I need some help.

[Sl33stak]

I have a part from one of our subs, and they had been checking this feature using an optical comparitor until their customer decided that a CMM is the way to check it. Now I need to figure out a "good" way to check it.

The attached picture shows the part, and the dimension i'm after. I need to pick up the Diameter indicated at a point of .1357 from its face. Of course it's on an angled surface too! I have no idea of an "easy" way to do this! The material is SS so no mag. chuck to help out either.

Anyone have any suggestions?

[craiger_ny]

Is that a cone?

Measure a cone, measure a plane. If the 0.1357 is basic offset the plane and construct a circle where the plane and cone intersect.

Craig

[dfiola66]

Is that a cone?

Measure a cone, measure a plane. If the 0.1357 is basic offset the plane and construct a circle where the plane and cone intersect.

Craig

I can't think of any other way. Nice Craiger!

[tking]

I would:

3d align to the -A- datum
translate .1357 plus in z axis
probe the conical feature (many points, 36 or so 3-4 levels)
create a plane at alignment (z plus)
intersect a circle between the created plane and the probed conical feature

Have fun,

TK

[kbotta]

Great way to explain it !

[John Kingston]

I do this all the time. I construct a cone from vector points. Then, depending on which is the basic, I constuct a circle (this is usually my basic) on the cone. I sent you a PM. Feel free to contact me.

[dwade]

Pesonally I think the part is too small (particularly the angled surface) to get any repeatable numbers from it. If you do try this you need to use the smallest tip you can find.

[Wes Cisco]

Pesonally I think the part is too small (particularly the angled surface) to get any repeatable numbers from it. If you do try this you need to use the smallest tip you can find.

I do this all the time with features this size and smaller to find what are called "gage points" critical in the proper fit and seal of o-ring components. I can be done and repeatable. Pc-Dmis gives you a great tool in the circle construction window. Near the bottom are two "radio" buttons. One for "height" and the other for "diameter". To use this create an alignment leveling to the plane the dimension comes from. Probe the cone. Open construct circle. Choose "height" and select the plane and the cone, click "create". Now you can dimension that circle as location>diameter and you are done.
If you needed the other way around, that is they want to know how far from the face a given size diameter occurs you do the same but use the "diameter" radio button instead of height, then you enter the diameter and then dimension the resultant circle location>Z(if in z+plane). HTH

If you are still having problems send me a PM and I'll give you my phone #.

[randy z]

measure plane - level and origin
measure cone
Access the Construct Circle Mode dialog box.
Select the Cone option.
Select one feature. The type must be a cone.
Select either DIAMETER or HEIGHT from the Type drop-down list.
Type a value for the diameter or height into the Value box.

[John Kingston]

Wes is correct. I do this all the time. That looks like one of my parts. Even the dimensions match. I sent you a PM with my phone # and email. Feel free to contact me.

[tking]

Wes,

Thanks, still learning the "demon" on my own and doing things so I know what it's doing. Hints about the bells and whistles are greatly appreciated.



TK

[Sl33stak]

Thanks everyone you guys are great, I'm having trouble getting to pick up the cone though. I'm using a 1x10 and still it keeps wanting to call it a plane. And I just don't feel comfortableusing the "override guess" feature. Back to workin on it!

BTW, this sucks to devote this much time to work for a sub and not my own shop!

[Sl33stak]

One more thing, I have tried it this way too.
Made a manual alignment: go to DCC mode
Recreate alignment in DCC
then using auto vector points take 4 points around the diameter at the required Z height. Then constructed a circle from these points and got my diameter this way. Would that be a good way as well?

[Matthew D. Hoedeman]

No, that would be a bad way. Your size WILL be wrong because your probe comp will be in the plane of the circle, but if it is a cone you are checking, then you can not comp in a flat plane, it have to be 3-D.

[Sl33stak]

Grrrrrrrrrr....... I was afraid.