Chamfered Laser Cut Bread Knife

In this instructable, we teach you how to make your very own serrated plastic bread knife with a laser cutter! You might ask, why bother? Well, in the process of developing some stuff here at Fremont Laser and Design, we figured out that we can - and that's reason enough for us. We think the jigging process is super cool and a great example of using a powerful tool in an unconventional way.

With that said, use your new powers for good, not evil! We are not liable for the actions of an individual or a group of individuals; this instructable was developed by trained professionals and is intended as a proof of concept. It is recommended to use proper safety equipment while operating a laser cutter and follow all provided instruction and safety manuals.

Step 1: Prep and Safety

!! WAIT !!

This project involves a Class 1 - 4 Laser depending on what you use and can be harmful or dangerous unless properly operated by a trained individual. Paired with the use of hand tools or optional power tools; you should take all safety precautions advised by the tools' manuals and wear proper safety equipment.

To add on, you're making a knife! Be careful, we all have accidents but we advise you to wear light gloves when handling the materials and blades as they can have many sharp pointy bits.

To prepare, find the provided materials in the next step, maybe do a readthrough beforehand, get some safety glasses and gloves, find a workspace, and maybe get some snacks...

Step 2: Materials and Tools

For this project you will need the following materials and tools. Some may not be pictured so be sure to read through!

• a laser cutter!
• 5.3mm birch plywood (~1/4")
• scrap plywood
• 2.8mm (~1/8") acrylic
• 13mm (~1/2") cedar or laser cutter friendly wood variety (softwood)
• 9.8mm (~3/8") wood dowel
• shop cloth or rag
• isopropyl alcohol
• blue painter's tape
• gloves
• safety glasses
• magnets!
• files/ angle grinder/ sander/ sandpaper (wood removal tools for shaping handle)
• wood glue
• acrylic cement
• spray poly. clear coat (satin gloss was our preference)

Step 3: Making the Jig

1. Use the magnets or tape to hold the plywood to the bed and cut the attached file from the 1/4" nominal birch plywood.
2. Assemble all parts as shown in the photos above.

There are three files in different formats of the same plans and there is a small square in each one that should measure 1" x 1" to use as a calibration measurement. Scale the file until the square is that dimension. The red lines indicate cut lines and the black (or white depending on software) indicate markings or optional etchings.

Step 4: Cutting the Blade

1. Open the Blade and Handle file (one of three), delete the handle piece and additional circle for now and set up the blade file. We cut four blanks so we could test out different serration patterns.
2. Use the magnets or tape to hold the acrylic to the bed and cut the attached file from the 1/8" nominal acrylic sheet.
3. Next, clear the bed and insert your piece of scrap plywood, cut a straight line in that to create a relative zero point, make sure it is also fixed to the bed using magnets and stays in the same position.
4. Now drop the bed down until you can fit the jig you built in. Butt the back edge of the jig up against the now zero point of the scrap piece. Make sure not to move the scrap while you affix the jig with magnets as well.
5. Now you can put a blank in the jig (use magnets, tape, or dowels to hold it in) and move the laser beam +1.5mm on the Y axis to put the laser beam on the right path.
6. Align the Z-axis how you see fit after aligning it to the appropriate distance first (we brought the bed up an additional 1mm for serrated blades).
7. Choose one of the provided Blade Patterns and let it rip! Due to the depth and angular nature of the cuts, the lens you use may not be built to cut this in one pass. You'll see a photo of a blade we cut in the jig that didn't quite work the first time for example. Don't lose hope!

There are three files in different formats of the same plans and there is a small square in each one that should measure 1" x 1" to use as a calibration measurement. Scale the file until the square is that dimension. The red lines indicate cut lines and the black (or white depending on software) indicate markings or optional etchings.

Step 5: Cutting the Handle

1. Grab your 1/2" handle material, we like cedar here in the PNW and cut your handle now from the Blade and Handle file you used before!
2. This cut might also take a few passes depending on the laser you use.

There are three files in different formats of the same plans and there is a small square in each one that should measure 1" x 1" to use as a calibration measurement. Scale the file until the square is that dimension. The red lines indicate cut lines and the black (or white depending on software) indicate markings or optional etchings.

Step 6: Assembly and Finishing

• Align and glue the handle and dowel into place with wood glue or acrylic cement, we used both for added security.
• File, grind, and sand your handle to it's finished shape.
• Tape off the blade with blue tape (careful holding it!).
• Spray your clear coat on to the handle to seal the wood and dowels. Make sure to spray in a well ventilated area and use multiple coats so that you properly seal the object.
• Pull of the tape and wipe down the finished product with alcohol and a cloth to sterilize and clean any dust left on it.

Step 7: Snack Time

Enjoy! You're not only way smarter now, you can split a cookie in half and give some to your friend (or eat it all)!

Please do be careful though; it's still not only a very sharp knife, it's made of acrylic. Make sure your blade doesn't crack or splinter while using it, most acrylic is food safe but not safe to ingest.

For more information, check us out at: laserfremont.com