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| alamwte:
Hi, I have a little PCB board with about 12*27 mm width that I want to design a box for it. I need to measure its width and the diameter of its holes and the accurate location of these holes. I have used a digital Calipers but It is not easy to masure hole location and it is not acuarate enough for width measuring too. Which tool do you recommand to me ? I attached some similar board photos below. Thanks. |
| pqass:
It doesn't look too thick. Try to make a photocopy (cover with a white paper sheet if you can't use the lid). Then markup and measure the photocopy with digital calipers like these: https://makezine.com/2015/11/13/how-to-use-your-digital-calipers-7-tips/ Derive w/h scale factors (likely very close to 1/1) by measuring width/height of actual PCB vs the photocopy width/height. |
| eugene:
I don't understand why/how digital calipers can't do what you need. Certainly outside dimensions of the PCB are trivial to measure with calipers. The inside diameter of a hole is also simple using the side of the caliper meant for inside measurements. To determine the location of a hole relative to an edge, measure the distance to both sides of the hole - side nearest to the edge and side farthest from the edge and average the two to find the center. I could probably perform a web search to find caliper tutorials online, but you can do that just as well. |
| Ian.M:
Digital calipers tend to do a really crappy job measuring the diameter of small holes due to the offset between their inside jaws so they can slide past each other. While you *should* have a set of precision adjustable hole gauges for transferring inside diameter measurements for readout with a micrometer, few of us who aren't trained machinists have them. One quick & dirty approach is to compare the hole to the shank end of a selection of plain drill bits (i.e. ones where the diameter at the cutting edge is the same as the shank). This is typically good enough for fixing holes. A more accurate measurement can be made with the aid of an appropriately sized taper pin. Insert the pin in the hole till it just stops, without forcing it, and use a fine tip Sharpie or similar to mark round the pin at the board surface. Check the pin in the hole inserted from the other side in case the hole is tapered, then remove it and use the calipers to measure the pin diameter at the edge of the mark where the board surface was. N.B. if the hole is significantly bell-mouthed or chamfered this will over-estimate its diameter. :( If you can see a visible gap between the mark you made and the circle of contact, try to compensate for it when measuring the pin diameter. The same pin inserted a bit more firmly in the hole can be used as a stop to allow measurement of distance from the board edge to the hole, using the caliper's depth probe. Don't forget to add half the diameter to get the distance from the edge to the hole center. |
| Domagoj T:
When doing stuff like this, I take a photo of it with a ruler in frame. Then I import the image into Solidworks (or whatever you'll be designing the enclosure in) and use the ruler for calibration (Solidworks has a dedicated tool for this). |
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