treadle hammer ?

I've built both of Clay Spencer's hammers, the swing arm and the inline. We actually built six of the latter. Both sets of plans are

*excellent*. Both hammers work nicely. The swing arm type is simpler, I put it together in four (intense) weekends when I was much less experienced. If you want any heavy hitting, do use a solid, heavy anvil. The inline hammer seems to hit harder; we tested this by striking coins, which is pretty demanding. Plans can be had from snipped-for-privacy@grove.net or Norm Larson books snipped-for-privacy@impulse.net

Steve Smith

james pelzer wrote:

The email address for Clay is about 1 or 2 back..........current is snipped-for-privacy@brmemc.net

I know this is correct having recently (last week) talked to Clay

Thanks, I haven't actually written Clay for awhile. I will update.

Steve

Rome Hutch>The email address for Clay is about 1 or 2 back..........current is

James,

The Grasshopper DOES look busy. Perhaps it's even more work to build than other hammers - I don't know because I haven't built any others. To allow for the need to properly build the thing, the plans for it are detailed. I think they're easy to follow.

But let me explain WHY the Grasshopper looks so different from other treadle hammers.

The original premise of the Grasshopper was to have a vertical-motion hammer that did not rely on sliders or rollers. Remember, Sheppard's Big Lick (slider-mounted vertical-motion hammer) and Spencer's vertical-motion hammer were inspirations for the Grasshopper. Both of those had been developed before I started on the Grasshopper.

So why no rollers or sliders? Both of these mechanisms are subject to dirt and wear. Blacksmiths shops are nothing if not gritty. (That scale from your hot iron and that ash from your coal both make pretty good abrasives.) Furthermore, though sliders and rollers seem simple, and may be simple to construct, I suspect some continuing effort has to go into keeping them in adjustment.

But the big reason is stroke. Both sliders and rollers must engage the ram over a considerable distance, and the stroke of the hammer is thereby limited. With the Grasshopper, the hammer stroke is 34". The clearance over the anvil is something like 22" (See the website for better stats.) That's unique for a vertical hammer.

If that were all there was to a Grasshopper, you could drop off two major subassembly - that makes the thing look busy. Those subassemblies are the eccentric pulley and the kickback adjustment. You can build the hammer without these, but you'll be missing a lot of the advantages. The eccentric pulley provides for a completely weightless ram. The springs don't lift the ram, they balance it. You can position the ram anywhere in the stroke and it stays there. Hence, you don't have to fight the springs as you work.

Now, to compensate for the lack of lift by the springs, it's necessary to add a little lifting force right at the bottom of the stroke. I call this "kickback". The mechanism to create the kickback looks imposing but is rather simple in fact.

Another major advantage of the Grasshopper is that the adjustments (kickback and treadle position) are made from the front, and are so quick that they can be made between pulling your iron out of the fire and putting it on the anvil. (There ARE other adjustments, but they're made once when the hammer is first set up, then left alone.) This means you never have to stop to make an adjustment and you never have go around or reach around the side of the hammer to make the adjustments. That's quicker and safer.

Hope this helps.

Bruce Freeman

Some time back, I got a set of plans from Centaur Forge, then modified them to suit my situation. I ended up with a 180 lb hammerhead floating on a dead scooter coil-over, connected to the support (a length of 6" structural pipe) by equal length links made from leaf spring stock. It maketh everything verrrrry flat with just a toe tap. The head does move in a partial arc, but the face stays parallel to the anvil top all through the travel. If I did the math right, 100 pounds of apply pressure on the toe pedal translates into just under

1100 pounds applied to the hammer. When I use it, it shakes the whole shop, and the neighbor says he can feel it in the ground. It hits a LOT harder than my 25 pound Little Giant, but not as fast. It was cheap to build, under 100 dollars US, including the lead for the head. It's been a lifesaver for hotpunching and cutting, and all those other operations that require three hands or an apprentice (Hold this chisel right here... don't flinch, you'll make me miss again.).

Pictures?

Sorry, no digital camera, no way to get them into the net. (wish I did, but the economy is in the crapper right now, and other things clamor for my meager funds.) I could CAD it up and send the file as an attatchment, if you have a copy of AutoCAD to play it on.

Save it as a DXF or DWG file and post it to the Metalworking.com dropbox, here:

Then post the address of the file in the dropbox.

Can do, might take a while, I'm in the middle of a major remodel at the folks house. I'll get on it as soon as practical.