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Recommended Digital Calipers for measuring parts (+ rare Clutch Test Implements.) - Printable Version

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Recommended Digital Calipers for measuring parts (+ rare Clutch Test Implements.) - tom alphin - 2021-01-09

I recently got my hands on some rare parts which are used to test LEGO parts.  They are described in the middle of an article on New Elementary as "Clutch Test Implements".  In my case, I have four of these parts in my hands:

  • Stud testing part
  • Small Towball testing part
  • Large towball testing part
  • Bar/clip testing part.


The first three have 5-digit part ID's, and the fourth one does not.  They are in a mix of uncolored ABS, Green/Dark Green ABS, and Trans-clear.  Since they have Part ID's, I was willing to make the required measurements to allow them to be added to LDraw Parts Library.

A few questions:
1) Can someone recommend a modest-priced pair of digital calipers that work well in measuring LEGO parts?  (ex: Are the Harbor Freight ones good enough?)
2) Are unreleased parts allowed in the LDraw Parts Library?
3) Are there tips to take the best and mot accurate measurements?

Thanks,
---tom

RE: Recommended Digital Calipers for measuring parts (+ rare Clutch Test Implements.) - Gerald Lasser - 2021-01-09

(2021-01-09, 7:01)tom alphin Wrote: I recently got my hands on some rare parts which are used to test LEGO parts.  They are described in the middle of an article on New Elementary as "Clutch Test Implements".  In my case, I have four of these parts in my hands:

  • Stud testing part
  • Small Towball testing part
  • Large towball testing part
  • Bar/clip testing part.


The first three have 5-digit part ID's, and the fourth one does not.  They are in a mix of uncolored ABS, Green/Dark Green ABS, and Trans-clear.  Since they have Part ID's, I was willing to make the required measurements to allow them to be added to LDraw Parts Library.

A few questions:
1) Can someone recommend a modest-priced pair of digital calipers that work well in measuring LEGO parts?  (ex: Are the Harbor Freight ones good enough?)
2) Are unreleased parts allowed in the LDraw Parts Library?
3) Are there tips to take the best and mot accurate measurements?

Thanks,
---tom

I got my digital Calipers from a discount store and they were around 10 EUR, it serves me well.

As those parts are  used for connection testing, I would compare the measurements between released parts and those test parts, i.e. stud size the same, bar size etc.?

Concerning the parts, I think they can be added, let's hear from the others.

RE: Recommended Digital Calipers for measuring parts (+ rare Clutch Test Implements.) - Philippe Hurbain - 2021-01-09

(2021-01-09, 17:35)Gerald Lasser Wrote: I got my digital Calipers from a discount store and they were around 10 EUR, it serves me well.
Got a cheap one too, more than precise enough!

Quote:As those parts are  used for connection testing, I would compare the measurements between released parts and those test parts, i.e. stud size the same, bar size etc.?
Anyway they will NOT match LDraw parts which are somewhat idealized...
eg. bars are modeled as 3.2mm while their official diameter is 3.18mm. And if we go physical, it's worse: just measured one which is not even cylindrical, I measure between 3.12mm and 3.28mm according to the place where I measure!
Quote:Concerning the parts, I think they can be added, let's hear from the others.
I see no problem! BTW, can you share the design numbers you read?

RE: Recommended Digital Calipers for measuring parts (+ rare Clutch Test Implements.) - tom alphin - 2021-01-11

(2021-01-09, 18:01)Philippe Hurbain Wrote: Got a cheap one too, more than precise enough!

Anyway they will NOT match LDraw parts which are somewhat idealized...
eg. bars are modeled as 3.2mm while their official diameter is 3.18mm. And if we go physical, it's worse: just measured one which is not even cylindrical, I measure between 3.12mm and 3.28mm according to the place where I measure!
I see no problem! BTW, can you share the design numbers you read?

My digital calipers arrived today.  I may try my hand at designing the parts for LDraw.  If not, I will take photos and annotate the photo with every measurement that we need to re-create it! 

Should I round my measurements to match the idealized values?

---tom

P.S. I plan to take excellent photos and write a short article on brickarchitect.com about these rare parts.

RE: Recommended Digital Calipers for measuring parts (+ rare Clutch Test Implements.) - tom alphin - 2021-03-19

I measured one of the parts and captured all of the dimensions (in MM) on a piece of paper.  Should this be enough precision to design an ldraw model of the part?
Any tips for capturing measurements in a format that's easier to translate into LDraw parts?  (I had considered capturing the measurements directly into a digital app like Adobe Illustrator, but paper was a lot faster and more flexible.)

---tom

RE: Recommended Digital Calipers for measuring parts (+ rare Clutch Test Implements.) - Willy Tschager - 2021-03-20

(2021-03-19, 4:55)tom alphin Wrote: I measured one of the parts and captured all of the dimensions (in MM) on a piece of paper.  Should this be enough precision to design an ldraw model of the part?
Any tips for capturing measurements in a format that's easier to translate into LDraw parts?  (I had considered capturing the measurements directly into a digital app like Adobe Illustrator, but paper was a lot faster and more flexible.)

---tom

Looks good. Instead of measuring in mm you could convert your measurments to LDU right away, which gives you some clues when comparing your part to other parts for reference:

http://www.holly-wood.it/ldraw/authoring-en.html

Conversion is best done using LDPE's converter or:

https://ldraw.heidemann.org/index.php?page=ldcalc

w.