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Dennis K

Kinyon style Air Hammer

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I would like to start a discussion on air hammers construction and the valve schematics. The hammer I built is a joy to use and not too difficult to build if you have some stick welding and steel fabrication ability. Don't waste your money on high CV valves if you don't plan on building a monster size hammer. Most 2 X 10 Air cylinders have 1/2 “ ports but the fittings have an ID of 3/8 so a valve with 2.9 CV is more than adequate for a 75 pound hammer head. This will work well for knives and damascus billets. If you plan to smash something big then step up to a 5. 5 CV valve and a piston with one inch ports. This will give you an inside diameter of 3/4 inch on all air fittings. Air hammers are very powerful machines and should be built heavy and stout. At 100 psi a 2x10 Air cylinder has 314 pounds of force, add a 75 pound hammer head and you get 389 pounds of force going up and down 3 times a second. My 75 pound hammer weighs 1350 pounds. I wouldn’t build one lighter. I also used 1/2” thick UHMW plastic for hammer guides instead of brass because it’s less expensive, and it’s great stuff to work with and your hammer will run faster. Enclosed is an air schematic for my hammer and as you can see, I have installed a regulator . I adjust this between 45 to 60 pounds on the line leading to the main valve that controls the up stroke helping to prevent the hammer slide plate from impacting the cylinder mounting plate. I installed one 1/4” needle valve between the spool valve and the main valve allowing me to control the speed and the force of the hammer.

 

I’d like to see pictures and air schematics by anyone else who has built an air hammer. I hope this helps anyone who is thinking of building an air hammer.

 

 

air_hammer_post_Pict0293_a.jpg

 

Hammer_schematic_post.jpg

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I would like to start a discussion on air hammers construction and the valve schematics. The hammer I built is a joy to use and not too difficult to build if you have some stick welding and steel fabrication ability. Don't waste your money on high CV valves if you don't plan on building a monster size hammer.

I’d like to see pictures and air schematics by anyone else who has built an air hammer. I hope this helps anyone who is thinking of building an air hammer.

air_hammer_post_Pict0293_a.jpg

 

Hammer_schematic_post.jpg

 

Dennis,

 

Beautiful hammer, who is going to post a photo after seeing yours. I have built an air hammer roughly based on Ron Kinyon's plans and I also think it is a joy to use. However, like yours, my anvil is a shaft, a 7" diameter section of Liberty Ship drive shaft. I do not know how it was heat treated but this thing is loud and I love my neighbors, so use it as little as possible (I have much quieter 50 LB LG.) I have been to Ron Kinyon's shop and have operated his original hammer, which was not nearly as loud as mine.

 

The hammer is an "H" frame with a head weight of about 90 lbs. and a 3" dia. cylinder, the valve is a two position, spring loaded elctric valve ( much smaller than the one recommended by Ron). The valve is told to change directions by a simlpe micro-

switch, the relative location of the micro-switch is adjustable for various forging applications. In the beginning, the valve was sticking and just before I was about to replace it with a pneumatically powered pilot valve, I took it apart and took another valve just like it appart to borrrow some "O" rings. When playing with the spools in the barrels, I noticed the "wrong" spool in the original barrel was a much looser fit. This fixed my problem.

I also have an adjustable valve in the main line as well as the exhaust line. The total weight of the hammer is about 1100 lbs.

 

I have a couple of questions:

Is the shelf attached to the anvil, for tools?

What role do the flow control valves play in the pilot air system?

Compared to a Chambersburg Utility hammer (5" bore) 19.6 SQ IN/200 lbs or 1 to 10 ratio

your hammer is (2" bore) 3.14 SQ IN to 75 lbs or 1 to 22 ratio

don't you think it is under powered? I think mine is at the full bore.

Why run the lifting pressure at 50 psi (are you not slowing it down)?

Jan

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Dennis, nice hammer. I bought some plans, and had the same idea about the UHMW instead of the brass, do you have to grease it at all? Is that a Parker cylinder? Thanks for sharing, Jim

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I have a couple of questions:

Is the shelf attached to the anvil, for tools?

What role do the flow control valves play in the pilot air system?

