Lets talk pneumatics: I need comprehensive info on air hammers

[FieryFurnace]

Alright folks. It has been almost three years since I purchased my first power hammer.

It was advertised on here for sale, and I travelled up to Fort Wayne Indiana to pick it up.
The hammer I bought was a 60 pound Kinyon-style air hammer.

It is still an essential part of my shop. My air hammer does the work my tire hammer cannot and the other way around too. However, there are times when I would really like some additional punch behind my air hammer, and also more throw (room between the dies.)

I would like to gather some info for a possible air hammer build sometime this winter.

My compressor is a 7.5 HP, 80 gallon rig, with a max PSI rating of 200. Comparable compressors pump about 24CFM at 175PSI.

Naturally, I would like to build the largest hammer I can. 100-150 pounds would be nice.

I am planning on using a "Coleman" operating system. Hopefully I won't get caught in the crossfire of "who came up with what design first" debates, through this. I just found some info online searching for various systems. The "Coleman" operating system seems to have a functionality similar to the KZ hammers. (Which are awesome by the way.)
He is a link to a site with some info on this system.
http://colemanstuff.wordpress.com/hammertime/

My current hammer has a 13-inch cylinder and currently uses about 12-inches of throw or less. I would like to increase this as much as possible. My initial and uneducated idea is to use a 24-inch cylinder.

So my first question is this. Can I reasonably expect to run a 100-150 pound home built hammer off of my size compressor, or is that too much? Should I stick with 100 pounds or less, or will I still be within the oporation abilities of my compressor to go on up to the 150 pound mark? (I know this will depend a lot on cylinder size, and efficiency in hoses, fittings, and valves.

Second question is this. Is a 24-inch cylinder way too big? Remember, I NEED throw. Most of the time I will only be using a 10 or 12-inch throw, but when you need the extra, it's nice to have it. You can adjust a bigger hammer down, but you can't make a smaller hammer big. My question is, what is normal for a 100-150 pound pnuematic hammer?

OK so the next question is based on the answer to the last. What size cylinder and shaft diameter should I choose for the length of the cylinder that you recommend? If you recommend I decrease to an 18-inch cylinder on a 100 pound hammer, what would you recommend the diameter of the cylinder and shaft be? If you recommend I go with a 20-inch on a 125 pounder, what cylinder and shaft diameter should I go with? Give me some options that you think will work well with my compressor.

Alright, let's talk hoses and valves. Based upon the size cylinder you've recommended, what size hoses and valve ports would you suggest? If I go with a smaller or larger size hose and port, what does that affect on the hammer? Speed? Power? Both? Something else?

Final question is, does anyone have an operating system similar to the Coleman controls and if so, would you mind sharing pictures? The website has very blurry photos and although I get the general idea of everything, it is rather sketchy and will leave a lot to trial and error. If you would be willing to share measurements, that would be great too.
(Although I love the operating system of the KZ hammers, I do not want anyone to send pictures of it's operating system. They have made a product to sell to make a living. Unfortunately I cannot afford their product, but I don't want access to their operating system through someone who has purchased it.)

Thoughts, suggestions, and resources welcome!
Thanks!

[jeremy k]

Dave - sell both your hammers and buy a hammer from Ken Zitur or John Larson

[FieryFurnace]

Dave - sell both your hammers and buy a hammer from Ken Zitur or John Larson

Wish I could but the tire hammer is essential too! I've got to have two!

[jeremy k]

With either Kens or Johns I think you'd have everything covered, with Kens anyway - as I've used his multiple times - John's looks good from the videos, I wish I could try his to compare.

[macbruce]

A stroke larger than say 16'' seems huge to me for a 150# hammer......You can fit larger tools/stock in between the dies if you build in a removable sow plate(s) but you have to be carefull not to crash the cylinder if you miss or better yet get a cushioned cyl........I think having a much greater stroke will increase your cfm requirements and might make it less ''snappy''.

[FieryFurnace]

With either Kens or Johns I think you'd have everything covered, with Kens anyway - as I've used his multiple times - John's looks good from the videos, I wish I could try his to compare.

Those hammers are capable and versatile, but I need two hammers set up with different tooling for some things. Also the tire hammer is a work horse and is cheaper to run.

[FieryFurnace]

A stroke larger than say 16'' seems huge to me for a 150# hammer......You can fit larger tools/stock in between the dies if you build in a removable sow plate(s) but you have to be carefull not to crash the cylinder if you miss or better yet get a cushioned cyl........I think having a much greater stroke will increase your cfm requirements and might make it less ''snappy''.

Interesting insight! I was planning on getting it cushioned. Any suggestions on port size?

