This is a plug follower used for Lock re-pinning. These typically run at least $2.50 per size and come in bags of $20-$40. I decided to make my own. This is the first version which is based on the ones you can buy. I have some ideas in mind for improved designs but wanted to get some feedback first.

You can use the openscad file to pick your lock type. Then, re-render and it should size itself correctly.

In openscad set the style variable in the first section of the code:

s398 = 5;   // Almont, Corbin(small), ILCO(peanut), Yale(small)
s498 = 6.3;   // Yale, Welch, Tayler, Taco, Segal, Sargent,
                          // National, Nesco, Lockwood,Kwickset, Keil,
                          // ILCO, Eagle, Dexter, Corbin, Arrow, Acrolock
s500 = 6.4;   // ILCO(rim), Keil(rim), Lockwood(rim)
s550 = 6.9; // Corbin(oversized), Russwin(oversized) 

// Set this style for the lock you want to repin
style = s498;

Then press F6 to re-render. After that you can create an STL for the makerbot. Note, You may need to make some adjustments depending on your extruder.

I have also had to sand down an edge of the circle based on the algorithm that makes circles causing a small hump, but no big deal.