Grumpy'sWorkshop

Treadle Hammer Design Question - "Backwards" suspended spring hammer

24 posts in this topic

Ok, so I'm just a beginner and this is a very crude design idea, so don't spend too much time on it.

Imho, a lot of treadle hammer designs I've seen are flawed in 2 ways - the weight is brought down by the foot through the linkage - so your foot feels the hit as it bottoms out, and the springs just bring the weight back up, fighting against the blow the whole way and adding nothing to the falling weight. I then saw this video, specifically the time shown, and I had a silly thought - why push down when the spring and weight are doing the work? If stomping on the treadle did the opposite, raising the head, enough whip could create quite an effective beater - hence the "backwards" treadle (I really don't know what to call things). Maybe it'd spring too much and be a one hit machine, but one assisted hit is better than none.

For this to work, you'd need to set it up so the weight is suspended by the spring off the anvil, but still has plenty of travel to give it a good bash. But you're no longer fighting lifting springs and there wouldn't be a direct shock to your feet. You could design it with an overhead spring or like the video linked, but I'd like to think a Little Giant or Champion spring design with the weight on a slide could work better. And down the road, it might even be able to be motorized without a full redesign or too much stress on the components.

I'm sure it's not anything new and someone here can tell me why it won't work, but I've been thinking about it for 3 days now, haven't come across anything like it, and am just short of setting about building it just to try it out.

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Welcome aboard Grumpy, glad to have you. If you'll put your general location in the header you might be surprised how many of the Iforge gang live within visiting distance.

Let me see if I have your idea right. Use leg power to lift the weight and let it fall. Yes? That's called a falling weight hammer they've been around in one form or another for a long time. Most guys striking coins use a falling weight or dead fall hammer.

You don't see them used except for striking say coins. They're really slow, a 30" fall takes about .39 seconds and hits going less than 1mph. so there isn't much momentum (kinetic energy) added to the hammer's weight.

Working it the other way with my 200lbs. driving the hammer down with the leverage advantage of a linkage connected to the weight arm 1/10 the distance from the pivot to the hammer pin gives it roughly 10g acceleration plus my 200lbs. Travel time is going to be maybe.04 seconds.

It makes for a faster harder hitting hammer and there is plenty of flexibility in the hammer arm and treadle arm you wont be taking impact shock at all. Well, tools held under the hammer a bit off will sting but that's not the same thing.

If you can run the numbers correctly please do. I'd love to know the difference in kinetic energy. I couldn't find an energy calculator except for pellet guns in the time I looked.

Frosty The Lucky.

 

 

 

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Sort of, more like using leg power to lift and preload the spring. Like a mechanical power hammer's upstroke. The following drop would have the spring and falling momentum driving the weight, with no direct connection to the treadle. The hit would be on a delay, but more like stomp-spring-bang vs stomp-bang. Repeated blows could come one after another if a rhythm can be maintained in time with the weight.

200 lbs at 1/10th the pivot distance is added force, but you're mostly just defeating the lifting springs and the weight's momentum is providing the bulk of the forging power. Travel time for the hit is immediate, but you have to account for lifting your foot between strokes, and in that case, stroke time would be similar.

Actual math isn't my strong suit, so idk, I'm just spitballin here. If it gets built, it'll be a full on experiment in both planning and actual use.

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How do you vary a hard fast stroke with a slow gentle one?  Control is a major factor in having the downward stroke be the powered one.  Lots of time you may want to tap it one time and whomp it the next---like setting a piece into some tooling and then doing the work with the tooling.

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I don't see any real advantage to this and I have to agree with Thomas about it being more difficult to control.  Have you used a treadle hammer? 

A treadle hammer is not a power hammer.  The treadle hammer is better for certain things than most if not all power hammers but it is not a tool for drawing out stock.  You will see people drawing out with a treadle hammer using top and bottom fullering tools. You can get the same effect using the corner of the anvil and the peen of your hammer.  I sold my treadle hammer a few years ago because of a lack of space.  I had to either get rid of my treadle hammer or my smaller power hammer, the treadle was the one to go.  I have missed it a few times and may build a new one now that I have more space.

