Parameterized shifter knob for Jeep automatic transmission by StevesHobbyRoom

Last crawled date: 3 years ago

I was getting tired of the Tee style shifter in my Jeep TJ so I decided to make a cool new one. I made everything parametric so it may be modified for different applications. If you have questions comment below but here are the basics....
All measurements are in mm. Measure DIAMETER, not radius! The diameter is already cut in half by the code.
First determine how big you want your knob. Input this as knobdiameter. 55 is pretty comfortable and looks beefy.
Second determine how big you want the press to shift button. Input this as buttondiameter.
Measure the diameter of your shifter shaft. Input this as shaftdiameter
Measure if the shaft has a swell under the knob. Input this as shaftdiameterb
Measure how far the original knob slides onto shaft. Input this as shaftheight
Measure the diameter of the pushbutton shaft on the shifter. This is the shaft that gets pressed when you push the button. Input this as buttonshaftdiameter
Measure how far the button shaft sticks above the shifter. Input this as buttonshaftheight
Measure how far the shaft moves when fully pressed. Input this as buttonmovement
Mine shifter had a small groove that the knob snaps into. Measure how far down this is from the top of the shifter shaft and input as clipringheight
Pick a bolt that looks nice such as an M3 socket head allen bolt. Measure the bolt head diameter and input as such.
Measure the bolt head thickness and input that as well. Make it slightly less if you want the bolt head to stick out a bit.
Input the actual bolt thread diameter as boltdiameter
Length of the bolt from head to tip. Still experimental.
Grubscrewdiameter is a small hole I put to hold a screw next to the shaft to secure the knob if it's too loose.
slotwidth is the width of the groove slot cut in the shifter shaft to keep the knob from rotating. This knob will have a tab that fits into it.
clearance is the clearance between fitting parts and around screw heads etc. You may want to experiment with this depending on your printers characteristics.
Once all the parameters are in uncomment all the module lines including the translate and rotate function and you can render the knob as a whole. To compile for .stl export comment every line except the module you wish to export. Export each as an individual piece, TOP,BOTTOM,BUTTON. Make sure to leave the translate and rotate function commented when compiling for export so that each piece is flat side down.
I printed mine at .15mm layer height and 25% infill and it worked nicely.