Pin Ball Retract Problem

[1CMM4ME]

Good evening, long time ...no discussion. I have read through the search posts, but have not really found what my problem is with programming small diameters. I have a part which is .500 in dia.(cylinder .500 dia. x 2.00 long), but has a thru-hole of .060 in the side of it that has to be checked. Every time I go to check the hole with the smallest stylus I have (1mm), it turns into a pinball game. I have set the retract values and the pre-touch values really low, but I cannot get this to work. It seems no matter what I do, when I take the first hit, the probe goes back too far and makes contact with the other side of the hole, thus creating the "pinball" effect. It is probably my newbie loss of reason setting in. All help is appreciated. Thanks
Patrick

B&S "one"
Demon version 4.1

[John Riggins]

Maybe turn off Circular Move?

But you would be better off with a smaller stylus, .5mm maybe.

Also, try putting a pin in the hole and check as an OD.

You also might try using the "find hole" option.

[1CMM4ME]

John, I am programming the hole manually, so circular move should not come into play........right? I don't have any .5mm probes. I'll give a pin for o.d.measuring a try. We make hundereds of these parts, so I don't want the operators to have to put a pin each part evary time they run the program. Hole sizes cound vary, causing a false location reading. This part was run on the old cordax machine with mm4 without a hitch, using the same probe diameter?

[JamesMannes]

Go to I think F10 and look at "manual retract". Don't know if that is the answer or not but it is a suggestion.

[bw_bob]

Thats only .020 clearance. That is probably to tight for a .039 probe. I would use a smaller probe. A .50 or .30 and you will have better luck. I would also do an auto circle if all possible...my.02

[JamesMannes]

John, I am programming the hole manually, so circular move should not come into play........right? I don't have any .5mm probes. I'll give a pin for o.d.measuring a try. We make hundereds of these parts, so I don't want the operators to have to put a pin each part evary time they run the program. Hole sizes cound vary, causing a false location reading. This part was run on the old cordax machine with mm4 without a hitch, using the same probe diameter?

I would do this measurement in DCC using AUTO-CIRCLE with "FIND HOLE" on.

[Matthew D. Hoedeman]

Yep, Autofeature CIRCLE is the way to go and use READ-POS, it works a little better that FIND HOLE. With READ POS, when it gets to the hole, it will stop above it (as long as you use AUTOMOVE) and wait for YOU to position the probe in the center of the hole. The PINBALL effect you are seeing is do to the fact that it will TRY to go back to the center of the hole (since it is so small) between hits. If it is far enough off location, then the center of the hole will cause a touch on the probe. However, if you do READ POS, it will use THAT position as the 'target' location and measure from there. I have had GREAT success using that on small holes. (3mm hole and 2mm ball).

[Underspec]

It's probably your manual retract that you need to change. This however, only affects when you teach it. You will have to change your dcc retract/prehit to match.

I agree that you should probably use an autocircle if possible. You don't have to know the exact coordinates of that hole. Just open up autocircle, take 3 hits for the plane, and 3-4 hits inside the hole and pcdmis will try and automatically update the autocircle setup. Just go in and tweak your vectors, dia, xyz, etc.

[JIM HARRIS]

If you are using fly mode turn it off for holes under .200.Fly mode will cause this to happen on small holes.

[Underspec]

If you are using fly mode turn it off for holes under .200.Fly mode will cause this to happen on small holes.

Good one Jim. I forgot about that one.

[bob mappes]

It's probably your manual retract that you need to change. This however, only affects when you teach it. You will have to change your dcc retract/prehit to match.

no changing the prehit and retract is needed.....if there is a small difference between the hole diameter and the stylus diameter, PCDMIS automatically calculates how much room it has inside the diameter for the given stylus diameter and will make movements accordingly....when there is a large amount of room THEN you can play with prehit and retract and have an effect..

bob

[Wingman]

Just a note. Circular move DOES affect manually taught holes if Circular Moves on Round Features is turned on in your setup. PC DMIS will automatically insert circular moves between all hits. This could still be your problem.

[1CMM4ME]

Well, I have been home sick with some crap somebody brought to the shop, as a 1/4 of our workforce is sick also. Anyway, "flymode" is off, I have tried all the suggestions and I still have the problem. A tech was in today trying to fix the tool changer, and he said the problem I was having is inherent with the system, as the machine will always pull back after I take a hit manually. He said there was no way to change it. It is a preprogrammed parameter in the contoller. It is a problem child of the controller he said. Well, that sucks. He said earlier Brown & Sharpe machines did not have this problem, as you could take a hit and then manually move the probe back to a safe ditance without the "PinBall" effect. Does anyone else have this problem, utilizing the same machine I have? How did you cure this? We have small intricate parts at our facility, so this problem need to be rectified somehow. I can't beleive the engineers at B&S wouldn't have thought this problem through.
Come now. This can't be real. Any thoughts?
Thanks everyone.

B&S "One"
PH10
TP20
Demon 4.1

[Wingman]

Well, I have been home sick with some crap somebody brought to the shop, as a 1/4 of our workforce is sick also. Anyway, "flymode" is off, I have tried all the suggestions and I still have the problem. A tech was in today trying to fix the tool changer, and he said the problem I was having is inherent with the system, as the machine will always pull back after I take a hit manually. He said there was no way to change it. It is a preprogrammed parameter in the contoller. It is a problem child of the controller he said. Well, that sucks. He said earlier Brown & Sharpe machines did not have this problem, as you could take a hit and then manually move the probe back to a safe ditance without the "PinBall" effect. Does anyone else have this problem, utilizing the same machine I have? How did you cure this? We have small intricate parts at our facility, so this problem need to be rectified somehow. I can't beleive the engineers at B&S wouldn't have thought this problem through.
Come now. This can't be real. Any thoughts?
Thanks everyone.

B&S "One"
PH10
TP20
Demon 4.1

Probably true. I know there is a seperate setting for the manual backoff. In a different version of DMIS I could adjust the manual backoff. Not a B&S Product though.

Still, all is not lost.

Place the probe in the hole as centered as you can get it.
Write down the XYZ of the current probe position.
Insert a Measured Circel via the Menu at the top of the screen.
F9 the Measure Circle Command and input the numbers you wrote down for the Location of the hole.
Input the correct diameter of the hole
It should now measure the hole for you.

As an alternative you can use Auto measure. Or, you can ask operator to potition the probe inside the hoile and do a read point in the program. Set zero to it and measure the hole at a location of 0,0

Just some options

[Underspec]

If you know the location of the hole, try using the "find hole" option.