NeatGuy Posted March 1, 2010 Share Posted March 1, 2010 I have been working on this design for some time and although it is still a work in progress I would like to hear any comments or ideas regarding the design. The attached drawing is not complete as I still have some detail to work out in addition there are some parts that have been omitted for clarity sake. The hammer works like a board drop hammer except in reverse. When the treadle is depressed a cam presses the board against a rotating cylinder See "DETAIL A" in drawing) . Friction on the board will over come the force of the springs and the hammer will move. My tests show that this system is capable of the gentlest blows to fairly hard blows. Board Treadle Hammer .PDF brad Quote Link to comment Share on other sites More sharing options...
Mills Posted March 1, 2010 Share Posted March 1, 2010 I like the clean lines you have there. That has me thinking about rearranging mine. As for the mechanics of it, I can see the cam action to catch the 'board'. I am unclear as to how power is supplied. Is this to be spring powered or is the friction device going to be run by a motor? another item it appears in view a the cam releases the board when treadle is depressed. may this help you. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 1, 2010 Share Posted March 1, 2010 This is not a treadle hammer but a form of triphammer/powerhammer or a "powered boardhammer". Neat idea! Less work on the user's leg. Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted March 1, 2010 Share Posted March 1, 2010 I made a similar hammer many years ago. Used a straight piece of "V" belt pinched into the groove by another roller, pretty much the same idea though. Principle was 100% the same. Didn't work at all first time out. The motor is spinning and the heavy ram/arms/etc. are standing still. When clutched in, either the motor stalled or the belt smoked. Had to find a way to accelerate the ram smoothly. If you look at the linkage on any power hammer you'll see that the crank can start turning without the ram moving. The ram is usually "lagging" the crank and always trying to catch up. A direct linkage tries to make the ram travel at a constant speed just like the drive. What you need is a way to turn the constant speed of the drive into acceleration of the ram. To prevent wearing out the board, you want it to travel at the speed as the drive. So you need an elastic connection between the board and the ram. I found the best way to do this was to create a “toggle” with two springs stretched horizontally along the swing arm. When the board pulls down in the middle of this, the first thing that happens is it pulls the springs into a “V” and starts accelerating the ram downward without inhibiting the travel of the board. So now if the board is traveling at a constant speed and the ram starts off slow it will end up traveling faster than the board at the bottom of the stroke! You'll want to move your roller clutch down a bit to allow it to keep tension on the springs. I got more I'll add later............... Quote Link to comment Share on other sites More sharing options...
Tim McCoy Posted March 2, 2010 Share Posted March 2, 2010 Excuse the uninformed query, but isn't this very similar to the Grasshopper hammer design with a motor for power?? Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted March 2, 2010 Share Posted March 2, 2010 It's certainly similar to many guided ram treadle hammers, the distinctive thing about a "Grasshopper" hammer is that it is not guided, it use a "straight-line" linkage to give a vertical travel. They look really cool on paper, but require a lot of precision work and still are pretty floppy due to the large number of joints in the linkage. "With a motor for power" sounds simple enough, but there is a lot of engineering to get the round-and-round turned into an effective up-and-down. Quote Link to comment Share on other sites More sharing options...
NeatGuy Posted March 2, 2010 Author Share Posted March 2, 2010 I like the clean lines you have there. That has me thinking about rearranging mine. As for the mechanics of it, I can see the cam action to catch the 'board'. I am unclear as to how power is supplied. Is this to be spring powered or is the friction device going to be run by a motor? another item it appears in view a the cam releases the board when treadle is depressed. may this help you. The springs run down the back of the frame there are two pulleys which guide the cable from the springs attached to the toggle arm. The power, via a motor, is supplied to the rear roller when the cam is lifted it presses the board to the rotating rear cylinder and pulls the board down. The cam is upside down sort of because I switch to use a remote foot peddle that has a cable when the foot peddle is pressed the cable pushes up. I will add some additional details and repost the drawing brad Quote Link to comment Share on other sites More sharing options...
youngdylan Posted March 2, 2010 Share Posted March 2, 2010 Neatguy/ anyone could somebody tell me what a "board hammer" is .... starting to feel rather thick! If it's what I think it is does it mean the tup drops down under gravity. What's the advantage of this compared to a "normal" oliver/ treadle hammer for small scale work. please scuse my ignorance Quote Link to comment Share on other sites More sharing options...
