What are some practical and inexpensive methods for determine the diameter of existing PCB holes?
I have several PCBs and I am thinking of fitting in terminals and posts designed for insertion and soldering.
I have several PCBs and I am thinking of fitting in terminals and posts designed for insertion and soldering.
This is a good suggestion; now need to find suitable caliper.
Your suggestion also resulted in an epiphany: use leads of known components with specified lead diameter.
Thank you so much for your suggestion!
Your suggestion also resulted in an epiphany: use leads of known components with specified lead diameter.
Thank you so much for your suggestion!
I test the holes with drill bits (0.8, 1.0, 1.2, 1.3, 1.5 mm are common hole sizes).
Thank you. I had thought about this but in the US drills have so many variant systems. Would be quite expensive to purchase sets of bits in different systems just for measuring.
0.6 is the common lead size, 0.8 mm is the hole size.
Order 1.0, 1.2, 1.4 and 1.6 mm as well, that is enough for the most part.
Order 1.0, 1.2, 1.4 and 1.6 mm as well, that is enough for the most part.
Tapered measuring rod like for rings, but much much smaller? Comparative photogrammetry? Make a set of measurement wires using a wire-drawing die plate? Measure the wiggle-angle for a metal pin that fits and use thickness and trigonometry? Use hole as a diffraction aperture with a laser pointer? Measure the flow velocity and mass-flow rate for a liquid through the hole?
Reminds me of the student who had to answer the question: " with the aid of a barometer, find out the height of a building"
Student: " I will climb up to the roof of the building, then drop the barometer over the edge. I will time how long it takes for the barometer to crash, and, using the gravity equation, calculate the building height"
Professor: that's not the answer I am looking for. Try again.
Student: I will again climb the stairs to the roof and mark off barameter heights on the stairwell wall. The number of marks times the barometer height gives me the building height.
Prof: No. Try again.
Student: On a sunny day I will walk onto the square in front of the building, and set down the barometer so that the sun shade from the rooftop just grazes the top of the barometer. Using the distance of the barometer to the building and the length of its shade I can calculate the building height using congruent triangles.
Prof (steaming): No! Try again!
Student: I will look up the building concierge and ask him, my good man, if you tell me the height of this building I will give you this here nice barometer.
Prof: Do you really not know the answer I want to hear!
Student: yes, of course I know, but that's sooo boring!
He was passed.
Jan
Student: " I will climb up to the roof of the building, then drop the barometer over the edge. I will time how long it takes for the barometer to crash, and, using the gravity equation, calculate the building height"
Professor: that's not the answer I am looking for. Try again.
Student: I will again climb the stairs to the roof and mark off barameter heights on the stairwell wall. The number of marks times the barometer height gives me the building height.
Prof: No. Try again.
Student: On a sunny day I will walk onto the square in front of the building, and set down the barometer so that the sun shade from the rooftop just grazes the top of the barometer. Using the distance of the barometer to the building and the length of its shade I can calculate the building height using congruent triangles.
Prof (steaming): No! Try again!
Student: I will look up the building concierge and ask him, my good man, if you tell me the height of this building I will give you this here nice barometer.
Prof: Do you really not know the answer I want to hear!
Student: yes, of course I know, but that's sooo boring!
He was passed.
Jan
Professionally we had pin guages. At home I use a drill index, with a combination of fractional, numbered and lettered drills which might have cost $50? Good enough and have a decent drill set will last a life time. Individual drills are a cheaper solution. Never had a need to use metric drills so far.
I use a loupe something like this one. Useful for measuring all sorts of things
https://uk.rs-online.com/web/p/magnifiers/2475555?gb=s
https://uk.rs-online.com/web/p/magnifiers/2475555?gb=s
The chuck end of bits can be used as pin gauges, they are generally a little undersized.
I tend to go 0.2 mm plus, easier for the leads to be wiggled about if needed, particularly when you have 16 or more pin ICs to be soldered in.
And it is easier when removing parts, tracks are not so easily damaged.
You can check the drawings of the components you intend to use, the wire or pin dimension may be given.
5 or so drill bits will be about $10 max., at least in my estimate.
Use HSS or carbon steel bits, the material is soft, and the harder bits tend to break if they are not truly vertical to the surface, difficult with a hand held drill...best use a press, and light feeds, and high rpm.
I feel there is no need to go for exotic systems, because most of the time you will find it easier to obtain PCBs from suppliers who do all the hard work!
And 0.64 mm is 25 thou, 1.6 mm is nearly 1/16"
So for a 25 thou pin, the drill size can be in the 30-35 thou range.
1 inch is 25.4 mm, and in my country I get steel scales with the data for inch-metric, and tap drill sizes etched on the back, quite handy.
A random net image:
View attachment 1223584
I tend to go 0.2 mm plus, easier for the leads to be wiggled about if needed, particularly when you have 16 or more pin ICs to be soldered in.
And it is easier when removing parts, tracks are not so easily damaged.
You can check the drawings of the components you intend to use, the wire or pin dimension may be given.
5 or so drill bits will be about $10 max., at least in my estimate.
Use HSS or carbon steel bits, the material is soft, and the harder bits tend to break if they are not truly vertical to the surface, difficult with a hand held drill...best use a press, and light feeds, and high rpm.
I feel there is no need to go for exotic systems, because most of the time you will find it easier to obtain PCBs from suppliers who do all the hard work!
And 0.64 mm is 25 thou, 1.6 mm is nearly 1/16"
So for a 25 thou pin, the drill size can be in the 30-35 thou range.
1 inch is 25.4 mm, and in my country I get steel scales with the data for inch-metric, and tap drill sizes etched on the back, quite handy.
A random net image:
View attachment 1223584
Last edited:
Just buy one set of mm drill sizes and forget the silly Middle Ages method based on the King´s thumb width size.
The American standard of measurement is Metric, since after the Civil War.
In case of a dispute, the final authority is the Metric system.
The Imperial units are defined in Metric Units, a yard is so many centimeters, and so on.
It is based on decadal values. not fractions, or some body measurement of a human (I believe the yard was also originally defined as such).
In any case, parts suppliers like Micro-Tools will have a selection of proper tools and pin vise / pin chuck, handy for such work.
Micro Tools is an example of a business specializing in watch repair equipment, and they must have competitors, I have no ties to them.
Have fun, being trained in Metric, I find the thread numbers / letters / fractional size bit to be confused, and quite irritating.
Likewise, the people who are used to the other system may not like Metric!
In case of a dispute, the final authority is the Metric system.
The Imperial units are defined in Metric Units, a yard is so many centimeters, and so on.
It is based on decadal values. not fractions, or some body measurement of a human (I believe the yard was also originally defined as such).
In any case, parts suppliers like Micro-Tools will have a selection of proper tools and pin vise / pin chuck, handy for such work.
Micro Tools is an example of a business specializing in watch repair equipment, and they must have competitors, I have no ties to them.
Have fun, being trained in Metric, I find the thread numbers / letters / fractional size bit to be confused, and quite irritating.
Likewise, the people who are used to the other system may not like Metric!
Physical Chemistry was the most boring course I've ever taken.
My first batch of homework assignments got graded at a C.
I took it to the professor, he took a look and gave me an immediate A.
The Prof knew my major was Physics.
The person doing the homework grading was a Chemistry major.
Besides, that prof was ignorant. Maybe the door to the roof was locked and you had to take the pressure measurement indoors, in an air conditioned environment while the ground floor was opened to the outside?
Definitely a Chemistry professor.
Last edited:
You got a problem with cubits per a forthnight?
If it was good enough for Caesar's legion, it's good enough for me.