[macbruce]

Interesting insight! I was planning on getting it cushioned. Any suggestions on port size?

Maybe KZ or JL will chime in but I think you will need a 3.5 to 4'' cyl for a 150 with 1/2'' MINIUM ports. Even without making the stroke longer your 7.5 hp compressor will run out of steam in full production imo and if you happen to be running both hammers at once you don't have a prayer.....Another 5hp would be nice, It's only money............ B)

[FieryFurnace]

I'll be selling the 60 but need to get a new one built first.

[LastRonin]

I have been thinking of building an air-hammer myself. I'm considering something like the new style kinyon. With the air cylinder working a leaf-spring guided helve. The point of stating all this, is to ask a question that could help both of us.

You could shift the connection point of the cylinder to the leaf spring to adjust the throw length, right?

(i.e.: The closer the connection point to the hinge, the greater the throw. You'd want a way to adjust the tup height, but I have an idea for that as well.)

[FieryFurnace]

I have been thinking of building an air-hammer myself. I'm considering something like the new style kinyon. With the air cylinder working a leaf-spring guided helve. The point of stating all this, is to ask a question that could help both of us.
You could shift the connection point of the cylinder to the leaf spring to adjust the throw length, right?
(i.e.: The closer the connection point to the hinge, the greater the throw. You'd want a way to adjust the tup height, but I have an idea for that as well.)

I suppose you could, but moving a roller valve by loosening two tiny screws, seems a little easier.

[mike-hr]

On My kinyon, I increased travel by fabbing a thin lower die (1-1/2"). I use it to get enough room to use slot punches and other top hand held tooling. Currently employ 3 x 12 cylinder.

[FieryFurnace]

My current cylinder is two inches in diameter. It has performed flawlessly for me for three years, and the guy before me had it for a year or two.

Not only do I need more throw, I need more weight.

I have looked into modifying mine, but the modification would have to be so extensive, it would just be more simple to build from scratch.

As the cylinder gets longer, why do you need more width? What does that do for you? I mean if a 2x12 cylinder cycles a 60 pound head (and I've even added an additional 20 pounds to my head before,) why wouldn't a 2 or 2.5 x 16 cycle a 100 pound head?

[FieryFurnace]

As the cylinder gets longer, why do you need more width? What does that do for you? I mean if a 2x12 cylinder cycles a 60 pound head (and I've even added an additional 20 pounds to my head before,) why wouldn't a 2 or 2.5 x 16 cycle a 100 pound head?

Ok I just read online where the increased width increases the pounds of force that the rod exerts.....rather drastically actually.

At 100 psi in a 16-inch tube you get the following.

269 pounds in a 2-inch cylinder
447 pounds in a 2.5-inch cylinder
662 pounds in a 3-inch cylinder
884 pounds in a 3.5-inch cylinder

Wow! Big difference!

[mike-hr]

A wise man once told me," decide what's the biggest stuff you're going to work, and hold the line there". I have a forklift, a fairly large bandsaw, a couple power hammers, and a great big imagination. As I get older, and the chiropractor visits get more frequent when I try to burst out of my self imposed bubble,  the more I try and hold true to the said advice. I've been following your work, and I'm very impressed.  If you lived closer, I would be happy to donate time to help you get closer to your goal, if I could.  Right now, I will postulate that you aren't looking at your existing tools, and using them for all they are worth. Make shorter top tools, finish on the hand anvil, dance with who brought you there. I consider myself a pro smith, even if I do a lot of machining and welding to keep my family fed. I make a lot of really nifty stuff, without a 24 inch throw on the power hammer. 

[FieryFurnace]

One of the big things that the larger hammer is needed for, is my hammer making. Extra throw would be nice and more weight is essential. This thread is to work out my ignorance of what size tube would be suitable for my current compressor and still be a suitable upgrade. I'm also looking for added control which will lower the amount of products I lose due to missed blows. I also need a larger die area, for making various products without having to swap dies, mid-heat.

This stuff can't simply be added to my current hammer.

I have run my hammer without the lower die, in the past to help gain extra throw, but when I'm working a piece that large, the hammer doesn't hit hard enough to do anything to it, not to mention being unable to switch immediately from long side to short side, and continue forging.

The biggest stuff I work with currently is 2.5-inch solid rounds, and I don't see increasing that anytime soon. That's about as much as the 50 pound tire hammer wants to handle. It would be great to be able to go from tire hammer dies, to the air hammer, during the same heat, without having to swap dies or grab a striker.

Perhaps a 14 or 16-inch cylinder is what I really need instead of a 24-inch. I don't really know, that's why I'm trying to get input here.

