How to messure???

[Leandro]

We are now getting some parts from a new customer with thigth tolerances in comparison with the pieces dimensions.

for example

Diameter 1339.97 to 1339.89 mm this represents in inchs 52.7547 to 52.7515.

This is IT6 (diameter 1340 g6)

This is just an example because we get different parts with different diameters and every time just one piece. The diameter range is between 1000 to 1400 aprox. (39" to 60")

How cann I messure this without to buying a lot of different micrometers?

Did somebody have a better idea.

 

Thanks in advanced

[crazy^millman]

Yeah but at $60 to $80k you might want to buy the micrometers. I would look to a high accuracy Laser Tracker or for $500k you could get a laser Radar from Metris/Nikon.

 

HTH

[taperlength]

What machine is being used, VTL? I would calibrate the tools on a smaller piece of scrap that I can mic and and then use the same speeds, feeds, and d.o.c. on the big part. By the way, is the temperature in the shop controlled?

[Leandro]

Yes a Vertical Lathe. Temperature is not controled.

Ok I understand your point. The problem is that I need to check this dimension. I can not turn this with your method and supposed its ok.

Did sombody use gages to compare dimensions like this?

 

Thanks

[DavidSV]

How is your customer going to check it? I would check it like they will.

 

.003 over 52"... I think just about any material will grow and shrink that much based on temperature.

[taperlength]

From some rough calculations, about .0007 inch per degree F at 52 inches. That's for aluminum, about half as much for steel.

[MotorCityMinion]

Pi tape?

[Allan]

How about a Pi tape?

Much cheaper than a Mic and very use full for large diameters like you mention, you should have no problem reading to within .002".

 

Allan

[Leandro]

Pi tape ???

What is this??

Is this method acuurated enough?

I will do a search for this ??

 

Thanks

[Leigh @ Kodiak]

I never heard of these Pi tapes before, and after looking it up on Google, I think I want one!! Their website says they are accurate to .001, though I'm sure thats dependent on how you use it.

[crazy^millman]

It is real dependent on how you use it, but yews very accurate if use correctly. When I did trubine work years ago we would use them to measure Turbine shaft upward to 84" and they were always within .001 to the hard measurements others got.

 

HTH

[[email protected]]

quote:

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but yews very accurate if use correctly

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Ron, You hittin the Rum down there on the Beach?

That sounds like KY talk

[Brad St.]

I have to agree with Dave's comment on "how does your customer check it" or require it?

 

One other idea is how about an interim artifact check where you have a known feature mounted on your machine and you simply indicate from there. Of course your machine would or should be validated if any real paperwork is needed to prove it out. If it is simply for your reference then it's an option.

[JPensack Acker Drill]

What about a probe used like a CMM?

[Leandro]

My customer is a VERY Huge Companie. They have all this Micrometers,Gages,Laser Gages and so on.

I cann borrow his tools but they are 1600 Km far away and is complicate the logistic of this.

A CMM is a posibility. Actually I check this dimensions in a Vertical Machinig center with a Renishaw probe. But I can not do this in the machine during the turning process. To do this in this machine is also a transport problem inside the shop. A timing problem and so on.