Treadle Hammer Design

[Jason M]

I am near the point of starting to build my treadle hammer and wanted to show my design and get some feedback. I have developed a linkage that allows the head to travel in a straight line without using any guide rails for the hammer. I admit that the mechanism is complex due to the amount of links required but that does not matter to me. Part of the reason is my affection for all things mechanical. The other is once I designed it I just have to build it. Over all specs are as follows. Height to "anvil" 38" with a "hammer" travel of about 16". The Base is a plate 22" X 28" and the overall height is about 87". The hammer weighs about 92 lbs. The relatively small footprint is a benefit of the linkage design. While researching straight line hammers I have only found styles that have a long pivoting bar at the top which takes up a lot of room. I have most of the steel which is 6" X 6" X .25" wall. The only items I will need to purchase is the material for the links and bolts. I don't have any specific questions other than I'd like to know how many people are interested in straight line linkage style hammers? I posted a video of the hammer in action here:

YouTube - Treadle Hammer "Mack Hammer"

Thanks for looking!

Edited April 1, 2009 by Splinter Forge

[element]

You thought outside the box,Very good looking design that looks functional.

[keykeeper]

Nice design, can't wait to see the real one in action on youtube. Better tell that fellow in the pic to move his hand though, before he steps on the treadle. He could lose a few fingers.:p

[Fe-Wood]

I like that design!! Nice small foot print!
would you be willing to share the linkage design as well?
I've been looking at building one to use as a striker

[ThomasPowers]

How do you modify the depth of throw so you can bring it close for small things and move it up for using tall tooling?

[Jason M]

How do you modify the depth of throw so you can bring it close for small things and move it up for using tall tooling?

Thank you for your question. That's exactly why I posted my design so that I could get questions and opinions before I started building my hammer. I am very new to blacksmithing and I have only used a treadle hammer once while taking a course and noticed an adjustment wheel but for whatever reason did not ask what it was for. If I understand your question correctly you want to be able to adjust/limit the height at which the head travels up? Currently I do not have an adjustment for that. I tried to keep the throat open. Where would you recommend placing an adjustment and how much would you like? Thanks again!

[Warren Nakkela]

Is the hammer guided by the slide? And how does your design compare with the grasshopper linkage?
Warren

[Frosty]

It bears a resemblance to Bruce Freeman's, Watt linkage, treadle hammer. The Grasshopper Treadle Hammer

I can't express an opinion without seeing how the linkages are attached and articulate inside the closed frame in the animation.

Off the top though there is a horizontal movement that must be allowed for in the vertical link to make up for the linear action of the ram. I don't see it expressed in the animation though it could be hidden.

If you'll click "User CO" and edit your profile to show your location it'll make a big difference. IFI is represented by members from more than 50 countries and a lot of info is location specific. Also if folk know where you are they can tip you to get togethers, tool deals and lend hands on help.

Frosty

[ThomasPowers]

Well it depends on what you want it to do with it; however you don't want to have to make full leg pushes for every blow when a lot of them only require a little tap and doing partial blows with your leg---where you stop the head from going all the way back up by using your leg is rough on your body.

If you make it adjustable make it easily adjusted; I looked at several lately that used the Screw adjustment leg from a trailer to run it up and down without a lot of effort and fuss on your part. They're over at the smithing school over that away!

Since I have both a screw press and a triphammer I won't be using a treadle hammer for drawing or some of the punching or chiselling that can be done with the screw press.

What you have and want to do with a treadle hammer depends on your set up.

I will mention that designing something before you have/understand all the requirements was generally looked down upon in my college courses---no matter how much fun it actually was to *do* something.

[Jason M]

Nice design, can't wait to see the real one in action on youtube. Better tell that fellow in the pic to move his hand though, before he steps on the treadle. He could lose a few fingers.

I plan to photograph and video the real one once I build it and post it on my site "which is not up yet".

[Jason M]

Is the hammer guided by the slide? And how does your design compare with the grasshopper linkage?
Warren

There are no captive guides that control the linear movement of the head. The linkage design provides the only linear constraints. Although the linkage bars are intertwined in such a way that they slide against each other through the range of motion which gives them guidance side to side. Again, just an inherent part of the design.

Grasshopper comparison: It is difficult to say how it compares to Bruce Freeman's design. I have not seen any photos of a hammer built using his design. I pondered the picture on his site for quite some time and have not been able to figure it out because the linkage is somewhat hidden which is understandable because he is selling plans for his design. I am considering selling plans as well which is why my linkage is covered. I have seen another "grasshopper" design here Grasshopper Treadle Hammer.
I modeled this design as well. It would take up too much space in my small garage shop.

