Ramsberg

Hey Anderson, Are you an ex-carnie? HA! The test apparatus looks just like those sledge hammer bell ringing deals. Same principle as a tetertotter that is struck on one side that throws up a weight on the other. Good deal man, I see a lot of useful information coming from duplications of that! With the old steam hammers they found that a really great speed of the hammer effected the "skin" of the work more then the "core". That is why the kept using bigger and bigger hammers instead of using bigger pistons and higher velocities. The same thing goes for knocking together timber frames, the old school method was to use a chunk of a trunk with a handy "handle branch" as a hammer to knock the joints together. Now a lot of people try to use "light" 15 lb sledge hammers swung rapidly and they mainly mar the end of the timber instead of drive it in! All inertia is not created equally! There is also a theory out there that as the speed of light is approached the force that is encountered is an "inertia wave", just like the "sound wave" is the sound barrier, this is a theory that I am fond of. Firebug, The swing is important, before I got into blacksmithing I was into boxing and found that a jab with a tight snap gave just as much force as a wind up punch, I used this when hammering, a quick snap with a loose grip basically throwing the hammer at the stock. I would lightly hold the hammer on the way down, then just before impact whip it and almost let go only starting the pivot of the hammer when the hand was 2/3 to 3/4 of the way through its stroke, like that I could heat up the stock from dull cherry to bright yellow with the hammer. I always believed that this was a very old technique, nothing new. The detrimental leverage of the head of a heavy hammer on a long handle is exactly what gave me the idea for the counterweighted hammer, that way a heavier hammer can be used without the serious and ill effects that build up. Caleb Ramsby

Hey MadDog, This might be what you are looking for. http://www.regoproducts.com/information/field_topics/lp-gas_tank_vapor_manifolds.htm Caleb Ramsby

Hey Dex, Please do add that story, I love old steam engines! Caleb Ramsby

Hey Luke, Glad to hear that things are progressing! The less restrictive you can make the air plumbing and tuyere the less head that will be required for the blast. Most of the old hand crank blowers that I have used were as Matt said, around 1/2 to 3/4 of a revolution per second on the hand crank. If you can use a big sprocket and rear derailer/sprocket pack from a change speed bike then team that up with a belt drive pully then you would be able to fine tune the ratio to exactly what you need! Good luck! Caleb Ramsby

Hey MonsterMetal, I would multiply the effects of welding chrome or galvinived surfaces by 10 for the effect of putting them into the forge. http://employment.alberta.ca/documents/WHS/WHS-PUB_ch032.pdf If in doubt. . . don't be an idiot and get yourself killed to save a few bucks. Remember also that the chrome coating is only the TOP coating in a layer of them, much like zinc coatings under most paint jobs, etc. Caleb Ramsby

Hey Grant, Absolutely right, that and the slight vacuum required to suck the air into the bellows(pump) are principally what add up to make the volumetric efficiency of the pump. Caleb Ramsby

Hey RMiles, Thanks for the info. Those 25 strokes per minute should be giving around 14 1/4 cfm from the bellows. Going through the 3/4" nozzle, with its .44 sq in opening would produce a nominal velocity of 77.7 fps, using a discharge coeffecient of .8, that would be an area of .352 sq in and produce a velocity of 97 fps, just about 66 mph. The head resistance at the nozzle would be around 2.16 inchs of water. The rest of the head produced by the bellows must be coming from resistance in the piping. These are all aproximate numbers since the volumetric effeciency of the bellows, crimping volume reduction effect of the fabric and discharge coeffecient of the nozzle are all assumed and estimated. Caleb Ramsby

Hey Grant, There may be a point of diminishing returns with the amount of balancing produced via the counterweight. A bolt holding babbit "washers" threaded into the end of a hammer would give on the ability to change the amoung of balance achieved, from none to 100%. Lead would also work, it weight .41 lbs per ci, a 3" disk of lead would weigh 2.9 lbs per inch. I like the leaf spring idea, I can imagine the spasmadic dance routine that using it might produce. It would sure be interesting to find out what that would do! Caleb Ramsby

Hey John, The amount of balance obtained is going to be a big question. Do you know off hand how much of the blades weight is balanced by the pommel nut? For a hammer, if there is a distance of 9" between the center of the hand on the handle and the center of the hammer head and the head weighs 2 lbs then the head would produce a torque of 18 inch pounds. If the counterweights center was 4 1/2" behind the center of the hand then to produce 18 inch pounds of torque it would need to be 4 lbs. That would completely balance the hammer head, not the handle but they are light. . . The dilema is how far back to extend the counterweight, if it were back as far as the hammer head is forward then it could be of the same weight and one could use it as a true two headed hammer, but the further back it is the more likely it will be to bang into you when it is used. I think that the latter will depend greatly on the individuals hammering technique, such as swing with the hammer to ones side or in front of the body. Caleb Ramsby

