Customizing hole sizes

[Dan B]

Customizing hole sizes

Is it possible to customize holes sizes, perhaps in a spreadsheet somewhere? I need to be able to distinguish between a drilled hole and a reamed hole for downstream CAM purposes. For example, a Ø1/4 reamed hole would be .250" but a Ø1/4 drilled hole would be .247". That subtle difference would be picked up by my feature recognition program and would treat the hole accordingly.

Thanks,

Dan

 

[volker]

Hi Dan,
have a look, here.
http://manufacturing.cadalyst.com/manuf ... ?id=377644
Until now, i didn`t really understand. Maybe you do.

Regards
Volker

 

[Dan B]

Thanks for the tip. I will check it out.

Dan

 

[flyboydave]

Re: Customizing hole sizes

Is it possible to customize holes sizes, perhaps in a spreadsheet somewhere? I need to be able to distinguish between a drilled hole and a reamed hole for downstream CAM purposes. For example, a Ø1/4 reamed hole would be .250" but a Ø1/4 drilled hole would be .247". That subtle difference would be picked up by my feature recognition program and would treat the hole accordingly.

Thanks,

Dan

In your case, where you're trying to get some other application to differentiate between hole sizes that differ only due to the hole machining method but are nominally the same size, I would just create them as actual different sizes. Create the drilled holes at .247" and the reamed holes at .250".

 

[Dan B]

I would just create them as actual different sizes. Create the drilled holes at .247" and the reamed holes at .250".

Ideally, yes that would work. However, if you factor in "dummy proofing" then this needs to be taken out of the hands of the operator. Forgetting to do this means machining the wrong type of hole, which then involves scrapping a part, or plugging the hole and re-doing it.

Dan

 

[warburton1]

Not had chance to try this, but as a suggestion, what about if you create a custom "Thread" configuration file that would have dummy values for the threading information but usable information for a downstream application, as an example a typical 1/4 threaded holes reads in the thread file as;

*1/4-20 UNC,20,0.207,2B,0.25,0.196,0.2175,2A,0.2489,0.1894,0.2164,1

in the following format
;; String *name;
;; Real pitch;
;; Real tapDrillDiameter;
;; String femaleClass
;; Real femaleMajorDiameter;
;; Real femaleMinorDiameter;
;; Real femalePitchDiameter
;; String maleClass
;; Real maleMajorDiameter;
;; Real maleMinorDiameter;
;; Real malePitchDiameter
;; Integer threadType;
;; 1 = UNC (units expressed as inches)
;; 2 = UNF (units expressed as inches)
;; 3 = UNEF (units expressed as inches)
;; 4 = UNS (units expressed as inches)
;; 5 = Metric Coarse (units expressed as millimeters)
;; 6 = Metric Fine (units expressed as millimeters)
;; 7 = Metric Special (units expressed as millimeters)
;; 9 = NPT (units expressed as inches)
;; 1000 = generic english (for user defined) (units expressed as inches)
;; 2000 = generic metric (for user defined) (units expressed as millimeters)

you could modify this to read as;-

1/4 Reamed,XXX,0.250,AA,.250,BBB,CCC,DD,EEEE,FFFF,GGGG,1000

this would create a 1/4in (.250 diameter hole) and you could use the other fields to carry additional data such as depth of ream etc., currently I am not sure whether this data can get "picked up" as parameters externally, however, the option may exist in the future. Furthermore, a spreadsheet maybe able to pick the details up from a lookup table that carries the same data.

Your other option maybe to create a series of catalog features based upon the hole and size information

 

[flyboydave]

That might create the correct hole notes on a drawing, but it sounded from his post that he is exporting the data to some other software that is comparing the actual geometry.

As for "dummy proofing", what are the dummies working with? Is it a digital model or a 2D drawing? If it's the digital model, then the only way a 3rd party softare will be able do differentiate different hole sizes is if they're actually different sizes.

For example - there are multiple ways you could end up with a .250 hole in the model - the hole tool with a .250 diameter, or you could create an extruded cut with a .250 diameter circle, or even a revolved cut with a .125 wide rectangle. But to third party softare looking at imported geometry, they would all be a .250 diameter hole.

Now if the dummies are working from a 2D print, then customizing the hole tables might be a good way to go.

 

[Dan B]

Yes, the models will be subjected to a feature recognition program, so differences in actual hole sizes are what I am after. There will never be prints made, just straight to CNC.



Dan

 

[indesign]

Then either customize the hole standards or just enter the drilled size. If all you need is an actual size difference then there is really nothing that has to be done. Enter the size hole you want.

 

[warburton1]

Even with a 3D model, customizing the hole table will work since the base hole size is one of the parameter features of the table, based on what your selected source is. Expanding on the hole table described you could quote the Base drill size as the tap size and the final reamed diameter as the Major Diameter. Then its up to the user to select his modelled hole size by selecting from the source list.

I assume you also want to standardize your hole creation by selecting predefined sizes rather than looking up a particular hole size every time you create a hole. As for picking this up externally then the modelled hole size will be accessible by analysis. It could also be used in an external spreadsheet, where the data can be "Looked Up" based upon the analysed hole size.

 

[Dan B]

I assume you also want to standardize your hole creation by selecting predefined sizes rather than looking up a particular hole size every time you create a hole.

Exactly. We currently do it this way in MDT through a program I wrote in VB to access a spreadsheet. It is important to maintain this method in our next modelling software.

Dan

 

[indesign]

Then using the hole database would be the best way. It is really pretty easy to modify the existing as well as adding many new hole specs.

 

[Dan B]

Thanks Tim. I will keep this in mind if we head in this direction.

Dan