TP20 Issue

[ag162]

Hello Everyone,
I've recently upgraded to the PH10T and TP20. I had these in Atlanta and never had this problem, however I feel the need to ask a question on this.
I'm checking a gauge and my TP20 is failing to register hits and is not stopping in the Z direction until it disengages the PH10. The TP20 is aproximately 1/16" or .0625" or 1.5mm from a solid metal surface. Is it possible that the magnetism from the TP20 is being disrupted by the closeness of the metal surface?

Thanks in Advance,
A.Gore

[mhesse]

I had that happen with a part that was magnetic. You should check and see if the fixture you are measuring is magnetic that would disable the probe.

[ag162]

I just answered my own question. After another check, this metal block is magnetized. The tooling person that made this gauge did not demagnetize his work. It will hold a 6" scale with no problem.

A.Gore

[Matthew D. Hoedeman]

There is also a different version of the TP20 that is not effected by magnetic fields. You might want to check into it and see what the cost of swapping over would be.

[ag162]

Hello mhesse,
I was doing the check and then I move the probe closer to the block, checking the responces by touching the TP20. It stopped registering hits at aprox .200" from the block. The toolmaker must have left the block on the magnet for a while and then had a brain fart,,,to not remember to demag the part before the assy.

A.Gore

[ag162]

Thanks Matt. I will check into it.

A.Gore

[george frick]

we fixtured most of our ferrous parts on magnets (plates,v-blocks,etc.) when programming on our zeiss machines. our b&s cmm's came fitted with ph10t heads & tp 20 probe modules so we had to come up with alternative ways to fixture the parts when programming on the b & s. rayco plates, clamps, etc. as matt stated there is a non-magnetic version of the tp20.

[Brian]

Non-magnetic TP-20

Will the non-magnetic version of the TP-20 still work in a MCR-20 change rack?

[Wes Cisco]

Caution

This comes from a salesman, so. . . I was told most
people who buy the non-magnetic version are not
happy with it and often exchange for the standard tp20.
For whatever a salesman's word is worth. I would try
to have the parts demagnetized and design non-magnetic
fixtures for parts to be checked with tp20. If all you do
is magnetized and/or requires magnetic fixuring, maybe
the best option would be a different type of probe. HTH

[jon_dav_uk]

We use non-inhibit TP20 modules here and they work great on parts that are magnetic. Dont think there is much difference in the price from new but we recently traded in all of out standard TP20's and upgarded to the non-inhibit version as part of a service exchange. If my memory serves me correct they will not work with certain change racks.

Hope this helps

[Brian]

Non-Inhibit TP-20

I just talked to Renishaw, the make what is called the Non-Inhibit TP-20 which is supposed to work in a magnetic field. There is a problem with using it on change racks, because it relies on the software to turn the probe on and off. (I hope this is making sense). He thought it was possible to use in PC-DMIS, but I'm not sure how you turn the probe on and off.

It has something to do with, when you remove the TP-20 module, you can no longer move the probe, apparently there is a line of code that can be put in that will still allow the probe to move.

If you are using a rack, you have to have it on to switch modules, but it is then turned off when checking your part, so that the magnetic field won't effect it.

Does anyone out there know what I'm talking about?

[jjewell]

non-inhibit is the term you can ask for, it is the same price and works the same, just some"non-magnetic hocus pokus" inside I guess