Dan P. Posted December 23, 2011 Author Share Posted December 23, 2011 Owen, I would very much appreciate a contact for a spring maker. The springs on at the moment have a little squiff to them that is more than just excess Christmas cheer, and a new set would put my mind at ease. Thanks also for your input on pulleys. I have had some conflicting feedback on motor speeds (over on Don Fogg's forum), which have suggested speeds more like 1500-1700 bpm. I have no idea how these things work, and I fear that my usual approach of trying something and then when that doesn't work trying something else might be hazardous when applied to heavy spinning metal. I fear I will have to go to the bother of putting in a jackshaft if only for the purpose of the belt slipping on too small a drive wheel, as you pointed out. I would like to avoid it, obviously, because it is more work and expense. If you don't mind I would like to get in touch with you about sourcing the pulleys and bearings for a jackshaft, sometime after the Xmas nightmare is over. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted December 23, 2011 Author Share Posted December 23, 2011 Your sole worry is winding the canvas tightly through the head, my friend I wish this were true in general! The strap I need to replace, it's not a big deal, and I think, along with your input (for which I am grateful), must be mostly common sense. The springs are a general to do project, not a huge priority. The one thing that is making me worry is how to drive the old girl! I am a fairly good smith in the strictest sense of the word, I have good spatial awareness and sense of proportion, etc., but I am not an engineer. Engineering fills me with a strange mixture of dread and boredom. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted December 23, 2011 Author Share Posted December 23, 2011 What is it to wrap the entire spring pack in leather? Better safe then sorry. that being said WOOOOOHOOOOOOOOO that is a cool hammer! I am currently setting up another hammer that you will like even better, Sam, as I seen to remember you have (had?) a helve fetish. Quote Link to comment Share on other sites More sharing options...
basher Posted December 23, 2011 Share Posted December 23, 2011 speed wise your hammer will have a sweet spot , a speed range at which it works best at. If you can find another set up somewhere in the world that will give you a clue ! normally the speed goes up as the weight goes down . my 60lb goliath runs at 240 bpm . some of the sheffiels cutlers hammers are nearer 400bpm. at 240 you can easily change stock from horizontal to vertical on the trot at higher speeds it becomes more like a flattening machine I would love to try a 400bpm power hammer. I ran my 1/2 hundred weight massey hammer at a few different speeds through a VFD and found a best speed for power and a best speed for control I could find no information on what speed it should run at.. there is a really useful DVD on tuning little giants that has a lot of good info on spring hammers in general . I cant remember who made it?. I would recommend it though . when people are mentioning speeds of 1500 and 1700 they are talking about motor speeds not hammer speeds. sure get in touch after christmas. Ebay uk had a lot of flat belt pulleys come up . Quote Link to comment Share on other sites More sharing options...
basher Posted December 23, 2011 Share Posted December 23, 2011 showing a picture of just a helve is not fair ! Quote Link to comment Share on other sites More sharing options...
Dan P. Posted December 23, 2011 Author Share Posted December 23, 2011 speed wise your hammer will have a sweet spot , a speed range at which it works best at. If you can find another set up somewhere in the world that will give you a clue ! I've done the research (i.e. google) in French and English, and it may just be that mine is one of few, if not the only, remaining in captivity. I think Bouhey only dabbled in power hammers before the were amalgamated in 1914 to form the company "SOMUA" (yes, fascinating). Quote Link to comment Share on other sites More sharing options...
Dan P. Posted December 23, 2011 Author Share Posted December 23, 2011 let me help you out with the configuration for powering the hammer. As I previously stated, your hammer needs to hit at around six strikes a second at maximum speed. If the flat pulley wheel on your motor shaft is 3 inches in diameter, and the diameter of the pulley wheel on your hammer is 15 inches, the motor pulley wheel will have to turn five times to turn the hammer pulley wheel once. This means that you have effectively geared down the speed of the motor by a factor of 5. So, if your electric motor is 1800 rpm's, or 30 rps(revolutions per second), this arrangement has slowed down the flat belt by a factor of five. 30 divided by 5 is 6 turns a second, which is perfect, with the pedal to the floor! Thank you for explaining that to me. This is still hard on my brain, you will have to give me time to process it, and then apply it to my situation, which is an approx 4" motor pulley going to an approx 8" drive wheel. If I think about this too hard hard I am afraid it might scare Santa away. -Dan Quote Link to comment Share on other sites More sharing options...
