Intro: Making Custom Knife With 3d Printer Ver.2
I made this custom Damascus slicer during my Autodesk artist residence. this is a different approach to make custom knife with the aid of 3d printing technology.
My first attempt of this custom knife making is posted https://www.instructables.com/id/made-custom-chef-k...
This Kitchen knife is a 10in slicer, with glow in the dark epoxy handle.
The blade is forged and hardened by blade smith in California. forging damascus steel is an art form itself. My post shows my approach to sharpen and etching the blade. My focus is on making custom handle. Model the handle in 3d program, derive the mold for the handle model, then 3d print the mold of the handle and cast it will resin.
Step 1: Design Ergonomic Handle
design an ergonomic grip start with building a clay model. with hard modeling clay I was able to capture the grip of my right hand and smooth out the marks. the process was posted on my other post https://www.instructables.com/id/made-custom-chef-k...
Once I have all the measurement for the clay model. I roughly created the shape in 3ds Max. the basic form is then modified with turbo smooth feature. shape is compared with design for the 1st knife handle to make sure the scale is correct. I am happy with the shape, now on to model the model for the handle
Step 2: Model the Handle Mold
Using the handle model as the base shape. Apply outer shell modifier to the model, I input 1/8in thickness. add flaps and holes for screws. Then slice the shape to four quarters. four part mold will ensure easy separation once cast resin. move all the parts to the right orientation and prepare for 3d printing.
Step 3: Print, Polish and Test Fit the Blade
I printed the mold on Connex 500 Objet printer. the accuracy is amazing and absolutely no wrapping on the edges. I was very happy with the printed mold. I just wet sand the inside from 600 grit all the way up to 2000 grit. Once that is done. I grind off some materials on the handle to have the metal fit inside the mold and also have some gaps from the edge.
The gaps will be filled with resin so I made sure the metal part is grind off and have enough space for the resin to bond.
Step 4: Etching and Sharpening the Blade
I gave a light sanding and polishing efore acid etching the blade. I marked the edge of the blade with a sharpe to protect it from the acid. The Acid I used is muriatic acid and I have also tried with white vinegar. I have also prepared another container with baking soda solution to neutralize the blade. the process is quite simple. etch the blade in acid for few minutes then take it out and lightly scrub away the black matter, then dip it back to the acid again. I did a few times to achieve the depth that i wanted then dip the blade in neutralizer to stop the reaction. whip clean the blade then I sharpened the blade on 3 different wet stones 180 grit, 600/1500 and 3000/8000 grit. finish sharpening by hone the blade with Wuthof toning steel.
Step 5: Engraving the Blade
I asked a friend to write calligraphy of my given name and my girlfriend's given name, though our name have different characters they all pronounce " yue". I scanned and added the Pier 9 Logo. spray the blade with Cermark and laser engraving the marks on both side of the blade.
Step 6: Cast the Handle
I drilled a 1/2 inch pour hole at the end of the mold. apply silicone release agent on both inside and outside of the mold，I mixed blue dye with glass fiber to make blue strained fibers. I have also mixed a batch of high quality uv resistant casting epoxy then divide to three batches. one mixed with mica powder, one mixed with graphite powder and last one tinted with transparent blue dye.
I lay the mold flat and used a dropper to dispense a bit of blue and metallic resin, make sure not to mix two together. I also dipped some dyed blue fiber in the resin. I did on both side and let it set.
Step 7: Fill the Mold With Glow in the Dark Resin
Once the first batch of resin is cured ( 24hrs later ) I mixed a glow in the dark resin to fill the rest of the mold. the mixture contains clear resin with small fiber and phosphorescent powder, mix small amount of powder at first, the resin should be semi opaque so light can penetrate all the way through the handle. Vaccum degas the mixture. assemble the 2 part mold and seal all the edges with hot glue. the translucent mold will ensure the blade is at its vertical position. fill the rest of the mold and let it fully cure.
Step 8: Break Open the Mold
when open the mold, pry the mold parts carefully and open it little by little the key is to break the vaccum seal between mold and the handle, but not crack the mold. because the mold is made of hard photopolymer, it is not very flexible, that is the reason it will break to 4 parts. after a good 10 mins wrestling I finally break open all the pieces. the handle should have a smooth finish and only minimal sanding required. I tested the knife handle in the dark, it glows nicely with a yellow hue.
The knife is well balanced, only a bit heavier on the handle to have steady control. It may not be the most practical knife but surely it is very beautiful to just look at, plus it glows in the dark !
Practice N Enjoy