Oddly Dimensioned Print

[Scott D. Haselden]

Bulb measurement.JPG

I have a print that is very oddly dimensioned, and it is actually done to the IEC code. The IEC has a standard that sets the measurement of the radius to the end of the part at this length. The IECin the same illustration, also allows the dimension of the .900 radius shown here to be measured from the datum location at the other end of the part. The type of measurement shown here, was designed for manufactured hard snap gage for function.

My question is this: Is the best way to measure this to take hits on the radius, creating a circle, and then taking a hit on the end of the part. Measuring from the hit on the end of the part, to the circle, minus the radius, along the datum line?

Engineering refuses to change the print for measurability sake, due to their interpretation of the IEC.

[Wakkadder]

To me it looks as though it is dimensioned in Imperial with the Metric equivalent in the brackets, I do agree that it is an unusual way of dimensioning a drawing

[DAN_M]

Looks like you've got a lot of tolerance there, I'd recommend an optical comparator, could even make a nice overlay for this.

If it has to stay on CMM, I have no idea about IEC stuff, sorry =/

My best attempt would be to find the high point at the end, make that an origin, then do some scans & apply a generic profile tolerance to it...OR... take some points, then check the pnts hack to the end (PR or T value).

[oddam]

I do not know IEC standards either, but my unprofessional opinion would be the view is asking for the distance where the .9 R intersects with the straight edge, then asking for the distance from the intersect to the top of the bulb, giving you the min & max distance. I would ask engineering exactly what the view is asking for.

Odda

[KIRBSTER269]

There giving you .050 tolerance, Aren't you being a little to picky? Throw it on a comparator and report it in MM, then in inches.

[bfire85]

Looks like a manual check on the comparator, if you ask me!

[KIRBSTER269]

On the Comparator. Take your points to create a circle, call your circle 0,0. From Center of circle measure down to the tip. Subtract that result from half of your circle size. There is your result in inches. Take your result and times that by 25.4, then there is your MM results. Next, Move on to the next part.





















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[Scott D. Haselden]

Unfortunately, the comparator is not an option. Ours is toast right now. (25 year old Mitutoyo… dead in its tracks and burned out) And this is a FAIR, which means they want EVERY dimension on the print, even though the prints were made for the tool makers, and no radius is dimensioned to radius center. I'm having to trig out the radius centers from the datums, angles, and other dimensional data. I have been trying to get this corrected since I started here, but I am only now getting them to see the error in trying to use tool maker prints for dimensional inspection. And of course, EVERYTHING is critical...

[Scott D. Haselden]

They also want everything in inches only. They just put the metric dimensions on the print for the suppliers, and tool makers, who live outside the US. They want a CMM report to reflect the dimensional data, so that there is "no way" we can fudge the data.

[KIRBSTER269]

Tell your boss, quit being cheap, and upgrade your comparator, or quit taking on jobs that your not capable of measuring. This is what our comparator spits out.

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[KIRBSTER269]

I'll be honest with you Scott, I checked out the Keyence, had them come in and go thru a presentation. My opinion over priced and over complicated, not worth the money, just my 2 cents

[vpt.se]

What machine/equipment is this from? KIRBSTER269

[KIRBSTER269]

vpt.se It is the Baty made from Fowler, only thing I don't like about this comparator is. We have a 25X lens and a 100X lens, when you switch between the lens, you have to switch the back magnifier, which is not at all an easy task, switching between the lenses is easy though , slide in slide out.

[kingsld1]

We've just replaced our measuring microscope with a vision machine from Nikon that runs CMM Manager. Wish that I would have had the budget to go a size or two bigger but on the other hand it has almost triple the measuring range of our measuring microscope. Don't remember the exact price, know that it was below $75k and I'm thinking it was in the low $60K range. This is a vision only machine but touch probe is available. I've been told that the touch probe can be easily added later on and we wouldn't get gouged too badly for it.

Like I said, we just got it so I don't know all the ins and outs and pitfalls but so far I really like it.

[Scott D. Haselden]

The model I looked into a couple of weeks ago, we are getting for $42,800, but it originally started out at $78,500. We were going to buy a benchtop OC but the vision system is much easier to operate and program. the operator just has to know how to operate a computer and mouse. they pull up a file name, place the part on the glass, and press the silver button. 3 seconds later, there is a report on the server that they cant change or lie about. Programming is as simple as dragging the cursor across the feature you want measured. Pretty simple. then manually change the nominal and tolerances in the report to match print. I can also upload a model, and just program to model. Its expensive, sure, but with no SMA, free training for life, and the same travel as the Optical Comparator we were looking at, it just makes more sense to us, as a company. We can also run calibrations through our Master Gage Blocks or Pins, which already cost, so no ongoing cost there.

We have to buy a comparator any way, and the best deal I was able to get for what we need in our application, was $24k. The Vision will pay for the overage in about 4 years.