Power hammers

I had a bit of a play with a cheap Chinese VFD on a Chinese hammer a while back. IIRC it was a new 25 kg (55 Lb) Anyang hammer with a 4 kW (5HP) motor, going to someone who did not have a 3-phase supply and the VFD was the cheapest way of getting 3-phase power. The variable speed seemed to make it more controllable for delicate tappy stuff, but I got the impression it was a not-unwelcome bonus, rather than a reason to use a VFD in itself.

The motor pulley was correct for a European 50 Hz supply and trying to push it any faster overloaded the motor/VFD combination. Turning it down to about 40 Hz for the delicate stuff seemed about as low as was realistic. Bear in mind that Kinetic energy varies as the square of the speed so 80% speed equates to roughly 64% blow energy. The reduction is in addition to the control provided by the hammer itself.

I'm (only) fairly certain a VFD without a clutch would not work well. Having to spin up the entire machine/motor system from standstill is a lot different to "just" having to spin up the machine with the motor already at full speed.
 
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Yeah, I was pretty skeptical about VFD control for mechanical hammers, no clutch... but it's been done, and well.
Check this out. You can see the TIG pedal being used...


Same guy, Steve Howell, running his 50... also with VFD. Note the back of the hammer, where the pass-through hole in the casting is, for the clutch/brake linkage... empty.

 
I didn't see where you posted what you want to use the hammer for. If you want to speed up forging knives then a 25lb is perfect for that in my experience. If you want to use it mostly to make damascus or reduce large stock then you likely wont be happy. I know the easy answer is "a little bit of everything" but that is kind of like asking what hand hammer should I use to pound in finish nails, frame a house and break up concrete. No one hammer will do all that just like no one power hammer will fit the bill for all forging tasks.

I own a 25lb LG and have used a 55kg Saymak air hammer at SOFA quite a bit. I knew the 25lber would probably leave me wanting a bigger hammer but i couldn't pass up the deal I got and the hammer is in great shape. I'll probably keep it and eventually get a larger air hammer.

As far as building one there is at least one set of air hammer plans out there and there is the tire hammer plans. I like building things but an air hammer is too far outside my wheel house and the time investment would be too great for me. But that is what my next hammer will be, I really liked the control you get with air. As a side note the coolest home made hammer I have ever seen and got to use is the 25lb Hans Peot mechanical SOFA has. It looks and handles like a factory built machine, very nice.

And regarding the VFD controlled hammer over a clutch, as Salem has pointed out guys have done it, but the one complaint I have heard about using one over a mechanical clutch is the lack of control. The "feel" you get using a treadle over a (digital) foot control seemed to be a problem. I've never used one so I can't say from experience but I've read that on IFI more than once on both hammers and presses.

If you build a hammer, especially an air hammer, it would be a great injustice not to post the WIP here!

Good luck

-Clint
 
Thanks Clint. To answer your first question, reducing stock and damascus mostly, but not to the degree some other guys do. Based on what I've read here and elsewhere I think a 50 or 75lb is the ticket.
 
I've used a BluMax 155 a couple times for pattern welding work, the one on Forged in Fire as a matter of fact. I quite liked it- some folks think they are just toys, but I found it to be solid and powerful. There are issues with them though, to be aware of... like the die receivers being prone to crack and blow out at the weak points.

I think if I was in the market for a new hammer, I'd be looking at either an Anyang 88 or larger, or a Say Mak. They are apparently available in the US once again... you can get an 88 lb'er for $12K. http://www.saymakhammers.com/about-us-1.html
 
Thanks Salem, I was hoping that they didn't have issues because they seem to be reasonably priced. I'll have to save a few more pennies for now.
Forgive my ignorance but it looks like Little Giants are no longer made? There website seemed to indicate that.
 
No Little Giants have been made for quite a while... Don Hanson got the last new one, but even that was a frame that they'd had from decades earlier when they stopped pouring them. They supply parts and a rebuilding service for them now. As far as new mechanical hammers, that's pretty much the territory of those folks building tire hammers and the like, now.
Those Say Maks are better than ever they say, having evolved in design and features from the ones available in the past...
 
Man Salem I didn't need to see that :)

So would you guys that would or could pony up for a new Saymak go for that or an old Nazel? I like the Saymak because its new and advancements in technology and materials have been implemented in the design and you can get parts and support readily.

Or... Nazel. Lol I just love the way they look. I have never had the pleasure of using one but I've never heard anyone complain that they don't do what they were meant to. I have heard some folks remark about fixing them and I'm not aware of any parts dealers or support, though I admit I've never really looked for it either.

What say you guys?

