Jump to content
I Forge Iron

Questions about the effectiveness of JHCC's treadle hammer


Recommended Posts

JHCC, if you knew how the treadle hammer would hit, would you still have made it? It doesn't seem to hit real hard, though hard to tell from the video. Seems you could do just as much or more with a hand hammer. 

                  Littleblacksmith

Link to comment
Share on other sites

35 minutes ago, littleblacksmith said:

JHCC, if you knew how the treadle hammer would hit, would you still have made it?

No, it's a total game-changer. If I'd known, I probably would have built it sooner!

(Actually, that's not quite true: back then, I didn't have access to the materials and tools that went into building it.)

Advantages:

  1. Hits a LOT harder than I can hit with a hand hammer. The biggest hand hammer I can use for more than a few minutes is three pounds; the head on this weighs 36 pounds. Since the mass of the treadle hammer head is twelve times that of a regular hammer and it travels just as fast (remembering that force = mass x acceleration), it's hitting with twelve times the force. There's no way I could get that kind of oomph with a hand hammer.
  2. Less tiring. Rather than using the smaller muscles of my arm, I'm using the big extensor muscles of the leg. These are some of the strongest muscles in the body and are designed for sustained effort.
  3. Better handling of tooling. I can use this with top and bottom fullers, spring swages, hot-cuts, my touchmarks, you name it. The flexibility is great, and you don't have to juggle tool, workpiece, hammer, and hold-down.
  4. Convenience. It is right there when I need it. All I have to do is take off the safety chain (which keeps it from moving while not in use) and shorten the linkage between the treadle and the arm, and I'm ready to go. When I'm done, I lengthen the linkage, which drops the treadle to the floor and raises the head towards the ceiling, giving me lots of room to maneuver around the anvil. If I'm in a long session, I'll sometimes leave the safety chain off, and put only put it on at the end of the day. It's just an insurance policy, not something that has to be there to keep the head up and out.
  5. CHEAP. Other than what I've spent on welding wire, grinding discs, and a few bits of hardware, the only expense was a set of legs off some piece of industrial equipment. These became the column at the back and the horizontal pieces that connect the column to the anvil stand, and I got them from a surplus place for $15. I've never properly calculated my total outlay, but I've got well under a hundred bucks in the thing  (and time, of course, but that's the advantage of being a hobbyist: any investment of time gives a return in pleasure). The rest of the steel was donated and salvaged, and the lead in the head was a gift from my dentist.

Disadvantages:

  1. Reduced access to the back of the anvil. Just can't walk around it the way I used to, and can't do smith-and-striker on the Mousehole (aka The Undisputed King of Anvils). However, I do have my striking anvil for that last.
  2. As Jennifer noted elsewhere, balancing on one foot and stomping with the other can put some strain on the stabilizing muscles, especially if you're not used to using them. Not a huge deal, and warmup exercises and stretching help.
  3. A bit noisy. Since I switched to a quieter blower, I sometimes forget to put in earplugs. At that first hit with the treadle hammer, I remember!
  4. Human-powered, so not as reliable or consistent as a power hammer or press. Since I'm not full-time, that's not a big deal.
9 minutes ago, ThomasPowers said:

Not enough snap (acceleration of the hammer head)?

This is something that I need to tweak a bit. When I first built it, the head and the return springs were perfectly balanced, so the acceleration of the stomp translated directly to the head. I've since modified the back of the arm to be slightly longer and at a different angle, which necessitated removing one of the springs, and I'm not sure the balance is as good as it was before. I also want to add some more lead to the head, which will probably mean putting that spring back on. We'll see how it works out.

That said, does it have as much snap as a power hammer (mechanical or air)? Probably not. I've never actually used one, so I don't have much of a frame of reference. I do know, however, that it is a great improvement over not having it at all, and I would not have been able to get into making hammers and split-rein tongs without it.