Hey Grant, Oh yeah! About a year and a half ago I switched from working on a steam car design to working on a steam motorcycle design. Not a steam powered bike, but a motorcycle, the design goals are 450 lbs dry weight, 1/4 mile in 9-10 seconds and 30-40 mpg in the real world, at first glance that sounds impossible and many steam experts believe it to be, but we will see. The burner is designed to run on any liquid that will burn. The boiler, engine and condensor elements are now finilized in regards to their basic design and many details have been worked out. So I am getting closer and closer to the point when I will have to start building and testing stuff! It has been a long eight year road to where I have gotten in the steam design now. I hope to make the levers and brackets via hand forging, it should be rather unique(if it ever gets built!). Caleb Ramsby

Hi All, I can't wait to hear about all of the different versions of the double headed/counterweighted/balanced hammer that you all come up with and the almost assuredly mixed bag of results that arise from them! I hope that at the least you all enjoy the experimentation with the idea as much as I do the sharing of it! Sometimes I wonder how the "closed clan" blacksmiths of many years ago would view our ability and willingness to share ideas and techniques. At that time it was in their best interest to keep things under the wrap of "trade secrets" as did the practitioners of almost all of the many trades. Here(in regards to this website) there seems to be a lot more hobby people then business blacksmiths and I doubt that many of the businesses compete head to head in regards to big contracts, so an openness makes a lot more sense. When my great-grandfather had his blacksmith shop, his(employing three to five people) was one of SEVEN in a relatively small city, Kirkland, Illinois, now a village. Getting off track now. Caleb Ramsby

Hey Rmiles, Cool setup! The head area would be 188.7 sq in and with 25 lbs on it would be producing a blast pressure inside the bellows of 3.66" of water. If the head weight itself wasn't included and it were five pounds then the pressure would be 4.4" of water. Both of those figures are right in line with what seems to be required for most forges, although maybe a bit high for a side blast type, maybe the wrinkled bendy tubing is thwarting the air passage a bit, it works and that is what matters most. What diameter is your tuyere? Each 6" stroke of the bottom bellows would give approximately 1,000 ci of air, assuming some loss of volume due to the crimping of the fabric and the volumetric efficiency of the suction action of the pump. So, around 1 and 3/4 pumps of the bottom bellows would give one cubic foot of air. If you would indulge a curious mind, could you count how many strokes you make of the pump in one minute when operating the forge? That figure divided by one and three quarters would give the approximate number of cubic feet per minute of air that is pumped. Caleb Ramsby

Hey Grant, I like the way that you think too. . . with your brain! HA! It's fun to have fun. Have fun with the idea, I am rather ashamed that I have never gotten around to doing anything with it, as you said, not that difficult of a project. Hey Marc, I think that it depends on the specific swing that one is using, if as Grant says it has a whip of the wrist at its end then the counterweight may actually be rotating up. Anytime the head rotates down then the counterweight will rotate up, so at the point of impact the inertia of the counterweight may actually be trying to lift your hand, which could be usefull. One thing that I am very curious about is what will happen to the vibrations of the hammer. My experiences with musical instruments tells me that it will probably be deadened by the counterweight. . . especially if a metal rod went through a hollow wooden handle from the head to the counterweight. That of course would complicate the hammer construction a bit and possibly weaken the handle, but it's an idea. Caleb Ramsby

Hey Maddog, The force of the hammer strike comes from the inertia of the hammer head, having a ball of babbitt on the other end won't change the inertia of the swung head, so the force of the strike would be the same. You are right, the rebound of the hammer off of a strong strike should be utilized as much as possible to lift the hammer head. Think though about how many lift you make of the hammer that are "dead", that is when you are returning to the anvil or after carefully changing the position of the stock that you are working on. Then you have no rebound to lift the hammer, so there is a lot of stress produced by lifting the hammer head on the unbalanced stick. I wrote Hofi a note about this a year or so back, he didn't like it, to each his own. Just having some fun and puting an idea out there. Caleb Ramsby

