Power hammer test

[mike-hr]

After reading and responding to Yesteryears thread on hammer performance, I feel kind of bad posting my opinion, because that's all it is... I did some thinking and came up with a test where we can all post out results, and maybe get a better idea of the hammers out there.
I took 8 inches of 1 inch mild steel square, marked each end at 2 inches. Use flat dies. Heat to near welding, put the 2 inch mark on the near edge of the dies, and hit 5 times real hard. Heat the other end to near welding heat, same thing, but hit 10 times. Wire brush, cool and measure how thin each end got with dial calipers. Anyway here's my results:

Hammer: 1909-ish MacGowan and Finnigan 'Perfect', 80# mechanical
5 hits: .825/inch
10 hits: .630/inch

Please try this and lets see what happens,
Mike

[steveh]

great idea Mike,makes me want my new hammer even more!

[brucegodlesky]

Mike, that's as straight forward a test as there is . 'l try it with my Fairbanks A. Thanks bruce

[Jose Gomez]

Mike-hr, I sure appreciate the fact that you took the time to reflect on the difference between opinion and measurable results. And again I appreciate the fact that you found a reasonable way to measure a hammers general performance. I performed the test using 8" of 1" mild steel square heated to near welding heat and then struck 2" of the end using flat dies, as instructed, on both the KA-75 and the Big Blu-BluMax 155 and here is what I got.

KA-75 with 175 PSI supply pressure
starting measure 0.995
5 hits 0.773"
10 hits 0.565

Blu Max 155 with 175 PSI supply pressure
starting measure 0.995
5 hits 0.705"
10 hits 0.475"

I listed the starting thickness in order to help eliminate any variation in original thickness, and air supply pressure because it has a measurable effect on utility hammer performance. I think your spot on with this test and that if other people participate then we will be able to build up a real world performance database that will help a lot of smiths compare these machines. I am really interested in seeing other Smith's results!! Thanks!

[nonjic]

This is intersting, but has some limitations. It does not take into account 'controllability' , or the blow rate (bpm) of the hammer which has a significant effect on the work that can be done in one heat.

However, full power is a performance measurement, so I will run the tests on the 15kg, 25kg and 40 kg Anyang hammers, as and when I get chance (I sell them in the UK, so if someone wants to do it independently let me know)

I didn't realize that folks run their hammers at 175 PSI , over 100 PSI in the shop lines and I start to get nervey !!

[Jose Gomez]

I actually made a mistake. I supply the Big Blu with full tank pressure (175 PSI) through a 1" 200 PSI rated jack hammer air hose, but the pressure is knocked down to 150 PSI by the regulator, filter, oiler on the hammer. The KA is running on 175PSI though. I had also thought about the blows per minute, and hammer controll issues, as far as BPM Big Blu claims 0-225 on the 155, and on the KA it depends on how fast you are with your foot, but I would guess that it would be hard to even keep it at 180 BPM. As far as controll.. I don't really know that we can devise a test to measure controll because that all really depends on the operator expierience, condition of the machine, temperature of the machine, etc. I think Mike-hr came up with a great full power test, but as for controll, I am willing to accept the educated opinion of other Power Hamer operators. I know that I have no problems drawing 1/4" stock to a fine point with any of my hammers, or delivering a single light tap, or full force blow, which is a little tricky with the mechanical hammers but a breeze with the air hammers (pun intended!!)

[Hofi]

JOSE,
Can u give me the no of BPM and the daylight between the dies when making the test.
This data is very importent to comper and avaluate hammers.
And pl give me the one while u made the test and not the one that is given in the ''book''
thank U in advance
Hofi

[Jose Gomez]

Mr. Hofi

I went to the forge and measured the BPM from the Hammer and was supprized to find that it is opperating at 240 blows per minute. Also, when I performed the test I had the stroke set at nearly 9 inches, which leaves the dies about 6 inches apart when the hammer is at rest. Let me know If you would like any more information or would like for me to perform any other tests.

Edited June 8, 2008 by Jose Gomez

[Hofi]

Sorry jose but I want to understand it more clear.
the actuel day light between the upperpart of the bottom die and the bottom part of the upper die were 6 or 9 '' when forging ? or in another words -what was the real daylight when forging?
thanx again and sorry for the noging
hofi

[Jose Gomez]

No problem! The stroke was set right at 9 inches (the maximum for this machine). So when forging there was 9 inches between die faces.

[Gayle Brooks]

Just a note, this isnt an attack or saying this "idea" is xxxx but seems to be coming up alot.

Hits per minute is an interesting idea, yet if it hits faster than you can control it, be efficient and produce a clean result, then it is a hazard. I agree that the dyes should have some clearance and that will be proportional to the size of hammer.

