2Tim215 Posted September 27, 2013 Share Posted September 27, 2013 This is the hammer I am planning to build over the next three months. I have about 80% of the materials allready - swapped a Knife for most of it with a scrap yard owner I know. The spring was ordered today at the local springsmiths. All that I need now is the guide plates cut, the fly wheel cut and machined and other bits and pieces. Drawing is too scale. If you see anything that should be changed please give me a heads up before I go and spend any money LOL Quote Link to comment Share on other sites More sharing options...
swedefiddle Posted September 28, 2013 Share Posted September 28, 2013 Good Morning, I assume that there is a slip belt for the drive, or a hydraulic motor? A brake on the main flywheel makes for a lot better control (I made ours with a leather belt and a spring, unloads when the pedal is depressed). Factory built hammers had a counterweight on the opposite side of the working flywheel from the pin. Is the pin location adjustable? Maybe the link to the pin is adjustable? Wrap the spring with old firehose or something similar to provide protection for your face and digets (I've heard it is difficult to pick your nose without fingers) :) :) It is difficult to make old technology with new technology. LOL :) Neil Quote Link to comment Share on other sites More sharing options...
Dodge Posted September 28, 2013 Share Posted September 28, 2013 drawings kinda small to make any design judgments (What size tire to drive ratio are you going with; what is the tup weight / anvil weight; etc.) That being said, if I was to build another tire hammer, I think I would also use the leaf type springs rather than the compression. Quote Link to comment Share on other sites More sharing options...
Geoff Keyes Posted September 28, 2013 Share Posted September 28, 2013 If it's a tire hammer, the tire (often one of those hard rubber spares) is driven by a small diameter steel wheel on the motor shaft. Stepping on the pedal pulls the wheel into contact with the tire, acting as a friction clutch. The harder you press, the faster you go, very simple, just the way I like it. I built this design in 2000, though with a belt and pulley clutch, I had never seen a tire drive at that point. Mine is #50 and is still working like a champ. Or a Champion (which is what we used to copy many things from). We used an enclosed guide, and it makes the dies smaller than I would like, but that is about the only thing I'd change. Geoff Quote Link to comment Share on other sites More sharing options...
2Tim215 Posted September 28, 2013 Author Share Posted September 28, 2013 The tire will be at the bottom driven by a motor. There will be a drive pully attached to the tire shaft that turns the top pully etc. Have built one before using this system and found it to have excellent control. Adjustments will be made on the shaft at the spring. Drawing not complete - started seeing dbl at two this morning. Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 28, 2013 Share Posted September 28, 2013 I'm thinking putting the tire at the bottom and driving the rest with a pulley is adding unnecessary mass for the motor to accelerate and unnecessary friction of the added bearings. It's not like having a flywheel that lends it's inertia to getting the ram moving. On a tire hammer the only thing that even approaches a fly wheel is the drive wheel on the motor shaft, everything else must be accelerated into motion by the motor. Making the motor work harder is my main and only real dislike of a tire hammer. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Dodge Posted September 28, 2013 Share Posted September 28, 2013 If it's a tire hammer, the tire (often one of those hard rubber spares) is driven by a small diameter steel wheel on the motor shaft. Stepping on the pedal pulls the wheel into contact with the tire, acting as a friction clutch. The harder you press, the faster you go, very simple, just the way I like it. I built this design in 2000, though with a belt and pulley clutch, I had never seen a tire drive at that point. Mine is #50 and is still working like a champ. Or a Champion (which is what we used to copy many things from). We used an enclosed guide, and it makes the dies smaller than I would like, but that is about the only thing I'd change. Geoff Usually they are the same rubber as any other tubless tire, just smaller. It is that reason you can get more acceleration with more pressure. A hard tire wouldn't give so speed would mostly be controlled by "slipping" the clutch I'm thinking putting the tire at the bottom and driving the rest with a pulley is adding unnecessary mass for the motor to accelerate and unnecessary friction of the added bearings. It's not like having a flywheel that lends it's inertia to getting the ram moving. On a tire hammer the only thing that even approaches a fly wheel is the drive wheel on the motor shaft, everything else must be accelerated into motion by the motor. Making the motor work harder is my main and only real dislike of a tire hammer. Frosty The Lucky. Gotta agree there. Just adding more moving parts to maintain. Quote Link to comment Share on other sites More sharing options...
2Tim215 Posted September 29, 2013 Author Share Posted September 29, 2013 Thanks for the input all. Below is what I think it all leads to? Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 29, 2013 Share Posted September 29, 2013 That looks a lot cleaner and more efficient. The flat bar under the tire is the brake? A little large if so but it'll work. The concept tire hammer I've been working on has the drive tire attached to the crank plate like you show. I'll be using a trailer spindle and hub rather than a shaft and pillow block bearings. The spindle bearings are automotive thrust bearings and will take the off center forces much better. I think I'll mount the motor and drive wheel on the side below center of the tire so I won't need return springs, let gravity work for me. the hinge plate the motor will mount to will have an arm above center with a friction pad to stop the hammer when I let off the treadle. Nothing new in that, what has me going slow is the crank plate arrangement, I don't like the amount of horizontally reciprocating mass of the standard crank arm, connecting rod and springs you see in most hammers yours, LG, most all of them. I'm still winkling it out but basing my brainstorming on the "sotch yoke". Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
LastRonin Posted September 30, 2013 Share Posted September 30, 2013 Nothing new in that, what has me going slow is the crank plate arrangement, I don't like the amount of horizontally reciprocating mass of the standard crank arm, connecting rod and springs you see in most hammers yours, LG, most all of them. I'm still winkling it out but basing my brainstorming on the "scotch yoke". Frosty The Lucky.I agree, and have been considering the same, but just didn't know the name of it. Quote Link to comment Share on other sites More sharing options...
