Finished fork lift tine anvil... Mostly

[ThomasPowers]

The gluelam is an appropriate analogy for a stack of plates with full penetration welds. Stack them up with just a 3/8" glue joint around the edges to get one appropriate for the case we have been discussing.

I don't believe I ever said it was done wrong; just that there may be a *better* method. I thought sharing better methods was a good idea. Mea Maxima Culpa

[Mainely,Bob]

Are we far enough off-topic yet?

I still haven`t heard any convincing arguments or verifiable facts to prove that vertical is superior to horizontal in a laminated anvil yet so I`m still in favor of wandering further afield if it`ll get us there. ;)

[Eric Farrar]

Laoich23,

Fine looking anvil you've got in the works there. I fabbed mine up from 1 chunk of big forklift tine and 2 cut up tank half shafts.... I didn't have any oxygen for the A/O torch when I was starting so I had to cut the 3" round off and then rough cut the horn with a hack saw... It was a good workout but made the grinding work much easier and I only went through 2 hacksaw blades...

What worked for me and might help you with shaping your horn is using a hacksaw just like you would draw round stock out with a hammer - square pyramid to octagon pyramid. Then move on to the grinder to round it out.

Good luck and happy forging!

Eric

[Laoich23]

Laoich23,

Fine looking anvil you've got in the works there. I fabbed mine up from 1 chunk of big forklift tine and 2 cut up tank half shafts.... I didn't have any oxygen for the A/O torch when I was starting so I had to cut the 3" round off and then rough cut the horn with a hack saw... It was a good workout but made the grinding work much easier and I only went through 2 hacksaw blades...

What worked for me and might help you with shaping your horn is using a hacksaw just like you would draw round stock out with a hammer - square pyramid to octagon pyramid. Then move on to the grinder to round it out.

Good luck and happy forging!

Eric

Thanks Eric! I think I might have talked my roommate into shaping the horn... hehehe But that is what I had in mind.

[Dragons lair]

Wow Drag!
Care to get a cup of coffee,sit a spell and tell us why you happen to be just a little grumpier than usual?
Gotta admit,I also have welded a lot of stuff together that folks told me wouldn`t last.That`s how I know 7018 will work on SOME cast iron.
Just tryin` to unravel who you`re aimin` this latest bit of rough cut wisdom at.
Coffee`s over there,I brewed it up fresh today.Help yourself while I fetch another chair.

Dang Bob, spent a half hour two fingering a PM to ya and get a member can't receive new messages. Your mailbox snowed in or what? LOL
Ken.

[BIGGUNDOCTOR]

Hacksaw? Naw. Porta-Band? Yes. Power is your friend, use it.

A torch would be faster,IF you are good with one. Otherwise you will end up with a lot of ragged edges to deal with. It would also do good for the hardy hole, especially if you can find someone with a pattern, or programmable torch. Tim McCoy had some tine sections that I milled for him. The hardy hole was drilled, then milled square with a 1/4" carbide endmill. The tine is really tough, so if you can use a drill press it will go a lot better for you.

[Mainely,Bob]

Dang Bob, spent a half hour two fingering a PM to ya and get a member can't receive new messages. Your mailbox snowed in or what? LOL
Ken.

Got the same message when I tried to PM you.That`s why I left the message on your profile.More bugs I suppose,guess we`ll have to just bat the breeze here,we`re all ready off track so drag up a chair.

Just wonderin` if you`re OK,after your one post we didn`t hear from you at all.
Hope I didn`t say anything to set you off.I can be long winded I know.
Maybe Glenn will be around here in a minute to tell us he fixed the glitch and our mailboxes will start workin` again.
How do you like the coffee?

[ciladog]

I still haven`t heard any convincing arguments or verifiable facts to prove that vertical is superior to horizontal in a laminated anvil yet so I`m still in favor of wandering further afield if it`ll get us there.

I doubt you have ever seen a martial arts expert break boards in the vertical orientation. They are actually breaking one board at a time as the force is transmitted from one to the next and they flex until they break. Glue the boards together and see what happens.

Once the plates on the anvil are welded together I doubt that it matters what the orientation is. Mass=mass. What force do you think it would take to flex just one of those plates?

