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Steel and concrete anvil stand


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On 11/9/2018 at 4:31 AM, arftist said:

Wrong.

You probably couldn't break your finger hammering on it with your anvil on belly.

 

Whip out that long boring explanation if you are going to make that claim.

It is all about inertia and a 2000 #

block has a lot more than a 200 #.

 

My unceremonious reply is due to your unceremonious post above. Not only it is silly but it is also false. I can guarantee to break anyone's finger laying between two chairs with a 20 lb or a 100 lb anvil on my belly and a 16 oz hammer or if you prefer a 3 lb hammer. 

Like I said, if you think that you can increase the mass of your anvil by having a bigger stand, join the rest of the believers and be happy with that assumption. I am in no way going to add to that. 

The rest of your boring long post that claims all I say is false is very funny, but is devoid of any substance and so merits no reply.  

Better luck next time. 

8 hours ago, arftist said:
8 hours ago, arftist said:

If you wish to be taken seriously then reply in a serious non-pejorative manner.

 

 

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On 11/8/2018 at 9:31 AM, arftist said:

On topic, yes, concrete has tremendous strength in compression...but small diameter rebar doesn't. 

In no way is this stand designed so that the rebars have compressive strength. 

Sorry, it just isn't.

Another thing about concrete,

It is light, it doesn't make a good filler. 

Use lead to fill pipes for weight,

The combination of 3/4" rebar and concrete gives this stand outstanding compressive strength, an order of magnitude beyond what it needs. The concrete insures there is absolutely no deflection in the rebar, which is it's main weakness in compression. 

Lead is a waste of money. It will dampen the sound, but adds little stiffness to the system. Concrete will also dampen the sound, just as well as lead in this instance, and it adds significant strength and stiffness to the support member. Once the stand is securely bolted down, weight makes no difference. It is only stiffness at that point. 

Contrary to a lot of the armchair quarterbacking going on in this thread, I actually build and test my theories. I know my stand works well because I built and tested it under real working conditions. I would highly recommend this type of stand to anyone who wants a rock solid platform for their anvil. In fact, it worked so well I'm building another one for the new anvil I'm getting.

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But isn't tension where a concrete anvil stand would give you trouble? It's not crumbling under compression, but from the low-pressure side of the impact curve. In other words, the concrete gives you strength during the blows, and the rebar gives you strength between the blows.

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2 hours ago, Ted Ewert said:

I would highly recommend this type of stand to anyone who wants a rock solid platform for their anvil. In fact, it worked so well I'm building another one for the new anvil I'm getting.

I have no doubt that your stand will stand for a long time. Consider the relatively pitiful shock you impart at it by hand after most is absorbed by the anvil, compared to the shock concrete in that size can withstand and you are miles ahead. i would have tried fibre reinforced concrete to get a multidirectional reinforcement as an academic exercise, but with the size steel you used, it seems overkill either way.

The only reason folks object to a concrete stand is because it is not done. I would love for you to build a concrete striking anvil with just a thick steel top plate.

Oh no! it will crack! Anathema! :P

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Hopefully this will all work out for you Ted.  Long-term will be the key.  Each year you should report how it is holding up.  If it's doing well, then the naysayers should see that and if it's developing cracks and problems, you should show that as well.  What you are doing really is an experiment and the other half of that is honestly reporting what you find over many years.  You may be onto something or it may be a complete failure in 5 years.  Nobody can tell which it will be at this point.  I'm hoping your design works well over the long haul, but I"ll keep my wooden stump that's worked well for me.  I think folks can miss that aspect,  Your concrete stand might work best for you but not for others just as my plain old wooden stump might not work for you.  

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On 11/12/2018 at 2:19 PM, JHCC said:

But isn't tension where a concrete anvil stand would give you trouble? It's not crumbling under compression, but from the low-pressure side of the impact curve. In other words, the concrete gives you strength during the blows, and the rebar gives you strength between the blows.