-Clint
 
A 50lb little giant is about the bare minimum IMO for damascus work, but a 25lb in good shape is a great machine to forge blades of all sizes on. I currently have a 150lb Bradley strap hammer, and a 125 Bull, have had a couple others. The Bradley is a beast, and will forge circles around any hammer in the same size class, but it's a bit aggressive for blade work. I got it for drawing billets primarily however, which is really the advantage of a hammer for making steel, not just the drawing but the activity that it beats into the pattern in a way that only a power hammer can. Even with a rolling mill, I do all my drawing to a point, with the hammer. A press puts activity into a billet also, but in a completely different way. It's very nice to have both, once you understand what does what where in the pattern. It's not just a question of what moves metal, it's how.


I often kick myself though for not buying a 25lb Anyang when i had the chance. It was so sweet for forging knives.
 
Javan, did you tell me that the latest version of the 33 lb anyang would do about the same work as the 50LG? I seem to recall that we talked about the Anyangs and the unfortunately no longer available Iron Kiss hammers. Is the Bradley strap hammer the same thing as the beam hammer? I have seen videos of them and they sure look like that whack hard, but not the last word in fine control. ;)
javand said:
A 50lb little giant is about the bare minimum IMO for damascus work, but a 25lb in good shape is a great machine to forge blades of all sizes on. I currently have a 150lb Bradley strap hammer, and a 125 Bull, have had a couple others. The Bradley is a beast, and will forge circles around any hammer in the same size class, but it's a bit aggressive for blade work. I got it for drawing billets primarily however, which is really the advantage of a hammer for making steel, not just the drawing but the activity that it beats into the pattern in a way that only a power hammer can. Even with a rolling mill, I do all my drawing to a point, with the hammer. A press puts activity into a billet also, but in a completely different way. It's very nice to have both, once you understand what does what where in the pattern. It's not just a question of what moves metal, it's how.


I often kick myself though for not buying a 25lb Anyang when i had the chance. It was so sweet for forging knives.
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Coincidentally I've been eyeing up Bradley's myself. I've been looking at a 200# beam style Bradley. The price on it seems a bit optimistic, but I imagine it'd move metal in a hurry. If it's still listed in a year or so I might try beating them down a ways...
 
Javan makes an excellent point there- the different ways in which the steel in a billet will move, depending on what machine you use to weld and draw it. A press will chomp large steel, but moves the inside of the billet much more, and causes the edges to curl up toward the sides. Partly this is because the surfaces of the billet are being gripped and cooled while the center is still quite hot and free to move. This can be specifically used to advantage, but normally can be quite annoying. A mid size hammer with drawing dies will draw the steel efficiently and directionally, and will tend to push the surface of the bar more. This, in tandem with the smaller/sharper die faces, will introduce a different sort of chaos and distortion into a pattern. The press and a drawing hammer can be used to keep a pattern roughly in balance together, but a big hammer with big flat dies is like a combination of both. It has the power to forge into the center of the billet, but the dies are big and flat so they help keep the pattern true throughout. They will still have a planishing effect at the surface which can be really nice, but won't cool the surface unduly fast since the dies are not resting on the steel, gripping and cooling it, but rather contacting it very quickly. This helps also to produce cleaner, scale-free forgings due to the percussive effect of the blows. Indeed, a big hammer can actually heat the steel while forging it- I've seen video of steel ending up white hot while drawing, that came out of the forge at a high orange. Welding is easily done with big flat dies, and tooling can be used to pattern with or to continue the forging process into forming integral bolsters and the like.
In answer to a question above, Nazels are pretty much the king of old air hammers here... C-burg too. They come in much larger weights than Say Mak, and once fixed up well are extremely industrial-duty, but may take a lot of money and doing to get there. Plus they will often need big power and a big foundation. The one-piece Say Maks can be installed normally with no need for additional concrete in your shop slab. That's a huge deal.
 