Link to comment
Share on other sites

The last couple of hammers I've made were from jackhammer bits (yes, yes; I know they're technically "pavement breaker bits"), and if memory serves, I punched the eye all the way through in two or three heats. The tongs I made last Sunday went from raw bar to finished tool in a bit more than an hour, and splitting the reins was a breeze.

Next time I have the forge fired up, I'll see about doing some tests for you.

Link to comment
Share on other sites

Umm...no, twelve times the force. F=ma where m=hand hammer mass, and F'=m'a where m' =treadle hammer mass. If m'=12m, then F'=12F.

(Not taking into account skill and efficiency at moving metal, of course. This is simply a fancy way of saying that *my* shop is a lot better for having the treadle hammer. Were I a professional with the budget for something with an external power source, I'd be all over it like red on rust.)

Link to comment
Share on other sites

Of course that assumes the same acceleration in both cases.  I'd be surprised if you indeed do have the same acceleration as a hand hammer.  However, I'm guessing Mark may be thinking that he can do the same amount of work in the same amount of heats with a hand hammer as you can do with the treadle hammer even though he said they appear to have about the same amount of force. 

Link to comment
Share on other sites

Even if I'm only getting half the acceleration (which is quite possible; I haven't actually measured it), that's still six times the force. As for Mark getting the same amount of work done as you describe, that wouldn't surprise me in the least: he is, after all, a much better smith than I am.

Link to comment
Share on other sites

9 minutes ago, JHCC said:

 he is, after all, a much better smith than I am.

You and me both.  One of my sons was looking over my shoulder while I was looking at some of Mark's work here on the site and I remarked that I'd like to spend a few days learning from him if I got the opportunity. My son said, "He looks like a teenager."  I said, "He is."  Then he questioned the wisdom of learning from a teenager at which point I informed him I'm happy to learn from anyone who knows more than me, which Mark clearly does.

Link to comment
Share on other sites

Oh boy. I had just meant that it seems to take about the same amount of heats as it would with a hand hammer, I shouldn't have said force. Yes I think if you could have the treadle hammer accelerate just as fast as a hand hammer it would be golden, but I don't think ive ever seen a foot powered treadle hammer hit as fast as a hand hammer. I'm sure it does have its place though, would be handy for using tooling. I was about to buy one this last February.  The treadle hammer had more mass but slower speed is the difference. I think.......... I'm no physics teacher though. 

                  Littleblacksmith 

Link to comment
Share on other sites

Well, now you've got me thinking that I should film myself using both the hand hammer (maybe a couple of different weights) and the treadle hammer, with a scale in the background to help me calculate acceleration (a la Mythbusters, for those who know that TV program). I think my cell phone camera has a slo-mo setting....

Link to comment
Share on other sites

I just saw your latest reply JHCC. Yes, apologies, it was my bad I should've not used the word force. 

Thank you, you're doing good also. I still have a long ways to go till I would say that I am good at it though. 

 

Thanl you buzzkill! Well if you are ever near me give me a shout and I'll show you my shop, that goes for anybody. That was all very nice if you to say. 

                       Littleblacksmith 

Yes JHCC that would be very interesting. Who knows, maybe it does hit as fast as a hand hammer and it just looks like it doesn't cause it's so big. Dunno. 

Link to comment
Share on other sites

No worries, Mark. Talking through things to clarify what we mean is always worthwhile.

8 minutes ago, littleblacksmith said:

would be handy for using tooling

This is certainly very, very true. In fact, I only ever use mine with tooling, whether hot-cutting, fullering, putting on my touchmark -- it all goes so much easier when all you have to do is hold the stock with one hand, hold the tool with the other, and stomp. No juggling with hold-downs or holding the stock between your thighs.

Link to comment
Share on other sites

There is a difference between the blows but for a given amount of metal moved the foot hammer would work better than a hand hammer..  

There is a difference in efficiently of movement and quickness with with the strikes happen concurrently..  