I've never understood the idea to "test" a hammer. So many factors are in play and these hammers can be adjusted is more than one way. The most important thing on the hammer is the smith (like any tool.) That hammer will be limited to what it can do by the smith using it. Most of the time smiths who can not use a hammer properly, do not know how to forge at the anvil properly either. They coincide of each other and use the same principles.

If anything the dyes/clutch (cylinder/ air relay if air) on the hammer need to be set properly to get the most out of it. This seems to be overlooked. None the less a larger hammer will always have more power, but if the person does not know how to get the most out of it then they will not be efficient and possibly a hazard to themselves. These tools are dangerous and very bad things can happen under them very fast.

The fullering dies putting force on a small amount of mass will obviously make that mass move faster. Pulling a piece of metal to a near welding heat...of course its going to move fast.

Our test for a hammer is by cycling it when you press the treadle down. Can you control it enough to just "tap" the dyes, does it hit consistent or skip, can you do a clean one hit blow, or does it need to cycle once to get power? The speed will always be there, if not then most likely it isn't adjusted or something is worn. Because it "hits hard" doesn't make is a good hammer.

Also, I am surprised how many people cannot draw a taper efficiently, do not have their hammers (both air and belt) setup properly (no stable, mounted base) and have a theory that these hammer like the blue need 175 psi because thats what the hose can hold. At that high of psi you are just giving your air compressor a workout.

Ours our set at 100 psi which goes to 90 when the hammer is in use. They have had minimal problems, the air compressors are fine (going on 10 years.) So far we have had to rebuild a blue and a Bull (which is an older version of the Phoenix) because the smith was running it at 145 psi. Both hammers lasted a year before the cylinder failed. Mine, which started at the same, time has done fine with no problems.

Again, this isn't a "Your idea is xxxx!" because it isn't. None the less the tool is limited by the person running it. Control is everything and the tool doesn't make the art, we do.

[Jose Gomez]

Dear Mr. The Dead,

One thing I learned when I was young is that if you start off with "this is not an attack" it usually is one, just wearing different clothes.

You are right about BPM, if *you* can't control it it is going too fast, and therefore is a hazard, But that does not mean that someone else is not perfectly comfortable with it. My 25# Little Giant is reved up to where it will provide around 300 BPM, though I never really push the treadle down that hard, If need be, I merely switch to a bigger hammer. Use the right tool for the right job, and know the safe limits of your machinery. Safe, clean results are always the goal, otherwise we would not be doing it by hand.

To clarify, the purpose of testing the hammers was to attempt to provide some type of numerical data on the performance of the machines under full power for the purpose of comparing hammers. Though full power is not commonly used in most smithing applications, it is the only non-operator influenced item that can be compared in order to give someone, that is not necessarily entirely familiar with the abilities of every style of hammer, an idea about the potential of the machines.

If you had read the portion of my reply in which I stated "As far as control.. I don't really know that we can devise a test to measure control because that all really depends on the operator experience, condition of the machine, temperature of the machine, etc." You will find that I agree with you that there are many factors in play, especially the machine operator. Every machine on the planet suffers from this same affliction (the human factor). A machine, be it a power hammer or the family car, is only as capable as it's operator. Again you are correct in saying that skill with a power hammer is directly related to skill at the anvil. Using a hand hammer and a power hammer are a set of skills that require the same foundation of knowledge.

Once again I agree with you that the operator should be entirely responsible for, and have an intimate familiarity with *any* machine that they will operate. From hand drills to combines, some of the most horrific accidents that I have seen were easily avoidable and caused by operator error or negligence. These are machines, and they do what we ask them to do, even if part of your body is in the way, respect them. That's the first rule of heavy equipment.

As for performing the test with flat dies with the bar near welding heat. This is in order to eliminate the effects of fullering dies of various radi on different machines. Flat is Flat no mater the machine, fullering dies vary. And welding heat is a more consistant mark than about yellow or somewhere around orange, so it might actually provide slightly more consistent results, again, one less variable.

On the topic of your hammer test I too do this and actually alluded to it in my previous post with "I think Mike-hr came up with a great full power test, but as for control, I am willing to accept the educated opinion of other Power Hammer operators. I know that I have no problems drawing 1/4" stock to a fine point with any of my hammers, or delivering a single light tap, or full force blow, which is a little tricky with the mechanical hammers but a breeze with the air hammers". I stated this because of the fact that I understand that power without control is nothing, yet the ability to hit hard it the very purpose of these machines, otherwise there would be no need for the larger hammers.