Salem Straub said:
Javan makes an excellent point there- the different ways in which the steel in a billet will move, depending on what machine you use to weld and draw it. A press will chomp large steel, but moves the inside of the billet much more, and causes the edges to curl up toward the sides. Partly this is because the surfaces of the billet are being gripped and cooled while the center is still quite hot and free to move. This can be specifically used to advantage, but normally can be quite annoying. A mid size hammer with drawing dies will draw the steel efficiently and directionally, and will tend to push the surface of the bar more. This, in tandem with the smaller/sharper die faces, will introduce a different sort of chaos and distortion into a pattern. The press and a drawing hammer can be used to keep a pattern roughly in balance together, but a big hammer with big flat dies is like a combination of both. It has the power to forge into the center of the billet, but the dies are big and flat so they help keep the pattern true throughout. They will still have a planishing effect at the surface which can be really nice, but won't cool the surface unduly fast since the dies are not resting on the steel, gripping and cooling it, but rather contacting it very quickly. This helps also to produce cleaner, scale-free forgings due to the percussive effect of the blows. Indeed, a big hammer can actually heat the steel while forging it- I've seen video of steel ending up white hot while drawing, that came out of the forge at a high orange. Welding is easily done with big flat dies, and tooling can be used to pattern with or to continue the forging process into forming integral bolsters and the like.
In answer to a question above, Nazels are pretty much the king of old air hammers here... C-burg too. They come in much larger weights than Say Mak, and once fixed up well are extremely industrial-duty, but may take a lot of money and doing to get there. Plus they will often need big power and a big foundation. The one-piece Say Maks can be installed normally with no need for additional concrete in your shop slab. That's a huge deal.
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If our buddy DH III's shop is a typical example, LG's from 100 lbs on up also benefit greatly from a pretty sturdy slab. Iron Kiss is the only new hammer where I recall the maker specifically saying that you don't even really need concrete until the hammer. At Batson's hammer-in at Tannehill, they stored that Anyang/Striker (IIRC) style hammer in a big closet and rolled it out onto what was essentially a picnic pavilion when they wanted to use it.
 
jdm61 said:
Javan, did you tell me that the latest version of the 33 lb anyang would do about the same work as the 50LG? I seem to recall that we talked about the Anyangs and the unfortunately no longer available Iron Kiss hammers. Is the Bradley strap hammer the same thing as the beam hammer? I have seen videos of them and they sure look like that whack hard, but not the last word in fine control. ;)
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To be upfront, I only worked on one for a short while, but from what i saw, I felt it was easily on par with a 50lb little giant, with better control. Of course I don't consider a 50lb LG to be big enough for any reasonable amount of damascus work either, although it's enough to make small billets and san mai without a press.

As Salem mentions above, the question of drawing is a tricky one. All press work and you squeeze 10-20% extra material out the ends of your billet from the center, which gets cut off as loss, too small a hammer, and you fishmouth the same amount, that ends up in the same scrap pile. Balance is the key if you want efficiency of metal, a bigger hammer can do more with just the hammer, but if you've got a press and a 75-100lb+ hammer (this is not an objective criteria, tup weights alone are misleading. I'd put my 150lb Bradley Stap against any 200lb tup hammer, and consider it 3x better at moving metal than a 155 big blu) you can balance out pretty easily. Do the first heavy stock reduction with the press, then draw with the hammer, and you should end up with nice reasonably square ends without either the top layers hanging over the center, or the center squeezed out, and you get more homogeneous movement for bar-end patterns. On the other hand, sometimes you want to move the center or the outside more, to manipulate the pattern in a certain way. You can do this also, then mitigate for loss, or just eat it in pursuit of activity.

FWIW, because of the patterns I make, and having a rolling mill, I've managed to get by without a press for years. I finally have mine about put back together, but it's just never been pressing (pardon the pun). ;P I don't do any patterns that are pressed in by dies, have made enough feathers to last me a lifetime, and for the most part, my patterns benefit from the activity i can beat in with a hammer. On the other hand, I can almost always spot someone's damascus that's done entirely on a press.
 
My Bradley is an "upright strap guided helve" style. It has metal 'helves' instead of a beam, and a tight leather 'strap' that connects the tup to the 'helve'. As it cycles, the strap has a kind of rubber-band effect that makes the stroke lengthen and gives it a really snappy blow.

Most that have used both types consider this to be the best. Bradley was notoriously generous about tup weights also, rounding down instead of up. Everybody i've talked to said their tups are significantly heavier than the listed weight, not including the 50lb dies. Running at around 300bpm, it's nothing to sneeze at. Actually has amazingly good control, the slip clutch and brake work insanely well. I can't easily do single blows, but i can do 2 with the tup landing at the top of the stroke pretty consistently, and my hammer still needs some tuning. Still, it's not a machine made for delicate free-hand work. These were the most industrially oriented mechanical hammers ever made. Designed to be run with specialized tooling doing specific operations, moving metal as quick as possible. Consider also that this "150lb" hammer, weighs 7,000lbs with the motor, the vast majority of it, in the anvil and sow-block, so it's got an insane tup-to-anvil weight ratio.

I bought it as a supplement to already having a 'general purpose' hammer, I wanted a beast that could draw like crazy. This fills that gap nicely. I don't even have it on an isolated pad yet, I've been babying it, and it still moves metal something crazy fast.

It was supposed to be a 200lb hammer, so i was upset when i figured out it wasn't then i realized that the 150 runs at much higher bpm, so really, it doesn't make much difference. Having run a lot of 100 and 150lb utility and self contained hammers though, i was wanting something "big", so was disappointed until i actually ran it, it's twice the hammer of anything else I've run it the supposed weight class, according to tup.
 
Dang! 300 bpm out of a 150/200? No wonder it moves metal fast.
 
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