Mark being young is going to hit a lot faster than old folks like myself so can get the same work done for a given amount of time though the output.. (energy output) is higher. 

I can not forge a thumblatch or spring lock in an hour and a half anymore the way I could 15 years ago.. With that said my quality of forging has gone up this also slows me down.. 

I will as some point be building my " Foot hammer"  and it will address a few key things that are lacking from most designs..   

A foot hammer is much like a treadle hammer..  the things done with the treadle are about the same.. Just different..  Having the extra hand free is a huge time saver.. 

Link to comment
Share on other sites

Well, my assumption that the two hammers were accelerating at the same rate was incorrect. When I'm wrong, I'm wrong -- or at least, somewhat inaccurate.

I did a slo-mo video of hitting with both the treadle and hand hammers, going more or less all-out with both. The quality isn't good enough to post, but a few takes-away:

  1. The hand hammer does travel faster than the treadle, taking about 3/4 of the time to cover the distance from the top to the bottom of the blow.
  2. In that time, the hammer covers a slightly longer distance, as the top of its arc is slightly higher than the uppermost position of the treadle hammer.
  3. Therefore, the hand hammer is accelerating faster than the treadle hammer. (N.B.: I haven't done precise measurements or calculations, but I'm going to guess that the ratio of hand hammer to treadle hammer acceleration is somewhere between 1:6 and 1:8.)
  4. It's worth noting that the range of motion on the treadle and the linkage does not bring the hammer all the way down to the anvil. The reasons for this are complicated, but this means that at the bottom of the stroke, the hammer is carried forward by its own inertia and is to a small extent fighting against the tension on the return springs, which may diminish the snap slightly. However, this is less of a problem when you're hitting a top tool, as the point of impact is higher above the anvil than when you're just hitting a 2x4.
  5. Recovery time between blows is shorter with a hand hammer than with the treadle hammer.

In sum, the treadle hammer hits harder but slower; the hand hammer hits lighter, but faster. More modifications to be made, more video to be shot, more calculations to figure....

Link to comment
Share on other sites

Even with the loss of momentum at the bottom of the treadle hammer's stroke, it has both more kinetic energy (KE = 1/2 mass x velocity^2) and more momentum (mass x velocity) simply because the head is so heavy. Because the KE equation is so heavily weighted toward velocity, it doesn't seem as impressive, but I suspect that momentum plays a bigger role in forge work... otherwise we'd all be swinging 4 oz. hammers as fast as we could.

Link to comment
Share on other sites

As noted in the “What did you do in the shop today?” thread, I added another 23 pounds of lead and adjusted the return springs. The return is a little slower than before, so the cycle is a bit sluggish overall. However, it hits a lot harder now, and I split the reins on another pair of tongs in five heats. (Probably could have done it in four, but the gouge that cuts the end of the split was giving me trouble.)

Link to comment
Share on other sites

  • 1 month later...

Great thread. My new treadle hammer (a prototype by a maker who may go public once his design/construction is dialed in) has nearly 50lbs of lead in the head. It is fun getting to learn the tool and certainly when doing fullering/flatting this machine can greatly speed up what I can do with a hand hammer. Still I love having the option to either use a hand hammer, which can offer a very different type of control and power. On another recent project, drew out the tang for a knife on the treadle and it was so easy. Far more efficient movement of the steel per heat than with a hand hammer, and far cleaner result because of the flattness of each blow. Looking forward to doing more piercing, cutting, and drifting to see how that does as well. Expect that to be far easier on my arm and faster as well. Will never crush big pieces of steel anywhere near as well as a power hammer or a hydraulic press....not even close! But it is going to be an arm saver for me in the months and years to come.

Ahead, I will need to make some additional smaller flat dies to help target the blow (1 1/2" top and bottom will be good for me) and make also some some rounded/angled dies for specific fullering. Already made a little angled fuller for setting the initial V-shaped grooves on a folded axe billet. Fun stuff!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...