Jump to content
I Forge Iron

Recommended Posts

Hi guys! First post here and I haven't seen a question placed just this way. If so, please excuse. My question is: What am I giving up, in a home shop setting, going with a quality tire hammer, like Clay Spenser's vs a quality air hammer like a smaller Big Blu? At something close to a 2 1/2 times difference in new price, the cost factor is obvious. What CAN'T I do with the tire hammer that I can do with the Big Blu and in your opinion, is it worth the extra cost in your home shop? Thanks for your replys!

Link to post
Share on other sites

One thing about mechanical hammers versus air hammers is that mechanical hammers are much more energy eficient. I figure they use about sixty percent less energy than an air hammer. Additionaly, if you build your own hammer, you will always be able to repair it yourself. With an air hammer you must buy parts every few years. I know this doesn't answer your question, but it is an important consideration to some.

Link to post
Share on other sites

Welcome aboard Wes, glad to have ya.

There are a few fundamental differences on the performance and capacity fronts.

First off as Arftist says a mechanical will give you more bang for your kilowatt. Lb for lb they tend to hit harder as well.

What a pneumatic utility hammer has though are some features a mechanical can't reproduce conveniently. They can have quite a bit of clearance between the ram and anvil, often in the 12-14" range. This means there is plenty of room for tools. Sure you can built a mechanical with that much room but the utility can use it all from paper thin to near the top without adjusting anything.

One of the most useful features after a good cycle speed is single blows, while it's possible with a mechanical it takes a well adjusted hammer and skill to strike single blows where a utility will deliver single blows with a quick tap on the treadle.

Another thing is clamp or dead blow Usually with a flip of a leaver a utility can deliver a dead blow, hit it hard and not retract the ram, this is essentially the same thng as clamping but with more force. Clamping is handy for twisting and such.

In a little bit I'm sure the guys who really know power hammers will be chiming in.

Frosty

Link to post
Share on other sites

Hello Wes, I'm going to be purchasing a power hammer near the end of this year. I've beat the web to death reading anything I can find on this subject. I don't have tons of time and money to travel and see all these things in person, but I can tell you what I've read.

Yes, the tire hammer is the cheapest form of power hammer to build or buy. Mostly what I read though is people looking for parts. There isn't any tire hammer store or name brand with corporate backing full of shelf items. Some of the tire hammers get built with different sized parts. I know a local guy who said he built his with a 5" dia. anvil post. Probably didn't want to pay $700 to buy an 8" dia steel post. From what I've heard, you can probably build them up or down to you're liking with all sorts of different sized components.

Machine shops can sometimes give people sticker shock with what they need to charge for their service. If you have an industrial lathe and mill, without a doubt, its probably a good way to go. If you're in good with the local machine shop and they can be reasonable with you, probably also a good way to go. That way you know you can always have something made to cover the "no shelf items" available issue.

On the other hand, an easily placed phone call to BIG BLUE with a credit card, model #, or serial #. could probably get you the part you need the next day! Just some food for thought. Regards, Spears

Edited by Spears
Link to post
Share on other sites

I am a tire hammer proponent, because of the reasons stated, cost, availability, etc, I went with that choice. I have not been disappointed, rather, the more I use it and talk to others who have them, I find my choice validated. In fact the only 2 things that would be considered "less" about the hammer, is the size of the dies, and the vertical clearance, which has not been a problem for me in either case. The upsides are cost, size, weight, moveability, and having built it, what to do if something goes wrong. I highly recommend taking the class with others to build one with Clay Spencer, it is a fun and valuable class, and memories are made, that last the rest of your life. We had a blast doing it, and everyone took a hammer home!!

Link to post
Share on other sites
Hi guys! First post here and I haven't seen a question placed just this way. If so, please excuse. My question is: What am I giving up, in a home shop setting, going with a quality tire hammer, like Clay Spenser's vs a quality air hammer like a smaller Big Blu? At something close to a 2 1/2 times difference in new price, the cost factor is obvious. What CAN'T I do with the tire hammer that I can do with the Big Blu and in your opinion, is it worth the extra cost in your home shop? Thanks for your replys!


