milwaukee fastback pocket knife fix

The fastback is (in my opinion) one of the best pocket knifes. The opening mechanism is awesome, and a removable blade means its always sharp… but it suffers from 2 major issues! The belt clip is backwards, meaning you have to rotate the knife in your hand after taking it out of your pocket. This makes it harder to use in a shop setting where you might be precariously holding something that you need to mark or cut with minimal movement.

The other issue is simply cosmetic. I don't want a knife im carrying every day to advertise a tool company. My design tried to keep the knife as simple looking as possible, while still having some small fillets on the edges so it is comfortable in the hand.

Change Log:

• 8 Apr 2025
  • Loosened up some tolerances to allow better button movement
  • Added a small bit of geometry that was causing the belt clip side metal insert to not sit flush

Project video:

This project requires the following (contains affiliate links):

• 1x milwaukee fastback compact (the version without the twine cutter)
  • https://amzn.to/3DZK7Xz 
• 1x torx T6 driver (non security)
  • Should be in an ifixit kit or similar ( https://amzn.to/3Yk9D0q )
• 2x torx T10 drivers
  • 1x from ifixit kit, plus another cheap one (ie: https://amzn.to/4cj20wW )
• 1x Phillips #2 driver
• M3.5 x .6 tap, and 2.9mm drill bit (optional, see bullet points below)
  • drill and tap combo: https://amzn.to/3Eo2o0C 
  • This is needed if you want to re-use the phillips #2 screw that comes with the knife. Below are two other options that will also work
    • You can also find a pan head screw that is a more sensible thread size. A screw around 1/8" dia should work
    • you can slightly oversize the new hole for the belt clip screw, then superglue the belt clip into the recessed part of the plastic, as well as adding some superglue to the threads of the screw. This seems like a bad method, but I did this on a prototype and it has not been an issue after 2 years of use.

Instructions:

• Disassemble the knife
• Print all parts with flat sides on the build plate. Parts are designed with 0.2mm layer lines in mind.
  • print with supports on build plate only or manual supports. For the button side, you will need supports on the one hole that is ‘countersunk’. For the clip side, you will need supports inside the bump, and for the two press fit parts.
    • If you notice sagging on top of the supports, i suggest tuning your supports to work with a 0.1mm interface. my settings are as follows:
      • 0.1mm contact distance
      • 3 top contact layers
      • change XY separation to 160% to make it easier to get behind the supports with a pick tool
      • lower temp until supports remove easily
• Superglue the two small pieces into their corresponding holes
• reassemble the knife
  • place the push button in the blade holder before re-inserting the blade holder on the rotation shaft. The knife will not open correctly if you slide it in after
  • its recommended to add some oil (not wd40! an actual oil like 3-in-1) onto the bronze washers during reassembly. This will make the knife open much smoother than how it came from the factory

Files include the scan data from both the Einstar VEGA and classic Einstar. The VEGA scans are much higher quality, and i would recommend using those if you want to attempt to reverse engineer the knife yourself. The original Einstar scans are only included in case you want to compare the scan quality between the two scanners. This project was originally done with the classic Einstar, but I re-scanned the knife with the vega and re-modeled the knife based on those scans for a more precise and well fitting knife. If you want to get an Einstar scanner for yourself, You can use this link ( https://www.einstar.com/?ref=iqghvpxy with the coupon code METHODICALMAKER for $50 off )

You may use the files uploaded here for non-commercial use only. Remixing and sharing modifications is ok as long as they are also licensed for non-commercial use. Remixes or modifications must include text indicating that a commercial license is available from the original author, and link to this model.

If you intend on printing or manufacturing these for commercial purposes, or if you want the STEP / f3d files to modify the design, contact [email protected]