2Tim215 Posted September 30, 2013 Author Share Posted September 30, 2013 That looks a lot cleaner and more efficient. The flat bar under the tire is the brake? A little large if so but it'll work. The concept tire hammer I've been working on has the drive tire attached to the crank plate like you show. I'll be using a trailer spindle and hub rather than a shaft and pillow block bearings. The spindle bearings are automotive thrust bearings and will take the off center forces much better. I think I'll mount the motor and drive wheel on the side below center of the tire so I won't need return springs, let gravity work for me. the hinge plate the motor will mount to will have an arm above center with a friction pad to stop the hammer when I let off the treadle. Nothing new in that, what has me going slow is the crank plate arrangement, I don't like the amount of horizontally reciprocating mass of the standard crank arm, connecting rod and springs you see in most hammers yours, LG, most all of them. I'm still winkling it out but basing my brainstorming on the "sotch yoke". Frosty The Lucky. Thanks Frosty. Will also be using a spindle hub, just couldn't draw it that well. Also agree on the crank plate arrangement and your scotch yoke thing got me surfing and thinking and you have just messed up all my plans coz' now I just have to give it a go. Quote Link to comment Share on other sites More sharing options...
2Tim215 Posted September 30, 2013 Author Share Posted September 30, 2013 Ahhh. Now youv'e really got me thinking. Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 30, 2013 Share Posted September 30, 2013 I messed up your plans Bwa ha ha ha. The spring connection is giving me the most pause. I'm playing with a shock absorber kind of thing with NO piston, etc. of course, just a coil spring on a shaft so the hammer element is supported on the spring. How much action the spring is going to have is what has me wondering, I'm just not good enough at math to do the numbers. That's not a bad video of how they work even though the kids making it aren't very mechanical. Still, it shows how it works well. A good guide and there's no lateral motion anywhere but the crank and that's only a few ozs to balance. If it works on the hammer I'm working on as well as I think it will I'm going to convert my LG get it to stop wanting to walk around the shop. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
petere76 Posted September 30, 2013 Share Posted September 30, 2013 A few ideas. On the anvil, consider a quick change style lower die holder. Not sure of the head lift. Design the lift height so that you can accommodate a few variations on the lower die side. Anything you can do to increase anvil mass is a good idea. I think the min spec is roughly a 17:1 ratio, hammer to anvil. Bigger is better. Base plate, get as big as you can afford. It helps to stabilize the rig from the oscillation moment. At 200 to 300 BPM this machines do want to move a little. Anything you can do to increase the mass. on the lower end will significantly reduce motion inertia and enhance stability. Good luck with your project. Peter Quote Link to comment Share on other sites More sharing options...
2Tim215 Posted September 30, 2013 Author Share Posted September 30, 2013 Thanks Peter - my anvil will be 250kgs plus a 1mtr x 1 mtr 20mm base plate and all the weight of everything else. Didn't draw all the extras for tooling - no time. Frosty - it's funny but I have also been thinking of a shock type system for the last four months. Was thinking of a coil spring made up to fit within a tube that is the same size as the hammer, there would have to be central guide shaft running through a plate welded in the middle of the tube and another coil spring above that would have another plate that fits snugly in the tube and then a bolt on the shaft that could adjust the tension. Don't know if that makes sense - will try and do a drawing. Quote Link to comment Share on other sites More sharing options...
2Tim215 Posted September 30, 2013 Author Share Posted September 30, 2013 This is what I had in mind. Quote Link to comment Share on other sites More sharing options...
Geoff Keyes Posted September 30, 2013 Share Posted September 30, 2013 One thing I learned after I built my hammer may be useful to you. The anvil should be a single piece, if you can. Any joins will vibrate and steal energy from the system. The tup, OTOH, can be built up from pieces and bolted together, or even just stacked, one on top of the other. Apparently the acceleration of the mass makes up for the loss of energy due to vibrational effects. I would have built my tup differently if I had known that. Geoff Quote Link to comment Share on other sites More sharing options...
2Tim215 Posted October 1, 2013 Author Share Posted October 1, 2013 Thanks Geoff, but I'm quite sure what a "tup or OTOH" is? Quote Link to comment Share on other sites More sharing options...
Geoff Keyes Posted October 1, 2013 Share Posted October 1, 2013 Sorry. Tup in the hammer head, the part that moves and holds the upper die. OTOH is shorthand for "On The Other Hand". Geoff Quote Link to comment Share on other sites More sharing options...
2Tim215 Posted October 2, 2013 Author Share Posted October 2, 2013 Thanks Geoff. Quote Link to comment Share on other sites More sharing options...
Frosty Posted October 2, 2013 Share Posted October 2, 2013 I drew up some spring shocks like that but they're too complicated. There's almost nothing but a thin piece of plate guiding the ram and the spring isn't connected to the hammer well. I kept running into varying degrees of unacceptable in all my similar ideas. One of my present concerns is keeping the hammer mass near 25lbs. When you consider the top ram bolt flange, the die and it's bolt flange you can add almost 10lbs easy so the hammer ram weight has to be pretty light weight. That's my quandry though. What I'm thinking about right now is much simpler but the description isn't and I don't know where the concept sketches are. I'll post one or two when I find or just redraw them. Stupid TREE! Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
2Tim215 Posted October 4, 2013 Author Share Posted October 4, 2013 Agreed. Think I'm going to stick to tried and tested for now and wait for you more intelligent folk to come up with the right way and then like my friends the chinese I'll copy it LOL Quote Link to comment Share on other sites More sharing options...
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