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09-01-2011, 12:05 AM
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Just a crazy idea.
I recently bought a beat up, old top break S&W and as an aspiring student of mechanical engineering with access to some of today's newly emerging technologies I figured why not try and improve on it. As any one knows the top breaks are heavy for what they are and the round they chamber. My plan is to take the trigger guard, trigger and side plate and reverse engineer IE Digitize the parts into Solid-works using either a laser or a CNC probe to create a point cloud. At which point the program will automatically set up tool paths to re machine the parts using the originals as molds if you will. I would like to recreate some of these parts in 7071 aluminum as it would represent a large weight savings over the steel and since these parts are not load bearing they should be OK in the strength department. After machining and fitting they would be anodized to prevent wear. The second part of this plan hinged on if I can find a suitable hunk of titanium to remachine the cylinder out of. The main problem here is going to be heat treating the Ti when I'm done and setting up a protective coating on the cheap. The cylinder may not be possible but the parts in 7071 are. It shouldn't be too hard of a process either once I digitize and tool path them; a 4 or 5 axis machine would knock em out in no time. Does anyone have any insight or suggestions? Any materials engineers want to chime in, maybe someone has a better idea as to how to convert a modern Ti cylinder without making one from scratch?
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09-01-2011, 01:00 AM
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Are you sure you're up to it? Requires a lot of expensive CNC equipment and considerable special knowledge to use it correctly. Unless it's in a well-equipped college or trade school machining lab and you have free and unfettered access to it, and someone who knows what they are about to help you (assuming you are new to machining), it's very impractical to consider. On the other hand, if you are using a college lab and have some skilled assistance available, you should also have access to extensive metallurgical information and heat treating equipment. So why are you asking those questions here?
Last edited by DWalt; 09-01-2011 at 01:09 AM.
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09-01-2011, 11:43 AM
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Top Breaks
I disagree with the statement that top breaks are heavy for what they are and the round they chamber. All but the big bore S&W's are very small revolvers, where the weight can be helpful not only in strength, but in moderating recoil. The S&W .38 and .32's certainly do not pose a recoil problem, but as small as they are, weight is not a negative factor. This is true of their SA's, DA's and Hammerless models.
If you feel compelled to re-engineer a product that was so well engineered and thought out over a hundred years ago, they still are shooters, plus their time of production ran for decades...go for it. Hard to improve a record like that, but you are welcome to try, if you have the time, equipment and desire to do so. Just remember it's hard to re-invent the wheel.
10/22.
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09-01-2011, 02:03 PM
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Absent Comrade US Veteran SWCA Founding Member
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Datsun, I think you are right. It's a crazy idea!
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09-01-2011, 02:16 PM
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I don't think datsun is looking to reinvent anything. It sounds like an interesting project for an engineering student and I look forward to seeing the results.
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09-01-2011, 04:30 PM
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Quote:
Originally Posted by -db-
I don't think datsun is looking to reinvent anything. It sounds like an interesting project for an engineering student and I look forward to seeing the results.
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That's why I said to go for it. But I think there are better uses of the equipment and his time.
10/22.
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09-01-2011, 05:34 PM
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GO FOR IT!
It's the 'doing ' that matters. I can't count the projects I have done just to prove something to myself or for amusement, etc. Many of them I put in $1000 worth of work into and in the end had something worth $200 in the market place. For example, rework of a H&R 922 to a 'SAA' look, shape of grip, ejector tube, loading gate etc, plus engraving it, then nickel plate. It didn't have to please anyone else. See another project of mine:
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09-01-2011, 06:02 PM
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Sounds like a reasonable project for the learning experience of digitizing an existing part.
The trigger is definitely a stressed part. You will note that modern lightweight guns with aluminum, scandium, titanium, or even cheap mung metal frames have steel hammers and triggers. Look at the engaging surfaces and think how long they would (not) last in aluminum instead of case hardened steel.
I know of no titanium cylinder that could be adapted. Maybe you can copy the original and use its steel extractor.
It would be interesting to weigh the parts you plan on replacing with lighter material and calculate just how much weight will be saved.
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09-02-2011, 11:24 AM
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Watson, I think you are correct on the trigger. I have disassembled the weapon and there would be alot of steel on aluminum contact in the internals and there would be alot of forces on the part in the pin areas. The guard however should be simple and doable. The cylinder I'm still looking into. I'll post an update if I ever made any head way.
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09-03-2011, 09:32 AM
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removed PC
Last edited by Speedo2; 11-27-2012 at 10:18 PM.
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09-05-2011, 02:48 PM
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I agree that it could be an interesting project but I would be concerned shooting anything that I was not certain was capable of handling the pressure. Some hand held firearms need to have some weight to counteract recoil. Good luck.
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