This is my take on TH8A/RS shifter H-pattern mod, it has a bunch of improvements over similar solutions available.

Overview: https://youtu.be/zjpHEQ71D44

If you like my designs consider a small tip: https://paypal.me/PeterMakesThings?locale.x=en_GB

Parts list:

• 3d model
• spring ball screws (m6 or m8): https://tinyurl.com/w6wjjx2
• teflon glide pads (20x20x6 mm, one needs to be cut to 15x14mm size!): https://tinyurl.com/wuhwbso
• zip tie
• bit of grease