basher Posted December 23, 2011 Share Posted December 23, 2011 to work out pulley sizes we need to know the rpm wanted at the hammer and the speed of your motor . lets say for example you have a 1400 rpm 4 pole motor which is a common type ( there are other uk motor speeds 2 pole=2800 6pole=900 and 8 pole =700 rpm) and that you want a final hammer speed of 200 (or whatever you decide) If we devide 1400 by 200 you get a reduction factor of 7 so your drive pulley needs to be 7 times as small as the final wheel on the hammer. as your final drive pulley is 210mm diameter you would need a drive wheel od 30mm to drive it directly. this is a little small for a slip belt drive however you should get the idea. I would go more like 210 flat belt to 210 flat belt on to a jack shaft and then run a secondary reduction from a large pulley to a smaller one on the motor say say 250mm to 50mm with v belt pulleys (one or two v's would be fine) the small drive wheel is not such a problem with a v belt as they have more ability to transfer drive. this would give you 280 rpm which is closer to stuarts suggested speeds. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted December 30, 2011 Author Share Posted December 30, 2011 Cool, thanks for that Owen, that makes a lot of sense. It turns out the dies, the upper at least, are wrought iron with a steel face welded on. Old school! Unfortunately it means that the upper die in particular is quite badly deformed. This is a good-looking hammer, but in considering its set-up I have noticed a very major design flaw; the working area between the dies is largely obscured from a normal standing position. It is visible from the side of the hammer, but the rise and fall of the spring makes this feel more hazardous. Given the old girl weighs a pound or two, she is unlikely to go up very far. I think this means I will have to come down, and perhaps rig up one of this nifty swinging chairs one sees in old industrial forges. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted December 31, 2011 Author Share Posted December 31, 2011 It's not that, Stewart, it is the fact that the body of the slide is too bulky. In your hammer, for instance, the body of the slide is located either side, allowing full view of the ram. To clarify, if you look at the photo of my hammer, and imagine someone standing standing in front of it, and then draw a line from their eyes to the dies. It is a problem, unless you work from the side (or what I perceive to be the side). It is not a big deal, just not ideal. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted January 2, 2012 Author Share Posted January 2, 2012 New question; Concerning the visibility of the working area; it would not be a problem if the working surface was lower, which is making me think about the configuration of the dies. You will see in the pictures below that the top of the sow block is closer to the correct working height, and with the die on top is too high. My solution is to do away with the sow block and make (or have made) a die that sits right on the anvil. The question is- is the sow block that important, given that changeability of dies is not something that is part of my plan for this hammer? You will see on the photos that I marked a bit out in chalk. That is where I was thinking of cutting away the frame so I could see the dies. As a last resort only, of course! Top picture is crouching over, I still can't see the working surfaces of the dies. Middle picture from the side- I can see the dies but I am at risk of the spring coving in my skull! Bottom picture, what I want to be seeing, and the configuration of the die and sow block. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted January 2, 2012 Author Share Posted January 2, 2012 The dies are touching because there is no strap. With the die locked tight to the sow block, why is there more chance of the anvil being damaged if there were no sow block, as the extent to which they move seperately of each other is negligible. In answering this question, bear in mind that if there were no sow block the die would be a similar size to the sow block. Quote Link to comment Share on other sites More sharing options...
basher Posted January 2, 2012 Share Posted January 2, 2012 Ill be honest lifting a tonne or so up onto a couple of railway sleepers height is not hard . I have done it with a engine hoist and a slope and pulley and also by making two brick pillars and using a bottle jack to raise one side of a scaffold tube whith the hammer tied to it, one brick height per side at a time, raise insert brick , raise other side repeat etc I would lift the hammer . what height is your bottom die face at? Cutting the frame is a job for only when you have used the hammer for a while and used up all other possibilities. I would try it and see how awkward it is in reality. Quote Link to comment Share on other sites More sharing options...
John B Posted January 2, 2012 Share Posted January 2, 2012 (edited) Hi Dan, Why not use some railway sleepers to lift the hammer to a more suitable useful position ? I had trouble with my old Blacker being too low, so built a base for it using sleepers which raised it to a more convenient height. Sleepers were about 7" x 12", over 6 foot long, if I remember correctly. If you need more than one, make sure the sizes are similar to allow it to sit flat on them, or you could slip a piece of ply between sleepers and machine base. Sorry posting this at the same time as Owen. Edited January 2, 2012 by John B Quote Link to comment Share on other sites More sharing options...
