gearhartironwerks Posted July 8, 2011 Share Posted July 8, 2011 Here's the video of the hammer working 1.25" sq stock John Quote Link to comment Share on other sites More sharing options...
Fe-Wood Posted July 8, 2011 Share Posted July 8, 2011 John, Thanks for posting! I like how snappy that hammer is with the upgrade!!! Quote Link to comment Share on other sites More sharing options...
Madmike Posted July 8, 2011 Share Posted July 8, 2011 Thanks John, I love this design, even simpler than UHMW (moving, bowing, collecting shop crap and grit...), totally rigid (I'm absolutely not able to machine octagons...)... The vid is great and really show what we need and want to see... So I need to find the right bronze bushings to fit my under the shelf (to heavy to put it on the shelf) hydro-cylinder rods It's 7:00 am here and you stuck to my face a smile for the day Quote Link to comment Share on other sites More sharing options...
basher Posted July 8, 2011 Share Posted July 8, 2011 It is a very elegant hammer design. I will be interested to see how long those bushings last , my guess would be not that long and there is a point force acting on them in the forward backward motion of the spring as well as uneven loading of the hammer face....but if it gives great motion control and is an easy swap out then no problem with that. I have never seen bronze on the slides of old hammers its always iron on iron....but I applaud your innovative engineering and think the hammer action looks amazing. Quote Link to comment Share on other sites More sharing options...
Backwoods Blacksmith Posted July 8, 2011 Share Posted July 8, 2011 I think you will find that the bronze bushings will last a long time. While there is some side load, most of the action is vertical and unloaded. If kept lubricated, the film will carry the load. Babbitt bushing on LG last a long time and Babbitt is much softer and not nearly as tough as bronze. The side load on the LG is much greater than will ever be seen in this application. Very nicdesignhn. What is youClarencece between the shaft and the bushing? Is ioil litete or navel bronze? I hope to come see it soon Quote Link to comment Share on other sites More sharing options...
Andrew T Posted July 8, 2011 Share Posted July 8, 2011 The right hand side ram guide of my Beaudry is bronze. Quote Link to comment Share on other sites More sharing options...
monstermetal Posted July 8, 2011 Share Posted July 8, 2011 I think you nailed it John.... You got me thinking about shop built hammers again.... Not that I will ever get around to building one but it keeps my mind occupied Quote Link to comment Share on other sites More sharing options...
gearhartironwerks Posted July 8, 2011 Author Share Posted July 8, 2011 It is a very elegant hammer design. I will be interested to see how long those bushings last , my guess would be not that long and there is a point force acting on them in the forward backward motion of the spring as well as uneven loading of the hammer face....but if it gives great motion control and is an easy swap out then no problem with that. I have never seen bronze on the slides of old hammers its always iron on iron....but I applaud your innovative engineering and think the hammer action looks amazing. I will also be interested to see how long they last. My guess is that it will be quite a while as oiled bronze is durable. The good thing is that replacing bushings is simple and economical as they cost less than $10. ea. The head was also designed to be easily removable for that eventuality. The next step up would be to use linear bearing at around $40. ea. John Quote Link to comment Share on other sites More sharing options...
mike-hr Posted July 9, 2011 Share Posted July 9, 2011 Great video JE.. Folks, I stormed into Gearhart with the family a couple weeks ago, I played in Johns shop for a couple days whilst the family got sunburned on the beach. I got to run this hammer for 6-8 beers. It kicks my 80# mechanical hammers' butt, both on squish power, and controll, and also price to build and maintain. Building one of these got bumped to the top of my project list. What I see as beautiful about this machine, is, if something does break on it, parts are available at the local auto and industrial shop, yer back to work in a couple hours. No need to try and tell the Turkish or Chinese liason about this mysterious pinging sound, and wait for weeks to get back to work. I'm all for it. Quote Link to comment Share on other sites More sharing options...