Sure, if he is doing full wind up blows with a 10 # sledge on the side of the horn.

Otherwise, not so much.

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One thing that has only lightly been touched upon is the inventiveness of people over time to make their environment better. (Or if it's a common and cheap thing; why are not more people already doing it?)  Had a professor once that told about a fellow getting an advanced degree and his thesis was on the correct height for an ironing board; He experimented with a large number of people all kitted out to measure their metabolism while ironing and came up with the correct height.  My prof when he heard about this sent out a bunch of his grad students to go around town knocking on doors and asking: Do you iron?  If so what height is your ironing board?  The numbers were nearly exactly the same. Also my Father told me about a study they did on telephone bells; they had been using them for 100 years but nobody had checked to see if they were the *best* ones.  That study too indicated that the bells that had been gradually improved for 100 years were spot on with the "properly designed" ones.

Now the big breakthroughs are when you get new materials and apply them to old problems.  So I would like to see experiments with concrete strengthened with the various filaments available now.

Of course you need a decent statistical universe---I see a bunch of horrible anvil stands done by folks who are not smiths and so don't know what they are trying to accomplish save for getting the anvil off the floor.

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On 11/12/2018 at 9:09 AM, arftist said:

Yes, concrete is very strong in compression BUT rerod only adds strength in tension.

Rebar is used to reinforce concrete in tension mode most of the time. However, it can also be used for compression. As long as it is kept from bending it has as much compressible strength (generally speaking) as any other type of steel. The way I have it configured is to take some of the shock load off the concrete, though I'm not completely convinced it even needs it. It also adds lateral strength when the anvil is struck on the sides. 

BTW, I find the road less traveled a lot more interesting...

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I started building a stand for the new anvil which should arrive shortly. After quite a bit of research, and soul searching, I decided to get a 200 lb TFS Smithy Special. I was leaning towards a Nimba Centurion, but they are out of stock and don't expect to have anymore until sometime next year. Being the impatient type, I started looking elsewhere and decided that TFS had just what I wanted. I was going to get the 300 lb, but after much internal debate decided that the 200 lb would be perfectly adequate for what I do. I also did some research into ductile iron and found it quite suitable as an anvil material. 

Anyway, this stand is also going to be a concrete reinforced steel stand. I'm building it mostly from stock I already had lying around. I started by cutting in half a piece of 3" x 3/8" angle iron, and filling in the gap with some other pieces of 3/8" flat bar. I added some rebar inside for support. The ends are capped with 1/8" sheet metal. 

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After all that welding, and some minor grinding, I managed to keep the top pretty flat.

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I had a long piece of 3" pipe behind the shed I decided to employ. I cut it up into legs which will populate the four corners of the top.

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The one on the far left I'll use to adjust for good contact. I'm going to use angle iron welded to the bottom of the legs to anchor it to the concrete. I will pour concrete to fill the base and between the legs, and also fill the legs. I bought some anchor epoxy and I'm going to try that method since I've never used it before. 

I'm waiting for the anvil to arrive before final assembly. I will have to figure out some sort hold down, that will require machining, which is much easier without legs attached to the top.   

Once I get that done, I'll weld the legs to the base and put some rebar between the legs for the concrete to adhere to. Then I'll form it up and pour it upside down. I'll post some more pics when I get to that point.

 

Ted

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I just got this completed today. I filled both inside the pipes and within the four pipes. 

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As the concrete is not the primary load bearing material, it does not extend all the way to the floor. This made the stand much easier to level and work into place.

The anchor bolts are epoxied into the concrete (for those of you who were worried the drop in anchors would work loose). The stand weighs about 300 lbs, the anvil 200 lbs and I don't know how much the slab weighs. The stand has high stiffness. 

Still getting used to the great expanse of real estate on this anvil. I built a simple hook and leaf today and it all worked very nicely. Had to stop halfway through and take the sharp edges off the top as they were leaving little marks in the work. 