Judson Yaggy Posted January 3, 2012 Share Posted January 3, 2012 I'll add my vote to the DON'T CUT IT side. You would be asking for breakage of the guides, the original manufacturer knew what they were doing, there is a lot of force pushing on the guides at the bottom of a stroke. First thing I'd try is lifting the hammer up onto a bed of timbers as previously suggested. If that is out of the question then make up new dies with the top of the die 90 degrees to the dovetail- this would let you work on the side of the hammer where there appears to be better visibility. Dies like this were used in the Champion hammers (amongst others), there are several threads here on them if you search. Quote Link to comment Share on other sites More sharing options...
peacock Posted January 3, 2012 Share Posted January 3, 2012 I think you are on the right track about making a lower die that lets you get rid of the sow block. If it were mine I would make a dovetail the same height as the top of the anvil, then make a bolt on lower die. However before I went to all this trouble you need to check to make SURE that the spring will not hit the frame with the new lower die setup. I wonder if this hammer came with a sow block? As it is now the ram does not come out the bottom of guides very much. Whatever you do do not cut the frame away. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted January 3, 2012 Author Share Posted January 3, 2012 Thanks for the input, everybody. I am still in the process of setting up my new workshop, and am doing a lot of head scratching. This hammer in particular is a puzzle, because I want to put it somewhere and leave it there. I'm not sure how much it weighs, but it put a 2 ton tail lift to the test! It will have to wait a while now, the holidays are over and there is work to be done, but I will post pics or a video when I have made some progress. Thanks again, Dan Quote Link to comment Share on other sites More sharing options...
peacock Posted January 5, 2012 Share Posted January 5, 2012 Stewart I never said to put a die in the anvil. I suggested makeing a sow block the same hieght as the anvil dove tail then bolt a die to that. I don't think that is any more risk than what he has now. P.S. please see post #1 open link, page 163 shows the hammer with out a sow block Quote Link to comment Share on other sites More sharing options...
nonjic Posted January 7, 2012 Share Posted January 7, 2012 Could you make a set of dies that orientated at 90 degress to the current ones so you can work the hammer from the side whilst facing the long edge of the dies? If you looked down on the die if would be a 'cross' shape. I vote for a booster cushion of railway sleepers aswell. Ive just done this on my 2 cwt Massey install and it has worked nicely to raise the height. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted January 9, 2012 Author Share Posted January 9, 2012 I suggested makeing a sow block the same hieght as the anvil dove tail then bolt a die to that. I think I may be going for this option. It will eliminate the need for expensive machining of a dovetail if I want to make new dies, which i will because these ones are wrought iron with a steel face and are pretty buggered (as I have mentioned before). I am also going for a direct drive from the motor. I have procured a 710 rpm motor, so the motor pulley (100mm OD) I think should be big enough to provide adequate surface area to power the hammer. I have done an assessment and have come to the conclusion that I will spend too much time fannying around trying get a jack-shaft right to make it my first choice, at least until direct transmission is shown definitively not to work. Next to be procured is some appropriate leather. Then sleepers. Onward, upward, then downward again, with force! -Dan Quote Link to comment Share on other sites More sharing options...
Dan P. Posted January 10, 2012 Author Share Posted January 10, 2012 A question for you, Peacock; How thick is the leather that you have used? The original on mine is around 6-7mm. The leather man says that he doesn't think you can get leather that thick from a cow. Thanks and regards, Dan Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted January 10, 2012 Share Posted January 10, 2012 Dan - could it have soaked up oil or something and swelled up? Al. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted January 10, 2012 Author Share Posted January 10, 2012 Dan - could it have soaked up oil or something and swelled up? Al. It could be, I have no idea. Leather is not my area of expertise. It is possible that it is something other than cow leather too. Quote Link to comment Share on other sites More sharing options...
John B Posted January 10, 2012 Share Posted January 10, 2012 A question for you, Peacock; How thick is the leather that you have used? The original on mine is around 6-7mm. The leather man says that he doesn't think you can get leather that thick from a cow. Thanks and regards, Dan So where do cobblers and shoemakers get their leather for soles from, they are/used to be thicker than 6mm/1/4" Quote Link to comment Share on other sites More sharing options...
basher Posted January 10, 2012 Share Posted January 10, 2012 I would try lyon leather northhampton .who defiantly sell sole leather. and should be able to cut straps for you. 01604639346 Quote Link to comment Share on other sites More sharing options...
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