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Pocket Knife Frustrations
angus_bott226
Member Posts: 8 ✭
Hello! My name is Angus and I am currently working on my own pocket knife design for my own use. The reason for this is due to me becoming bored with the designs currently on the market and the ones I am interested in are $300+
I would love any assistance available from people who know more than I on knife design and CAD in general as I am self taught. I am reachable on discord and would love to LEARN what will be done to improve and fine tune my design. The "rough" shape is about 85% of the way done. Then it's prototyping and fine tuning.
The end goal is to make my forever EDC and be able to gift one to my uncle before he passes.
Comments
Welcome to Onshape @angus_bott226! Please let us know what questions you have and share a link to your document so we can help you better.
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https://cad.onshape.com/documents/b95e531d7ba20f7e90b7e9d6/w/5e1e625ad9fec78d09e06851/e/e03b2963aadc51cef5c8625e
Questions are for general organization and improvements of feature use and design, fine tuning tips and tricks, etc. I've done most of what I can reasonably do on my own at this point while juggling life and hobbies. I came to the forums for some live instruction(?) while working on it so I can retain the knowledge. I learn best through hands on direct instruction. Show me don't tell me, if that makes sense. I have trouble processing instructional videos for some reason, maybe my autism has something to do with it, not sure. I just really want to make a great knife for my uncle and to have something more to bond over. He's loved knives and woodworking his entire life and I haven't gotten to know him super well due to various factors.
@angus_bott226 - One small thought here, because Onshape is so easy to use on any computer, you might want to think about including your uncle in the design process. Either online collaboration, or even in person with him looking over your shoulder. Keep it up.
How will you physically make the knife? What tools and materials will you use?
Look up "hollow ground blades". The bevel on your blade is not how most knives are made.
Re-draw the handle so its in its real position, rather than in a random place and then transformed.
@nick_papageorge073 The knife will be made at a local machine shop I have ties with, CNC machining over manual. Blade steel is going to be similar to Magnacut but a bit more refined.
I'm aware of hollow ground blades, and I chose the bevel I did purposely. If during prototyping the bevel becomes an issue, then I'll address it and try the hollow ground style.
Please elaborate or rephrase that last point, I am not understanding what you mean by the comment.
@rick_randall sadly the lovely old man HATES computers with a burning passion. He still manually writes out all the math for his woodworking. Has a rotary landline and a flip phone. If I could convince him to even buy a chromebook, I would.
Addendum to previous reply that I forgot to add: He lives three hours away in another state, so seeing him isn't the easiest task in the world. Generally a planned weekend trip so the entire family can go down and my computer is not mobile.
You modeled the blade first.
When it was finished, you started modeling the handle. You modeled it at some random place in space, that was not where it would be in real life. Then, you used the transform command 3 times to move the handle so it aligned with the pivot point of the blade.
That's not good modeling practice. Instead, start the handle over, and model it aligned with the blade's pivot. You can choose to either model it in the open or closed position, that's up to you. (I'd probably do open). But in either case, their pivots should be coincident.
Well it looks like you have Onshape down ok. Now you just need to google some knife videos or images to learn exactly how the mechanism and tolerances need to be.
Also you will need to do research on the general knife making process, you can't just cut it out and assemble. For example:
Your first knife will be terrible. So I recommend making several prototypes to completion until you are satisfied with the quality of end product. This is important not only for cosmetics, but for durability of the blade too. You don't want to make a blade that dent's when you drop it or try to cut something.
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The next step was figuring out which button lock style I wanted to use, whether that be compression, button actuated top liner, or triad lock.
I have some experience with knives through blacksmithing and am familiar with blade steels, I was going to go with either Magnacut/Vanax or ApexUltra which appears to be best in class for the uses I am intending to go for. Going for around 60-61 HRC and will have the blade DLC coated for extra durability and flare. The prototypes will be made with more affordable materials and once I have all the issues worked out, then I'll go for the big ticket materials. Phosphor bronze washers and skiff bearings for the pivot, titanium for the locking mechanism that I finally decide on, and I'm going to try my hand at making some timascus for the handles since I have the tools at home to forge weld some. Going canister style with grade 2 and grade 5 titanium pieces and a powder to fill the negative space that's a 60/40 mix of grade 7 titanium and black zirconium. And yes, I have already looked at the patents for it that expired a bit over a year ago and am aware that I need to constantly purge the chamber with argon to prevent unwanted oxidation and to keep between 1700-2000 degrees. I was planning to have the forge around the 1850 mark to play it safe.
here is the patent linked for reference: https://patents.google.com/patent/US6857558B2/en
Also @nick_papageorge073 I did the transforms to move the blade and made it so wherever the blade and handle meet, the pivot moves with the blade that way I can fine tune the placement and once I'm happy with it, I'll fix it in place and do that. If that is such bad practice, I'd love for you to show me better methods. I previously stated I learn better with the "show me, don't tell me" methods as being told and shown while working hands on is an infinitely better way for my brain to absorb and lock in the information for future use. I appreciate your input so far, it has not gone unnoticed or ignored. I still need to fine tune where the pivot on the blade is to ensure better opening and closing (and so everything fits properly).
Overall I expect this design process to take another couple months minimum before I hit the first prototyping stage which will be FDM 3D prints just to make sure everything fits and actuates properly. Once the 3D printed prototype is without issue, then I'll move on to acetate and mild steel, tighten my tolerances where needed, and eventually move onto the true final prototypes. My projected funds for this are only going to allow me a maximum of five prototypes per stage, so I'm trying to work as much out in CAD as possible. If anyone is willing to give live instruction while I work on the model, that would be absolutely heavenly. Thank you everyone for the feedback and input you've given thus far!
I can't see any logic for making the handle here. That's what I'm referring to. With multi-part modeling, you draw the parts where they will live in real life. There are many advantages and time savings to doing this. Otherwise, there is no point to mulit-part modeling, and just draw each part in its own part studio. When you add more detail and draw the rivet, the lock, etc, you draw them all in-place, where they will live. Start this over now and it will save you a headache later.