If I get around to building another I will try an idea I have of using a counterweight on the back  instead of a spring.  The advantage of this is that at the point of impact the inertia of the counterweight will be helping the blow rather than resisting  the blow.  It may be a slower recovery than a spring or the snap form the counterweight may actually make it faster.  I am not sure and it may take some experimentation to get the geometry right, but I think it will be more efficient.

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Spitballing is a good thing, I love brainstorming ideas, even the oldest most disproven ideas have turned out to be usable. Sometimes it's a matter of materials Da Vinci had the idea of a helicopter but the materials of the time didn't allow him to experiment or he would've invented the rotary wing rather than an impeller screw. A version of his "flying" impeller screw concept makes jet boats go.

The return springs on a treadle hammer only have to overcome the weight of the ram by a few lbs. to return it to the top so you only have to apply say 10lbs. +/- to counter the springs.

As Thomas points out a treadle hammer needs fine control not a preset blow. John remakes the point by poinnting out a treadle hammer is NOT a power hammer. A treadle hammer is actually a "striker" you don't have to pay or feed. They free up both your hands, one for the stock the other for the tool. I have friends who do chasing and repouse under a treadle hammer and believe me you want to be able how hard it strikes with surgical precision or impromptu surgery might be the result. 

You might want to take a look at the "Oliver" hammers, I think they come closer to what you're thinking about but they were often dedicated to one job, say welding chain links.

Frosty The Lucky.

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Most power hammers have blow control as well and the old steam ones were rather famous for the amount of control---being able to transfer a drop of oil from the top die to a watch crystal without smashing the watch crystal and then being able to take down 1" steel on the next blow.

I too am wondering if you have the experience needed to redesign such a system.  One generally has to know something thoroughly to be able to improve it.

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Thomas, the discussion is on treadle hammers not power hammers.

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Judson, per my reading of the entire thread: Some people may be thinking that a power hammer strikes at a constant force or rate when they don't.  Neither treadle hammers not powerhammers run without control of striking force or rate!

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Trip hammers, on the other hand....

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The key thing about trip hammers and tilt hammers using water or other power to lift the hammer....whether they just rely on falling weight or spring assistance for the blow...is that they are lifted by external power. 

You don't get energy for nothing, so if you are relying on leg muscles to lift both hammer head and the spring assisted return, you are getting no advantage from the system. You have lost the direct control and sensitivity of variable blow weight, and are still having to push down on treadle just as hard even if you only require a light tap...which you would have to gauge by the length of treadle stroke and hammer arc length...rather than just by the direct and intuitive adjustment of push power.

All the Oliver hammers I have seen in the chain and nail making shops...were treadle down and spring return. The less sophisticated ones were a plank or forked branch on the ground with a chain, rope or leather strap going to the hammer shaft to bring the hammer down. Another strap going from just behind the hammer head up to a plank or pole spring wedged in the rafters of the roof for the return. Identical configuration to a chair bodger's pole lathe.

Alan

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4 hours ago, Alan Evans said:

Identical configuration to a chair bodger's pole lathe.

Alan

Hence the origin of the term Lathe.

Frosty The Lucky.

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4 hours ago, Frosty said:

Hence the origin of the term Lathe.

Frosty The Lucky.

Interesting...never  noticed that link before...is this just idle conjecture, or do you have any supporting evidence?

The nearest I have come to lathe in that context is when dealing with our old cottage walls which are lime and horse hair plaster on lathe.

Foul job if you have to drill or remove bits...dust everywhere. Definitely gives one a good excuse to get plastered with a few too many bottles of beer afterwards though!

Alan

 

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I don't have a cite but it came up a number of times in my reading over the years. However doing a online search I don't see any relation between a spring pole lathe and a "flat stick lathe" as in lathe and plaster. 

If I think about it when I'm close to my Oxford Compact I'll see what it says, it has very thorough etymology for everything. It makes looking up A word really hard, I get lost.

So, lacking any proper evidence I'll have to admit I may have been accepting the relation on hearsay. I may be completely wrong so I withdraw the comment. If I run across a cite I may bring it up again but till then. . . .Nevermind.:unsure:

Frosty The Lucky.

