Locating with two diamond locators.
Locating with two diamond locators.
(OP)
Hi,
I want to locate two parts (with each two holes) very precise with locatings pins. Normally one uses a round locating pin in combination with a diamond shaped pin. However, this set-up only prevents rotation around the round pin. Translation between the two holes is still possible (pitch of the two holes, see fig. 3.19 on page 11 in the link below). In order to prevent also this translation, I found something were one uses two diamond locating pins as shown in this document (page 11, figure 3.20) instead of one round pin in combination with a diamond shaped pin.
http: //www.wads worthmedia .com/marke ting/sampl e_chapters /140181107 8_ch03.pdf
Is this a common way so solve my problem?
I want to locate two parts (with each two holes) very precise with locatings pins. Normally one uses a round locating pin in combination with a diamond shaped pin. However, this set-up only prevents rotation around the round pin. Translation between the two holes is still possible (pitch of the two holes, see fig. 3.19 on page 11 in the link below). In order to prevent also this translation, I found something were one uses two diamond locating pins as shown in this document (page 11, figure 3.20) instead of one round pin in combination with a diamond shaped pin.
http:
Is this a common way so solve my problem?





RE: Locating with two diamond locators.
-handleman, CSWP (The new, easy test)
RE: Locating with two diamond locators.
Thanks for your reply!! Thus in words of accuracy one round/one diamond pin is the best solution? Or two round pins?
Thanks
RE: Locating with two diamond locators.
Comprehension is not understanding. Understanding is not wisdom. And it is wisdom that gives us the ability to apply what we know, to our real world situations
RE: Locating with two diamond locators.
Conclusion: two round accurate pins (h6) in reamed holes (H7) will be most accurate positioning the parts?
RE: Locating with two diamond locators.
I have seen jigs with diamond pin 90 deg. to proper orientation and engineers wondering why parts come out so sloppy.
RE: Locating with two diamond locators.
Comprehension is not understanding. Understanding is not wisdom. And it is wisdom that gives us the ability to apply what we know, to our real world situations
RE: Locating with two diamond locators.
Here is what Carrr-Lane has
http://ca
You may want check out the other locating pin options available
RE: Locating with two diamond locators.
RE: Locating with two diamond locators.
And, you may want to look at using a kinematic mount approach, which actually uses more than two dimensional features to control repeatability: http://en.wikipedia.org/wiki/Mirror_mount
TTFN
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RE: Locating with two diamond locators.
DIAMOND PINS ARE NOT USED TO INCREASE LOCATING PRECISION!!!!!!!
The purpose of diamond pins is to ease assembly/disassembly. If used correctly with one round and one diamond, locating precision will not decrease. Depending on the final clearance condition between the pins and the holes, two diamonds may or may not give less precise positioning than one round and one diamond. If toleranced properly, two diamonds will not decrease accuracy.
The biggest effect on assembly accuracy is going to be the location of your holes. If your holes are 1mm off, no matter what pin you use the assembly won't go together.
-handleman, CSWP (The new, easy test)
RE: Locating with two diamond locators.
RE: Locating with two diamond locators.
Other alternatives can be using pins with some limited flexibility, such as roll pins, and plain holes. In some situations this may better simulate the pattern of holes being the datum.
To some extent you're going about this backwards, what 'accuracy' do you need based on function?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Locating with two diamond locators.
Diamond pins are used to correct for mechanical fabrication tolerances. Normally, your hole clearance is a function of how accurately you can locate hole. The diamond pin can be shifted some distance off nominal and still engage the hole, in spite of an ultra accurate fit.
I do not see how figure_3.20 can work. It allows rotation about the right hand hole.