It is not a balanced hammer, it is a hammer with a relatively well balanced head. If the head were square looking at it from the end and solid metal then it would be a "perfectly" balanced head. A number of years ago I came up with the idea to make a balanced hammer, which I never got around to doing before I moved to a place that doesn't have a shop or provisions for installing one. Anyways, I had come to the conclusion that a lot of the stress involved in swinging a hammer was produced by the hammer head having leverage on the hand, especially on the up swing. I tested this theory by holding a Babbitt hammer back wards in the same hand as my blacksmithing hammer. That way the heavier Babbitt head was on the opposite side of the hand as the lighter blacksmithing hammer head. I must say that I was shocked by how much lighter the hammer felt even though the total load lifted was heavier. It is similar to holding one eight foot long 2 by 4 by its end, then doubling the weight by attaching another 2 by 4 to the end that you are holding, so that now you are holding it in the center of the load. Yes the two boards are heavier, but holding them in a balanced way will drastically lighten stress on all of the muscles used to counter the unbalanced load of the single board held by its end. In other words, the two boards could be held with a single finger if balanced in the center, the single board held by its end would require a lot of hand strength and stress to hold onto. If anyone want to give this hammer idea a try, go for it. A chunk of Babbitt or something lagged into the hand end of the hammers handle would give a lot of balance, it wouldn't need to perfectly balance the head, just help out a bit. Caleb Ramsby

Hey Mark, In Charles McRavens book "Country Blacksmithing" he illustrates a shop that he made with a timber frame "gazebo" with three foot tall stone walls all around having the masonary forge set into them. That is one really neat open sided shop. Have you considered making the "windows" detachable. Say with a hook and eye system at the top and a double eye with rod system at the bottom? Something like some luber or plywood with windows set into them that could be removed from the wall(from the inside). That way in the summer you could just remove them, lean them up against something and have true open walls. Caleb Ramsby

Hey Fciron, If that context of usage you described, "...Oh, and if you're really good, you can draw hex too.", is the one in which it is usually used I believe that it may have been sarcasm. Sort of like saying that a really good pilot can fly without wings. Kinda like the old car shops sending a guy around to their friends shops since they were out of muffler bearings. Caleb Ramsby

Thanks Grant for the compliment, thanks also for clearing up the consumption of coal per hour question. My memory and estimate about that was WAY off in that bellows discussion! Luke, glad that I could be of some help, good luck and have fun! Caleb Ramsby

Hey Luke, I forgot, check and make sure that the gear box isn't a worm type. Many of the extreme reduction gear boxs are worm gears that can't transmit power from the slow shaft to the fast shaft, only from the fast shaft to the slow shaft. Caleb Ramsby

Hey Luke, On the required air pressure it appears that 1 1/2 ounces per square inch is enough. I am shop and forgeless right now otherwise I would make a manometer and hook it up to the air delivery to the forge and find out for sure! 1 1/2 ounces equals roughly 2 1/2" of a water column, 3" of water equals 1.731 ounces per square inch. The equation for air velocity to velocity head pressure is V = 66 * sqrt H. Where V = velocity and H = head in inchs of water. To go from head pressure to velocity H = (V/66) * (V/66). The amount of air required is dependent on the qunatity of fuel consumed in a given time. Say one is burning 2 lbs of coal an hour and the forge is being pumped air 1/2 of the time, then the fuel consumption rate when heating the metal is 4 lbs per hour. Each lb of coal provides roughly 12,000 btu, this depends on the type of coal of course. Generally for most all fuels each 1,000 btu requires 8/10 of a pound of air. A pound of air takes up roughly 13 cf. So for each lb of coal per hour one would need at a minimum 125 cf of air. So for a firing rate of 4 lbs of coal per hour, that would equal .066 lbs per min, so .066 * 125 = 8.25 cfm. This is assuming just enough air for the coal burned, for practicality I would increase it by 150%. It is also assuming the weight of coal burned per hour and the amount of time that the fire is getting a blast of air. In other words, if you are burning 2 lbs of coal per hour and have the blast going 60 minutes out of the hour then the firing rate is 2 lbs per hour, if you burn 2 lbs per working hour and the blast is going only 15 minutes out of the hour then the actual firing rate is 8 lbs per hour. I hope that makes sense. To figure the CFM output of a fan figure the blast area at its outlet in square feet, the velocity of the exiting air(in feet per minute) and then use a coeffecient of discharge for the blast area. So if the blast area is 3" by 3" that is 9 sq inchs, which is .0625 sq ft. If the velocity pressure is 1/2" water that is 46.7 fps or 2,802 fpm. Use .8 as a discharge coeffecient. So .0625 sq ft times 2,802 fpm times .8 equals 140 cfm! That would be the blast area an open fan, but we are not dealing with an open fan we are dealing with a forge. The two types of solid fuel forges are side blast and bottom blast. Their tuyeres have very different coeffecient of discharges. The coeffecient of discharge is essentially the actual area of the air column going through the tuyere. As the air goes through the opening it tapers down in cross section and the volume of discharge for a given air velocity is decreased. Side blast forges generally have a tapered or straight pipe as a tuyere and they have a very good coeffecient of discharge, around .9 to .8. Bottom blast forges have a clinker breaker or grate of some sort that generally has a very bas coeffecient of discharge, around .4 to .6. So for a bottom blast forge to have the same cross section of an air column as a side blast the tuyere opening would need to be around twice the size. Lets use a bottom blast forge with a grate(tuyere) opening of 3 sq in as an example. The effective air column cross section would actually be 3 times between .4 and .6, lets go with .5. So the actual opening is 1 1/2 square inchs, which equals .0104 sq ft. If it were to supply 10 cfm of air the air velocity would need to be, 10 / .0104 = 962 fpm or 16 fps. Using the above formula for air velocity to inchs of water head we would require .059 inchs of VELOCITY pressure. This is not including the static resistance produced by the coal in the firepot. Said resistance is very significant and would amount to around 1" to 2" of water depending on the depth of the coal and its compactness. So basically the velocity pressure from the fan is split up into two uses, one is to provide the static pressure to counter the resistance of the piping, grate/tuyere and coal, the other is to actually supply the movement of the air. If one were to remove the coal from the firepot and just run the fan a massive amount of air would be moved, since there is very little resistance to its movement, all of the fans velocity pressure is being used to move the air. Here is something that happened to me that illustrates the point. I was experimenting with wood pellets with the forge I made that used the hand crank drier fan. The wood pellets got hot enough, but they broke up instantly, produces TONS of sparks and rapidly cloged up the bottom blast grate that I had made. This was especially true when one left the fire to hammer hot iron. So, I went back to the forge to heat some more iron and the grate was clogged, I was cranking like mad and not air was moving, so still cranking like crazy I stired up the fire a bit and it let LOOSE! The fuel instantly jumped two feet into the air above the firepot! The fan was producing a lot of pressure but the clog was restricting the air from moving, once I removed the clog the resistance droped dramatically and the air flow increased greatly. I hope all of this made sense. Caleb Ramsby