Compared to a Chambersburg Utility hammer (5" bore) 19.6 SQ IN/200 lbs or 1 to 10 ratio

your hammer is (2" bore) 3.14 SQ IN to 75 lbs or 1 to 22 ratio

don't you think it is under powered? I think mine is at the full bore.

Why run the lifting pressure at 50 psi (are you not slowing it down)?

Jan

 

Yes the shelf is for tools.

 

Jan, in the schematic I show two 1/4” needle valves but you only need one, the lower one. (see photo) This controls the force and speed of the hammer; turn the needle out and it hits light, turn it in it hits hard and fast.

 

This hammer hits hard , more then enough to beat a 2” diameter x 7” piece of L6 in to submission.

 

I adjusted the regulator psi for optimum up stroke and speed in unison with the 1/4” needle valve. If the hammer is running fast and hard you need less psi for the up stoke and if its running slow and light it needs more psi. Its the best way to get a full up stroke and prevent the hammer slide plate from smashing in to the cylinder mounting plate and the best part is the needle valve cost under 4 dollars.

 

Needle_valve.jpg

Edited by Dennis K

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Dennis, nice hammer. I bought some plans, and had the same idea about the UHMW instead of the brass, do you have to grease it at all? Is that a Parker cylinder? Thanks for sharing, Jim

 

Hi Jim,

 

Nope, no grease is necessary, it's slick and waxy and stands up very well to punishment. Yes, it is a Parker cylinder. If you're thinking about buying one, get the largest thread size possible on the end of the shaft. Mine is a 1" x 14 thread. The original one had a 3/4" and it lasted 18 months 2 weeks (2 WEEKS PAST THE WARRANTY) before it snapped off. :)

 

Later on, I'll post pictures of the broken piece.

 

If anyone else has alot of questions, e-mail me your phone number and a time to call you.

 

 

 

Dennis

Edited by Dennis K

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If you’re thinking of building an air hammer, this information will be helpful. Air hammers and 4x4 offroad vehicles have one thing in common; all bolts need either a nylon locking nut or a star lock washer and two nuts or it will loosen up. I recommend examining your air hammer every time you use it. Don’t bother wasting your time welding anything over 1/4” with a mig welder. Your welds will more than likely fail due to vibration. I had to install a X brace bracket (see photo) made from 3/8” x 3” flat stock between the hammer guide mount and the main upright to prevent the hammerhead and guide mount from oscillating at high rpm. If you’re going to use a piece of I-beam for the main upright, look it over carefully for twists as this steel is usually used and may have been hammered hard by a pile driver.

 

Hope this helps.

 

Dennis K.

 

 

 

PICT0006_640x480_opti.jpg

Edited by Dennis K

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Just out of curiosity. What do you guys make of the kits that Blacksmith's Depot is selling? Click this link

 

 

Leil if you shop around for the best price you will save hundreds of dollars off the kit price. Look up parker pneumatic in Norway for prices .

 

Dennis

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Dennis,

 

 

How much air does it use, and where do you find a compresser large enough to run it?

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Dennis,

 

 

How much air does it use, and where do you find a compresser large enough to run it?

 

 

Greg, Thanks for bringing the post back up. I bought a new air compressor in 1994 for my shop. It’s a Speedaire 7.5 HP 80 gallon and at 175 PSI it has 25 CFM. Since steel is only workable for less than a minute between heats, a 5 HP compressor should be sufficient for cable knives and 1-1/2 x 1-1/2 x 6” pattern welded Damascus billets.

 

Hope this helps.

 

Dennis K

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That helps some - I guess what I am asking, is how does one determine the size and capacity for a air hammer of a given size?

 

Say I wanted to build a slightly larger hammer, how would I know what kind of capacity the air compressor should have?

Edited by Greg H.

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That helps some - I guess what I am asking, is how does one determine the size and capacity for a air hammer of a given size?

 

Say I wanted to build a slightly larger hammer, how would I know what kind of capacity the air compressor should have?

