Parallel Shift question from a newbie

[SporeMonkey]

Good day ladies and gentlemen,
You guys and gals have a really nice little community here! I guess it ain’t that little since I see worldwide participation!
I am brand new to the robot field but have enjoyed my manufacturing career for more than 36 years.
We purchased this robot second hand and I spent a week in Ohio last April for the XRC basic programming. [Wow! When they say ‘basic’ they really mean BASIC!] I made sure to have the secretary pick a hotel for me to stay at that had a bar. [Just in case I needed a place to study in the evenings.]
Along with limping my way through learning the fundamentals, I have spent the last 3 months reading the previous posts and have gained a wealth of information from them. I can only hope to return a fraction of the knowledge I have gained from all of you. Now it's time for me to chime in.

First-
Controller: XRC-2001
Robot: EA1900-A02
2- MH-450 rotary positioners with our designed tables, stations 1 and 2.
Welder: Miller Auto Axcess 450

Here's my query:
I often use the parallel shift utility since we create fixtures to hold multiple parts for welding. Some of these programs are pushing 1000 steps.  I start with a program number [Example: 15] and any subsequent shift programs will simply have a letter suffix. [15A, 15B, etc.] This way I can easily keep track of all of the children associated with the parent program. It is common for me to bounce back and forth between the various parts to dissipate heat, have the Bot move clamps and various other reasons. At this point, I teach the robot the respective corresponding points on each part EACH time I perform the parallel shift function. Time consuming and potentially adding a margin of error. The question is this: After I establish the initial shift, is there any way for me to manually input the ‘shift’ amounts as opposed to having to teach the robot each time.

I thank you in advance for any input you can provide.

[Fabian Munoz]

Hi SporeMonkey

Welcome to the robot-forum

I hope you enjoyed your stay in West Carrolton.

Thanks for posting your hardware.You're breaking the forum rules 

 

I believe there is an option when you parallel shift  thta you can 'attach" the children to say, 15.
Is that your problem, that you have to do 15a, 15b .... every time ?

 

[SporeMonkey]

Thanks for the welcome, Somar!
West Carrolton is a nice city and Ohio is a nice state. The people that I came in contact with were also great.  Flying in at a time of year just before the fields are planted...I never saw so much brown dirt in my life!! Sure, we've got dirt in NY but not to that extent. Oh, sorry about breaking the rules.
Anyway...
With respect to the 15A, B... children of the main program: After each P/S is done, I slightly modify the new child and use it as a 'Call Job 15A'. Works great. I don't do the entire program at once. I take a series of steps that I want duplicated and do them. Then I may do that a few times for a complete program. I'm looking to streamline some of the BS that I have to go through to do the P/S several times.
When I go to the P/S utility, there are 6 choices for the coordinate settings. I use the 'Robot' coordinate and teach the robot the respective offsets by picking a specific point on the part or fixture as the 'source point' and then pick the same point on another part as the 'destination point'. The controller then does all of the dirty work to derive the 'X, Y and Z' distance and duplicates the program that distance away from the first. (The offsets are usually in a straight line.) Although the Bot gives me what it calls a 'shift value', I can't make sense of the coordinate differences. I'm usually pretty good with manuals but with these things I sometimes feel like I've accidentally pressed the shift and area keys.
What I'm looking to be able to do is manually enter that shift value obtained from the first teaching and enter it for each subsequent shift.

[Fabian Munoz]

wow,
 i'm a bit confused because I always input them manually !!!! That's normal procedure for me, something is weird here.
I'm home right now, but I will check tomorrow with the robot.

Maybe your parameters setup is different and you don't see that option and MAYBE somebody from Motoman can give us a tip

 

[Robo Guru]

After I establish the initial shift, is there any way for me to manually input the ‘shift’ amounts as opposed to having to teach the robot each time.

I'm not quite certain I understand your question.  Can you provide a bit more info?

RoboGuru

[SporeMonkey]

Somar:
I don't know the accuracy of the X and Y axis of the robot as compared to the X and Y of our tables. Should be pretty close but for the type of welding that we're doing, I need dead nuts on. It's not uncommon for me to have to adjust a weld by 3 or 4 clicks in the inch mode to correct a weld issue. Hence, but asking the Bot to find the shift in all 3 directions I'm guaranteed of obtaining the correct spacing. When you say that you input them manually, how do you mean that?

RoboGuru:
I'm looking for the Robot to find the first offsets, via the P/S utility, and then be able to input manually the derived and or calculated data for the subsequent shifts. The fixtures that we build are either CNC milled, if it's a thick plate or, laser cut if the material is under a half-inch. The banking points for the parts are givens. They will not vary. The holding or securing mechanics are just as accurate. Either way, the accuracy of the fixture is well within .005”. If the fixture has 10.0” offsets between the parts, then whatever the initial offset is, those dimensions should be maintained along all of the parts. For example: If the table has a 1 degree error on the X axis the Bot would give me a 10” offset for the X (hypotenuse) and a .175” offset for the Y. Likewise, if there is a starboard list on the Z axis, the Bot will tell me that also. When I look at the figures after I have done a P/S I conspicuously notice a minimal difference in the Z. Sometimes zero. Whatever the error is, it should carry through to the entire row of parts.

Gentlemen, I apologize for not being clear with my question and thank you for your patience. Of course, it is possible that I can't do what I'm looking to do. It sounds like a good idea in my world.

Thanks again.

[Fabian Munoz]

You don't have to apologize, the first challenge in this forum is not the robot problem, it's actually trying to understand the set up of the person questioning

The picture shows the NX100 setup but the XRC has a very similar setup, I couldn't find a picture for XRC.
What I like from this method is that I can first shift large dimension , then smaller and smaller. As a simple example for one axis only (x for example)

first shift   20 mm
second shift 5 mm
third shift 1.5           total shift on x = 26.5
Now I know all the children have to move 26,5 mm on the x

[SporeMonkey]

Somar,
Thanks for the info. The Bot is busy today and will be over the weekend. As soon as I get a chance to play I'll do so and let you know how I make out.
Thanks again.

Hopefully, I can get this resolved so I can go on to my next question.
Bet you can't wait!

[amarkangda]

Well, I have understood the problem. And i have used both the methods for parallel shift. In the P/S option, you get an option to select "Teach "points or you can directly enter the X,Y,Z coordinates. As Spore Monkey said, you have to teach the source and destination points in the "Teach" option, but if you donot select Teach option, you can directly enter the X,Y,Z coordinates.