D1.1-2015
New Lincoln Electric Robot
Mild steel - A36 or equ.
GMAW-P mode 22
0.045", L56 wire
ArC 90/10
1G and 2F
So, I'm a pretty experienced guy here but recently I found myself helping a company preform a PQR on a new Robot. While running several test joints before we found a repeatable setting with a very good visually acceptable welds (internal and external) I found myself a little stumped on how to correctly transfer some of the variables from the PQR to the WPS. Granted it's a robot and there's a program and I should be able to sleep at night but what would happening if the world would almost come to the end and the robot crashed and the programs were wiped clean? So, where I am really stuck is if I found that my trim and Ultimarc affected the quality of the welds, naturally I would document it on the PQR. But like travel speed, volts, amps, etc. there are tolerances that I can apply when finalizing the WPS. So for an example if travel speed gets plus/minus 10% what would I give to the trim or Ultimarc or some other setting that that the robot uses that's not an essential variable per D1.1? Can I just give them a plus/minus 3 or 4% knowing that if they had too much freedom it would impact it the quality but I gave them nothing then they may have a bad day and would have to rerunning new PQR's?
The welding standard of code lists the minimum requirements for information that must be included in the documentation, i.e., the essential variables (and in the case of ASME, the nonessential and supplementary variables). The contractor is free to include any additional variables and the appropriate ranges they feel are prudent.
The inclusion of information not required by the code or standard can drive anal retentive auditors crazy because they don't know how to handle the additional information. Likewise, if it isn't in the exact format as the sample provided by the working document, they get confused and will sometimes ask that the documentation format made to conform with the sample. The contractor has to make a decision to dig their heels in and stand their ground ( the right course of action) or buckle in and satisfy the dweeb doing the audit (wrong course of action).
One of the problems I've encountered is the nonstandard terminology developed by the manufacturer's marketeers. Their efforts are intentional to make it difficult to apply the WPS to any competitor's welding machine. It keeps the contractor captive because it is very difficult to adapt the WPS to a different model or to a different manufacturer's equipment.
The work around is to record the data using a multichannel oscilloscope and list the parameters using standard AWS terminology. Then the WPS can be used to setup/program any welding machine.
Just my thoughts on the subject.
Best regards - Al
Your "trim" value can be converted to volts with your Lincoln power supply... Its just a setting change in PowerWave Manager (See Attached) My experience is to be very conservative in providing a range for the unit... The wider the range the wider the door has been opened for operators to mess things up.
The "Ultimarc" settings, as Al mentioned can be set into your WPS if you choose to.. If you have a system that works, why provide a range at all with the Ultimarc?
Robots should be very consistent, meaning ranges can often be very narrow.
Topic American Welding Society Services / Technical Standards & Publications / PQR WPS Documenting Trim
