basher Posted February 24, 2015 Share Posted February 24, 2015 I have been grinding blades a while now and find that I am good and quick at it , (relatively).I am heavy and strong and good angular control of my hands. However I find it hard on my body, the constant force applied through wrists locked in a very controlled manner leaves me in pain , wrists , elbows forearm the whole power train so to speak. Now that is not too surprising really as I have been grinding and smithing for 20 years and have pushed myself a little too much in the past. however I have had a growing suspicion that we (us modern folk) are missing a trick or two that the "old time" grinders of yesteryear did not miss. and slowly a realisation has grown upon me .. sheffield grinders apply pressure by putting the work under a board they sit on, using their body weight (thanks Josh for bringing that one to my realisation.) French Bill hook grinders use a kind of board that fits over their lower leg and lean into the wheel, using their body weight.and I have seen another (black and white) vid of sickle grinders using a levered arm that applies pressure to the steel using their foot power. In all these cases , especially the modern sheffield grinder they are doing super fast work, using their body weight to apply force to the blade and there hands to guide the blade.They are using stones......but can a grinding stone be as good as modern ceramic belts? probably not?So I have been experimenting . I tried using a foot lever to apply pressure but found it did not have the control I needed and just ruined work and threw belts. so I went simpler. I grind sitting down. so I made this..... Basically a wooden cross, with a space to put my knees (i wear knee pads when using it in anger) and another cross to hold a blade , with a couple of screws in it to keep the blade in place. I ride it a bit like a motorbike. applying force by leaning my body weight through my knees and shins. and moving it side to side in an ark, I get a 12" pass before I have to reposition the blade. Its a very basic set up , I adjust the angle of the board to the platen by moving the board back and forth. I have found that I do not need it fixed to the floor , although that would be the logical thing to do , either with some adjustment or locating holes in the floor for a pin at the base of the board to allow the pivoting action of grinding side to side.. I can easily adjust it to give me an edge biased grind, of full grind or spine biased grind. I have been amazed at the difference in my grinding effort and output. I have done no quantitive tests as I do not production make the same stuff. However My belts bite in deeper and last a lot longer (about 4 times as long) . grinding is much much faster and easier on the arms. I do not think that under normal circumstance I can put enough pressure on my steel to make my 36 grit belts work to their optimum and this way they seem to be doing that. It may be that I am finally getting the ceramic belts to break down at a rate that self sharpens them (like the manufacturers talk about). So far I would not use this method for finish grinding , but for hogging it has changed my grinding life. there are no doubt dangers and associated risks with putting more force into a grinding belt and I would urge any of you that think this is a good idea to take your own steps to make sure what you are doing is safe. Quote Link to comment Share on other sites More sharing options...
Crazy Ivan Posted February 24, 2015 Share Posted February 24, 2015 I have seen similar things to what you are talking about in old school videos on youtube. Here is one that came to mind. Even though it is an axe being forged, I think it could be worked to translate to blades as well. The part I am talking about comes in around 7:40. https://www.youtube.com/watch?v=Qr4VTCwEfko Quote Link to comment Share on other sites More sharing options...
basher Posted February 24, 2015 Author Share Posted February 24, 2015 great link I have seen that vid half a dozen times and that did not click. Quote Link to comment Share on other sites More sharing options...
basher Posted February 24, 2015 Author Share Posted February 24, 2015 here is another similar thing. Quote Link to comment Share on other sites More sharing options...
Ric Furrer Posted February 25, 2015 Share Posted February 25, 2015 (edited) Notice the grinder turns the other way and is low. I think this does several things......you do not get the dross and spark into your body, Your body weight is used more effectively and you can watch the spark to see where the action is happening. With a belt it means that a breakage throws the belt away from you.Owen I would think one could set the modern grinder this way with a bit of design and just "saddle up" when the time comes. Maybe a hard stop under the seat so you can not over push? I can see you will need a Cowboy hat soon for your helmet.A few springs under or air cylinder or cords from the ceiling to the saddle would mean you could teeter-totter your weight without fatigue. Have it take 100 pounds of you (more in my case) so you have a limit to the force applied and less leg work to support yourself.Ric Edited February 25, 2015 by Ric Furrer Quote Link to comment Share on other sites More sharing options...
basher Posted February 25, 2015 Author Share Posted February 25, 2015 Notice the grinder turns the other way and is low. I think this does several things......you do not get the dross and spark into your body, Your body weight is used more effectively and you can watch the spark to see where the action is happening. With a belt it means that a breakage throws the belt away from you.Owen I would think one could set the modern grinder this way with a bit of design and just "saddle up" when the time comes. Maybe a hard stop under the seat so you can not over push? I can see you will need a Cowboy hat soon for your helmet.A few springs under or air cylinder or cords from the ceiling to the saddle would mean you could teeter-totter your weight without fatigue. Have it take 100 pounds of you (more in my case) so you have a limit to the force applied and less leg work to support yourself.RicYup pretty much to all of the above. After 20 years grinding towards myself I fine the idea of doing it the other way odd . however its just habit, a bit of hanging on as oposed to pushiing against may even me up a little. I have all the air "stuff" that I would need to rig a nearly weightless seat, it could be as simple as a pulley and a (medium) anvil!! the "cross" that I use enables me to grind as I "normally" would , with just a quick switcheroo. the next step is a whole different machine. I think for the couple of days to do it it could be worth it. Quote Link to comment Share on other sites More sharing options...
ianinsa Posted February 25, 2015 Share Posted February 25, 2015 Owen, it(your bike setup ) seems wrong at first, until one thinks about it , applying logic rather than habit. I've often seen large grinders wheels go cheap at auctions and I have ignored them in the past as I couldn't think of a constructive use for them. Now you've planted a seed. Thanks I think? 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.