What are you going to use it for? and how often? this will determine what you need

a self contained air hammer is the only real choice for a professional who is forging a couple thousand hours a year or more or a Factory built mechanical hammer depending on personal prefreance

a tire hammer or homebuilt mechanical is probley perfect for someone not wanting to spend alot and doesnt want to hammer entirely by hand
Link to post
Share on other sites
What are you going to use it for? and how often? this will determine what you need

a self contained air hammer is the only real choice for a professional who is forging a couple thousand hours a year or more or a Factory built mechanical hammer depending on personal prefreance

a tire hammer or homebuilt mechanical is probley perfect for someone not wanting to spend alot and doesnt want to hammer entirely by hand


This may be true for certain poorly built examples, but a lot of us have built mechanical hammers with every bit as much performance, quality and durability as factory made hammers, if not more so. Please don't generalize about others and their creations/craftsmanship.
Link to post
Share on other sites

Economically speaking, I agree that the tire hammer wins, hands down. And, as pointed out, if you build it, you can repair it. I was going to build a Kinyon style air hammer; had the air cylinder, steel for the frame base and anvil, etc, but then I discovered the tire hammer concept, and realized I could build that for less than the remainder of the cost for air control components. I really liked the idea of the clamping and single blow features of an air hammer, but I personally, couldn't justify the cost for those conveniences. With a little practice however, I've learned to do single blows! :)

Link to post
Share on other sites

Bryan,
you may want to talk to the owner of Lightening Forge in Salt Lake Utah, I bet he does as much forging as anyone out there, and guess what he has?? Thats right, 2 tire hammers!! and he loves em, so to respond to your statement regarding tire hammers, ppphhhllllbbbbb!! (sic) I understand your statement, some home made jobbies are just not up to it, but the tire hammer design has proven itself, over and over again. Go Clay Spencer!!

Link to post
Share on other sites

The tire hammer mimicks the construction of older mechanicals like the Little Giant. So it performs like them. Soooooo many people have had success with the tire hammers and its parents that I think that speaks louder than words.

But there are differences between mechanical hammers and the two basic kinds of air hammers. Frosty did a good job of telling the story. I'd add that the mechanical hammers have a "slapping" blow whereas an air hammer has more of a "punching" blow. Each correspondingly varies in energy input and energy output. Mechanical hammer proponents suggest their relatively low power input is due to air hammer inefficiency. Ya gotta examine one type of machine's input relative to its output. Bottom line IMHO tends to be that a mechanical's hammer head weight has to be bigger than an air hammer's hammer head for a given block of hot steel.

The umba's online librarian will sell you a $7 dvd of Clay Spencer showing the tire hammer at its best with all kinds of his tooling for it. Check it out.

Link to post
Share on other sites

The school I go to has a sayha and a sahinler in the 150lb range and a couple other smaller self contained hammers one of which a 33lb anyang. I have also used a small big blue style hammer with a 100 gallon air compressor. Those self contained hammers can whoop some metal, as much as you can throw at it. The big blue style hammer with air compressor worked alright as long as I was forging one iron but xxxx near quit hitting when I started forging two and three irons. a self contained hammer will cost ten thousand but they can hit all day long with out complaint. Big lue style hammers hit weak and you still need a beefy highvolume air compressor. I'll be building a mechanical hammer until I can afford a heavy hitter. My two cents.

Link to post
Share on other sites
This may be true for certain poorly built examples, but a lot of us have built mechanical hammers with every bit as much performance, quality and durability as factory made hammers, if not more so. Please don't generalize about others and their creations/craftsmanship.


This was not my intention hopefully you werent offended,

Its not easy to build a mechanical hammer that wont need some adjusting after a bunch of work you would probley be best to find a used mechanical because they are around for reasonable prices

Anyone can build something if your dedicated enough in fact you could build a self contained hammer if you chose to it wouldnt be easy I am certain you would learn quite abit in the process.

ultimately if building a hammer is a project you want to take on and dedicate yourself to and search for the right metal and pieces for reasonable prices because the price of fresh steel isnt cheap
Link to post
Share on other sites

I took the tire hammer bit of using the compact spare and combined with the Rusty style mechanical I have. The compact spare is a great drive for a mechanical. Good controlability, and reliability. My 45# spring helve cost $45 when I built it.(I am a good scrounger, living in the land of the big scrap yard) When I increased to 45# from 32#, I bought a bigger new motor, added more anvil by scabbing plate on, and did some other bits and pieces. I now have acontrolable, hard hitting, reliable, mechanical I can make parts for, understand completly, and I have a little less than $200 invested. I did put a lot of manhours in, but I enjoyed that part, and I am time rich dollar poor.

And I would love an Iron kiss, even if I gently disagree with John about the difference in blows. I think that foot-pounds is foot-pounds. There can be a difference if either type is set to reverse too soon.

Link to post
Share on other sites
  • 3 weeks later...

@ ptree There is a big difference in how an air hammer and a mech. hammer hits(Little Giant style/tire hammer). No matter what size stock you put in an air hammer you get the same hit. In a mechanical that changes. As you increase the size of your stock, or if you start using tooling, generally you lose power because the spring doesnt get a chance to unload its energy. You can adjust it to get some power back but not much.
And this is with one disclaimer. A mechanical Helve style hammer is a beautiful thing. Its more of a direct drive pushing the ram as opposed to throwing it.