As far as machine set up goes, you are right on with the notion that all machinery should be properly anchored and installed in accordance with manufacturers specs. I assure you that all of my hammers are bolted down to a slab that meets or exceeds specification, and that all are maintained and or tuned daily in order to ensure that they will operate safely for as long as possible. That being said, you can understand that when you state that you are "surprised how many people cannot draw a taper efficiently, do not have their hammers (both air and belt) setup properly (no stable, mounted base) and have a theory that these hammer like the blue need 175 psi because thats what the hose can hold". I draw a direct correlation between your post and the statements that I have made in previous posts. And to that, I must admit, I do take a bit of offense.

If you were to read the entire thread you will find the section in which I posted "I actually made a mistake. I supply the Big Blu with full tank pressure (175 PSI) through a 1" 200 PSI rated jack hammer air hose, but the pressure is knocked down to 150 PSI by the regulator, filter, oiler on the hammer". The pressure is not set to 175 "because thats what the hose can hold", the reason the hose rating was given was to re-enforce that the supply line was in fact sufficiently rated to *safely* handle the ammount and preasure of air that was to be expected of it, something that John n had commented on in the post prior to mine.

As for hammer air supply pressure, the regulator on the hammer is set to 150 PSI and drops to just under 140 during operation which is *exactly* what Big Blu calls for on this equipment "The hammer will run well at 21 cfm’s at 140 psi, but the more air you can supply to the hammer the more efficient it will run." This information is directly from the manufacturer, absolutely no theorizing involved on my part. If that is what the hammer needs then thats what the compressor has to supply, work out or not.

I like the idea of de-tuning the hammer to 90 PSI for doing light work, normaly I just don't push the treadle down as far, but I am willing to try anything that will reduce the amount of wear and tear on this expensive and invaluable equipment.

None the less, the tool should be limited by the person, not the opposite. Control is everything and the tool doesn't make the art, we do. We also make the tools, and the right tools used the right way sure help to produce the clean results we all strive to achieve.

Edited June 9, 2008 by Jose Gomez

[jeremy k]

Good points by everyone - one other variable which may or may not be involved is the age and wear on an existing hammer. New hammers should work great, older ones have as much control as possible only related to maintenance / use.

[Gayle Brooks]

Great reply.

To clarify, the purpose of testing the hammers was to attempt to provide some type of numerical data on the performance of the machines under full power for the purpose of comparing hammers. Though full power is not commonly used in most smithing applications, it is the only non-operator influenced item that can be compared in order to give someone, that is not necessarily entirely familiar with the abilities of every style of hammer, an idea about the potential of the machines.

Typicaly the size of the hammer is all that is needed.

As for hammer air supply pressure, the regulator on the hammer is set to 150 PSI and drops to just under 140 during operation which is *exactly* what Big Blu calls for on this equipment "The hammer will run well at 21 cfm’s at 140 psi, but the more air you can supply to the hammer the more efficient it will run." This information is directly from the manufacturer, absolutely no theorizing involved on my part. If that is what the hammer needs then thats what the compressor has to supply, work out or not.

By all means please do it then. Again from what I have seen the cylinder can not hold it and runs just as well at 90-100. Though in the end it is your tool and your $.

There are points I think we could probably go back and forth on and never have a resolution. None the less, like any tool (as we have stated already) needs to be appropriate for the work and the smith.

From you reply we are on the same page. I am not seeing much value in the current "idea" and thats why we have these topics. They are great to get people talking, theories buildings and other to express perspectives, thoughts and suggestions.

As for the warning that this wasn't an attack, or some comment that you thought was directed to you.. I dont know anyone on these forums and some wear their hearts on their sleeves. Kinda xxxxx if I bring it up and xxxxx if I dont. So again I apologize if it seemed that way, wasn't intentional.

jeremy k: Good points by everyone - one other variable which may or may not be involved is the age and wear on an existing hammer. New hammers should work great, older ones have as much control as possible only related to maintenance / use.

Oh yes

Edited June 9, 2008 by Tald the dead

[David E.]

Well I think the test is a good idea:p Yes I know they all have rated values but I dont think for a moment anyone thinks all hammers of the same value are identical in performance, everyone has their favourite, based on their subjective , good control, footprint, supply reqd, price, etc That is the point of this test, it is an objective view on one aspect, if there are enough examples, we can make an assumption on averages if need be.
Personally I expect to see a difference between the one piece air hammers (sahinler, Anyang, Striker, Kuhn, etc) and the others. ;)

[steveh]

I am hoping we get a good cross section of hammers.It will be interesting to see the difference between the smaller hammers against the bigger ones.

[ThomasPowers]

in my experience the size of the hammer is only loosely correlated with how much it's good for.

I have used hammers rated more than twice as large as others but they actually seemed to do 1/2 the work in real life.

[Chris Pook]

in my experience the size of the hammer is only loosely correlated with how much it's good for.