Thanks, Jason

[ThomasPowers]

"I am very new to blacksmithing and I have only used a treadle hammer once ", "I am considering selling plans as well which is why my linkage is covered."

Please do not sell plans till you have a lot of experience smithing and using treadle hammers; try to get a bunch of hours on the various common types so you can improve on the performance of what is already out there---ergonomics is often a wide open field on treadle hammers!

Edited April 1, 2009 by ThomasPowers

[Jason M]

Well it depends on what you want it to do with it; however you don't want to have to make full leg pushes for every blow when a lot of them only require a little tap and doing partial blows with your leg---where you stop the head from going all the way back up by using your leg is rough on your body.

If you make it adjustable make it easily adjusted; I looked at several lately that used the Screw adjustment leg from a trailer to run it up and down without a lot of effort and fuss on your part. They're over at the smithing school over that away!

Since I have both a screw press and a triphammer I won't be using a treadle hammer for drawing or some of the punching or chiselling that can be done with the screw press.

What you have and want to do with a treadle hammer depends on your set up.

I will mention that designing something before you have/understand all the requirements was generally looked down upon in my college courses---no matter how much fun it actually was to *do* something.

Good point. At first thought there are a couple of ways to go about it. I could adjust the travel of the foot treadle. Or I could make the rear most link adjustable in length. If I adjust the treadle up travel the pedal home position would vary. If I adjust the rear link length the home position would always be the same. I will definately look into this. I think I understand your point about designing before all is known which is one of the reasons I posted here. Although it isn't always possible to foresee every need. I will inevitably run into some situation which will necessitate some change or addition.

Thanks, Jason

P.S. See above for a responce to your grasshopper question.

[Jason M]

I like that design!! Nice small foot print!
would you be willing to share the linkage design as well?
I've been looking at building one to use as a striker

I am considering sharing at some point depending on interest. I'm looking forward to getting started soon on the real deal.

Thanks, Jason

[Jason M]

"I am very new to blacksmithing and I have only used a treadle hammer once ", "I am considering selling plans as well which is why my linkage is covered."

Please do not sell plans till you have a lot of experience smithing and using treadle hammers; try to get a bunch of hours on the various common types so you can improve on what is already out there---ergonomics is often a wide open field on treadle hammers!

I do plan to prove out the design as much as possible. Plans are ultimately only an idea transmitted by paper which are open to interpretation and modification. If I were to sell plans, it would only be with the understanding of the purchaser that I make no claims to the performance, functionality, or usability of the hammer. I have good morals and would never knowingly sell anything for the sake of making money. If I do decide to sell plans at any stage it is ultimately up to the purchaser to determine the value, if any, of the plans to the individual. There you did it, you made me sound like a lawyer. (insert smiley here in case the one I typed was omitted).

Thanks, Jason

[Frosty]

Jason:

The site you linked has a better pic of the linkage. The arms anchored to the frame are the short ones closest to the front of the hammer. The anchored arm pivots are the closest to the front.

This is a simple Watt Linkage and the grasshopper hammer is heavily influenced by Bruce and so is overcomplicated. Regardless, if you haven't researched linear linkages and don't follow how a simple Watt linkage works I don't see how you're going to improve or reinvent the thing.

As Thomas says attempting to design a piece of equipment for a job you have never done isn't a general rule for success.

On the other hand, I've seen many gems come of just such things so go ahead, model the thing, build the thing and let us know how it works.

Oh, one thing Bruce did that is a genuine improvement on treadle hammer design is what he calls a weightless hammer. The return springs exactly balance the weight of the ram throughout it's stroke so your leg muscles don't have to overcome spring resistance. There is a pretty clever "kicker" that increases spring tension just before impact to raise the ram.

Frosty

Edited April 1, 2009 by Frosty

[Jason M]

Jason:

The site you linked has a better pic of the linkage. The arms anchored to the frame are the short ones closest to the front of the hammer. The anchored arm pivots are the closest to the front.

This is a simple Watt Linkage and the grasshopper hammer is heavily influenced by Bruce and so is overcomplicated. Regardless, if you haven't researched linear linkages and don't follow how a simple Watt linkage works I don't see how you're going to improve or reinvent the thing.

As Thomas says attempting to design a piece of equipment for a job you have never done isn't a general rule for success.

On the other hand, I've seen many gems come of just such things so go ahead, model the thing, build the thing and let us know how it works.