Edited by dragon leaf
Link to post
Share on other sites
@ ptree There is a big difference in how an air hammer and a mech. hammer hits(Little Giant style/tire hammer). No matter what size stock you put in an air hammer you get the same hit. In a mechanical that changes. As you increase the size of your stock, or if you start using tooling, generally you lose power because the spring doesnt get a chance to unload its energy. You can adjust it to get some power back but not much.
And this is with one disclaimer. A mechanical Helve style hammer is a beautiful thing. Its more of a direct drive pushing the ram as opposed to throwing it.



Not quite. When you lessen the stroke of an air hammer you surely lessen the velocity of the tup, unless you are trying to tell me it reaches maximum velocity instantly.

As far as the mechanical hammers go, if properly designed, there is no loss of throw whatsoever. The older hammers with the dupont linkage may suffer this limitation, as well as the tire hammers if they also have the dupont linkage, but helve hammers can easily be set up to have a six inch or more variation in bottom dead center.
In addition to this adjustability, in my hammer (based on a rusty), I set the bottom of the stroke when adjusted all the way down on top of two 1.5" spacers, which I can remove anytime I need more height for tooling, thick stock or whatever.
Link to post
Share on other sites
Not quite. When you lessen the stroke of an air hammer you surely lessen the velocity of the tup, unless you are trying to tell me it reaches maximum velocity instantly.

As far as the mechanical hammers go, if properly designed, there is no loss of throw whatsoever. The older hammers with the dupont linkage may suffer this limitation, as well as the tire hammers if they also have the dupont linkage, but helve hammers can easily be set up to have a six inch or more variation in bottom dead center.
In addition to this adjustability, in my hammer (based on a rusty), I set the bottom of the stroke when adjusted all the way down on top of two 1.5" spacers, which I can remove anytime I need more height for tooling, thick stock or whatever.


Air hammers dont reach full velocity, but they do keep pushing. They dont need the "slap" of the spring to move metal. If that spring cant expand and open up the energy never gets released.
The beauty of making your own hammer is the ability to lower your anvil and step up the dies. It gives you that the versatility to be able to use tooling and not lose your blow. Beautiful thing if you know before you make it.
Helve hammers have the ability to "open " up, as I stated. I love Helve hammers.
Link to post
Share on other sites
  • 9 years later...

I have used both 50# Little Giant hammers and 110# German air hammers. For my money the LG will do more work! the problem with them is that most of the old guys who knew how to  tune them are dead, and if they are not tuned properly they are much less efficient. I don't know if tire hammers have the same problem; id guess that they don't. I am planning  to build a guided-helve hammer. Wish me luck. If anyone has any tips on them, pass it on.

Link to post
Share on other sites
  • 2 weeks later...

CLEAR! *thudthud*

From a purely engineering perspective, if we're talking straight energy efficiency, it's very hard to beat mechanical to mechanical component efficiency.  This is due to the compressibility of gases or flow inefficiencies in liquids. However, there are drawbacks, and many of them have been aforementioned.  Unfortunately I'm working on the very same, building my own hammer. 

From an engineering perspective, one has to consider the whole system, aside from energy efficiency.  The problems with any fully mechanical system are thus:  Moving parts, friction, tolerance control, and compliance.  The biggest issue that many mechanical hammer designers can attest to is the final, compliance.  ANY system that interacts with a solid object must include some degree of flexibility, or compliance, in the system or the shock load can sheer linkages, shafts, et cetera.  This problem is multiplied in a mechanical hammer because the system is not only designed to impact a solid (if malleable) object with force over many thousands of cycles, these objects change under impact and increase the travel the dies must take before impact (and rebound) occur.  

You can look at any mechanical hammer and see some form of dial-able travel length, and some form of spring (compliant) element.  In the background, however, there are also a plethora of rotating parts, all of which need a bearing and/or bearing surface with (in)consumable friction reduction (grease, babbitt, thrust bearing, roller bearings, etc.).  These all also require tight tolerances, axial alignment, and unless your spring element has near perfect shock absorption, all drive components are subject to cyclical shock loads.  Any/all off these components, once catastrophic failure occurs, require full overhaul of the hammer, and if poor safety shielding was in place a very unfortunate trip to the local emergency room.  Mechanical hammers also have a tendency to take up significant retail space.  This isn't much an issue if you're either a hobbyist and use a small amount of equipment or have a surplus of room.  

Pneumatic hammers, although pricier and less power efficient, have several benefits that far outweigh mechanical hammers.  Gaseous fluids have natural compliance, so no spring elements are required in the design, as long as the design of the hammer accounts for compressibles heat and pressure rises.  A poorly designed pneumatic hammer requires cooldown cycles because the heat rise, and air volume increase, causes the dies to travel less or stop travelling all together.  Pressure vessel failure can be far more catastrophic than mechanical failure in most cases, but again this is due primarily to poor design.  