I have used hammers rated more than twice as large as others but they actually seemed to do 1/2 the work in real life.

What hammers would these be?

If I had to have only one I'd take my Nazel 3b (300lb) over my 100lb little Giant thats been tuned and had a brake added. There is no comparison to the control and on demand power the Nazel has vs the Little Giant.

I've used home made air hammers, and my general feeling has been that they seem to hit light for their stated weight. :confused: Could just be the ones I have used.

The small AnYang that I used when it was on demo at a NWBA meeting, had some quirks with the linkage and the oiler, and once we had worked on the linkage it seemed to work pretty decent and I was impressed with how hard it could hit for its size. Down side being they need work to be decent hammers, dies need to be fitted, key ways need to worked etc.

[steveh]

hey Chris,are you going to do the test with your Nazel and Little Giant?

[Chris Pook]

I'll be forging tomorrow or Wednesday so I'll throw a couple pieces under the hammer.

IMHO I'd have to agree it doesn't seem to be the best way to "test" a hammer. But other than hands on testing I'm not sure what would be a good test.

[Jose Gomez]

Thats the point. we cant all play with every hammer, and A larger head weight does not mean that the hammer hits harder. The force with which any hammer hits is directly prportional to its velocity. This means that a fast 85 pound hammer can easily hit harder than a slow 100 pounder. Unless I am mistaken that is why Mr Hofi was interested in gathering more information about the ammount of "daylight" between the dies on my hammer when the test was performed. Because if you know the Hammer weight, how many blows per minute, and the total lenth of stroke you can calculate the speed of the hammer, and therefore, total kinetic energy. The formula for this if I recall correctly is Kinetic energy = 1/2 of mass times velosity squared. The fact that you sqare the velocity is what makes it possible for a smaller faster hammer to actually transfer more energy to the workpieces than a heavier slower hammer. Hense the purpose of this test, to measure the actual effectivness of the particular hammer under full load, and to give those infamiliar with power hammers a little bit of an idea of what these machines are capable of.

[ThomasPowers]

Chris, a couple of the home-made air hammers I have seen/used seemed to hit slow/light for their stated ram weight with none of the snap I was used to from mechanical hammers.

OTOH a helve hammer can be quite heavy but not have that snap either if it's gravity powered---I've seen some real oldies in operation in several countries.

[nonjic]

a good test for control is removing the shell from a hard boiled egg, without destroying the inner ! - Our company used to do this on 10 ton ram double acting steam hammers!

The only way to correctly measure the energy of a hammer is either hitting a lump of pure lead of a known size and measuring the deformation, or using a velocity recorder (which we do), if you know the mass of the ram, and the actual velocity at the point of impact it is simple to calculate the energy of the blow. Assuming constants such as a 10x nominal falling weight anvil block 2 hammers from different manufacturers can be directly compared. Hammer efficency as a % can then be calculated by knowing the energy 'draw' of the motor.

Once you start to compare the difference on the forging (workpiece) of a high velocity, small ram weight blow of say 1000 ftlbs, and a low velocity heavy ram weight 1000 ftlbs it starts to get complicated!

[Chris Pook]

Chris, a couple of the home-made air hammers I have seen/used seemed to hit slow/light for their stated ram weight with none of the snap I was used to from mechanical hammers.

OTOH a helve hammer can be quite heavy but not have that snap either if it's gravity powered---I've seen some real oldies in operation in several countries.

I can see that, Thats the one downside I believe the homemade style air hammers have. They are limited by how much/ fast they can move the air. A heavy head weight without larger valves/lines and more air volume is actually going to be bad for the hammers performance. The valve ports and lines are so small they just can't move the air fast enough in effect slowing/softening the blows.

The mechanicals are nice when setup that the spring actually builds force. I would have no problem believing a 100lb mechanical properly setup and tuned would out work a 100lb home made air hammer. The downside to the mechanical only being the need to reset the head height for tooling etc. Edited June 10, 2008 by Chris Pook

[Hofi]

JUST FOR THE FUN OF IT I MADE THE TEST WITH MY 110# 20 YEARS OLD ''SHAHINLER''
AND WITH THE 55# ''ANYANG'' NEW HAMMER.
EVERY TEST I REPEATED 3 TIMES ON COLD ROLL AND HOT ROLL 1020 STEEL 25mm SQUER .THE RESULTS ARE THE AVEREGE OF THE 3.
WHICH IS 0.985 THOU. TO START WITH.
''SHAHINLER'' 110#
5 BLOWES 0543
10 BLOWES 0397

ANYANG 55#

I TRIED ONLY THE 10 BLOWES 0545 THOU
HERE I MADE THE TEST TWICE AND GOT THE SAME RESULT
HOFI

HOFI