Hey Luke, The amount of air pumped by a centrifugal fan is dependent on the head resistance, the head produced and the blast area exiting the fan. I can't suggest greatly enough that you should get your hands on a copy of Gingerys "How to design and build centrifugal fans for the home shop" from Lindsay Publications. It shows you not only how to make a centrifugal fan, but also how to simply calculate the output of said fan at different speeds, this is exactly what you need. I would also suggest that you skip the gears(unless you have a bunch of them laying around) and just use sprockets and chains from pedal bikes with a hand crank. The fan rpm will be dictated by the head resistance to the air flow and the fan diameter, for say 3" of water resistance the air must be traveling at 114 fps to equal it, the tip speed of the fan must be at least this fast, so for a 3" fan that would be .7854 feet circumference. The fan blade tips would need to be traveling at 6,840 fpm(114 * 60) so that would be 8,709 rpm. If the fan were 12" dia that would cut the fan rpm in 1/4 for the same fan tip speed, so 2,177 rpm. For a hand crank speed of 30 rpm you would need a ratio of 1 hand crank to 72.5 fan revolutions. A 1 to 9 ratio in series with a 1 to 8 would give this ratio. The bigger the fan the slower its speed needs to be for the same air velocity and velocity head pressure, also the deeper the fan blades the better it is at producing a significant head pressure. I made a forge once in which I used a fan from a cloths drier and used a series of pullys and belts to get around a 1 to 80 ratio of crank to fan, that worked OK, but it had an issue producing enough pressure for coal, for charcoal it was OK. I didn't like the belts, with the significant ratios and very small driven wheels it tended to slip when pushed hard and I beleive that this was the cause of the lack of significant head produced. I hope this helps some. Caleb Ramsby

I may have to pick my self up a pair of wooden shoes! Just for the curious, back in the mid 1860's in France they began using mechanical snow removal equipment for the city streets, the workers who had done this work by hand didn't appreciate this inovation since it took their jobs. So they took their sabots(wooden shoes) and threw them into the gears of the mechanisms of the snow removal equipment. This revolt via the destruction of machines or property became known as sabotage! Caleb Ramsby

Hey Dave, The future, as it always has, belongs to the makers of things. Welcome to the future! Caleb Ramsby

Hey Dave, Looking really good man! You will be back at the anvil with hot metal in no time at all! Caleb Ramsby

Hey Dave, I just love it when a plan comes together! If you end up having to weld it then a small tack on the edge of a flat to the round stock can be done when it is inside the forge and easily ground off with the ash pipe still attached to remove the clinker breaker. I would like to second what Phil said, a tap and die set is very usefull, if a new one is out of reach then check out some flea markets and garage sales they sometimes have an old set or two there. Buy enough of them and you end up with a "complete" set of taps and dies. Those taps can be used for a lot of stuff not just threading holes but picking your teeth or yanking out that odd nose or ear hair. . . Caleb Ramsby