Warren Nakkela Posted February 9, 2009 Posted February 9, 2009 How does a pneumatic treadle hammer work? Linkages and valving? Warren Quote
Warren Nakkela Posted February 9, 2009 Author Posted February 9, 2009 I was thinking of a pneumatic enhanced Oliver. Quote
Frosty Posted February 9, 2009 Posted February 9, 2009 How do you want to set it up? If I were going to convert an Oliver I'd use a rather small single acting pneumatic cylinder between the helve and frame. Push or pull would depend on how the Oliver was constructed. If I were building a treadle hammer from scratch and wanted to put a pneumatic kicker on it I'd incorporate a truck air can on an escapement so I could use it manually without having to disconnect anything. The linkage would have to be close to the pivot point because brake air cans don't have much throw but with oh say 95 sq/in they pack a serious punch. Frosty Quote
Warren Nakkela Posted February 9, 2009 Author Posted February 9, 2009 (edited) Yeah, Frosty I was thinking along those same lines. An automatic disconnect when you stomp on the treadle but when you step on the air valve, down comes the hammer. Then my sometimes fertile mind conjures up other ideas. Say you don't use springs to balance the hammer but rather use counterweights. You will have more inertia to overcome when you stomp but when the hammer strikes you will have the combined inertia and hammer weight impacting plus no spring force to overcome. And Frosty, I like the air can idea. Just don't use maxi cans! Warren Don't fall in love with your first idea A pneumatic kicker, Frosty, you sure have a way with words. I was think more along the lines of a classic treadle hammer in a slide. Edited February 9, 2009 by Warren Nakkela More thinking goin' on Quote
Warren Nakkela Posted February 9, 2009 Author Posted February 9, 2009 All one would need is a short auxillary arm above the helve so when the air can is activated it pushes down. An air valve could be opened by a portion of the treadle that you will eventually learn where it is at! Warren Great minds think alike Quote
Frosty Posted February 9, 2009 Posted February 9, 2009 My thought is to have separate controls. The treadle is the manual and a truck air brake pedal controls the brake can. The escapement is on both linkages so if ypu press the treadle the hammer arm moves away from the brake can and if you use the brake pedal the hammer arm moves away from the treadle linkage. It keeps you from mashing your toe under the treadle when you give it the air. Frosty Quote
Warren Nakkela Posted February 9, 2009 Author Posted February 9, 2009 (edited) I probably have enough stuff to make one of them. Got this old Michigan truck shovel with all sorts of goodies. Warren If you have separate treadle and brake valve you have either air or foot operation. That may be enough, but what if you want foot power with an air booster? Edited February 9, 2009 by Warren Nakkela Quote
Frosty Posted February 9, 2009 Posted February 9, 2009 The last time I put a shopping list together I could buy a brand new 11" x 1 7/8" spring brake can for $45 at NAPA. The primary treadle valve and body, (brake pedal) lines, secondary valves and all ran about $250 and I would've had a pedal that said NAPA right on it. Don't get better than that! Frosty Quote
Warren Nakkela Posted February 9, 2009 Author Posted February 9, 2009 Frosty: Do you have an idea how to make a selector between foot operated and pneumatic or both? Brake controllers are good as they allow increasing pressure as you depress the pedal. Warren Quote
Frosty Posted February 9, 2009 Posted February 9, 2009 Yeah. Put both linkages on escapements. Think of it like putting a rod with a nut and washer on the end through a hole in a lever. If you pull on the rod it moves the lever. However if you move the lever it slides over the rod without moving it. Super simple, think of it as a mechanical check valve. No need for a selector other than which thing you put your foot on. Frosty Quote
Warren Nakkela Posted February 9, 2009 Author Posted February 9, 2009 Frosty: Wouldn't be much to add a couple of valves to give it a pneumatic boost to the treadle. One valve to turn off the brake controller and another valve operated by by the initial movement the treadle shaft. The first increment of treadle motion opens the valve and gives full pressure to the air can. when you release the foot pressure on the treadle the valve closes and dumps the can air. Then you could have three modes of operation. Wouldn't have to do them all at once. First make the treadle hammer. Next the air can and brake controller and last add the valving for the treadle booster. If the booster runs a little wild one can always add a restrictor or pressure regulator on that circuit. One should approach these pneumatic additions as being experimental. I believe the system will work with a little tinkering. If you use your 1/4 inch shop air hose you will need a small air tank at the hammer. Warren Quote
Frosty Posted February 10, 2009 Posted February 10, 2009 (edited) Agreed, it would be pretty simple to incorporate the air controls into the treadle. Either as an additional component, think break lever on handle bars or as part of the treadle action itself. I thought about several variants but think there's a good chance that the shock from operating the treadle under "manual Pedal(?)" control might cause the air valving to activate. Then again I considered a rocker for the valve that wouldn't be susceptible. There are a number of good ways to set one of these up. I just prefer to have the pneumatic controls separate from the mechanical for few basic reasons. First, is general safety, if the air controls are divorced from the manual there is no way to accidentally activate the pneumatics while doing manual striking. Second, I've never discovered in the middle of a stroke I needed to hit something super hard instead of just hard. It's like the old Jeep adds where they'd put a Jeep in a really tough spot, a blasted ledge with a cliff going down on one side and another going up on the other, and ask if you wanted to try getting out to engage the hubs. Well, if you didn't know you needed to engage the hubs before you got yourself in that situation 4x4 ain't gonna do you any good at all. Lastly, (though I'm sure we can think of other reasons pro and con) Why lift your leg to treadle height if you don't have to? Hmmmm? In truth it comes down to personal preference in this case so long as it's set up with reasonable safety considerations. A treadle hammer is a DANGEROUS piece of equipment as they stand, adding a pneumatic kicker only increases the consequences of screwing up. When I build my Watt linkage treadle hammer, (see Grasshopper treadle hammer. Links here http://www.iforgeiron.com/forum/f7/treadle-hammer-bearings-7963/ ) it'll have a pneumatic kicker. Maybe not a brake can but it'll have something to save my lazy old self some work. I also have concept sketches of other devices using brake cans for shop tools. Their compact size and great power make them perfect for hand held and easily portable devices. Here are a couple ideas for brake can powered tools: Shear, vise, upsetting/striking hammer, punch/drift, rivet set, crimper, etc. Frosty Edited February 10, 2009 by Frosty Some sentences just aughta make sense. Quote
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