Also in a pneumatic system, force is a product of psi rather than velocity, and reciprocation is not dependent upon the rotation of a mechanical linkage attached to some form of flywheel.  A properly designed pneumatic hammer can generate significant force over a very small travel distance, allowing the vast majority of the space between the fully open dies to be used as working volume.  This is possible with mechanical hammers, but the travel distance must be periodically tuned to the diminishing height of the work piece (there is a range of travel that must be tuned).  In the case of tire hammers, the vast majority have a set range of work based on the size of the hub used and the spring travel distance once maximum angular velocity is reached. 

All of this to say, if you have the equipment and know-how for it, mechanical hammers are the way to go when on a budget.  The catch is that it's cheapest if you have a good sized lathe yourself or access to one for a reasonable price, or know a very generous machinist.  Also having decent welding skills is very much a plus, and have the experience to properly align your parts and such.  Pneumatic hammers have the edge once you start factoring in having to hire a professional machinist or fabrication shop by the hour for parts.  You can go to any equipment store and buy a large enough compressor to run a hobby pneumatic hammer for $500USD.  Hit a local scrapyard and buy up some sizable I-beam (I built a 750lb ASO for about $350usd at $.30 a pound plus machinists fees to clean up and square off the stock, I did the welding at the local community college for free) and a basic hammer design for another couple hundred and they'll cut it to size usually.  Get a cheap stick welder and sticks, a good drill and decent angle grinder for a couple hundred more, plus a pneumatic cylinder of good quality and you are set. 

It sounds like a lot, and it is, but a machinist will charge easily $25/hr for machining and will have other fee's for getting the frame laid out properly (and you want to drop money here, a machinist will lay out all your parts per your drawings and use his own experience to help you with the design if you're nice).  A welder will charge double that probably.  Once you buy the stuff you need to make the frame for the hammer you're going to spend as much on the frame for it (at least) as you would a pneumatic hammer. Then you have to buy pillow blocks or some other form of bearings, many of them, and all the drive components plus those machining costs.  You save a vast amount of money building mechanical hammers if either you or someone you know can do a lot of the technical labor for free or very cheap, and the motor (or some form of prime mover) can be had for cheap for the thrifty or well connected.  Buying all the equipment you will need to build a mechanical hammer will shoot well into the thousands at minimum (mind you, a good lathe can be used for a plethora of projects. If you have the money drop it).  It's possible to pick up all the drive components, shafts, etc. from refurbished equipment and other sources so long as you know the parts are true and use them directly with some ingenuity all on the cheap, but that's as much to do with sheer luck than anything.  

On the other hand, you don't have to get axial alignment, bearings, spring elements, or even squared off corners on some parts of your framework so long as you can lay surfaces flat on each other and run good weld beads for a good, level, robust I-beam frame.  Anchor the cylinder firmly and make sure it's  vertically square over whatever you are using for the anvil surface, and have it anchored on a sturdy, heavy base, and your pneumatic hammer requires only a couple control components, tubing, and power to the compressor.  Yes, you still have to approach it carefully, making sure your frame is plum straight up and down, good anchor points, et cetera, but the technical labor is nothing compared to machining the drive components for any of the mechanical hammer types.  You can incorporate increasingly complex valving over time easily to give your hammer more versatility, whereas a mechanical hammer is pretty well set in stone unless you do a major overhaul.

 

You can go on the extreme other side of the spectrum, where I am.  I'm frankensteining together a self contained hydro-pneumatic hammer that uses a 17.5hp lawnmower engine, 22gpm 2 stage pump to drive a short stroke, large bore double-acting hydraulic cylinder tied to a tandem shaft pneumatic linear pump of the same bore size, which in turns drives the hammer head via air-tight steel plumbing.  The linear pneumatic pump is sized to completely aspirate 80% of the air in the system each cycle using muffled check valves set to certain psi ratings.  I can dial these check valves to modulate the impact strength, or clamp the workpiece.  The hydraulic cylinder and rod are going to have to be custom machined, and the actual pneumatic hammer cylinder.  The thing is, I'm lucky enough to be in a place that has several scrap yards where the local foundries drop off their cast off stock.  I can get plenty of frame components for $.30 a pound, and have free access to a welding shop.  I can drop several hundred dollars on custom machining, or hopefully find someone I know that has a lathe and mill the pneumatic portions of the pumps myself, and come out on the cheap.  This is very much due to my proximity to various industries and resources.  For instance, the anvil shaped object I made I picked up a 6 foot section of 5 inch solid round stock and 32x18 inch plate steel, and they had plenty more I wanted to get but physically couldn't transport at the time.  Be creative, do your research, learn your area's resources, and make the decision on which one works best for you.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...