Poor intonation is a hallmark of most ukuleles, the note played will be sharper the higher up the fretboard you go. This part may lessen or eliminate the issue completely on your instrument. Prints fast and solves many headaches!
Made for a Diamond Head DU-200C concert Ukulele, but will work on many concert (and possibly soprano) ukuleles.
Update: Thingiverse user Mackrash has informed me via the comments that this worked for a Tenor ukulele as well; It was also printed in ABS and seems to work just fine. Feel free to give it a shot.
print is solid, with two shells. even with a raft, it should print fast. I recommend PLA or Nylon, abs may be too soft.
Tuning and installation:
You will need to use some fine grit sandpaper or an emery board to smooth the surface of the curves that touch the strings. small files would be helpful with fine tuning the saddle.
loosen your strings, remove your original saddle and put in a safe place. if the height of your saddle is lower, you may need to rescale the part or file it down. If it's not high enough, you will need to rescale the part or shim it (rescaling the part vertically would be best.)
Make sure to use sandpaper on a sheet of glass to smooth the bottom of the saddle, you may also need to thin the saddle slightly to fit in your bridge. fit should be snug, but not too tight (easily inserted and removed from the groove in the bridge)
install the new saddle in the bridge, with the notchces toward the headstock, Carefully sliding it under your strings, starting from the G string side. make sure your strings are loose (a good six full turns on the tunnig machine heads)
now, with a clip-on tuner, pluck a string and tune it up to the nearest note on each string. pluck a string, then press that string on the 12th fret. if it's within a cent or two, you're good. if it's too sharp, remove the saddle, and lightly file or sand with fine paper on the corresponding bevel on the saddle to lengthen the scale slightly. repeat the process. for each string. if you take your time, filing/sanding in small increments you can get it perfect.
I made this for my Diamond Head Concert Uke. I only had to slightly file the bevel on the G and C strings. Straight off the machine (after smoothing the part a little) it was almost perfect, and loads better than the factory saddle. printing took about 10 minutes, tuning the saddle took about 5 minutes.
Flat notes (note is flat at the 12th fret) will need to be adjusted by editing the part and re-printing it, you need to shorten the scale (lengthen the beveled portion) of the affected string.
This may work on sopranos as well., I haven't tested it yet. Will definitely work on many concert ukes.
Best part is, you can print spares. If you screw up fine-tuning the intonation, just print another and start over.
Lastly, if you're too nervous to do this yourself, take it to a Luthier or a Guitar tech, and they should be able to help you out.