[ianinsa]

This has been a spirited discussion!.
I recon that stack of tines will probably outlast most of us.(horisontal or not)
I've seen the advice on making the horn using powertools and cutting torches and even the hacksaw chirp now I think it's time for someone(a ludite) to mention that a 'true' craftsman would use a file and sandpaper to form the horn? Personally I'd give it a bash shaving it with a plasma cutter.
As a homemade anvil I think that one is certaily better than most-- Good Job!
Ian

[Sweany]

I can`t help but wonder why the fork lift tines we`re cutting up aren`t being used in a vertically oriented mode rather than on the flat if there`s a real advantage to having them that way.

thats easy, forklift tines on edge won't go in the pallets!

Just be sure to orient the horn of the anvil to true magnetic north.

[brucegodlesky]

thats easy, forklift tines on edge won't go in the pallets!

Just be sure to orient the horn of the anvil to true magnetic north.

And reinforce it with rebar!! :D

[Pat Roy]

Just a question Pat.You`re talking about floor joists which are something working over an unsupported distance.I understand the theory and that goes along with the idea of bending a flat bar "the easy way or the hard way".
When the work is fully supported along it`s length like this anvil is on a stump does this still hold true?

I can`t help but wonder why the fork lift tines we`re cutting up aren`t being used in a vertically oriented mode rather than on the flat if there`s a real advantage to having them that way.

It may be an insignificant point but I believe the vertical orientation of the plates would produce a stiffer unit to resist the impact. But that is the mechanical engineer in me. In actual use, a 4 lb hammer impacting that mass of steel might be a thimble in the ocean so to speak.

As far as those fork lift tines in service; they are strong and tough but the are not subjected to impact loads and they do deflect a measurable amount but are not loaded to the point they permanently deform.

I'm just glad I am not tasked to shape that horn. I'm happy to have found anvils to buy rather than make. Good luck with your project OP, it's looking good.

[ThomasPowers]

File a horn? We're *BLACKSMITHS*! Gotta use fire somehow in the shaping---how about getting your friends together and forging it to shape?

[Mainely,Bob]

File a horn? We're *BLACKSMITHS*! Gotta use fire somehow in the shaping---how about getting your friends together and forging it to shape?

I`m picturing 3 guys on the end of a pair of 6 foot tongs and a chainfall w/overhead track in your future there Laoich23.
Look at some of the old silent movies on here dealing with wrought iron anchors and such to see what I mean.
That would just be the high point of the year to be part of a project like that!
Closest thing I`ve seen in the present day is Phil`s and James` videos of big stuff being handled by fork lift powered hydraulically rotated tongs under mega hammers.
That sort of stuff will make any blacksmith smile. :)

[stribett1]

Finished my version earlier this week. Weighs 100/110 lbs. It has good rebound. Its main purpose is for Boy Scouts to pound on. I made the hardy from left overs. Paraphrasing someone smarter than I , " If it breaks, it is still just scrap."

[Fosterob]

I can't believe that nobody has brought up that a good amount of "real" anvils are made with a tool steel plate laid flat on top of a body. This is almost the gold standard for anvils. Now to compare it to Grants gluelam beam I would think it to be a good analogy. Think of it as one large piece, not like a leaf spring. As Thomas and others have speculated that vertical laminations are "better" and if only welded around the edges I must agree. Bobs way of compressing the laminations before welding is an improvement of flat laminations.
If anyone has tried to use an anvil that the tool steel face has started to delaminate would understand how flat plates can not be as good as vertical plates. Otherwise we would never consider doing the sand test on a used anvil to check that.
Are the plates in a flat layout going to work? Of course they will. I also know it is a lot easier to get a larger face that is flat that way.
In the end if you can hit hot metal on it it will work no mater what you choose to use.
All the homemade anvils on here look really great and will outlast their makers grandkids. Good work.
Rob

[evfreek]

I still haven`t heard any convincing arguments or verifiable facts to prove that vertical is superior to horizontal in a laminated anvil yet so I`m still in favor of wandering further afield if it`ll get us there.

Hi Bob. Thanks for focusing the discussion. It is amazing how warm people are getting just sitting around, drinking coffee, and chatting. Since everyone has been so patient, I will give you some more verifiable facts.

The comment about plates flexing and taking up energy is right on target. The observation that this effect is larger for a horizontal stack than a vertical stack is also very appropriate. What you are looking for, probably, is some approximate numbers, and perhaps an academic reference.

