Spring loaded hand hammer

[larrynjr]

I started to build a treadle hammer last week and as the project progressed I decided I would add an electric motor and make it a powered hammer instead.  This week as I get closer to completion I've changed my focus again and planning on it being a spring loaded hand hammer.  From my photo you can see the pivot point and the spring that pulls the hammer back up after the strike.  The angle iron that the spring is hooked on had to be added because the 150 lb door spring wasn't strong enough to lift the hammer with the short lever arm.  I plan on attaching some sort of handle to either the arm just above the "hammer" or to the hammer itself so I can control the strikes better.  I've never used a treadle hammer but have heard that it's tiring and hard to get into a fast enough rhythm using your foot / leg.  I think using it as a hand hammer will more closely replicate an actual hand hammer but be less tiring to my 54 year old shoulder.

What do you think?

[lyuv]

If your goal is to ease the load on your arm, you need to gain some advantage. Mechanical, energetic or ergonomic. And I see none. You need to move the same mass and your arm provides all the energy. The differance is the path, that seems less natural - further from the body, and arched away. Another differance - more force downward and less upward. I have no idea if this is better or worst.

I think you can gain advantage by increasing the swing length. Hence, less force/strain (but for a longer time). The device will also enable you to "hammer" with your weak hand.

Another point - Any moving mass that is not the hammer itself (the angle iron, the arm ect) , is wasting your energy. You need to accelerate it, and gain very little of it's momentum into the forging itself. Do try to minimize that excess mass and/or it's distance from the pivot point.

[larrynjr]

perhaps the 52 lb hammer will help

[Judson Yaggy]

Hook it to your leg.  Swinging that by hand will wreck your arm faster than learning to hammer properly.  

[Frosty]

A treadle hammer isn't really a general forging hammer the cycle rate is too slow. They REALLY SHINE for striking tools. 

For the purposes of discussion let's go over your idea. Working a treadle hammer fast is very tiring, oh yeah. But working the same hammer by hand? Even one leg is many times stronger than both arms and they're designed to push downwards rapidly. I can't think of an advantage to powering a hammer by hand that I can by foot. 

So how about this. Build a treadle hammer with the treadle on an escapement say a cable to keep it simple for now. And here's the grabber. . . Put handles on it so you can give your leg a break without stopping work at. Maybe?

Frosty The Lucky.

[larrynjr]

Thanks Frosty, I wasn't planning on it replacing hand hammering completely but more for setting forge welds and drawing out billets.  Once I have the handle completed I'll post a video of it in action.  The way I have it set up should allow for fairly quick cycle of blows with the spring do the work of raising the hammer back up.  the way it's built I can easily convert it to foot power and probably to motor powered with a bit of re-engineering.

[George N. M.]

Dear Larry,

Just remember that what you are trying to do with a treadle hammer is to use something other than your arm and shoulder to provide the momentum to the hammer, leg muscles, gravity, motor, etc..  Also, you have to somehow provide the energy to reset the hammer for the next blow.  For a non-motorized system that is going to be, in some way, your muscles.  For example, in the present set up you have to accelerate the hammer down to strike the work but at the same time you are are putting energy into extending the springs to raise the hammer after it hits the work.  This seems to me to be counter productive, particularly if you are using your arm and shoulder muscles to produce the energy.  I have found with my treadle hammer, as Frosty says, that the advantage is to hit exactly in the same place every time, I do not find much advantage for moving metal over hand hammering.

BTW, my shoulders and muscles are 19 years older than yours and I do have to consider how much energy I exert and where and when is the most efficient use of my strength.

"By hammer and hand all arts do stand."

[Latticino]

On 12/31/2019 at 8:02 PM, larrynjr said:

I've never used a treadle hammer

Don't you think it makes a little sense to use one first before trying to reinvent the concept?  It will be a lot easier to see where they shine and have drawbacks.  I love mine, but mostly use it in place of having a striker for operations like precise shouldering or fullering, punching holes and chisel work.

[ThomasPowers]

What I'd worry about is providing force at a distance from the body.  Very hard on the joints!  The sledge you can at least keep close to your core; reaching out and up and pulling down is not suggested.  Also the basic laws of thermodynamics say you can't get more energy than you put into the system---which is why powered trip hammers are popular---you put another source of power into the system and just use your energy to control it.

[larrynjr]

good thing I wasn't looking for encouragement from my fellow smiths...certainly none to be found here.

[Irondragon Forge ClayWorks]

I have found they tell the truth, not what I'm looking for.

[Glenn]

Folks have provided plenty of encouragement, and suggestions.  We want you to succeed but in a way that you do not injure yourself. 

[Daswulf]

Iforgeiron has many experienced blacksmiths that have a wealth of knowledge to help and share. Many times they will freely share that knowledge or their ideas on something when asked. Other than absolute proven safety concerns, it is to try to help you improve past failures or flaws or things they experienced or know about. Now, just remember, there is a mass of people that just find or look these subjects up and find these topics that never post or comment. You are free and encouraged to come up with something. Those that post might see the problems with the idea and point them out, out of friendly concern or bad experiences. That doesnt make it completely wrong. You are free to find different ways to do things. No real discouragement there. Just some experienced people offering their opinions. You are free to try and succeed or not. Atleast come back and let us know how it worked. No one here knows it all or everything. It is all just a learning experience and those that posted comments have experience, and just have opposing opinions on functionality.there are many ways to skin a cat. They are just offering their experience. 

