Power hammer (may need some help)

[Peldor]

Ok, I am taking my mechanical engineering degree and want to start a project to make a power hammer. I have designed 2 of them, one using the overhead leaf spring design, another using the 'little giant' design. The only thing that I am having the problem with is the hammer linkage on the 'little giant' hammer plans.
I could build it like they are build on the 'little giant' hammer but i want to keep the price as low as possible. I was able to make the overhead leaf spring design for around 200$
(assumptions were made on scrounging parts from a junkyard like truck axles, leaf springs, some cabling and bearings. the builder would also have to have access to a steel scrap yard, cutting torch and arc wealder)

I am going to be building one of the leaf spring hammers in the next few months and may sell it afterwards.

But back to the subject at hand, I need some ideas on the linkage for the 'little giant' hammer (between the drive shaft and the hammer)

Either I have to redesign the entire thing using easy to find materials or scrap that entire idea.

 

[jdm61]

Bill Moran's Little Giant type hammer used a leaf spring instead of a coil if i recall corrctly from the videos.

 

[Don Hanson III]

Bill Moran's Little Giant type hammer used a leaf spring instead of a coil if i recall corrctly from the videos.

Joe, Bill had two hammers, one Little Giant and the other with Leaf spring. All LGs had coil springs.

 

[kricket]

The small powerhammer in Bill's shop was a little champion...or at least thats what he called it during the tour of his shop.

 

[jdm61]

After hearing Ed Caffrey talk in his video about the occasional tendency of those coils to shatter and go ballistic, maybe that leaf spring deal ain't such a bad idea...lol. That hammer of Bill's look a lot like an LG.

 

[deker]

I've seen a toggle-arm style hammer built by a guy in NC where he used trailing arms from a racecar for the arms. I can't find the link right now, but he simply used the 2 pivot points at the end of the trailing arms as well...the pivot points, and welded spring cups to them to hold the coil spring. It would likely take a bit of fidgeting to get right, but it's a simple junkyard answer to the toggle-arm problem.

-d

 

[Don Hanson III]

After hearing Ed Caffrey talk in his video about the occasional tendency of those coils to shatter and go ballistic, maybe that leaf spring deal ain't such a bad idea...lol. That hammer of Bill's look a lot like an LG.

A leaf spring in a power hammer is much safer. I've only boken one spring in over 12 years and it didn't kill me I do like the performance of the LGs and now have a guard between me and the spring

 

[Peldor]

A leaf spring in a power hammer is much safer. I've only boken one spring in over 12 years and it didn't kill me I do like the performance of the LGs and now have a guard between me and the spring

If you don't mind me asking, where did it break? at the pivot point or one of the connections?

 

[Don Hanson III]

If you don't mind me asking, where did it break? at the pivot point or one of the connections?

Mine is a 100# LG with a big spring (7/8'' dia, coil, 10'' or so long). Spring just broke about 1/3 from the the end and it was a new spring. I put the old one back in and that was 4 years ago. I like the old spring better