My Secret To Perfectly Fitting 3D Prints

This makes sense for layouts, curves, complex shapes. But for the diameters of those cylinders, hole distances, etc. I think it's still better to use a caliper.

Took me a long time to figure out the "as far away as possible" photo trick... this makes a huge difference

If you have a scanner, you don't only get a perfectly orthographic photo, you also get a fixed scale. So if you can, use a flatbed scanner.

A major cheat to copying in a pre-existing item is to remember that any patterns are probably symmetical and dimensions are often the usual sorts of numbers that designers are wont to pull out of the air. So in something like this, the bolt holes will be on a fixed grid (ie the lines between them will be parallel and perpendicular to each other) and probably at multiples of 5mm apart. In the same vein, corner fillets are often 5mm or 10mm radius. While I've used the photo method, I've also drawn up all sorts of things to match something with nothing more than a ruler.

Useful stuff! Some thoughts: 1. When initially measuring, make sure to do so in both Imperial AND Metric. (If measuring in Imperial and the last two decimal digits is close to a multiple of 25, that is a good sign that the part was designed with Imperial measurements.) 2. Don't waste time and materials when testing fits. A thin plate on a raft with holes in it--as he used here--is all you need to check initial fitting. 3. Unless you are doing a one-off, don't bother fiddling with your phone to scan the part in. Instead, pick up a cheap-as-chips scanner or all-in-one from your local classifieds. You won't have to worry about zooming/etc, and everything will be perfectly aligned. 4. Print a precisely-sized rectangle larger than what you need to scan, cut a rough hole in the center big enough for the object--without touching the rectangle, of course, then lay both on the scanner, facing downwards. You can then accurately scale the image using the high-contrast rectangle instead of the object, itself. Cheers!

In Fusion 360 you can calibrate that imported image - you choose two points and enter what distance this is. Not aware of other CAD software, but in Fusion it's very simple. For me making a simple model (as shown in the video) is faster with calipers, but your method is great while working with odd shapes, curves etc.

Very interesting. Maybe you can shoot your ruler at the same time as the object, that should simplify the scaling.

other really easy workflow; check for manufacturer documentation. Especially for technical elements, like stepper motors, sliprings, etc. They usually have a technical drawing somewhere with the exact dimensions on it for everything.

A flatbed scanner also works well if the face is pretty flat and doesn't have an axis pointing out the bottom.

0.2 mm is the difference between press fit and loose fit. I use this technique for low-accuracy work. However, when precision is needed I break out the calipers

For fitting round parts I usually print a small wall 5mm high and try it from there. The repeat accuracy of these printers is actually quite good.

I've done something very similar using a flatbed scanner for parts that can be scanned. If you only care about a flat part on the end, the scanner will scan the portion of interest with 2400 dpi resolution and the portion above the scanner bed will be fuzzy and out of focus. The scanned image can be opened in GIMP, which has tools that can measure any dimensions you like with sub-pixel accuracy. A scanner and GIMP is a very inexpensive optical measuring system, similar to having a microscope with built-in micrometer. I use a scanner and GIMP for determining the hardness of a material using the Brinell method. A hard ball is pressed into the surface using a fixed force. The diameter of the spherical impression indicates the hardness of the material. I scan these small impressions at 2400 dpi and GIMP can make six measurements of the diameter at different angles, with sub-pixel accuracy. I average the measurements. It's far more accurate than using an optical scale on a pocket magnifier.

Hey just a wee thank you for the orthographic photo trick, never would've considered doing it - take a gold star sticker for your jotter ⭐

Great idea on using background compression. For the photo, I’d suggest using a cutting mat that has either a 1cm or 1/4 inch grid on it. Place the object on it and you have the X and Y scale right there.

it's amazing - very simple and easy way. thank you

Good video, again. I already do this, well, except for the tolerance tower test, but you explained it easily for others which I am sure will help more people.

I got your precision gears and bolts add on. Totally stoked!

Nice vid, would love to see this with resin and a before and after curing tolerance with different resins.

Thank you !!

this is genius and the delivery is perfect. Thanks a ton