Madmike Posted July 9, 2011 Share Posted July 9, 2011 ...step up would be to use linear bearing at around $40... That's not even the cost of an oiled bronze bushing here... The circular bronze bushings can support load in every direction, the linear you're thinking about also ? Quote Link to comment Share on other sites More sharing options...
gearhartironwerks Posted July 10, 2011 Author Share Posted July 10, 2011 That's not even the cost of an oiled bronze bushing here... The circular bronze bushings can support load in every direction, the linear you're thinking about also ? Linear bearings will provide less friction than the oiled bronze bushings. If I build another hammer, I'll try the linear bearings. Less friction= greater speed. This is an awesome hammer equal to any commercial utility hammer in its class at approx 1/4th the cost. Do it yourself...that's what it's all about. JE Quote Link to comment Share on other sites More sharing options...
nonjic Posted July 10, 2011 Share Posted July 10, 2011 Thats a slick looking piece of engineering ! nice solution on the ram guiding, thats looks to be the weak spot in the design of many 'homebuilds' - if the bushes are easily accesable for replacement I cant see it being any more of an issue that changing a band saw blade I assume its a function of the valving of the hammer, but it seems to slow down when doing light blows. I can see this being a bit annoying as if anything I would want the light 'planishing' blows to be quicker. When John Larson talks about a 'stroke adjusting lever' on the Ironkiss hammers is this basically just lowering the trip valve so the hammer can run at a higher 'blows per min' but with lower ram velocity ? Quote Link to comment Share on other sites More sharing options...
Ferguson Posted July 10, 2011 Share Posted July 10, 2011 I am going to make an assertion that I am not 100% sure is right. My assertion is that for a hammer to hit less hard it will strike fewer blows per minute. I believe that to be true of the traditional mechanical hammers as well as the home built Kinyon style air hammer. The mechanical hammers have a slip clutch, and light blows are the result of slipping the clutch, so fewer hits per minute. If the Kinyon style air hammer is throttled through the exhaust valve, then the head will move slowly, meaning that it will take longer to go from the bottom or top of the stroke to where it resets the microswitch. However, the self-contained air hammers work on a different principle, and I believe that they operate at the same BPM when hitting softly and hitting hard. I would believe that would be an advantage of the self-contained hammers. I would be interested to see if people with experience on these hammers would confirm or deny my assertions. Richard Quote Link to comment Share on other sites More sharing options...
ianinsa Posted July 10, 2011 Share Posted July 10, 2011 John, That 'upgrade' looks fantastic, I hope you don't mind if we pinch the idea? Ian Quote Link to comment Share on other sites More sharing options...
John Larson Posted July 10, 2011 Share Posted July 10, 2011 John, thanks for the video. Couple of comments/opinions: 1. As you evolve your design, or as others use your idea, I think spacing the two pairs of bushings apart more (and lengthening the shafts, of course) will add stability and longevity. Maybe you've gotten the spacing perfect, but it's something to keep in mind. My experience is that guides should be longer than the stroke length. 2. The cylinder bore is really too small for your total reciprocating weight. That's my experience. If you use 3.25" bore cylinders you will find snappier reciprocation and the ability to use much lower air pressures. My 75s run quite nicely on 40 psi and the 100s run easily on 60 psi. Therefore your can get more work done per tank of air. And, once the cylinder size is increased you will find that air pressure becomes a major tuning factor. 3. I agree that check valves are not necessary. I've stopped using them without ruining any regulators. The air gauge needle bounces more, but not much more. 4. The leaf spring really does not have to be "springy" because the air cylinder provides all the cushioning needed. So your bigger, stronger spring may not be flexing very much at all. And, 5. (for John N) the Iron Kiss stroke adjustment lever positions the roller valve. Another system (pneumatic) controls stroke length and speed. What I really like about your posts is that you are doing the hard empirical work to prove out ideas. Keep up the good work!!!!! Quote Link to comment Share on other sites More sharing options...
