I've got an abundance of compression type springs and no pull type springs usually used. Does anyone have pictures of hammers using them? Or plans? I have a few ideas such as running the spring right at the head or maybe a sliding rod back off the head along the swing arm.

You could telescope it like a strut on a vehicle. Make a top and bottom catch plate that is larger than the spring OD with an inner ring to keep the spring centered. Each side of the circuit has a shaft (think black water pipe) one side slides into the other (maybe 1" inside 1-1/4"). The inner piece is a little longer than the outer and has a key to prevent the assembly coming apart. It's a cheesy drawing but something like this

:]--------- ////////// ====[:
Top sleeve,Spring, Bottom sleeve

Edited July 29, 200916 yr by HWooldridge

I've thought about it but never came up with something I like very well.

Hollis's suggestion is about as good as I came up with.

How about a torsion bar instead?

Frosty

I was thinking of using two 2x2 for uprights and running a rod between them from the foot pedal and having the spring on the other side of the 2x2. Then it would be like a stretch spring but on the other side of the uprights.

If you can have a look in the back of the book "Werk Und Werkzeug Des Kunstschmeids" by Otto Schmirler. It has a Oliver hammer that uses a compression spring. I have heard that this was what the origional ABANA treadle hammer was based on. The spring is set up similar to Hollis's suggestion. There is a long pipe that the sping is inside fastened to the frame, inside the spring runs a long piece of round bar which is fastened to the arm. The book while expensive is an excellent reference as well, my copy is in German English and French.

You can also do what I did when I could only find long compression springs. I took a torch and heated a small spot on the spring and bent it up to form a link. I then just let it air cool. The two springs I used were still working after ten years when I sold it recently. I used to repair T-bar springs this way when I worked in the ski business and they stood up as well as the new ones.