Thread: Opinions wanted

I recently started going to the local college to get a degree in CAD. I was hoping I could get some opinions of a razor and scales I drew up. I am hoping someone can tell me if this drawing is practical, if it includes the elements that would be needed to actually use them as a blue print to build the razor and if the sizes , etc are realistic. I tried to combine aspects of different razors I liked and have seen on SRP and have changed the design at least 8 or 10 times. I'm hoping to find out from a CAD/Machinist perspective but all opinions are welcome. I can send the .dwg files to any one that wants to see them.
I'm thinking of using this as my final project in December. Not sure yet.

Thanks,
Bob

That is one really cool looking razor, I love the profile of the blade. 3/8”s would make for a very hefty razor, that is the only thing that I might think about.


Again, very nice design work.


Charlie

Build a working model and check it for usability and as Charlie says 3/8s will be extremely hefty!

Looks like it will be difficult to hone, but nice design.

I like it very much. Looks a bit like one that I drew up and Robert Williams made for me. It ain't easy to hone but it is nice to shave with.

Cool looking razor, JimmyHAD. But, I doubt it would shave worth a hoot. Can I try it a few weeks?

Are you asking from a CNC/CAD point of view, a usable razor point of view, or a technical drawing point of view?

a)CNC/CAD- A good CNC program could probably read that no problem. Is it fully constrained?

b)Usable razor- you won't know until you try.

c)Technical Drawing- it lacks a lot of details/annotations. First of all you need quite a few length dimensions in the top (spine) view, as well as an angle on that taper, and a centerline for the hole. You need to add center marks and radii for all the profiles in the side view, as well as dimension the locations of all the centermarks- I suggest from the very tip of the tang, seems to be the easiest to me. You also need to specify (either explicitly or in an annotation) the filet/round radii for places like the spine at the toe, the tip of the tang, the edge side of the barber notch, the heel, and the bump between the barber notch and the tang. The end view begs a lot but it would be very complicated so I would just add a centerline to the pin hole and maybe the grind angle. My biggest advice though is to add a sliced view through a section of the blade and show grind angle and a few height dimensions. This is by far the easiest way to dimension a profile that has been extruded along a spline (vs. a strict end view- which yours isn't detailed enough- if it was it would just be a giant mess so I wouldn't make it strict.) If you want I can try and find a way to make a pictorial.

PS: what program is that?

Originally Posted by khaos

Are you asking from a CNC/CAD point of view, a usable razor point of view, or a technical drawing point of view?
PS: what program is that?

All three points of view, mostly the Technical drawing aspect tho.
I didn't realize all the dimensions that were left out until I started adding the ones you talked about. Should this all be on one drawing or separate pages?
Once I get this marked up I'll ask you about the sliced view. This is done on AutoCad 2010

Thanks,
Bob

Lol @ Autocad. I guess its a good tool but I much prefer both Autodesk Inventor and Solidworks.

If you're going by hard and fast drawing techniques your whole layout is wrong too- what you've got is an orthogonal drawing. So you're gonna want to place the front view (I know this is a "side view" but its called front view, its typically the face with the most detail), then line up the top view and right view so the key points match. Your scales seem to be laid out right for comparison. The whole point of this is you don't have to duplicate dimensions. In your current layout, technically you would have to mark the length on both top and front view.

With regards to dimensions there are two schools of thought. The hard and fast rule is put as many as you can on the front view, without a dimension line crossing an object, hidden, or other dimension line and such that all dimensions are off of the object. Then top view, same rules, then right view, same rules.

Then, you can either add dimensions in a manner that breaks as few rules as possible, or add alternate views that follow those rules, but describe the object better than the f/t/r views do.

In your case, with so many curves and off set lines, it might be better to use alternate views. If the spine curve and edge curve are concentric, a slice radial to that circle will give a VERY good view of the blade profile, and will knock out a few dimensions.

Something less professional that you might consider doing is to have two drawings, one with some dimensions and another with the rest, for instance, this one with radii and another with the locations. I would really try and get it all on one sheet though. If you expand your drawing space it will be easier to organize your dimensions.

Ideally, you want every aspect to have a dimension, without repeating information. This is a stupidly complicated and convoluted field and I have two whole textbooks on technical drawing/sketching. There are standards for everything. But 99% of the time you can get away with a lot provided 4 things: the drawing is clear, the drawing is accurate, everything is dimensionally constrained, nothing is dimensioned twice.

Interesting design. Will you be actually producing the razor. As as said previously, some measurements and lines are missing and it is not totally in accordance to drawing rules. Khaos already gave you lots of pointers.

It would be a good practice to double-check drawings other people have made and get experience that way - maybe your teacher might give you some detailed drawings. I've learned tremendously doing similar thing.

I see you've got a tapered tang. How does that fare while pinning and opening? Will the flex in the scales adapt or will it slowly be working itself loose? Are there any production razors with tapered tang? (I just don't know). Another thing: With those things you have a true wedge in your hands (no grind). Or were you planning to have just the blank made and then grinding yourself? If so, lose the bevel grind, or the machinist might make a nice bevel for you with a grinder .

I can just see the guy who actually produces the razor, while reading the drawing, going "Who are Escher and Thuringian and why do they have to run laps?"