Makers Edge - Utility Knife with Cover

I designed this utility blade handle as a bit of drawing/design practice. I use these utility blades all the time, and I have quite a few handles, both 3d printed and store-bought, but I thought I'd give designing my own a shot. 

The design has been through a few internal revisions for tolerances, feel in the hand, and convenience, and I think this version is one I'd like to share! 

It works well for me, over the last week or so, I've found myself reaching for it for all my maker projects. 

It features a blade handle, which the standard utility blade slots into, and a cover plate secured with 3 screws to create some clamping force to keep the blade in place. This seems to work well, but we'll see how it holds up over time.

I also have a hole through the hilt for hanging it on a wall/mount for easy access, and a blade cover because I tend to be a bit clumsy. It's all designed in onshape, which I've been getting to know better.

Printing Details

I printed this with 3 walls, 25% adaptive cubic infill, and no supports. It seems plenty strong enough for everyday use, but you might want to increase these if you feel like you'd like a bit more weight in the hand, or strength overall. 

Both the handle and mount should be in the correct orientation for slicing, but the blade cover should be rotated 90 degrees on the X axis, and placed on the flat bottom to print without supports. I've included a screenshot of how I oriented mine for slicing. 

The design uses 45 degree chamfers to allow the edges to print without supports, so as long as you stick to these orientations, most printers should be able to print cleanly.

Assembly

You will need: M4 10mm bolts/screws (3 of these to secure the mount to the handle)

I've designed the mount to fix to the handle with these bolts and they should self tap as you thread them into the parts. (See tolerances for details)

The cover plate has 8mm of head clearance to that the head of the screw/bolts sits tucked into the knife. The total width of the blade handle should leave about 1mm of space on the other side of the knife, meaning no threads sticking out when using a 10mm bolt.

The holes do pass-through the whole design, so you can change this however you like.

Tolerances

I've designed this to be printed on my Ender 2 Pro which is relatively dialed in, but it's still a new addition to my print-fleet, so it might not be perfect on your side. I've included the step files so you can remix it however you need to get these tolerances right. 

With that said, it should work alright for most people. I'm printing with a 0.4 line width, so bear that in mind. 

• M4 Holes: 3.9mm (Self tap) 
• Blade: 0.2mm (On either edge, allowing it to snap fit)

All other clearances, for example the mount to the body has ample room to not be an issue.

Blade Dimensions

A friend mentioned that some blades do have different dimensions, and I thought they were all standardized! So I thought I best share some dimensions here: 

• Upper edge: 30mm
• Lowed edge (sharp): 60mm 
• Height: 18mm 
• Thickness: 0.64 

These are approximate values, the design has some tolerances here, but I believe Stanley blades might be shorter than the 60mm mentioned, so your mileage may vary. My blades are generic blades, no name brand associated and they fit great. 

Print Details

• Make: Ender 2 Pro (But it shouldn't matter)
• Layer Height: 0.16mm
• Supports: No
• Brim: No
• Nozzle: 0.4mm

Note: I may revise the design based on feedback, but again step files are included, so go for it! Some friends are printing this at the moment, and I might create more tolerance based on their feedback (and yours!).