I only have the one rack as of yet. 

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  • 2 weeks later...

I had an issue with ringing, even though the anvil was bolted down. I found that the bottom of the anvil is not absolutely flat. There were small gaps between the base and the anvil. I loosened things up and put some steel shims in. Tightened everything back up and the ringing stopped. 

I can see where silicone would have the same effect, but I think steel shims are a better solution on a steel stand as it won't compress. 

Anyway, the stand remains rock steady. I would also mention that vertical legs work perfectly well if they're bolted to the floor. I've beat on this anvil from every angle and it stays very stiff. 

I would also say, after much thought, that an anvil and the stand become one mass when securely fastened together. I can offer up a proof for this if anyone is interested. 

Ted

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It's all basic physics, I don't see why people have such a problem with it. If you attach any two objects together, the total mass is the sum of both. There is no arguing that fact. If it weren't, you could fill an airplane with lead and it wouldn't make any difference in its ability to take off

When we talk about an anvil and a stand, the same laws of physics apply. 

Does anyone still not understand this?

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It would be pointless to revisit the topic, but telling others they "don't understand" is rather puerile and so is the comparison with the load of an aircraft. 

There are many other factors involving the behaviour of objects in a collision, not only gravity. 

But I have said this already more than once and it's getting rather boring. 

I thought you were joking when you included the slab in your evaluations. Obviously I was mistaken. 

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Sorry but physics tends not to be an all or nothing thing.  You can find quite a difference in how an anvil attached to a solid steel mass by a full penetration weld will react to a vibration pulse and one of the same weight/shape that is just strongly clamped or bolted together----hook up a transducer and an oscilloscope and see! 

I had a student that milled an ASO a flat as he could get it and tried bolting a steel plate to it---aslo milled flat.  He was not pleased with the results

Ever use heat transfer through a billet to locate a cold shut? May be "attached" all around it; but the discontinuity makes a difference!

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2 hours ago, Marc1 said:

It would be pointless to revisit the topic,

Revisit? I stopped visiting at all till YOU suckered me in this time. And not just because I was so wrong, I'm good with being wrong I'm used to it. He won't get it, could maybe but won't. 

I think you've run into one you're love of a good argument, no wrong word, disagreement, is wasted on.

Frosty The Lucky.

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3 hours ago, ThomasPowers said:

but the discontinuity makes a difference!

Bingo!

Ted, no need to get angry over this. It is not a case of adding up mass, it is not intuitive and it does not really matter after all. All you want is for you anvil to make your hammer blow work. 

If there is no continuity in the density of an object or if it is made with two different materials, the object will behave differently in a collision. 

The case of an anvil floating on sand, and the same anvil bolted to a stump of equal mass, yet behaving in a similar fashion, should tell the story.

To find a value that takes into account the contribution of the stand as a secondary object in a collision requires a lot of mumbo jumbo and would have a number of variables, and surely it is not a matter of adding up like you do when you load a lorry.

Oh ... and "puerile" was my big word of the day :P 

Peace man, keep on posting your work. I do like the concrete stumps and I was the one who told you it will work. It may not add much mass to the anvil, but it works as a great stand. 

 

 

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I fully understand collisions involve dissimilar materials, mass, inertia, momentum, kinetic energy, centrifugal and centripetal forces, and a myriad of other physical principals. I can't tell you how many physics books I've read. I have also done many experiments involving these principals.

Trying to explain anything further, as was said, is a waste of time. I will continue to build, based on my own knowledge, and post the results. You guys can take it or leave it. 

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The steel and mortar striking pad didn't work when I tested it this evening. The top plate started to dent. It was only eighth inch plate so no real surprise. A much thicker plate might work, but I have no real desire to build one. 

What I am thinking of is a swage block. Some different sized pipes cut in half and welded together around a square perimeter and filled in with concrete might just work. We'll see. 

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