 

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Probably not. "Lath" (with variations in spelling) has meant more or less the same thing since its appearance in Old English. "Lathe", on the other hand, appears to have come into English by way of Danish (gotta love those Vikings) and originally carried the meaning of a supporting stand or structure, "turning lathe" being the transition from that earlier meaning to the present. 

However, the OED does note in its entry on "lathe": "As the older form of turning-lathe, used as late as the 19th century, was worked by means of a spring-lath overhead (see drawing in Encycl. Brit. ed. 9, XIV. 323), it is not wholly impossible that the word may be a modification of lath n.; but against this is the occurrence of the word in the wider Danish sense (see sense 1)."
 

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Exactly John, there are so many definitions and etymologies for lathe I don't think I can say with any certainty where the heck it comes from. As deep as I read the Danish origin translates as pile as in disorganized stack of stuff.

Not one definition or etymology I just went through says a word about metal spinning lathes and they're maybe the  oldest metal working machine. I do know spring pole lathes are ancient in the extreme. Some of the vessels entombed with Pharohs were spun gold, silver and or argentium? 

There's almost no leap between throwing pottery, burnishing metal and spinning it in a lathe. As I recall I read articles that said the potter's wheel is a development of the spring pole lathe. The heart of many ancient machinery is the walking beam (teeter totter) and spring poles. How many times would it take getting smacked in the face by a branch pushed out of the way by someone walking in front for those clever monkeys with big brains and thumbs to start thinking of ways to use a spring pole? 

Frosty The Lucky.

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7 minutes ago, Frosty said:

How many times would it take getting smacked in the face by a branch pushed out of the way by someone walking in front for those clever monkeys with big brains and thumbs to start thinking of ways to use a spring pole? 

As something other than a sibling-punisher, that is.

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so I wasn't alone with that application!

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Giving, or receiving?

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I was always taught that it was better to give than to receive.

Alan

 

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Giving or Receiving?---YES!

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3 hours ago, ThomasPowers said:

Giving or Receiving?---YES!

Giving and receiving . . . while alone.

Frosty The Lucky.

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Hi guys I have joined this group to try and learn as much as I can about different hammers, my other half is a blacksmith, he is still learning but is very clever with everything he does with his hands, bone carving pyrography knifemaking and forge work. Last Saturday he was experimenting with a retort kiln to make charcoal. he was cutting some small pieces of wood to burn when the bench saw grabbed his hand, the injury is horrendous. Of course it is his dominant hand but he has great dexterity with his left hand, his biggest worry is never being able to hold a hammer again and want to be able to show him plans and ideas for as many hammers as I can. Can you guys give me any advice

cheers Maree 

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1 hour ago, maree said:

Hi guys I have joined this group to try and learn as much as I can about different hammers, my other half is a blacksmith, he is still learning but is very clever with everything he does with his hands, bone carving pyrography knifemaking and forge work. Last Saturday he was experimenting with a retort kiln to make charcoal. he was cutting some small pieces of wood to burn when the bench saw grabbed his hand, the injury is horrendous. Of course it is his dominant hand but he has great dexterity with his left hand, his biggest worry is never being able to hold a hammer again and want to be able to show him plans and ideas for as many hammers as I can. Can you guys give me any advice

cheers Maree 

Hi, Maree, and welcome aboard -- and thank you for doing this to help your other half. I have  few suggestions:

1. Repost this message as its own thread. I'd recommend making it broader than just different types of hammers, because what you're really trying to do (if I understand you correctly) is helping your other half do blacksmithing after a potentially debilitating injury. If I were you, I'd post this in the "Blacksmithing, General Discussion" thread with the title "Adaptive Blacksmithing after Hand Injury" (or something like that) and ask not only about different kinds of power hammers, but also about other adaptations that people have used or would recommend for supporting workpieces (both in the forge and on the anvil), using tooling, adapting to non-dominant hand use, etc.

2. Put up a new thread on the Introduce Yourself page, but make sure to Read This First!

3. Start blacksmithing yourself! Not only is it the Single Best Hobby in the World (as I'm sure everyone here would agree), but if you and your other half can do it together, you'll be able help him, and he'll be able to help you. Remember, before there ever were power hammers, there were assistants with sledgehammers.

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