I recently bought a Little Giant 25lb power hammer.  I have posted about it in a few threads but got a request to make a thread here about it so...





The hammer as I got it.


It took some effort to get it into the shed.  All I had to move it was a 10' chain-hoist.  So I used a tree as an anchor to get it near the door, then ran a strap out the back wall to the axle of my truck to drag it into the shed.  From there I made a beam out of 2x10's and plywood glued and screwed and mounted it up in the rafters of the shed. I then made two 4x4 posts with 2x4 forks to go under the beam when using it.  That allowed me to get the hammer positioned on it's new pad.  And to lift it again to install a cut piece of horse-stall matt as a dampener.

Checking location with a 'hammer approximation device'



The form prepped.  I did add rebar before pouring.


Pad poured


Hammer on pad



Been working on getting the new dies installed in the hammer.

Tricky to align these as they use tapered keys to install in the dovetails in the knee and ram. The existing dovetails have to be hand-filed to make the geometry of the dies line up.

I had to make a set of shims to move the lower die back enough to line up with the top die and then had to do some filing on the rear bottom of the knee dovetail to rotate the die face up to align with the upper die face.



You can see above that I need to do some filing at the lower 50% of the rear dovetail on the base, as the angle does not match the new die properly. This should help the lower key fit better, but I am still pretty sure I will need a smaller key on the bottom because I had to add 0.169" worth of shim on the front.



Here the left/right alignment is of no concern, as I can fix that in the dovetail of either die. Look closely though and you will see the slight gap on the left front side. This is caused by a transverse problem in the dovetail. Essentially the front left 'foot' of this 'chair' is too short. As I cannot make it longer, we remove material from the rear left foot and a tiny bit from the right front to fix this.

There is actually a small depression under most of the die. Maybe 3/16" deep. I think they added this so that adjusting the die geometry would be easier than if the entire dovetail floor was the same height. You only have to file the perimeter material. However, I do not like the idea of the edges of the die taking all the abuse and transferring that to the knee only around the edges. I can see damage on the dovetail ends that clearly shows the negative results of this. So I did a little research and it seems brass has better yield strength and tensile strength than cast iron. So I am going to figure out a way to pour brass into that cavity. I think I can grind a piece of flat bar the width of the dovetail bottom and then drill it for a pour hole and escape hole. The brass will shrink about 1.5%, but that is only a few thousandths of an inch at this thickness.

I talked to the guy at Little Giant about this and he thought it was a bad ass idea. He is very looking forward to hearing how it works out.

Great job!  Thanks for sharing the pics and good luck with it!

You do need some flooring, however!

Chris

I actually prefer the gravel over concrete.

Sweet!

I know a guy that has 3 or 4 of them from 25lb to 250lb.  The 250lb is a monster

I built a 25lb air hammer many moons ago and it made forging soooooo much easier.

It's strange to me that the manufacturer intends for the frame to be fitted to the dies instead of the other way.

Well, the frame is a casting, so it is never perfect.

The reference point is the machined V cut into the frame above the die area, everything references from there.

So true top die to ram, then true bottom die to top die.

Do you think that pad is thick enough?  I know some guys that pour two and three feet thick pads for their hammers. I have seen them on 6x6's too (on the pad).

In talking to Roger at LG, yes, it will be fine.

Their concerns are more that it be properly bolted down (it now is) and that it have some form of padding between the base and the concrete (I have used horse-stall matt).

That makes sense.  Are there different shaped dies that you can interchange to suit the work?  If so, how do you fit the frame for multiple dies?

I'll try to get a pic of the die options.

If you look at this pic you can see the top and bottom dies are really two pieces.  You can sort of see the hole where the cap-head bolts are tightened through the changeable die head into the die base.

I couldn't work out how you'd fit the frame for multiple dies sets, unless the dies were all identical.  Fitting the frame for the base of the die and changing out the "top" half makes much more sense.

Here's a shot of the other dies I have.





Here's the casting 'jig' I made to pour the brass into the cavity.  




After the pour...(I'll have a full vid on my youtube page when I get the footage edited)




The jig wasn't at the same height as the die base sits, since the plate I made used both the front and rear dovetails.  So I ground some flats and hacked it up on the mill, leaving a few pads that were then easy to hand grind down to the proper heights.  This is probably pointless, but it made me feel better about wear in the dovetail and it was fun.

Thanks for the video.  It explained a lot.

Glad to hear it.  I mean that is the point of the videos.

Brake is installed...

I am envious of you OP!

I got out of making knives many years ago but if I could find a 25lb/50lb Little Giant within a couple hundred miles of me that was in good shape for a reasonable price I would probably buy it and start making them again LOL.

I would probably buy a new one if they ever started making them again but I doubt that will ever happen
Here is another idea for a brake that I stumbled across.

You made me start searching for Little Giant videos LOL.

Got some time today to do some work with the hammer.

No video...sorry...I just figured the first effort would be a complete failure and didn't bother shooting video.

Turned out better than I expected. This is the first 'damascus' billet I forge-welded probably 15 years ago now hammered out and ready to be cut and rewelded for another draw. It was about 1/4 this length when I started today.

The goal here was to keep it the same width and try for a uniform thickness. Obviously thickness is NOT uniform, but the width came out OK. I think it will work and will cut, grind faces, and re-weld again next time I have the daylight.

Awesome!  Can't wait to see what comes out of it!

Looks like you're getting to know the new equipment pretty well.  After seeing how many blows the power hammer takes to weld that stack up, it's amazing to me that people do/did it by hand.

Well, back in the day they had apprentices!

Cool pattern.

Are we looking at the one of the sides of the stack, or the top or bottom?  I imagine it gets hard to keep that straight after a while of smashing it.

That is one of the 'flats', so the layers would be seen best on the sides as it is oriented here.

It's actually very easy to tell orientation, as any oxidation tends to display the pattern pretty quickly.

Due to both hammering and grinding, there is a fair amount of deviation near the edges.

But I am new to this, and am just glad it seems to be going well.

I imagine just getting the stack to stay "stuck" together has a steep learning curve.

Yes, but I learned to forge weld in a coal fire back in my early smithing days, so the propane forge makes that much easier.  It's really more prep work than forge time.

Forge welding from a coal fire is tough, so many variables to manage.

Any new projects in the shop?

No, it has been hot and other projects have been interfering.

I made a small cut-off tool for the hardy hole, and I noticed the blade was also angled in much the same way my billets have been forging with an angle.  Not sure what is going wrong with this and need to sort it out.  The ram is nice and tight, and the dies are aligned, it may be an operator error of some kind.

I plan to put a camera behind the hammer so I can watch it to see if the problem is obvious during forging.

If it's something you are doing, the camera should help you figure it out. Just like filming yourself shooting, golfing, batting, or whatever.

I'd love to see more detail when you start finishing the bowie knife handle. Getting handle parts to fit together well is something that I struggle with.

OK, but someplace else, this be a power hammer thread.

You make the thread, I'll bug you in it.  Lol

Were you able to figure out the issue of the material hammering unevenly? I'd love to see it in action in person.

Right now I am pretty sure it is me spending too much time on one rotation, but I need to do more testing.

If we can sort out a time/date, you are welcome to come by the forge and try it.  PM me.