 

 

Greg, companies who sell pneumatic equipment can answer your questions about airflow Cv factor. Start with the air cylinder and decide what size you’re going to use. For a 50 to 75 pound hammer you need a 2”x 10” cylinder and a 2.9 CV control valve. For a 100 pound hammer a 2-1/2”x12” cylinder and a 4.0 Cv valve should work. A 125 pound hammer with a 3”x14”cylinder with 1” ports needs at lest a 5.5 Cv control valve with 1”ports and a lot of air. Do a Google search for Kinyon style air hammer.

 

Again, visit my website htttp://www.actionpistol.net under photos. This should help anyone building a hammer.

 

 

hope this helps,

Dennis K

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On 12/2/2007 at 9:10 AM, Jan Ysselstein said:

Compared to a Chambersburg Utility hammer (5" bore) 19.6 SQ IN/200 lbs ....

 

Hey, can I ask you what the cylinder stroke is on a Chambersburg Utility hammer with a 5'' bore? By the way is it precisely 5'' ? I'm asking because I built a hammer already, a smaller version with a 90 lb ram weight and a 2½'' bore, 10'' stroke. I'm dreaming about a new hammer in the future that would have the same size cylinder as the 200 lb Chambersburg. I'm a big fan of old Chambersburg hammers but they're pretty hard to come by in Europe, Finland. I'm thinking of buying this cylinder to use in my next hammer:

 

Paineilmasylinteri 135-30-300

 

Price is 120 €/cylinder.

Rod 1 and 3/16 in

Bore 5 and 5/16 in

Stroke about 12 in

 

Thanks,

 

Jakob Staffans

Vasa, Finland

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Welcome aboard, Jakob!

You may want to start a new thread about this, most of the people who have posted on this one are not reading anymore. 

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In trying to figure out just by the picture how to go about mounting one of these to a machine? Maybe some more pictures would help?

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I've got the vast majority of the materials to do a build like this. It's been on my list of things to do. I have been planning to build it once the zombie apocalypse started and I was no longer working. However, I never anticipated the zombie apocalypse would be a zombie VIRUS apocalypse and that it would require me to work MORE. :angry:However, once I can practice a little less social distancing I'll have Jeremy Blohm over to help me get some work done. I need to get smarter on the valves for this. I understand the principles of plumbing this, how the air cylinder operates and so forth. But when it comes to the valves and such what I read doesn't exactly match up with the items I find available through various suppliers. I bought "the book" for this build and it is a pretty good start. But I know I've still got education to gather. Well, back to the zombie hordes....I got a crawler at the door! Gotta get the crossbow! If I don't make it, Jeremy, you can have my tools and sh*t!!!

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@ChrisBriggs I'd love to see your build progress if you can take the time to share it with us.  That's a big ask, but something like this is about the only way I would get a hammer in the next few years.

 

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19 hours ago, ChrisBriggs said:

I need to get smarter on the valves for this.

 

If I were to build my hammer again I would use electrically actuated valves. Like in this video, observe though - this hammer is a single-hit-hammer but electrical valves can still be used in a continously hitting hammer.

 

 

With my current design the ram is banging into the roller valves mechanically. I bought the stronger type of roller valves and they're still made of plastic. I expect them to break eventually. The only drawbacks to using electrical valves is that you need a $15 inverter also, and of course electricity. The valving is literally the simplest thing ever. Just make sure the supply tubes and outlet tubes are large, as large as the cylinder valves at minimum.

 

airhammer1.jpg

Here's my hammer. The foot lever is temporary.

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I really like the hammer in the video.  Will yours be working in the same manner, or are you going to set it up for a continuously hitting hammer.............and at what advantage?

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My current hammer is the one in the picture, that's a continuously hitting hammer for general forging. I can do  single hits with it if I step on the treadly quickly. The one I'm thinking of building but have not yet decided on would be similar. A continously hitting hammer, using electric sensors to adjust an electrical 5/2-valve. Single hit hammers are used for precision, where you only one want hit. They're useful if you need too evaluate the forging during the forging, which is often useful. Hit once, check, hit again, check. Or for stuff like stamping logos or doing fullers or set downs, specific forging where you don't want more than one hit at a time.

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Thanks for the explanation.  I'm new to all of this and have a lot to learn.

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