Iterative alignment- several parts

[poobar]

I have to measure several parts using iterative alignment since no alignable gage is available, just a holding fixture. I've written the iterative alignment program as well as the part program for taking measurements on one part and have run the program. There are quite a few move points, probe rotations, etc.

Do I now have to write a new alignment program for each of the next two parts and re-click the actual measurement points on the CAD model for each part or is there a way I can use the original iterative alignment program from the first part to run the next two parts?

I know this is probably a basic question but I don't often have to write iterative alignments in the course of my work.

Thanks

[Don Henger]

I have to measure several parts using iterative alignment since no alignable gage is available, just a holding fixture. I've written the iterative alignment program as well as the part program for taking measurements on one part and have run the program. There are quite a few move points, probe rotations, etc.

Do I now have to write a new alignment program for each of the next two parts and re-click the actual measurement points on the CAD model for each part or is there a way I can use the original iterative alignment program from the first part to run the next two parts?

I know this is probably a basic question but I don't often have to write iterative alignments in the course of my work.

Thanks

Usually after the iterative you want to do a dcc alignment on your datum scheme. Since you have a holding fixture they should be in the same location from one part to the next. after your dcc alignment you should be able to do the rest of your parts without re-clicking the meaurement points by going by the dcc alignment in your program. I hope this helps.
Welcome to the forum.. The guru's should be in around 6:00 to 7:00 they have bankers hours.

[poobar]

Don: Thank you for the reply. I did write a DCC alignment as part of the original program thinking that I could just run that again on the next parts without having to re-click everything. However, when I tried to run the DCC alignment on the next part the CMM would only run the alignment points twice and then acted as though it didn't know where it was. Maybe I'm not starting the DCC alignment correctly?

Thanks again

Jim

[JamesMannes]

Poobar,
try this doc. If it doesn't help give a shout back and we'll set you up.

GO HERE

[Don Henger]

Don: Thank you for the reply. I did write a DCC alignment as part of the original program thinking that I could just run that again on the next parts without having to re-click everything. However, when I tried to run the DCC alignment on the next part the CMM would only run the alignment points twice and then acted as though it didn't know where it was. Maybe I'm not starting the DCC alignment correctly?

Thanks again

Jim

Well it is hard for me to say what is going on unless you post your code that you used. It should run all the dcc alignment features. What I do is run the first part with the iterative alignment. Place a operator pause to tell that you are going into dcc. Book mark the pause. Then you should have your dcc alignment features next. Make sure that they are all marked. Hopfully its an easy alignment as in three points for a plane (minimum) two points for your line and one point to stop rotation. This should work. Then all you have to do is start from your dcc alignment not the iterative. I hope this helps. Good document James I new the guru's would role in.

[poobar]

Thanks. I'll take a look at that. Hopefully then I'll be all set.

[JamesMannes]

Well it is hard for me to say what is going on unless you post your code that you used. It should run all the dcc alignment features. What I do is run the first part with the iterative alignment. Place a operator pause to tell that you are going into dcc. Book mark the pause. Then you should have your dcc alignment features next. Make sure that they are all marked. Hopfully its an easy alignment as in three points for a plane (minimum) two points for your line and one point to stop rotation. This should work. Then all you have to do is start from your dcc alignment not the iterative. I hope this helps.

As a differing opinion, I myself start after the manual iterative alignment. This way, the machine can "find" the part before going to measure the print datums. I do this only because the part may not sit exactly in the same spot every time one ios loaded. This more applicable if you have a rough fixture and not a fixture built by someone who makes them for a living(most of the time mine are made by a monkey ion out toolroom, no offense to the skilled monkies of the world).

[JamesMannes]

Oh, by the way I got that document from Winston. Just givng credit where it is due.

[Don Henger]

[QUOTE=JamesMannes;61512]As a differing opinion, I myself start after the manual iterative alignment. This way, the machine can "find" the part before going to measure the print datums. I do this only because the part may not sit exactly in the same spot every time one ios loaded. This more applicable if you have a rough fixture and not a fixture built by someone who makes them for a living(most of the time mine are made by a monkey out in the toolroom, no offense to the skilled monkies of the world).[/QUOTE]

I'm fortunate I guess, I build my own with the Rayco plate and with stamped parts I run they are usually the same within reason. I being an old skilled trades monkey that they put out to pasture, no offense taken.(we have some monkies too)

[Underspec]

With a fixture you should not have to realign. Just save your fixture alignment and recall it from your program.

Not sure how your setup is but this is what I do. With the die casting alignments I have, they give me 6 points (3-2-1 alignment). I then create auto surface points and enter my x,y,z coordinates per print (Theoritcal locations). I then go and manually run these (dcc off) to tell the program where my actuals are. Then I do an iterative alignment from those 6 points. Mark these for DCC and good to go.

[dwade]

I run iterative alignments on some of the knees we make and once I set the part for the time I (almost) never run my manual points on the remaining parts. Use a Rayco plate, a mini vise and clamp so the first part off in the run is what I set it up to and everything else will run if they follow the instructions.

[Don Henger]

I run iterative alignments on some of the knees we make and once I set the part for the time I (almost) never run my manual points on the remaining parts. Use a Rayco plate, a mini vise and clamp so the first part off in the run is what I set it up to and everything else will run if they follow the instructions.

Ditto for me to Dwade. I think we are lucky and have some parts that match one to the other within reason so we can start from the dcc alignment Some of the guy's aren't so lucky

[Matthew D. Hoedeman]

Ditto for me to Dwade. I think we are lucky and have some parts that match one to the other within reason so we can start from the dcc alignment Some of the guy's aren't so lucky

If it is an issue of the parts being different enough, you can do several things:

1) Increase the prehit & retract values
2) Start with a different alignment, you don't have to use the ABC or anything else, use something that is easy, then do the ABC
3) Try better fixturing, even if it is nothing more than bolting a bar to the table to push the part up against.

I work sheet metal and rarly don;t have a fixture. However, I do happen to have a pair of parts in here right now without a fixture. This part sits just on 2 magnets. I can get it close enough by eye, that my first DCC alignment (which does NOT use ABC) can find the part if it is within 10mm of the original part, then it goes on and does the ABC DCC alignment, I only measure the manual on the first part I set up.

[Don Henger]

If it is an issue of the parts being different enough, you can do several things:

1) Increase the prehit & retract values
2) Start with a different alignment, you don't have to use the ABC or anything else, use something that is easy, then do the ABC
3) Try better fixturing, even if it is nothing more than bolting a bar to the table to push the part up against.

I work sheet metal and rarly don;t have a fixture. However, I do happen to have a pair of parts in here right now without a fixture. This part sits just on 2 magnets. I can get it close enough by eye, that my first DCC alignment (which does NOT use ABC) can find the part if it is within 10mm of the original part, then it goes on and does the ABC DCC alignment, I only measure the manual on the first part I set up.

Those are all good points Matt.
Sometimes I'll use a read point at the start of the program by placing the probe at the face plane of a hole and set my origan to the read point. Then do a find hole & go from there to my abc alignment. Another $.02

[Sl33stak]

I have a really stupid question now.................. Is ABC the same as 123?

And thanks to you guys I have the Jackson five stuck in my head now!

Grrrrr..............