There are two key steps that we need to realize in order to quantify the loss of forging efficiency. These steps are absent from most mechanical engineering textbooks, but some of the older ones include them. The first step is to apply the principle of conservation of energy. This principle says that, for deformations of the plates restricted to be elastic, the most energy that can be stored ("lost") in a deforming plate is that associated with its bending. In other words, for a given force, beam theory tells us what is the total amount of energy stored in the displaced beam. There can be no more, but there can be less, due to various factors. The second important concept is that for linear deformations restricted to the elastic region of the stress strain relationship, the energy stored in the beam is just that stored in a linear spring with a spring constant given by the material properties and dimensions. In other words, F = kx, E = 1/2 k x^2 , where the caret denotes exponentiation, implying E = 1/2 F^2/k. This not so familiar result has the very familiar conclusion that the energy storage is inversely proportional to the stiffness. For example, the requirement of stiffness in hydraulic systems is equivalent to the restriction against excessive elastic energy storage.

Moving on, let us estimate k. For a simple beam, x = 1/48 FL^3/EI, where L is the length of the beam, E is the elastic modulus, and I is the moment of inertia. Thus,
k = 48EI/L^3

If we assign some sensible dimensions, the longitudinal welds support the ends of a very short but wide beam. L = 3", b = 10", d = 2", and I = 1/12 bd^3. The dimensions are approximate from the photos. Substituting the numbers in to the above equations and eliminating a lot of steps, we get E = 0.2 in-lb. We use F = 12000 lb, from the approximate impact force of a 2 pound hammer swung at a reasonable speed. This computation is beyond the scope of this document, but can be found in various textbooks or web pages. The total energy of the hammer is equivalently 60 in-lb, which corresponds to a 2 pound weight falling 30 inches. Of course, nobody drops a hammer 30 inches, but the speed was calibrated from photos taken at MIT of a blacksmith's hammer swing. It is reasonable that the speed would be higher than that at free fall.

This computation shows that the energy loss is 0.33%. Small, but perhaps not negligible. Lets examine a couple of key assumptions from above. First, the assumption of the validity of a 1 dimensional simple beam calculation. This is obviously not correct. The impact is a point, not a line impact. But, it will spread through the plate. In that case, b is overestimated. It is likely that only 1/5 of the beam is actively involved in bending. This drops k by a factor of 5, and it is possible that the energy loss is 5X larger, or 1.7%. This is the difference between a 100 and a 200 lb anvil, so it may be noticeable. Second assumption: what about the second interface? The stack has more than one plate. Well, the picture of the karate demonstration is misleading. First, the plates are in elastic deformation. In the photo of the karate demonstration, the wood planks are obviously stressed past their elastic limit. Linear elastic deformation theory is completely inapplicable for the karate picture. Fortunately, it is in our case. The verification of this fact is left to the reader. The reason why the second plate does not deform as much is that it is probably not contacted by the first plate. Why? Back calculating gives x = 27/32 x 10^-5". There is no way that a backyard blacksmith can fit two plates to an accuracy of 8 microinches. This is even beyond the capability of most machine shops. Instead, most of the "dissipation" goes into the two welds supporting the simple beam. These may be considered to be a simple compression spring, and the same analysis applied to them. Using reasonable values of 10" x 2 x 1/8" area and corresponding thickness gives even smaller energy losses than above. Third assumption, we considered the energy loss for a hammer directly impacting the top plate. Nobody does this, not even backyard blacksmiths . Typically, there would be a softer target of hot metal in between. Thus, the above calculation is pessimistic.

So, the horizontal plates are worse, but not that much worse.

How about vertical plates? That exercise is left to the reader, with the hint that the Euler buckling criterion is applicable. It will be found that the energy "dissipation" is really quite negligible.

As for a reference, the following text is great, but any strength of materials text, such as Timoshenko's classic may be used.

Mechanics of Materials, Mansfeld Merriman, John Wiley & Sons, NY, 1914.

The above analysis is mine, and will appear in a forthcoming paper, so don't sue me if you steal the copyright and discover it later.

