect from the CAD.

2nd: Measure the circle with the SP600 via touch points with the Auto Circle.
The circle is clearly off location in X by about 1mm and slightly large in D, but I've expected to see this also.

3rd: Create an alignment to the auto feature, and measured circle. The CAD model and the hole become realigned perfectly as expected.

4th: Using the Linear closed scan above I click on my starting point and the direction of the scan, then change the value in Z to match my depth I want to measure the hole (-0.5mm) at and this also levels my cut plane (0,0,1). After verifying that only the CAD surfaces that I want are selected (in this case the hole), I then click on the Generate command. The Demon shows 365 hits in the hole exactly were I want them.

5th: Verifing that the following settings have been selected, and I uncheck measure option. Then click create. The screen goes nuts for a second as it generates hits for the scan but then the scan command looks ok.

Linear Closed Scan Settings:
Direction 1 Tech: = Nullfilter
Exec Controls = Defined
Probe Comp = Checked
Nominals Method = Nominals
Tolerance = 0.100mm
Only Selected = Checked

Now heres where it goes wrong for me..

If I construct a circle before measuring the actual hole, the constructed circle turns out with the correct Theo data from the pre-measured Scan points.

But if I construct the circle after I execute the scan I get garbage Theos for my constructed circle. Actually the Theo appear "almost" perfect to the measured results (within a micron plus or minus).

Regardless, I spuradically get the "could not Find Nominals" error message box. Considering that Im working directly off the CAD model, and I dont want it to be looking for "new" nominals. I want it to use the original Theos which were created from the CAD model when I first created the scanned hole.

I also have Find Nominals turned off in the Setup options.

Both my Low Level Matrix and my Probe Calibration are setup and seem good. I dont believe these would have anything to do with my theo values changing anyway?

What else could I be missing? It clearly isnt working as I would have expected. I just got my new toy (the SP600) a couple of days ago, but I dont think its me this time.

Thanks in advance guys

[Mike N.]

At first I would have thought you were using 3.5mr2 (like me)....but no...4.1....I'm surprised that the Nominals/findnominals thing is still acting strange after so many updated versions.

Sorry no positive advice from me but a shoulder to cry on....I have a sp600 and similar trouble with 3.5mr2 and findnoms/nominals

[MrComment]

I'm surprised that the Nominals/findnominals thing is still acting strange after so many updated versions.

Sorry no positive advice from me but a shoulder to cry on....I have a sp600 and similar trouble with 3.5mr2 and findnoms/nominals

Well, at least I know Im not the only one that noticed this error, and that its not just v4.1.

Strangely Im not surprised it does work right.

Thinking as Im writing this..

Any of our VB gurus tried this or know if this would end up working right, before I try it myself? Ideally Id like the scan to work like an auto feature. Meaning I could have seperate target values for each of the scan points to allow for significant yet repeatable part deviation (I work in plastics ). If it would work right it would save me from having to touch point measure and then align to each circle prior to the scan.

1. Create a new scan, but leave it unmeasured.

2. Send the correct Theo values for each generated hit to a text file or excel, whichever. (Before they get screwed up by PCDMIS, "Findnoms")

3. Change the Scan settings to "Master" nominals mode. (Only to rid yourself of the bogus "Findnom" error message)

4. Execute the Scan.

5. Save the measured values of each hit to a seperate text file as your Target hit values.

6. Thereafter prior to executing each scan upload the target data file into the Theo values for each hit.

7. Execute the Scan, which now has the uploaded target data.

8. After the Scan has completed run another script to replace each hits Theos with the "original" and correct saved Theos in the first text file.

Sure seems like there would be an easier way.

Anyone got an suggestions or easier work arounds?

[Boomer]

Well, at least I know Im not the only one that noticed this error, and that its not just v4.1.

Strangely Im not surprised it does work right.

Thinking as Im writing this..