gearhartironwerks Posted July 10, 2011 Author Share Posted July 10, 2011 John, thanks for the video. Couple of comments/opinions: 1. As you evolve your design, or as others use your idea, I think spacing the two pairs of bushings apart more (and lengthening the shafts, of course) will add stability and longevity. Maybe you've gotten the spacing perfect, but it's something to keep in mind. My experience is that guides should be longer than the stroke length. 2. The cylinder bore is really too small for your total reciprocating weight. That's my experience. If you use 3.25" bore cylinders you will find snappier reciprocation and the ability to use much lower air pressures. My 75s run quite nicely on 40 psi and the 100s run easily on 60 psi. Therefore your can get more work done per tank of air. And, once the cylinder size is increased you will find that air pressure becomes a major tuning factor. 3. I agree that check valves are not necessary. I've stopped using them without ruining any regulators. The air gauge needle bounces more, but not much more. 4. The leaf spring really does not have to be "springy" because the air cylinder provides all the cushioning needed. So your bigger, stronger spring may not be flexing very much at all. And, 5. (for John N) the Iron Kiss stroke adjustment lever positions the roller valve. Another system (pneumatic) controls stroke length and speed. What I really like about your posts is that you are doing the hard empirical work to prove out ideas. Keep up the good work!!!!! JL, Thanks for the input. To clarify, the stroke length is about 10", so you're saying that the spacing of the 2 blocks of steel with the bushings in the head should be greater than 10"? Also, the cylinder I'm using (hydraulic) has no cushions built in. Everything is dependent upon the positioning of the limit switch and dies to prevent topping and bottoming out. I'm still not clear as to the necessity of the leaf spring in how important it is that it have much spring. The 3/8"x 2.5 had little, and the 1/4 x 2.5 has a lot. Both seem to work. Any ideas? Also, thanks for your suggestion of a larger cylinder. I have a 3x12 and will install it as soon as I get some time. JE Quote Link to comment Share on other sites More sharing options...
gearhartironwerks Posted July 11, 2011 Author Share Posted July 11, 2011 John, That 'upgrade' looks fantastic, I hope you don't mind if we pinch the idea? Ian Have at it! JE Quote Link to comment Share on other sites More sharing options...
macbruce Posted July 11, 2011 Share Posted July 11, 2011 2. The cylinder bore is really too small for your total reciprocating weight. That's my experience. If you use 3.25" bore cylinders you will find snappier reciprocation and the ability to use much lower air pressures. My 75s run quite nicely on 40 psi and the 100s run easily on 60 psi. Therefore your can get more work done per tank of air. And, once the cylinder size is increased you will find that air pressure becomes a major tuning factor. I have come to this same conclusion, I have a 100lb hammer I built of the Bull configuration. It ran for years on a 2'' cyl. Not real snappy and air pressure didn't seem to affect the speed much at all........Then I got my hands on a 2.5'' cyl like new for $15. Well the hammer wasn't broke but being a natural born tinkerer I fitted the 2.5 into the 100.....WOW the thing really woke up, I was using 120 psi with the 2'' and had to turn it back to 90 or less to settle it down and it still ran at more bpm. I concluded that if a cyl is too small or marginal, air pressure doesn't seem to increase bpm or snappyness .........mb Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted July 11, 2011 Share Posted July 11, 2011 Nice execution on the hammer John. Looks like a runner, for sure. I played with a similar design a few years ago, but didn't do much with it. Don't think you'll see too many people copying it because of the need for some accurate machine work. I've toyed with some similar thoughts using one large rod (on center) and a smaller one just to prevent rotation. Quote Link to comment Share on other sites More sharing options...
gearhartironwerks Posted July 11, 2011 Author Share Posted July 11, 2011 Nice execution on the hammer John. Looks like a runner, for sure. I played with a similar design a few years ago, but didn't do much with it. Don't think you'll see too many people copying it because of the need for some accurate machine work. I've toyed with some similar thoughts using one large rod (on center) and a smaller one just to prevent rotation. Grant, Thanks. I farmed out the machining to the cost of $340. and I provided the steel. The head was then welded. A better way would be to weld the head, then have the head line bored to reduce distortion and having to do a lot of jinking around. All in all, the process wasn't that difficult and certainly not out of the realm of home construction. John Quote Link to comment Share on other sites More sharing options...
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