HWooldridge Posted January 11, 2012 Share Posted January 11, 2012 I've got scads of saddle leather laying around that goes up to 1/4" thickness - sometimes thicker. Of course, an old bull's skin over the chuck will be much thicker than a young cow's bellyskin. OTOH. it's probably easier to laminate layers of thinner leather until you get what you want in thickness. Contact cement works well to glue leather to itself...I use 3M spray 77 adhesive; it's great stuff. Quote Link to comment Share on other sites More sharing options...
peacock Posted January 11, 2012 Share Posted January 11, 2012 I have 15/16 oz. leather. In the US each oz. is equal to1/64 th inch or.0156 so that would be .250 for 16 oz. I have had some bull hide that was 3/4 tich over the shoulder but it thins out as you go down and back on the hide so most is spilt to a given thickness. 17 oz is the thickest listed by my supplier. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted February 2, 2012 Author Share Posted February 2, 2012 I found today that the main spring is broken. There is a crack that goes all the way through, but was hiding behind a bolt where I didn't notice it before. I expect the hammer would be operational as it is, because the leaves are all riveted together. However, in the interests of optimal efficiency and safety, this is not something I am going to do. The springs as they are a very specific shape. The individual leaves are also tapered. I will have to have these made up by a specialist spring shop. The funny curvature, as well as the fact that they are tapered or "feathered" suggests to me that having replacements made is going to cost quite a lot (I am waiting on an estimate of exactly how much). So here are a few more questions; Do you think the shape of the springs is important, as long as they are in a general bow shape? Do you think it is important that they be feathered? I have seen on Japanese hammer single, chunky bow springs. What are the pros/cons of that? Here is another idea; I have the capacity to forge the springs to shape myself, but I would send them away to be heat treated. Has anyone tried this? I am wondering if they would be better heat treated all riveted together or individually. Individually they might warp, just a little, but enough to no longer be a perfect fit. Your thoughts please ladies & gents! -Dan Quote Link to comment Share on other sites More sharing options...
peacock Posted February 2, 2012 Share Posted February 2, 2012 I would go for the make myself and send out for heat treat. I would try to match the broken spring as close as possible to the broken one. You can use the spring next to it to get the shape correct. Treat them as single pieces, you could not get a proper quench in a stack. The warpage will correct it's self when you rivet/bolt them back together. Quote Link to comment Share on other sites More sharing options...
basher Posted February 2, 2012 Share Posted February 2, 2012 personally I would not re invent the wheel. there is a fair chance that the spring shape as is is optimal for the function of the hammer. Do all the springs nestle tightly when the stack is unbolted ? My experience with having springs made is that the cost is less than if I did it myself. the cross section of the spring over its span is very important as far as the spring sharing the flex along its length and not just bending when it leaves the stack .. If you forge to shape make sure you stay within the material forging range, and have no indents or sharp cross sectional changes . the spring will need to be normalised before it is heat treated best have this done by a heat treater . the surface condition of springs affects their longevity so linishing them would help as well. in the ht and tempered condition it is normally possible to bend springs if they have warped by over bending them until they take a set .THIS IS POTENTIALLY DANGEROUS OR LETHAL THOUGH do not take it too far.!! I have quite a stock of en45 and will probably have a bit around the size you need . or you could think like a farmer and weld it backup and bolt it back together and wrap it thoroughly in leather or innertubes or some such and get bashing it would be ok for for a week or a year or ten? Quote Link to comment Share on other sites More sharing options...
Sam Salvati Posted February 2, 2012 Share Posted February 2, 2012 You need to box this hammer up and SEND IT TO ME. i will return it to you fixed like new and running like a top in 20 years time. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted February 2, 2012 Author Share Posted February 2, 2012 Extremely helpful replies, thank you Peacock, Owen. Owen, the leaves are about 60mm wide, maximum 8mm thick. I have yet to hear back from the spring people (not the firm you suggested, they recommended another firm who do leaf springs), but might you have this section? I think this spring already has a farmer weld repair. It might take another, we'll see how it goes. Of course, the crack itself seems to have originated from a center punch. Sam, your offer to import, refurbish, then return my hammer ALL FOR FREE is exceptionally generous! What's you address? This is going to be GREAT! Quote Link to comment Share on other sites More sharing options...
Sam Salvati Posted February 2, 2012 Share Posted February 2, 2012 Use your mouse to highlight my entire post, I think you missed the fine print :D Quote Link to comment Share on other sites More sharing options...
Dan P. Posted February 2, 2012 Author Share Posted February 2, 2012 Use your mouse to highlight my entire post, I think you missed the fine print Good Lord... Quote Link to comment Share on other sites More sharing options...
Sam Salvati Posted February 2, 2012 Share Posted February 2, 2012 I would attempt to do a one piece spring like some of the japanese hammers. Funny though it would take a powerhammer to make that, so how do you make a part for the powerhammer you need to use for making the part? Maybe stacked leaves are the way to go..... Quote Link to comment Share on other sites More sharing options...
Dan P. Posted April 12, 2012 Author Share Posted April 12, 2012 I put a new strap on. It seemed tight enough, but the weight of the ram still makes it sag. I feel that this will be bad for the spring. Your thoughts? Quote Link to comment Share on other sites More sharing options...
basher Posted April 12, 2012 Share Posted April 12, 2012 If it helps I will have en45 steel in roughly that size next week email me if you want a bit. all the best owen Quote Link to comment Share on other sites More sharing options...
peacock Posted April 12, 2012 Share Posted April 12, 2012 It looks pretty good to me. The top has a little sag but the bottom run is pretty striaght. If the strap is too loose the top of the ram will hit the bolts that clamp the spring to the pitman. If you are not sure if it is hitting put some tape on th top of the ram, run it hard and look for marks in the tape. If you need to snug it up some you will need to pull the ends of the spring together with a clamp while you re-wrap the leather. You can tighten it up some buy making thick walled bushings to put over the bolts that the strap wraps around, these could even be made of good wood. You will also need to use the clamp on the spring to install the bushings. Looks good, be glad when you report al is well. Quote Link to comment Share on other sites More sharing options...
Dan P. Posted April 12, 2012 Author Share Posted April 12, 2012 Thanks for the replies, gents. Owen, I don't plan to be in London anytime soon, but just in case, what size/s are you getting in? Sam, this is power hammer project B. It will be some time before this hammer sees any action. I will be starting a thread about power hammer project A shortly. The helve hammer you spied earlier in this thread. Peacock, I spent a good deal of time scratching my head over a means to tighten the strapping without redoing it entirely, your solution is an excellent one, thank you. -Dan Quote Link to comment Share on other sites More sharing options...
Dave H. Posted April 12, 2012 Share Posted April 12, 2012 I think you need to put metal links in like the hammer came with. How else can you adjust the tension of the spring?? Quote Link to comment Share on other sites More sharing options...
Dan P. Posted April 13, 2012 Author Share Posted April 13, 2012 I think you need to put metal links in like the hammer came with. How else can you adjust the tension of the spring?? This hammer didn't come with metal links, and the ram has no capacity to be attached to metal links. However, your question about tensioning the spring is a good one, and one I don't have the answer to. Quote Link to comment Share on other sites More sharing options...
peacock Posted April 13, 2012 Share Posted April 13, 2012 I think the leather was made off the hammer to a certain size, Then the spring was compressed to install the bolts. The strap needs to be somewhat loose to give the whip to the blow. As I said before just not so loose it hits the pitman clamp. I would run the hammer as it is now and see how it works. You may find it is good to go. Quote Link to comment Share on other sites More sharing options...
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