[macbruce]

Drasticly increasing stroke will of course increase you air consumption. I get the feeling you won't be happy with a 100lb'er and a 7.5

will be at it's outer limits running a 150.....16 inches is a big jump.

[jeremy k]

Dave - power hammer tooling is shorter - so you don't need that much travel - ask others that make hammer heads on any standard power hammer.

[FieryFurnace]

I measured my cylinder and it is a 13 inch, however the stroke at maximum width is only 8-inch. Haha! So really I could get a 2.5 or 3 inch cylinder 14-inches long and just make sure the hammer I build actually uses the whole stroke, at it's maximum operating range.

The KZ hammers run off of a 12 x 2.5 cylinder with a custom 1.75 inch rod. The website says it will run on a 5hp, 80 gallon compressor, with 17 CFM. (All of this info is available publicly on the website.)

[macbruce]

I measured my cylinder and it is a 13 inch, however the stroke at maximum width is only 8-inch. Haha! So really I could get a 2.5 or 3 inch cylinder 14-inches long and just make sure the hammer I build actually uses the whole stroke, at it's maximum operating range.

 

The KZ hammers run off of a 12 x 2.5 cylinder with a custom 1.75 inch rod. The website says it will run on a 5hp, 80 gallon compressor, with 17 CFM. (All of this info is available publicly on the website.)

 

A 14'' cyl will likely be special order cylinder so it will cost a bit more.

The old Bull 125's run off a 2.5 x 12'' cyl and do ok with a 5hp comp.

A 3'' cyl is nearly twice a big as a 2.5, or a 2.5 cyl=4.9 sq inches and a 3''= 9.61sq inches.......I'd say a 150 would need at least 3'' for sure.......

[territorialmillworks]

I spent a very frustrating year with the Coleman design. Even with a lathe and mill to fabricate the controls, I couldn't get this set-up to perform with consistency and it was under-powered. I salvaged the frame and anvil and built the new style Kinyon and never looked back. Might want to find someone who has successfully built a Coleman design before going down that road alone........

[trinculo]

I have a homemade "bull style" hammer with a 2.5" cylinder @ 110lbs. At the same air  pressure it is considerably more sluggish than my 75 pound Iron kiss with a 3.5" cylinder. The Iron Kiss runs great down to 60lbs pressure. The 110lb doesn't come into it's own until >100 psi.

 

fwiw I make brazil type hammers solo both slitting and upsetting into a rounding die under the iron kiss and I made a set of narrow fullers for cheeking on the home-brew hammer. I do agree that two hammers are great for setting up different tooling for using often times under the same heat. I still drift manually on the anvil using a set of"camelbacks".

 

I  am really impressed with the videos of KZ 150 and it's control.  Ken told me it has something like 14" of stoke. If it is built anywhere near the robustness of John's hammers that's the way I would go. I've looked at the numbers for building my own hammer and just can't compete with what you can get from either John or Ken.

[FieryFurnace]

macbruce: McMaster has the 14-inch cylinders. It looks like around $200 or less will get me outfitted! Less if I go with a shorter cylinder. I did not think about the increased volume. I mean I knew it was more, obviously, but I just didn't realize it was twice as much.
I think it would be the more wise option for me to not go much above 100 pounds. That will be a sufficient upgrade for me, and will be more likely to operate within my compressor's ability.

Keith: thanks for sharing your experience with the Coleman linkage.

Trinculo: Due to my readily available steel source, and the selection there, I can build an entire hammer for the same cost as the KZ control kit. I've beat up some 2x4 under the KZ and absolutely love it's control and power.

[John Larson]

Fiery Furnace, all air hammers have an inherent stroking length of their hammer heads. It is generally shorter than the maximum air space between the dies. So when considering air usage you need to realize that it is the inherent stroke length that matters, not the maximum possible air space. The inherent stroke length is determined by the triggering mechanism. You can design your hammer with a very long cylinder and a correspondingly long hammer head (with long guides to keep things true), allowing yourself the ability to use long punches for drifting the hammer head eyes, and still only use several inches of inherent stroking. Long drifts and punches are extraordinarily dangerous. The advice to use short tooling is good and well meant.

As far as design goes, you might consider the KA 75 hammers sold by Bob Bergman and used by Nathan Robertson to make hammers. The air space is quite large and it is a single blow machine aimed at mimicking a striker with a sledge. It was designed to run on a small air compressor.

[peacock]

2 times the diameter  = 4 times the volume.  that means you need lots more air and much bigger lines and valves. that equals big money.   Don't over look the mechanical hammers. A really good 100 to 150# mechanical hammer will do a lot of work.  Most time you don't need more stroke you need more die opening.