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  • A useful project...

    I need to cut a good amount of thin sheet brass - .015 and the like - for a series of projects. While I've frequently used a piercing saw something mechanized seemed in order. Good variable speed scroll saws can be quite expensive but I found R. S. Hedin's well thought out design in Book One of Projects in Metal to be just the ticket and I've just finished it:



    I tried out a cheap sewing machine motor for openers but found it both weak and lacking decent variable speed, so after looking around a bit the Sherline DC motor and speed control proved absolutely ideal and I'm very happy with it.



    The belt is of the .25 inch polyurethane variety from McMaster Carr. Next time I'll go with .187, which I suspect will be perfect for such projects.

    Some thoughts for those who might want to build one of these:

    1) Probably best to leave the crank pin at least .010 thick, braze up the crankshaft assembly, then offset the assembly in the four jaw to turn the pin down so it will run absolutely true. If the crankshaft is not perfect, the lower arm will wobble and you will not be happy. Because the connecting rod attaches to the arm midway, any slight inaccuracy gets magnified...

    2) If you're cutting thin sheet metal with this saw, get yourself some metal blocks and stick them to whatever you're cutting with double sided tape so the blade doesn't pick the piece off the table. I'm going to cut some aluminum blocks with slight shoulders so I don't even need to use the tape one of these days...

    3) Don't bother machining the bronze bearings, just buy oilite bearings and press them in (very gently! they'll squash if you're not careful!). Turns out Lowes even stocks some sizes of oilite bearing though the clerk won't know what oilite is...

    4) Cut the blade chuck slots with a blade that you'll be using most in a piercing saw. Get some good German blades from the folks who sell the expensive red scroll saws.

    5) I like a dull shellac finish because it goes on over oil discoloration just fine. With so many wood parts, you're going to find you've gotten some oil here and there during trial assembly. Sand it a bit and the shellac will go right on.

    6) After you braze up an assembly with tapped holes, run the tap back in so the screws don't strip while encountering some microscopic bit of brazing rod. Then you have to drill out the screw, then the tap breaks, then you've got the whole setup in the milling machine with a 2 mm carbide end mill and you really would rather raise geraniums...

    Well, that's that. On to the Universal Pillar Tool and then to the Metal Lathe Accessories Die Filer to round out my shop for reproducing the Hawkins/ Peale polygraph of 1804....

    Regards, Charles Morrill

  • #2
    Nice work, but you can buy one at home depot for less than 150$

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    • #3
      Originally posted by RB211 View Post
      Nice work, but you can buy one at home depot for less than 150$
      this is the home shop machinist board, not the home shopping network!!!!!!

      great job, I like the wood.

      make it instead of buying it!

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      • #4
        Absolutely true about being able to buy one, but if you want to get good at making things, you have to make things. I learned so very much, and I suspect that will help me down the road.

        In a queer sort of way, this project was also very much part of the technological world of 1803-4 that I find interesting. Material goods were often mostly wood, but sometimes partly metal: sort of like the Eli Terry wooden works clocks with their metal escapements.

        Regards, Charles

        Charles
        Last edited by waumbek; 12-28-2015, 11:45 PM. Reason: grammer

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        • #5
          I like it! And it goes with the really strange and weird concept that once you build a thing, you understand the world
          of things better. Now why is that?

          Pete @ been making things for 60 years
          1973 SB 10K .
          BenchMaster mill.

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          • #6
            Originally posted by RB211 View Post
            but you can buy one at home depot for less than 150$
            buy what, one of these: http://www.homedepot.com/p/Genesis-1...S160/203656938

            I can guess what its like. the lowly delta is $400, the excaliber $800.....but if you want a really good one, try 2400.

            http://www.sears.com/hegner-18inch-v...1&blockType=G1

            I don't advocate make for the sake of making if great, cheap stuff is available (spend your timing making special stuff instead).....and I don't know where Hedin's fits in the spectrum, but the point is its a big spectrum....and with careful precision work you could produce a good saw. Once you've used a Hegner no way you'd be happy that $150 thing and making a high quality one might make sense

            OP, good looking project....the UPT is a very useful tool....here's a thread of pics i put up of mine
            http://bbs.homeshopmachinist.net/thr...-photo-warning


            ....my posts are starting look like OT's....i"ll have to watch that
            Last edited by Mcgyver; 12-29-2015, 12:07 AM.
            .

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            • #7
              Very nice job.
              Paul A.

              Make it fit.
              You can't win and there is a penalty for trying!

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              • #8
                Classy looking little saw, like it. Straight cut or spiral blades?

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                • #9
                  Very nice build! There is a great satisfaction to be had using a tool you built yourself.
                  Andy

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                  • #10
                    Originally posted by metalbender View Post
                    Classy looking little saw, like it. Straight cut or spiral blades?
                    So far I'm just using straight cut. Is there an advantage to using spiral blades for sheet brass?

                    Regards, Charles

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                    • #11
                      Originally posted by Mcgyver View Post
                      buy what, one of these: http://www.homedepot.com/p/Genesis-1...S160/203656938

                      I can guess what its like. the lowly delta is $400, the excaliber $800.....but if you want a really good one, try 2400.
                      Or here from Amazon: http://www.amazon.com/Hegner-Variabl.../dp/B000ANIQGC

                      I had no idea scroll saws go so spendy. I can see spending $400-500 on a decent one but I just can't imagine spending upwards of $1k on a scroll saw. Maybe if I was in the business of making jigsaw puzzles... or would I just buy a jigsaw?

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                      • #12
                        Spiral blades let you cut without spinning the piece around so much. They cut fwd, sideways and backwards. I think the kerf is a tad wider though.

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                        • #13
                          Originally posted by Fasttrack View Post
                          I had no idea scroll saws go so spendy.
                          its Levin or Schaublin vs the hf 7x12....both can be a lot of fun and make parts for their owners.....but they're not the same lol. There are certain hobbies like marquetry and inlaying where the saw is the main tool so you spend for the best ......vs your or my every now and again use where it seems too much. I've got a Hegner (got a great deal so no didn't spend the big dollars) and it is really nice vs a busy bee thing I had from years ago. I scraped the BB it was so bad. shake rattle and roll with miserable blade holding mechanism were the objections.
                          Last edited by Mcgyver; 12-29-2015, 12:20 PM.
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                          • #14
                            So you are spending much more simply for better balancing and blade holding? I can see the advantages of the OP's as it has less reciprocating mass. I have a Ryobi that works just fine for the 150$ or less I spent.


                            Sent from my iPhone using Tapatalk

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                            • #15
                              Originally posted by RB211 View Post
                              I have a Ryobi that works just fine for the 150$ or less I spent.
                              and that's fine, I have no interest in trying to convince otherwise. Mine was used and a fraction of the new price....i'm not saying 'only Hegner will do'; the point as I said is there is a continuum of quality and its not correct to assume the $150 saw is what the OP wanted or got.

                              on the Hegner thing, before deciding you should try both. Like most expensive tools i've acquired, patience and kijiji is my approach....vs a big limit visa card . Not sure where you are however you are welcome to come by and take it for test drive.....maybe you'd find it awesomely better, or maybe not.
                              Last edited by Mcgyver; 12-29-2015, 02:42 PM.
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