NeatGuy Posted March 2, 2010 Author Share Posted March 2, 2010 Neatguy/ anyone could somebody tell me what a "board hammer" is .... starting to feel rather thick! If it's what I think it is does it mean the tup drops down under gravity. What's the advantage of this compared to a "normal" oliver/ treadle hammer for small scale work. please scuse my ignorance It is a type of drop hammer that uses a board to raise the hammer before it is dropped.Drop Hammer The advantage, at least to me as I tend to do a lot of chasing, not having to stand on on leg for hours driving the hammer down. Quote Link to comment Share on other sites More sharing options...
youngdylan Posted March 2, 2010 Share Posted March 2, 2010 It is a type of drop hammer that uses a board to raise the hammer before it is dropped.Drop Hammer The advantage, at least to me as I tend to do a lot of chasing, not having to stand on on leg for hours driving the hammer down. Interesting, I like it! If you're into air hammers it might be worth you looking at a thread I started recently about using a controlled pulse of air to give a one off controllable and repeatable blow with Kinyon style hammers. Guess this thread has made me realise what I'd built was a drop (+air) hammer Quote Link to comment Share on other sites More sharing options...
Sam Thompson Posted March 2, 2010 Share Posted March 2, 2010 Here's the plans for a board hammer: http://www.freepatentsonline.com/1388671.pdf Quote Link to comment Share on other sites More sharing options...
freemab Posted March 3, 2010 Share Posted March 3, 2010 It's an interesting concept, but shouldn't you call this a "power hammer", not a "treadle hammer"? Quote Link to comment Share on other sites More sharing options...
NeatGuy Posted March 3, 2010 Author Share Posted March 3, 2010 It's an interesting concept, but shouldn't you call this a "power hammer", not a "treadle hammer"? True ... but before I retro fitted it; it was a treadle hammer brad Quote Link to comment Share on other sites More sharing options...
freemab Posted May 20, 2010 Share Posted May 20, 2010 It's certainly similar to many guided ram treadle hammers, the distinctive thing about a "Grasshopper" hammer is that it is not guided, it use a "straight-line" linkage to give a vertical travel. They look really cool on paper, but require a lot of precision work and still are pretty floppy due to the large number of joints in the linkage. Grant, You are correct that the Grasshopper Treadle Hammer uses a straight-line linkage, avoiding the use roller or slider guides. However, I beg to differ on your other points. The Grasshopper does not require "a lot" of precision work, and is not the least bit "floppy". There is no part that requires any operation more precise than a drill press. Certain alignments must be done with care, but "precision" scarecely applies. I invite you or anyone else to Marshall's shop (see http://njba.abana-chapter.com/ "open forge") to check out the prototype Grasshopper. (Right now, the lateral positioning of the head of the prototype is not up to snuff due to a problem with collars coming loose. The final version Grasshopper does not use collars for this function, however.) Bruce NJ Quote Link to comment Share on other sites More sharing options...
freemab Posted October 26, 2012 Share Posted October 26, 2012 Grant, Have we met? Your name's familiar but I'm not placing you. I have to take umbrage to your comment. Believe me, if the Grasshopper had required "a lot of precision work", the prototype would never have got built. One unskilled builder built a Grasshopper in 40 hours, with a little help from an experienced worker. That would hardly constitute "a lot of precision work." Also, I have no idea where you got the idea the Grasshopper was "pretty floppy." Have you EVER SEEN a Grasshopper, much less tried it out? The prototype gets sloppy (not floppy) only when a part comes loose, and all those problems were fixed in the version shown in the published plans. Really, it's insulting to have one's treadle hammer criticized by somebody who has apparently never even seen the machine. Bruce Freeman BTW, I no longer have any economic incentive here, as I no longer sell the plans. (P.S. -- Gee! What fussy software this is! It wouldn't let me post first try because quotation marks weren't paired!) Quothe: Grant Sarver "..., the distinctive thing about a "Grasshopper" hammer is that it is not guided, it use a 'straight-line' linkage to give a vertical travel. They look really cool on paper, but require a lot of precision work and still are pretty floppy due to the large number of joints in the linkage." Quote Link to comment Share on other sites More sharing options...
Bob S Posted October 26, 2012 Share Posted October 26, 2012 Grant, Have we met? Your name's familiar but I'm not placing you. Bruce, Sad to say it but Grant passed on suddenly last January. We all miss him.http://blacksmith.or...ighlight=sarver Quote Link to comment Share on other sites More sharing options...
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