Any of our VB gurus tried this or know if this would end up working right, before I try it myself? Ideally Id like the scan to work like an auto feature. Meaning I could have seperate target values for each of the scan points to allow for significant yet repeatable part deviation (I work in plastics ). If it would work right it would save me from having to touch point measure and then align to each circle prior to the scan.

1. Create a new scan, but leave it unmeasured.

2. Send the correct Theo values for each generated hit to a text file or excel, whichever. (Before they get screwed up by PCDMIS, "Findnoms")

3. Change the Scan settings to "Master" nominals mode. (Only to rid yourself of the bogus "Findnom" error message)

4. Execute the Scan.

5. Save the measured values of each hit to a seperate text file as your Target hit values.

6. Thereafter prior to executing each scan upload the target data file into the Theo values for each hit.

7. Execute the Scan, which now has the uploaded target data.

8. After the Scan has completed run another script to replace each hits Theos with the "original" and correct saved Theos in the first text file.

Sure seems like there would be an easier way.

Anyone got an suggestions or easier work arounds?

If you are using 3.7 or later, which you are, try using circle scan (insert->scan->circle) you have almost all the same options as a auto circle. I use it all the time with our sp600..like it much better that using the linear closed scan on a diameter for the same reasons that you talked about (nominals issue). heres a clip..

MOVE/CLEARPLANE
OD_SCN =BASICSCAN/CIRCLE,SHOWHITS=NO,SHOWALLPARAMS=NO
ENDSCAN
OD_CIR =FEAT/CIRCLE,RECT,OUT,LEAST_SQR
THEO/0,0,-0.1731,0,0,1,10.313
ACTL/-0.0002,0.0003,-0.1745,0,0,1,10.3091
CONSTR/CIRCLE,BF,OD_SCN,,
OUTLIER_REMOVAL/ON,3
FILTER/ON,UPR=50

[MrComment]

Boomer,

I took a look at the Circle Scan settings, but I didnt see a "nominals" option in the drop down list?

Master and Findnoms are my only options for that type of scan. Why isnt there an option to just use the CAD Theos it finds during creation for these scans? As we all know "Findnoms" questionably works at best. Ok maybe its just me, but I dont trust the software to keep finding the theos over and over again. You know the PCDMIS moto "If it isnt already broke it will be". Maybe I have to choose different settings for it to appear in the list somewhere else first? You know one of those bizzion little checkboxes scattered everywhere. Maybe one of them isnt checked in my software.

Also anyone know where the check box is thats says, "Make PCDMIS work as intended!" I seem to have forgot.

Thanks again

[MrComment]

Ok heres an update and a new problem.

Problem 1: ---- Update ----
The "Findnoms" option on is the only way to get the CAD nominals into the Scan's Theo values. I dont like this option, but its the only one that remotely works at the moment.

Problem #2:
The scans do not have the same number of "hits" between executions or the originally generated points.

1. I generate the hits for SCN1, and the hit count will be say 241.
2. Execute the scan on a machine for part1, and follow with this command ASSIGN/V1 = SCN1.NUMHITS (results will be around 236)
3. Even worse Part to part I rarely ever have the same number of hits. (230-240ish typically)

I have no idea how to fix this.

Maybe PCDMIS is ignoring some of the hits? By I have no idea which ones.

Anyone else notice this problem or have a way to fix it? I want to compare the T values for each hit Part to Part for statiscial Analysis. but since I dont have the same number of hits for each scan It making this extremely annoying...

Thanks again

[Boomer]

Surface finish question

What is the surface finish of the surfaces like?? If it is a bit on the rough side, I could see a variation in the number of hits. 2ndly what is your scan speed set at, have you done a graphical analysis of the scan, does it look like it jumped over areas??? Try setting your scan speed at half it current value.

[MrComment]

Its a smooth finish on a plastic molded part.
The graphical analysis looked ok for the first part, but I'll have to look at a few more parts in detail.
The scan speed is currently set at 10mm/sec.
I'll try it at half speed again.