motorised pounding mallet

[lemiant]

Here is my suggestion: http://www.youtube.com/watch?v=U5tHtntT9gU

The constant speed stick is running at 12RPM, which will give you a pound every 5 seconds.
To achieve this I recommend using a CIM (http://www.andymark.com/product-p/am-0255.htm) running through a high reduction planetary gearbox (http://banebots.com/pc/P80K-S4/P80K-4444-0005). You can put a standard #35 chain 12 tooth sprocket (http://www.andymark.com/product-p/am-0166.htm) on the output of the gearbox, and attach a 22 tooth sprocket to the stick (http://www.andymark.com/product-p/am-0216.htm), then run #35 chain between them.
I have more ideas about the construction of it, and the exact configuration of the drive system (shafts, keys and bearings), if you would like extra details like that just ask.

PS After typing that I realized that you may or may not understand any of the words I wrote, feel free to ask for clarification and I will explain our CD jargon.

[Garrett.d.w]

The easiest (albeit crudest) way that I can think of doing this involves some 2*4 lumber, a few half inch bolts, a drill, and duct tape.

First, build two triangles out of some 2*4 lumber (these triangles can be any size that you want, as long as they are the same).

Next, mount them so that they are parallel to each other. The mounts must be sturdy if you don't want this thing to discombobulate in the middle of the demonstration.

Finally drill a hole that is a half in diameter at the same height on both triangles (this will be the pivot point for your lever.

That will be your base.

Now for the arm.

Simply take a large piece of lumber, drill a hole 3/4 of the way down the length (1/2 to match the holes that are located on the frame).

Using tape, or any other method, secure your hammer to the end of the longer side of the arm.

Attach this to the frame using a half inch bolt through the mounting holes we drilled earlier.
With any luck, it should now look like a medieval trebuchet.

Now we need to power this contraption. To do this, we will attach a short length of 2*4 lumber to a variable speed drill (this will be our cam). You will have to play around with the mounting and size of the cam. Your goal is to have the cam push the short end of the lever down (raising the other end), and then drop it so that the hammer can descend.

If you want, I can draw this all for you. It will probably be easier to understand.

[klunk]

Looks like I found the right place!

Thanks for ALL the input, kind folk. There's a lot of information here.
Back soon with questions.

Thanks again,
K

[Alex Cormier]

Originally Posted by klunk

Looks like I found the right place!

Thanks for ALL the input, kind folk. There's a lot of information here.
Back soon with questions.

Thanks again,
K

I told ya this place could easily help you out.

[klunk]

Thanks Alex!