Oh, one thing Bruce did that is a genuine improvement on treadle hammer design is what he calls a weightless hammer. The return springs exactly balance the weight of the ram throughout it's stroke so your leg muscles don't have to overcome spring resistance. There is a pretty clever "kicker" that increases spring tension just before impact to raise the ram.

Frosty

I have spent countless hours researching "straight line linkages" including the Watt linkage. One really great site is How round is your circle?. Aside from modeling the linkage I made a wooden version of the design which functions well. I'll admit that my design is complex. There are 15 linkage bars in the mechanism alone. I don't know if my design improves anything other than being compact and as far as reinventing I may not have done that either. I may have just unknowingly copied Bruce's design. It is difficult to see how it has 34" of travel. It looks short front to back like mine which only has about 16" of travel. The spring balance is something I hope to achieve as well. Thanks, again, Jason

[Frosty]

That's a cool site.

The Watt linkage shown is only one of his and I don't see the one the Grasshopper uses on the site. Grasshopper is the name it was given by folk watching the RR engines that used it instead of more modern guides.

The max ram travel is double the length of the primary arms. I don't think anyone has built a hammer that takes the arms to vertical though so the actual max stroke is probably more like 38-40"

Frosty

[Jason M]

That's a cool site.

The Watt linkage shown is only one of his and I don't see the one the Grasshopper uses on the site. Grasshopper is the name it was given by folk watching the RR engines that used it instead of more modern guides.

The max ram travel is double the length of the primary arms. I don't think anyone has built a hammer that takes the arms to vertical though so the actual max stroke is probably more like 38-40"

Frosty

You seem to know a lot about the grasshopper. Do you own one? The first mechanisms I designed would travel more than 16". Like a lot of straight line linkages only a certain portion of the movement travels in a straight line and can arc in and out. I'll have to see if I can animate one of those designs and post it for the heck of it. I sacrificed that arc travel in order to reduce the number of link arms. I have another site that might be of interest. I was going to mention it earlier but did not have it bookmarked. There are movies for some of the linkages.
KMODDL - Kinematic Models for Design Digital Library Edited April 2, 2009 by Splinter Forge
Add information

[Jason M]

YouTube - SplinterForge's Channel

[Frosty]

I've modeled one and started building one a few years ago but ended up building a proper shop instead, then injured myself and haven't dusted the components off yet.

A double link grasshopper only has 8 members. None rub on each other and the footprint isn't substantially larger than stability demands. Bruce is a chemist, not a mechanical engineer nor much of a builder. He designed his hammer and another fellow built it for him. Things like a 34" stroke, the size footprint, excessive overkill in the frame, arms, etc. the complexity and expense of his multiple adjustment mechanisms, etc. can be pared down considerably for a more efficient and easier to produce hammer.

Bruce has had his design out there for quite a while and as far as I know only a few have been built. I only know a few people who think the added power of an unguided linear hammer worth the PITA such a complex design demands MIGHT be worth the trouble. His design is substantially simpler than yours.

To make one of these things work, accuracy is more important than almost anything else. In all those parallel linkage arms if one pivot is off by 1/32" it's going to bind, 1/16" will bind for sure and probably lock up. To make one of these actually efficient, the fewer pivots and linkage arms you have the better and bearings really improve it.

Bearing's will be a must with as many pivots as your design has and if you have arms touch let alone rub against each other it'll be a drag, probably a sweaty, leg killing, wimp hitting, drag.

No "straight line" linkage holds a perfect straight line, even if you could build it perfectly. Still, the grasshopper over a 30" stroke holds to a couple thousandths displacement which is plenty accurate for a smithy.

My design called for a 24" stroke (still pretty excessive) and the footprint was just over 40" x 24" (treadle to rear swing clearance) and I could've easily cut it to 16" wide but prefer the stability and a plate on the floor doesn't take up significant space.

A 24" vertical stroke has 12" horizontal movement so the hammer will have to have that 12" clearance. A long vertical swing arm isn't necessary as a roller guide works better and can be tucked forward between the long arms rather than allow for it in back and so reduce the footprint further over Bruce's design.

Where are you going to put your return springs?

Frosty

Edited April 2, 2009 by Frosty

[Jason M]

I've modeled one and started building one a few years ago but ended up building a proper shop instead, then injured myself and haven't dusted the components off yet.

