Gianluca Posted April 27, 2009 Share Posted April 27, 2009 He at all, I'm new, sorry for my english, I cam from Italy, before I red lot of ours message and I'm asking help, I'm loocking for plans to built a Air power hammer, for me it'll be better made a power hammer with 2 cylinders because my compressor is very small. many thanks waiting your news Gianluca Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 28, 2009 Share Posted April 28, 2009 Welcome Gianluca, good to have you aboard. Someone will be along shortly with good advice, experience and probably plans. They are for sale but I don't have a link handy. What I can say is using two cylinders won't reduce air consumption. It takes a certain amount of ram surface to produce enough force to run the hammer. In fact using more than one cylinder will make it use more air because of increased friction. A way around a small compressor is to enlarge the air tank so it has more reserve. Before I found my mechanical hammer I was considering a utility air hammer and collected several high pressure tanks to use as a large reservoir. Frosty Quote Link to comment Share on other sites More sharing options...
Madmike Posted April 28, 2009 Share Posted April 28, 2009 Frosty, I think he meams building a self contained... I don't know if it isn't harder building a self contained than saving a few bucks to buy a bigger compressor ?!? Gianluca, you found the right place, welcome aboard ;) Quote Link to comment Share on other sites More sharing options...
Dave Leppo Posted April 28, 2009 Share Posted April 28, 2009 (edited) http://www.anvilfire.com/power/jyh/pelgroms/be-jyh.htm CLICK ON "PELGROM'S SELF-CONTAINED HAMMER SHOP-BUILT SELF-CONTAINED HAMMER SORRY IF THIS IS NOT WHAT YOU REFER TO Copyright Edited April 28, 2009 by GOATMAN Quote Link to comment Share on other sites More sharing options...
Gianluca Posted April 28, 2009 Author Share Posted April 28, 2009 Exactly what I want to build! Do you know (after pelgroms) wher I can find informations? many thanks Gianluca Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 28, 2009 Share Posted April 28, 2009 Ah, a self contained. My mistake. I guess it depends on your point of view which is harder to build. I always thought the self contained would be the easier but that's just me. Frosty Quote Link to comment Share on other sites More sharing options...
Madmike Posted April 29, 2009 Share Posted April 29, 2009 Daydreaming I was wondering what material to use as a bearing on the friction surface of a 'scotch yoke'... Do you think of a way to avoid overheating if using to air cylinders in a self-contained ? Patrick Pelgrom's air-scheme seems to be very efficient and is super simple... Quote Link to comment Share on other sites More sharing options...
Gianluca Posted April 29, 2009 Author Share Posted April 29, 2009 Many thanks at all Gianluca Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 29, 2009 Share Posted April 29, 2009 (edited) You use a roller bearing in a scotch yoke for something this heavy duty. There should only be enough space between the bearing and the yoke it'll clear the far side on a push stroke to minimize impact at turn around. The Pelgrom hammer's valving looks okay but it's more complicated than the earlier commercial hammers. Do a Google Patent search for this number 707246. It's the 1902 Massey self contained power hammer and it's valving is extremely simple and if you use a check valve in the control valve(s) it yields all the functions the commercial hammers offer. Tup up at idle, full cycle, dead blow and clamp. I couldn't make heads nor tales of the drawings till I printed the whole thing out and sat down with a highlighter, read the text and studied the drawings. It is elegantly, beautifully simple and the valving scheme I planned on using. Heck, I still might build one, I have almost everything I need except something sufficient for the anvil. Oh, overheating's no problem. These things operate on peak pressures of 15-18psi so I planned on making the cylinders from aluminum and either putting cooling fins or water jackets on them. The pistons, rods and tup are steel of course but the cylinders don't need to be cast iron so long as the rest of the hammer has enough mass to it. Frosty Edited April 29, 2009 by Frosty Quote Link to comment Share on other sites More sharing options...
Madmike Posted April 29, 2009 Share Posted April 29, 2009 Yeah I was also thinking that tie rods cylinders could easily be double-walled to include a water cooling rig... Just add a car engine water pump on the belt, a HX and a fan... Do you think the air-cushion of large bore air cylinders would be enough when the ram will get back to top idling... Thinking loud... Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 29, 2009 Share Posted April 29, 2009 I think just cooling the cylinder walls would be more than enough to keep the whole thing right. Some warm up is necessary but smoking oil isn't good. Water jackets and a small radiator would probably be just about perfect. That's what surprised me some years ago some friends were discussing building one of these type hammers and he put a pressure gauge on a Nazel 3B. Even on impact it developed pressure spikes under 18psi. At idle it was something like 3-4psi to keep the 350lb+/- tup raised. These are low pressure high volume systems. The pistons have large surface areas so it doesn't much pressure to make them work, just lots of air instead. Low pressure and high volume helps keep the heat, wear and tear down. Frosty Quote Link to comment Share on other sites More sharing options...
Judson Yaggy Posted April 30, 2009 Share Posted April 30, 2009 I was all set to start building my external source air hammer, even have a 1700# block of cast iron for the anvil mass, a big I beam and a 2" thick base plate, and you go and show us that cool patent. I'm printing and sharpening my highlighter as we speak and I'm sure my wife will roll her eyes at this one! But seriously, from just a quick look at the drawings, is there a reason for the mechanical connection of the two cylinders or did they just need all that iron because they didn't have the nifty materials we modern smiths have today like quality air hoses? Also, were you going to machine your valves yourself or is there a commercially available product that would do the same thing? Thanks! Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 30, 2009 Share Posted April 30, 2009 Well, it's all part of being a guy to keep the wife's eyeballs well exercised isn't it? I'm not sure what you mean by "mechanical" connections between the cylinders. for the sake of a reply I'll assume you're talking about having them as close together as possible with solid cast airways. Well, hoses are nifty things alright however they waste energy by stretching and flexing every time the pressure changes. More importantly though the shorter the airways the less loss of energy due to having to compress more air than necessary. It isn't like running an air tool off a compressor where long lines actually act as a reservoir, in these things that's a . . . well, not a BAD thing but not good for efficiency. I haven't decided how to address the control valve(s) with their integral check valves. For one thing the air lines on a hammer the size I want to build would be 1 1/4" or better and the check valves need to not restrict flow so the valves themselves need to be considerably larger. Some years ago a fellow simply used a 1/4 turn ball valve and his hammer worked just fine but without the added features we all want like raised tup at idle, dead blow and clamp. These must have the check valve in the circuit. Anyway, I figure if I use a large enough ball valve I should be able to just put a check valve in it but I have no proof, it's just my thoughts. Lastly (for now of course) once you have a good handle on how the thing works think about what shape you want the hammer. It does not NEED to be mounted on a "C" or "A" frame over the anvil. Also, as advertised in the patent it's easy to plumb hoses to the compressor cylinder and use it for "remote" hammering. Think upsetter, etc. Pretty neat eh? Frosty Quote Link to comment Share on other sites More sharing options...
Judson Yaggy Posted April 30, 2009 Share Posted April 30, 2009 Thanks for the quick reply! Yes, that's what I meant by mechanical connection. I see what you mean about the loss but if you assume rigid lines (pipe?) would there be a noticeable loss if you had say 2 feet of line rather than 2 inches? Why not just up-size your compressing cylinder? Ok, I'll stop asking stupid questions and read the patent in detail. I'm sure I'll be back in a day or two with more questions. Thanks again Frosty. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.