Development of the Black Fox ONE 2x72 belt knife Grinder

Engineering started in June of 2017 with the goal of making a knife grinder that would be versatile enough for anybody to achieve their ONE goal. The benchmarks of design were:

  1. Combine the functionality of a vertical and horizontal grinder
  2. Use standard grinder components
  3. Use standard industry part components
  4. Manufacture easily
  5. Be cost effective

The first design iteration was subjected to stringent finite element analysis (FEA) and computer modeling.

 First design revision FEA results: Shows the von mises stress with a torsional load and weight applied by the motor

First design revision FEA results: Shows the von mises stress with a torsional load and weight applied by the motor

 Shows the displacement of the same loads applied as the stress model.

Shows the displacement of the same loads applied as the stress model.

Even though the results of the FEA testing showed that the grinder had low stress and deflection it was found thru a quick poll of peers that the grinder looked not as robust as it should. With this feedback in hand we upsized the sheet metal material thickness to increase the robust look of the grinder.

The first prototype of the grinder was built in August of 2017.

 Prototype design

Prototype design

The prototype grinder hit many of the benchmarks:

  1. Can be positioned horizontally or vertically
  2. Uses standard knife making components
  3. Uses industry standard fasteners and components
  4. Costing at high quantities could produce a competitive pricing model

Some small details needed to be addressed:

  1. Tube had a seam and therefore a modification of a standard 1.5" arm was used
  2. Head unit was not as straight as it should have been
  3. Tracking block only allowed for limited motion
  4. Although the pivot locking system worked well we wanted it to work better

After some testing we decided that to take the design to the next level it had to be reviewed by a Master bladesmith. Luckily Bruce Bump lives in the same town. I contact Bruce to see if he was interested in taking a look at my prototype and providing feedback. Thankfully he was open to the idea and willing to take some time to review it. I trucked my prototype design over to Bruce's house where he and his apprentice picked apart my design have gave me some wonderful suggestions to bring the design up to another level. With Bruce's feedback in hand as well as the details I knew needed to be addressed I spent another 2 months tweaking the design. 

The final design pushes the limits of what a great knife grinder should be and sets the benchmark high for future grinders. Not only do we believe that this 2x72" belt grinder will do well in the knife making industry it will do well in woodworking, fabrication, and any application where precision material removal is needed. We have received great feedback on the design and look forward to seeing what 2018 holds for us.

The first production run will be ready to ship the last week of December 2017 with a second batch of 5 that will be ready mid to late January. 

 Rendering of the final design

Rendering of the final design