Stupid question

[S/X]

Just a dumb question but one that has baffled me for some reason. Has anyone cut a piece of A2 steel (size for size), sent it out for heat treat,

have it come back, recut it to clean it up and cut it undersize? To answer a few questions mabey before their asked, I did pick my X0 Y0 up correctly, it was indicated correctly and the right cutter was used. It cut it 0.005" under.

[robk]

quote:

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I did pick my X0 Y0 up correctly

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How about your Z ?

 

 

Rob

[mayday]

A2 generally will not change in size going thru H.T. very very little if any. so if you cut it size for size as you said and then did a cleanup cut after H.T. something tells me it will be undersize.

Did you mike it after H.T.?

[Eric S.]

Did you check the stock to leave for the contour? Make sure it is not a negative value.

[Jammer™]

How big was your block? If it's long and narrow, it could move in heat treat easier than a small square size.

[S/X]

Robk

 

Yes my Z was picked up right, but i wasn.t to concerned about that as it is the X & Y axis area's that have been affected.

 

Mayday

 

No I didn't check it after heat treat.

 

Eric

 

I did double check my stock to leave and it was left at zero.

 

Jammer

 

It was a bit of a narrow block but nothing (I would have thought) that should have moved.

[Surface]

quote:

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I did pick my X0 Y0 up correctly

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Were you picking up a corner, the center of the part, or a hole? I would think that the latter choices would offer more accurate results. Still, .005 seems like a lot regardless of method.

[KCollins]

did you have any cutter comp in your control?

[Eric S.]

Next time maybe you should bump up your cutter comp a bit, cut it then measure the part. adjust cutter comp. accordingly then run program again. This will save you the headache of having to start over next time.

 

Eric

[S/X]

Surface:

 

I picked up an edge as I didn't have a toolig hole or dowel to locate off of. It cut the thicker part fine but at the thinner end it cut too much. Now I guess you could hold that as being from warping in the heat treat, but the way the part is, it's not likely. I do't want to boggle your minds with something to menial as this

I think for next time I might put a small toling pin in or leave extra stock on.

 

KCollins:

 

No I didn't put any cutter comp. on, I don't use that too much as our Fadal machine doesn't seem to agree with it very nicely

[Müřlıń®]

quote:

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A2 generally will not change in size going thru H.T. very very little if any.

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+1 A2 will only move .0001 per inch during HT.

 

It is one of the most stable materials there is.

 

Sounds to me like the heattreat guys bent it.

 

If they laid it down instead of hanging it to cool, it probably warped.

 

 

Murlin

[crazy^millman]

Coxy When we use to make our parts out of A-2 we would leave .005 per side ofr finishing after HT. there are alot of people making Hard cutting tools out there. I woudl aslo use a CBN grinding wheel in our CNC Mills to finish bore and otehr critical features. If you need to do alot of this I would recommend a speed increaser to soemthing like 40000 rpms and woudl be suprised what types and quality of finishes you can get.

 

Crazy Millman

[S/X]

Thank-you very much evryone for your input.

As usual very valuble and helpful information from everyone.