CAD drawings and the complaints they generate
CAD drawings and the complaints they generate
There have been a lot of 3D models posted which generate complaints that they cannot be fabricated for a variety reasons and statements like they are “un-machinableâ€
I'll step up; as I'd definitely be guilty if I were one of those being charged {of complaining - edit}.
Nothing wrong with 3-D CAD drawings. They're fantastic for conveying an idea, especially to those who do not read prints regularly. But they're just fancy pictures, you can't build anything with that data alone. It's simply a perspective drawing. There are no dimensions, as no one ever bothers to include the 2-D data with proper dimensions.
If all one wants is a pretty picture of an idea, then fine. Here's a penny for your thoughts, glad you dreamed something up and put your idea on paper. But, if these are looked at as a set of instructions (which they are) then they are not nearly complete. Most of what is posted does not even include the type of material to be used. Machining a mono-core out of 6061T6 aluminum is very different than cutting it out of 316 stainless.
I will suggest that most of the people creating these 'wonders' on their computer have never built anything as nearly as complex as what they can design. I won't say these designs can't be built, but they generally aren't practical or economical to manufacture. They aren't practical because those doing the designing usually do not have the shop floor experience to know what can and can't be done. That's not an insult, it is very unusual to find someone who has the skill and talent to both design or program AND build.
I don't do any design, but I do build things that others design. As a builder with a lot of experience, I have a unique perspective as to how things could best be designed to assist in the manufacturing of those items. Little details like fillets and such do make a difference. The devil is in the details. Too small a radius can result in stress cracks and might require wire EDM where a larger radius could easily be machined and be much stronger.
Ultimately, I really feel that those only posting 3-D pictures are saying, "Hey, look at this; see the great idea I dreamed up. Please tell me this is fantastic even though I could never actually make it and have NO idea if it will really work." Big deal, I've got plenty of suppressor ideas too. I just don't post half-baked pics of 'em all just to see what people think.
Nothing wrong with 3-D CAD drawings. They're fantastic for conveying an idea, especially to those who do not read prints regularly. But they're just fancy pictures, you can't build anything with that data alone. It's simply a perspective drawing. There are no dimensions, as no one ever bothers to include the 2-D data with proper dimensions.
If all one wants is a pretty picture of an idea, then fine. Here's a penny for your thoughts, glad you dreamed something up and put your idea on paper. But, if these are looked at as a set of instructions (which they are) then they are not nearly complete. Most of what is posted does not even include the type of material to be used. Machining a mono-core out of 6061T6 aluminum is very different than cutting it out of 316 stainless.
I will suggest that most of the people creating these 'wonders' on their computer have never built anything as nearly as complex as what they can design. I won't say these designs can't be built, but they generally aren't practical or economical to manufacture. They aren't practical because those doing the designing usually do not have the shop floor experience to know what can and can't be done. That's not an insult, it is very unusual to find someone who has the skill and talent to both design or program AND build.
I don't do any design, but I do build things that others design. As a builder with a lot of experience, I have a unique perspective as to how things could best be designed to assist in the manufacturing of those items. Little details like fillets and such do make a difference. The devil is in the details. Too small a radius can result in stress cracks and might require wire EDM where a larger radius could easily be machined and be much stronger.
Ultimately, I really feel that those only posting 3-D pictures are saying, "Hey, look at this; see the great idea I dreamed up. Please tell me this is fantastic even though I could never actually make it and have NO idea if it will really work." Big deal, I've got plenty of suppressor ideas too. I just don't post half-baked pics of 'em all just to see what people think.
Last edited by Wicked on Mon Feb 08, 2010 2:35 pm, edited 1 time in total.
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Pretty much.Wicked wrote:Ultimately, I really feel that those only posting 3-D pictures are saying, "Hey, look at this; see the great idea I dreamed up. Please tell me this is fantastic even though I could never actually make it and have NO idea if it will really work." Big deal, I've got plenty of suppressor ideas too. I just don't post half-baked pics of 'em all just to see what people think.
I think you are missing my point (perhaps it was not clear) but to say something can’t be made or is too difficult to be practical without any explanation of why is not helpful and just makes you look ignorant or too elitist to tell us why. Particularly because most of the CAD drawing I have seen only have a one or two features and sometimes none that I think would be challenging for a modern shop.
One example is Winsor’s “S-Lonâ€
One example is Winsor’s “S-Lonâ€
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generaldisarray
- Silent But Deadly
- Posts: 388
- Joined: Sat Dec 12, 2009 10:59 am
- Location: sho me state
The solid models aren't made to impress. Modelling lets the idea out of your head so the rest of us can see it. I was really surprised how many guys on this forum use CAD modelling, but it makes sense if you consider what attracts someone creative to 'silencersmithing'. I'm just a new nobody but really appreciate anyone brave enough to share their ideas.
