Fastprobe

[dwade]

I've searched the forum and can't find much on this and tech support hasn't responded to my case inquiry (it's been a week....) but I am wanting to know if turning on FASTPROBE has any adverse affects to adaptive scanning.

Running 2019R2 with the LEITZ_LSPX1H_T probe head

Any and all input is greatly appreciated

Duane

[BKulpa]

I haven't seen any affects. I use fast probing on production programs to do my preliminary alignments in DCC. Just a 3 point plane, 4 point circle, single point for rotation. Basically to ensure the part is located in the fixture before the scanning magic starts. It was recommended by an applications engineer from Hexagon who was trying to help speed up my routines. V2016-2019

[Matthew D. Hoedeman]

I think (THINK!) that fast-probe is only effective for single point touches. What it does is register the touch on contact instead of "hit, draw back slow, register when the deflection hits zero", makes it like a TP20.

It shouldn't have any effect on scanning as those are not single touches.

[BKulpa]

Dan is correct on this. But it's no as accurate as your normal points with a scanning head.

[Matthew D. Hoedeman]

dan? who is 'dan'?

[DAN_M]

BKulpa was thinking about little ole' me

[Schlag]

Yep, what Matt said. It has no effects on scanning. We use it all the time Speeds it up a ton. You do +/-.005 and such, you will see no change what so ever.

[dwade]

What I've been playing with is using FASTPROBE and adjusting the TOUCHSPEED settings to reduce run times. I've gotten very good and repeatable results (correlation between measurement and type1 data) by using FASTPROBE and and TOUCHSPEED at 2mm/sec. The parts I've been trying to reduce runtime on have positional callouts at 0.05mm and linear dims to +/-0.025mm. The lowest CG from the type1 was 1.54 (must be 1.33 or above to pass) with most running 15-80 CG. Correlation between standard probing with the LEITZ_LSPX1H_T and FASTPROBE turned on is less than 14% of feature tolerance as our procedure states 25% max to pass.

I've taken a 7:43 minute program down to 6:03 minutes on 1 mill op CMM program and the final audit program ran at 11:53 minutes and it is down to 10:14. I've also turned FLY on but am having issues with the probe clipping the mouth of the Ø3.25mm holes. I've tried adjusting the move points up to 12mm above the surface of the part and it still clips the mouth and I've tried using AUTOMOVES within the auto circles and it still clips the mouth of the hole so I ended up turning FLY off when measuring the 16 holes in the part. Hexagon tech support simply told me they removed the option of adjusting the radius for the fly and when I asked for help in determining what parameters I need to play with I've heard nothing back and that has been 2 weeks ago....

Than k you all for the feed back and help.

[DAN_M]

What I've been playing with is using FASTPROBE and adjusting the TOUCHSPEED settings to reduce run times. I've gotten very good and repeatable results (correlation between measurement and type1 data) by using FASTPROBE and and TOUCHSPEED at 2mm/sec. The parts I've been trying to reduce runtime on have positional callouts at 0.05mm and linear dims to +/-0.025mm. The lowest CG from the type1 was 1.54 (must be 1.33 or above to pass) with most running 15-80 CG. Correlation between standard probing with the LEITZ_LSPX1H_T and FASTPROBE turned on is less than 14% of feature tolerance as our procedure states 25% max to pass.

I've taken a 7:43 minute program down to 6:03 minutes on 1 mill op CMM program and the final audit program ran at 11:53 minutes and it is down to 10:14. I've also turned FLY on but am having issues with the probe clipping the mouth of the Ø3.25mm holes. I've tried adjusting the move points up to 12mm above the surface of the part and it still clips the mouth and I've tried using AUTOMOVES within the auto circles and it still clips the mouth of the hole so I ended up turning FLY off when measuring the 16 holes in the part. Hexagon tech support simply told me they removed the option of adjusting the radius for the fly and when I asked for help in determining what parameters I need to play with I've heard nothing back and that has been 2 weeks ago....

Than k you all for the feed back and help.

about fly...can confirm...you used to be able to edit the value of the arc size it will travel but now you can't as of like 2016-ish or something

i use fly all of the time...every once in a while when it wants to clip a surface like you described I turn fly off in that area and then turn it back on after that feature is probed & good to go after that

[dwade]

Aggravating that they took this option away and I can understand why based on what the AE told me but.... they should have set it to a specific radius movement and not made it variable based on controller model, movespeed, prehit/retract and anything they felt like adding in. A 1/2" of clearance should clear those holes and I can't see going any higher. It moves around the outer edges of the part just like it should with 6mm of clearance between move points but it doesn't like small holes.

[Hi-Tech Redneck]

So, if I'm reading this correctly, Say I have a program with single point touches and scans and I turn the "Fastprobe" command on at the beginning of the program, it will only affect the single point touches?
Or, do i have to disable it before every scan and re-enable afterwards?
Thanks

[neil.challinor]

It only affects single point probing. It turns off the normal analogue probe functionality and makes it function in a similar way to touch trigger systems. Probing individual hits will be slightly quicker (~1sec per hit rather than ~1.5sec) but also less accurate - which is why the high accuracy machines (like Leitz PMM) do not support fastprobe.

Normally when an analogue probe takes a discrete hit it waits until a maximum force setting is reached. Then it starts to back away in the opposite direction to which it is deflected - constantly adjusting this "back off vector" whilst streaming points to the controller until it senses that it is no longer in contact with the part. The controller uses some proprietary algorithms to determine the optimum point and surface vector and returns these to the software.

For touch trigger probing systems and analogue systems that have fastprobe active, the probe will travel in along the THEO surface vector until it detects a certain level of deflection, at which point it will record the probe position as the measured value.

[Cris_C]

So, if I'm reading this correctly, Say I have a program with single point touches and scans and I turn the "Fastprobe" command on at the beginning of the program, it will only affect the single point touches?
Or, do i have to disable it before every scan and re-enable afterwards?
Thanks

Fastprobe mode is only for touch points. If it is enabled, analog scans will still operate as normal.

[DAN_M]

So, if I'm reading this correctly, Say I have a program with single point touches and scans and I turn the "Fastprobe" command on at the beginning of the program, it will only affect the single point touches?
Or, do i have to disable it before every scan and re-enable afterwards?
Thanks

no need to disable the command. it will only work for touch points. drag-scans will still be normal

[Peter Fuller]

I can confirm that fast probe is not active while analogue scans are taking place. This changes the behavior of single point type measurement.

[garrybrown]

Thanks for this interesting information!