A double link grasshopper only has 8 members. None rub on each other and the footprint isn't substantially larger than stability demands. Bruce is a chemist, not a mechanical engineer nor much of a builder. He designed his hammer and another fellow built it for him. Things like a 34" stroke, the size footprint, excessive overkill in the frame, arms, etc. the complexity and expense of his multiple adjustment mechanisms, etc. can be pared down considerably for a more efficient and easier to produce hammer.

Bruce has had his design out there for quite a while and as far as I know only a few have been built. I only know a few people who think the added power of an unguided linear hammer worth the PITA such a complex design demands MIGHT be worth the trouble. His design is substantially simpler than yours.

To make one of these things work, accuracy is more important than almost anything else. In all those parallel linkage arms if one pivot is off by 1/32" it's going to bind, 1/16" will bind for sure and probably lock up. To make one of these actually efficient, the fewer pivots and linkage arms you have the better and bearings really improve it.

Bearing's will be a must with as many pivots as your design has and if you have arms touch let alone rub against each other it'll be a drag, probably a sweaty, leg killing, wimp hitting, drag.

No "straight line" linkage holds a perfect straight line, even if you could build it perfectly. Still, the grasshopper over a 30" stroke holds to a couple thousandths displacement which is plenty accurate for a smithy.

My design called for a 24" stroke (still pretty excessive) and the footprint was just over 40" x 24" (treadle to rear swing clearance) and I could've easily cut it to 16" wide but prefer the stability and a plate on the floor doesn't take up significant space.

A 24" vertical stroke has 12" horizontal movement so the hammer will have to have that 12" clearance. A long vertical swing arm isn't necessary as a roller guide works better and can be tucked forward between the long arms rather than allow for it in back and so reduce the footprint further over Bruce's design.

Where are you going to put your return springs?

Frosty

I should correct myself. There are only 8 links required for my mechanism. 15 once you assemble another set of arms on the other side just like a human. I'm guessing that you say his design is simpler than mine based on number of links because you have not seen mine linkage. I don't see any problem drilling accurate holes. I do have full use of a machine shop but will build it at home. I have considered drag between the links but don't think it will be a problem. If necessary I will purchase some washer shaped shims. I got a kick out of your "sweaty, leg killing, wimp hitting, drag" comment. There won't be any ball or roller bearing needed. I was aware of the fact that it is not a true straight line. A more accurate description might be a parallel linkage but thought it might confuse some. I am convince my design is different than Bruce's if there is 12" of horizontal movement for 24" of vertical. There is only one pivot in my design that moves in a horizontal like motion and it travels 6" or so. There are tabs in the rear at about anvil height that the springs will attach to. If you have any pics of your hammer I'd like to see them if your willing to share.
Thanks again, Jason

[Frosty]

Grasshopper has 8 link arms and yes that's both sides. Nearly doubling the pivots isn't going to make for less friction. Rubbing the arms together, even on washer (whatever they're called) bushings is still going to be more friction. After a point increases of friction stop being linear and become geometric.

I double checked and his hammer as designed has a 22" stroke. So there's 11" of horizontal displacement.

All my hammer is right now is a shop sketch based on materials at hand and a cut list, the link arms and a pile of scrounged components.

My aim has altered towards building a power hammer in the 35lb range first and seeing as I'll use spring tooling under a mechanical hammer, a dual swing arm treadle hammer will work just fine and I won't need to make duplicate tooling. Building a version Bruce's "weightless" return into it will be easy enough so I'll have that benefit.

I may build a Watt linkage hammer down the road but it's definitely back burner for now. Who knows, I may even find a deal on a fly press and never build a treadle hammer at all.

Regardless, I love brainstorming and will be happy to offer whatever help I can to your efforts.

Frosty

Edited April 3, 2009 by Frosty

[freemab]

Jason,

I can't really get any idea of what your design is. Is that "splinterforge" youtube video yours or what? That video shows the Grasshopper Treadle Hammer linkage, except for inverting the (stationary) frame. And I don't mean approximately -- that is EXACTLY the Grasshopper TH mechanizm. Don't let that bother you -- it's not patented and you're free to use it.

However, if that's the linkage your using, you're reinventing the wheel. I solved all the problems of that design already. My version is fully adjustable and has a weightless ram. Since I never went around hosting treadlehammer workshops the way Clay Spencer has done with his designs, there are relatively few Grasshoppers out there, but they exist. Here's one:
http://macramedia.net/art/tools/hammer/

I have a website that shows a line drawing, but it's not up to date. I am no longer selling the plans, as it was not economically feasible.

BTW, I don't know why Frosty keeps calling this a "watts linkage." It's nothing like a watts linkage. It is a doubled grasshopper linkage.