[CurlyGeorge]

You know, fellas. All this theory and engineering is great. But this is an anvil that is going to be used under a hand hammer and I just really doubt that the force applied by a hand hammer is really going to make that anvil bow. The man did a great job using materials that were available and it will serve him well, for hand forging, for many years to come. I am not an engineer, nor do I ever want to be. But as for the project that started all of this technical discussion in the first place, GREAT job!!!B)

[Mainely,Bob]

OK.let me run something by you as long as I have someone who understands and is willing to articulate theory on the line.
One of the standard tests we have for anvils is rebound right?It`s my understanding that rebound is a function of localized deformation and the material`s ability to "push back" like a spring does only on a far more limited scale.We harden the face of anvils in order to take maximum advantage of this quality of the steel.If this resistance to deformation yet ability to "spring back" or rebound is a primary consideration in anvil construction then it seems to me that,within certain limits,an optimum configuration for a built up anvil would be a rather rigid body(we all know this and agree that it`s so) yet wouldn`t the face of the anvil made with material like a fork lift tine better serve these conditions by having a slight crown meeting that body only on the ends and having a body that contains the ends yet allows the face to deform somewhat and then use that energy to "push back" and help move the metal?
I think we talked about the mechanics of this in an old thread on drop forges or presses where rather than having your anvil serve in a static state if you made it work in a dynamic fashion you could accomplish far more work per cycle of the machine.
As long as we are talking about optimizing a blacksmith`s anvil why not talk about making it dynamic instead of static?

You have no idea how pleased I am to have someone take the time to present this in detail like you have but to also be able to track it as well as I have.I attribute that to your presentation rather than my mental capacity because I struggled to graduate high school(it was the 60`s/70`s after all).
Your presentation also turned on the light that illuminated the dynamic anvil post and got me thinking in a different direction.I have yet to decide if that`s a good thing.
Perhaps I should visit the bathroom,look in the mirror and see for myself how much smoke is pouring out of my ears.

You can count on me to grab onto something and run off the end of the earth with it. :rolleyes:

[Laoich23]

Glad this has struck up so much conversation. I start heading towards my mechanical engineering degree this summer, so this is rather intriguing. Anyways, If anyone cares, I added the feet and it know weighs in a 112.2 lbs.

[bajajoaquin]

How about vertical plates? That exercise is left to the reader, with the hint that the Euler buckling criterion is applicable.

This totally reminds me of the movie Fletch: "C'mon, guys! It's all ball bearings these days!"


Will you tell us when the paper comes out? Or can you tell us about the paper now? Is it specifically about smithing and anvils, or is it about something else, and anvils are a good analog?

[ThomasPowers]

I have a friend whose father was a research metallurgist for Batelle. One of his projects was measuring how steel moved under micro forces. Kind of amusing to see a couple inch sq bar of steel all wired up and the meters going wild when you lay a finger on it.

So yes I do believe it will bow even if it's not enough to detect without fancy equipment. OTOH just like most experiments we throw out a lot of stuff to make it easier---like tidal effects!

[Nakedanvil - Grant Sarver]

Looks to me like using a hammer a couple ounces heavier will make up for any perceived deficiencies in the anvil. Most of my "theory" revolves around conclusions drawn from experience and voracious reading. Research would involve the scientific approach of hammering a piece of hot steel on the anvil and crying "eureka! this frigging anvil is good/bad/ugly"!

[ThomasPowers]

Pretty easy to design an experiment: drop a weight from a known repeatable height onto a known repeatable chunk of iron at a known repeatable temp and then measure deformation after cooling. Note that making sure there is no difference in oxide layer thickness will be needed as well. Repeat 100 times each and crunch the numbers---anybody got a student that needs a senior year research project to graduate?

I would suggest an induction furnace used with an optical pyrometer so heat up/hold time is minimized and use an alloy that can be quenched immediately after the strike to cut down on further oxidation.

The idea is that the anvil make up is the only difference.


Be interesting to vary the weight to see if any differences take affect under different anvil to "hammer" ratios too!

Franky a lot of nit picky work for little payout! I think I would rather argue over which one of us is the biggest Vermicious Knid!

[maddog]

Excellent post evfreek. Thanks for taking the time to lay that out. I'd like to see that analysis applied to the issue of anvil shape vs effective mass. I'd love to read the paper when it's available.

Interesting that Dave Budd's practical experience suggests that the orientation is significant. But there are a lot of variables which weren't controled in that "experiment".

The plates will flex even if you drop a grain of sand on them. It will be a tiny deflection but it's there.

Bob, I think you are right about the crowned surface. Probably the most effective surface for rebound would be the top of a cone.