Treadle hammer anvil and accessories

[Jason M]

I've been looking at treadle hammers for ideas to use when I build mine. I noticed some have solid anvils and many have two pieces of round stock with a plate on top. What is the reason for that? Also, I'd appreciate pictures and or descriptions of your holders, tools, etc, that you have created for use with your hammer.

Thanks, Jason

[tinbender]

test...........

[tinbender]

Hi Jason,

I've been studying treadle hammers too but have not started one yet. I think you are referring to the filled pipe anvil and striker. My understanding is less cost and the ability to easily tune the weight. I may use that type to tweek the machine and replace with solid when happy with the way it works.

Good luck, Dave

[Charlotte]

There are many different designs for tredle hammers and their anvils.

After watching and listening to Clay Spencer several times, and interviewing other designs in person and in plan view, I have come to the conlusion that the anvil has only two real pre requisits:

1) It needs to have a big enough mass to take the weight of the head.
10:1 sounds about right.

2). You should make some provision for changing out to different striking surfaces. Most people make a provision for a taper key in a slot in the anvils body.

I'm personally partial to Clays's anvil which, as I recall, is 5 rectangular bars, bartacked together at several points down the length with the middle bar shorter to provide a space for the taper key. The top has a square hole in 1/2 plate through which a drifted shank attached to the working surface is placed and a taper key hold down.

I'm currently working up a grasshoppers hammer design for light work. While the head and the remainer of the treadle hammer will be light. I will make the anvil as heavy as I can manage without buying special material.

Edited April 11, 2009 by Charlotte
Word left out

[Charlotte]

Incidentally, I've been toying with the idea of filling the head of mine about half way with lead shot and then adding 40 wt motor oil.

Kind of like a dead blow hammer. Since I 'm planning to use this for cold work reposse I think this might be more effective for that purpose.

Anybody tried this experiment??

[Frosty]

The hydraulically driven, drive hammer weights we used on the drill rig were filled with powdered lead and did indeed produce a much deader blow than the solid steel manual drive hammers.

Are you following Bruce's plans or are you winging the grasshopper?

Frosty

[Charlotte]

My Grasshopper hammer:

There is no secret to the grass hopper hammer so it is not necessary to follow anyone's plans. I'm designing it to meet my needs.

The only rule that needs to be followed is that the square root length of the stabilizing arm has to equal the product of the division of the swing arm.
In other words:

If the length A_B is the long (swinging or driven arm ) arm and point C divides that arm into two segments A_C & C_B then the length of the Stabilizing arm D_C must equal the square root of A_C X C_B.
Point A is the parallel motion point and B is the end point or piviot.
(C_D) X (C_D) = (A_C) X (C_

It can be seen that the most convient solution to the above equation is to create C_D equal to A_C= C_B.

The point B is actually the fulcrum of the lever arm A_B. Its small motion compensates for the other wise greater horizontal motion of point A.

The height of Point B is arbritary but should be high enough that the midpoint of the vertical motion of of A to allow the maximum benifit of the hammers motion.

Provision of a second arm set A'_B' & C'_D' prime above the first arm set is of course a logical necessity based on the need to keep the hammer from pivioting to freely around point A.

The rest of the treadle hammer is open to cleaverness and mechanical inventiveness of the builder.

[Frosty]

When I modeled the thing I found all you really need is for all the pivots in the horizontal arms as a set and the vertical pivots as a set, to be the same, while the total length of the long arms has to support two sets of pivot points plus the enough extra moment to supply a reasonable return spring track.

Basically the long arm has three pivot points and the return cable track while the short arms have two. Making the long arms twice as long at the pivots.

I modeled it physically in three scales, first with an erector set at whatever scale that is. (3 holes between horizontal pivots and 2 on the vertical) Then at half scale and finally at "full" scale or approximately 20-24" stroke. (it's been about 6-7 years and I'm not positive about the stroke #)

Agreed, no need for Bruce's plans if you understand the principles and have the fab skills.

Frosty

Edited April 11, 2009 by Frosty

[Charlotte]

Yup Frosty,

I went into the math thing so others would have a chance of understanding that there is a reason to make it the way your describe.

There is a nice website that gives animated views of several kinds steam engine linkages, Go to "http://www.animatedengines.com." All of the engines are fun if you are interested in things that produce motion.

I came up on this site while investigating the Idea of a cable driven excentric wheel as the driver for hammer. Got switched over the grasshopper when I realized that I still had a problem with frictional loses because of the need to control out of plain rebound vectors.

[Jason M]

Thanks for the info guys. I have some 6x6x.25 wall tube which I am using for the frame of my hammer. I have some 6x6x6 square blocks of steel which I was going to use one for the hammer and one for the anvil. I will probably add some additional tubing under the anvil for support. I am building a parallel linkage type based on the Roberts linkage which I mistakenly referred to it as a grasshopper type in another thread. I started cutting the frame pieces last week. I am going to order the steel for the linkage next week.

[freemab]

I'd be very interested in your work with the Roberts linkage, as this was a linkage I have also considered employing.
Bruce