I do not advocate piracy. Solidworks is NOT on easynews, to be downloaded and run on your personal system for educational purposes. Even though easynews has a two week free trial with enough bandwidth to retrieve solidworks, you would best heed this warning. Even though sw will change your life but cost around 5k, getting it this way is just something I can't abide, even if it is the best. (wildfire users leave me alone)
I do not advocate piracy. Solidworks is NOT on easynews, to be downloaded and run on your personal system for educational purposes. Even though easynews has a two week free trial with enough bandwidth to retrieve solidworks, you would best heed this warning. Even though sw will change your life but cost around 5k, getting it this way is just something I can't abide, even if it is the best. (wildfire users leave me alone)
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MisterWilson
- Silent But Deadly
- Posts: 1089
- Joined: Sat Jan 12, 2008 9:42 pm
I have always consulted with my machinist and modified my designs accordingly, attempting to learn meanwhile. They have all started out as more complicated and been inevitably modified for ease of manufacturing.
Take my recent Mk.45. It's a superb design in terms of performance, but very time consuming to produce: The core alone took over 8 man hours to stamp and weld, and 10 baffles had to be stamped to get 3 right. Granted, there was a learning curve involved for the machinist as well, plus the manufacture of specialized tooling (e.g. the baffle dies, aligning rods, mandrel for barrel threading, etc.). But still, total production cost for the one unit was aroung US$250, which means my design is not economical for mass production at this stage.
I will agree that most CAD drawings start out having details that are too complicated for mass production, while not adding enough benefit to compensate their cost; however, with the help and guidance of a good machinist they can be worked out.
The fact that one of my machinist's specialities is building custom mufflers for racing motorcycles no doubt helps.
Take my recent Mk.45. It's a superb design in terms of performance, but very time consuming to produce: The core alone took over 8 man hours to stamp and weld, and 10 baffles had to be stamped to get 3 right. Granted, there was a learning curve involved for the machinist as well, plus the manufacture of specialized tooling (e.g. the baffle dies, aligning rods, mandrel for barrel threading, etc.). But still, total production cost for the one unit was aroung US$250, which means my design is not economical for mass production at this stage.
I will agree that most CAD drawings start out having details that are too complicated for mass production, while not adding enough benefit to compensate their cost; however, with the help and guidance of a good machinist they can be worked out.
The fact that one of my machinist's specialities is building custom mufflers for racing motorcycles no doubt helps.
"There are no stupid questions, only stupid people". -MAJ MALFUNCTION
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TNPittbull
- Senior Silent Operator
- Posts: 119
- Joined: Sun Jul 01, 2007 11:00 pm
If there are no details with the design then the only input that can be provided is "pretty picture".mx201er wrote:the 3d drawing put on here are not meant to be specs for everyone to copy exact replicas.. they are meant to share an idea and get input. I like seeing them, it gives me ideas to build upon and is easier to visualize a project before I design it
Any rendering software will be able to convert to a dimensional drawing - how about posting both?
Details like caliber, sub/supersonic ammo, host , material(s) and some basic dimension are essential to getting any real feedback.
Getting "ideas to build upon" from a design with no details is as useless as the untested design. Even more so when you consider the fact that different designs will work differently with different calibers, hosts, etc.
Sharing ideas is great, but I like to see the whole story to form an opinion.
Regarding the machining complexity, I think it would be very interesting to include the type of equipment you will be manufacturing with if you intend to actually make something. If you draw something that will take wire EDM and a multi-axis CNC lathe, take a second to brag about the cool eqiupment that you have
It will make you look like you actually know that it is complex at least...
From a collaborative perspective 3D models are excellent. They get the concept out for review quickly.
Sure someone could post a platform neutral file that holds scale but is that really necessary to convey concept? If I'm taking it to manufacture then tolerances, materials, heat treating & surface finish become important. Until cdr it's a non issue.
Let the ideas flow. Those with manufacturing expertise, help them along.
Sure someone could post a platform neutral file that holds scale but is that really necessary to convey concept? If I'm taking it to manufacture then tolerances, materials, heat treating & surface finish become important. Until cdr it's a non issue.
Let the ideas flow. Those with manufacturing expertise, help them along.
I know some people leave out the simple things like fillets where necessary and such, but not only is it good practice to model something whilst thinking about the manufacturing end of it, it'll also save a bunch of people posting "damn, you're going to have to EDM that because it's just so damn complicated.
It also makes you a better design engineer
It also makes you a better design engineer