This is a follow on to the spring loaded jack brace I posted in Guilded 7 months ago. I wanted to have more control over the force the jack applies while maintaining a compact size.

The new brace jack is basically 4 parts. The holes in the top of the jack tube are for inserting something to retain the thumb screw in the jack post when winding it back down. I think the easiest way is to slightly enlarge one of the holes and push in some fret dot plastic. The printed retainer is too brittle when printed with PLA. The D ring works well if you happen to have some #18 gauge wire. A piece of an old bass G string might work as well.

I printed the brace jack shown in the pictures on an Ender-3 using PLA which I mention because I toleranced the threads to work with the inaccuracies of that combination. I used the default settings for an Ender-3 in PrusaSlicer to produce the G code. PrusaSlicer complained about possible print stability issues, but using just a quick mist of hair spray on the print platform worked fine.

Once I had the parts printed, I used the brace post like a tap to clean out the strings in the thumb wheel threads. After a couple of trips up and down the post the thumb wheel turns pretty freely. The screw guide for the bottom of the post needs friction to work properly, so I just wind it on to the bottom of the post and leave it be. The assembled post, thumb wheel, screw guide works well as a tool to clean out the strings inside the jack tube.

The looth group has some endlessly talented people, so I have no doubt there are improvements that could be made. If you don’t have an immediate use for one of these after you have printed it out, I found it makes a pretty decent fidgit toy too!

BRACE JACK FILE DOWNLOAD

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