 

[Latticino]

11 hours ago, larrynjr said:

good thing I wasn't looking for encouragement from my fellow smiths...certainly none to be found here

Oh, you wanted a pat on the back, sorry I thought you asked for what we thought...

As far as the former, you have certainly achieved a method for accurately targeting heavy hammer blows on an anvil (provided the wheels on your contraption don't slide).  That will certainly make a helpful tool.  I'm looking forward to hearing what you think of the design after use.  The assembly looks robust and should stand up to normal use.  If you do plan on powering it in the future you may wish to consider some form of shock absorption so it doesn't self destruct, unless you plan on moving the head using a DaVinci cam.

As regards using it with as a hand actuated tool I think you are losing some of the key functionality that a treadle hammer has: the ability to hold struck tooling in your non-stock handling hand.  Virtually every time I use my treadle hammer I use it in conjunction with a top tool of some sort.   Also, the treadle hammer in our group shop was constructed from the Clay Spenser in-line treadle hammer plans and has a hand grip handle on the business end as well as a foot treadle.  I've never seen anyone use the hand grip for anything but locking the machine down for safety.

[JHCC]

On 12/31/2019 at 8:02 PM, larrynjr said:

What do you think?

Don't ask a question if you don't want to hear the answer.

That said, I think Latticino's last comment sums up my thoughts on this. When I use my treadle hammer for drawing out, I always find myself holding the stock with one hand and a fuller or flatter with the other. Without something to hold either your top tool or your workpiece, you're going to have a lot of difficulty using this to its full potential. I would strongly recommend adding a treadle.

 

[pnut]

A treadle hammer is not a substitute for a power hammer.  

Pnut

[ThomasPowers]

Actually pretty much every one of the blacksmith "toys" are not substitutes for other ones; with a well tuned and properly died powerhammer being the closest to an all in one.

So the treadle hammer doesn't draw like a power hammer but is easier for tool use. A rolling mill can draw out billets like magic but doesn't help doing odd shapes or tapers, a flypress is great for individual stamping/tool pushing but has a slower cycle time, a hydraulic press does great squishes but pulls heat from the metal and has a slow cycle time, etc.

When people say that they want to build a tool to use for a task it is not great at I always wonder "WHY?"

As to safety aspects: I had a friend who was the full time smith at a historical village in the midwest. They had a bellows blown forge with the bellows in rafters; but whoever set it up did not balance the bellows correctly.  To use it he would wrap the strap around his arm and pull down with all his might. It destroyed his shoulder and hip in only 10 years.  Meanwhile I built my own double lunged bellows of similar size and could pump it to welding heat in the forge with my pinkie.  Reaching out and up and pulling down is NOT a good motion for the human body.  We want you arguing with us about smithing for decades not sidelined and wondering about getting surgery!

[larrynjr]

I did get it completed today and used it to finish a Damascus billet that had started previously.  While it does indeed require some effort to move the hammer down, the spring brings it back up quickly so the overall effort seems similar to my 3.5lb Hofi hammer but with the 52 lb head it moves thing more quickly.  I'll get a video posted soon so you see exactly what I've created and how it functions for me.

I apologize for my post from the other day, I was either hungry or drunk or both and I tend to post things better left not posted.

[larrynjr]

Here are the video's of me using the pivot hammer.  It seems to work well for setting a billet weld.  The upper handle doesn't work as well as I'd like and the lower handle leaves my hand a bit too close to the hot steel, so I'll probably remove the top and move the lower up a bit.  Otherwise I'm happy with the end result.....for now.

[buickmarti]

Just a wet behind the ears amateur her but I really like the look of it.

Might I suggest you hang a welding blanket or a sheet of drywall between your hammer and the burnables on the rack behind it. 

[Irondragon Forge ClayWorks]

2 hours ago, buickmarti said:

wet behind the ears amateur

Welcome to IFI... Have you read this yet? READ THIS FIRST  It will help you get the best out of the forum with tips like editing your profile to show location, how to do a better search and keep the moderators happy.

Good suggestion to isolate the hammer from burnables. We are big on safety here.

[JHCC]

21 hours ago, larrynjr said:

I'm happy with the end result.....for now.

I really think you'd be a LOT happier if you put a treadle on that thing. Thomas is right that you'll be putting a lot of stress on your shoulder, and you could really be doing yourself an injury over time. 

Rig up a temporary treadle and see how you like it!

[Ted Ewert]

If it works for what you need it for, congrats! Nice build too.

I'd have to agree with JHCC's suggestion of a treadle though. It would be easy to build, and you could get a lot more bang while freeing up an extra hand. 

As for the "criticism", you have to expect it if you're building anything a little different. Take it for what it's worth, but don't take it personally.