my take on a homemade power hammer

[Ed Steinkirchner]

started this project around the end of august i believe, and managed to get it done about a week ago.

instead of the normal tube in a tube construction of typical tire hammer tup/guides, i went with a 45 degree dovetail guide and ram, just to keep things as compact as possible to fit in my narrow and relatively low shop. i also deviated from normal tire hammer territory in the rotating assembly and crank sections. Instead of the trailor spindle i used pillow blocks and a 1.5 inch diameter shaft, in which was mounted a hub to carry the spare tire. The crank assembly is entirely separate from the wheel and hub, keyed to the shaft and removable allowing for replacement/rotation of the tire and rim in the future. Another noticeable difference,  and the last major one, is the leaf spring dupont linkage (though i dont know is that still counts as a dupont) which i made by splitting a brand new small trailor spring and mounting each half in the orientation shown.

 

a big consideration when building the hammer was the ability to disassemble it into pieces that could be moved with a dolly into the shop, so each part (except the anvil) is under 200 pounds.

so here's the specs:

tup weight is about 35 pounds,  anvil is near 400, power is from a 1.5 HP single phase motor with a 1.5 inch pulley, the whole unit probably weighs about 1000 pounds, aand stands just over 7 feet tall.

 

i will take more detailed pics tomorrow and dig up some progress pics as well.

but i can honestly say that im extremely happy with its performance thus far!

[Ed Steinkirchner]

some in progress pics.

[ThomasPowers]

How much flex do you get in the springs?  Do they "throw" the top die at the bottom of the stroke?

There are a whole lot of ways to make the linkage. I have both Champion and LG hammers, the champion use leaf springs, the LG a coil spring, a friend has a Bradly with the "rubber" cushions, etc.

[Frosty]

That's a darned nice looking power hammer Ed. It looks clean and solid, I like it. I'm wondering about how much throw the springs have in that configuration too. 

Maybe post a short video of it one of these days?

Frosty The Lucky.

[Ed Steinkirchner]

it has very good snap to the blows, i would say comparative to a 25# LG,  maybe a touch stiffer but i thing things will soften up slightly with use. the full throw is about double the crank throw. So i would say the full throw is an additional 2-3 inches up and down beyond the 4 inch crank throw, for a total whip travel of the ram of about 8-10 inches

frosty: i have a short video clip actually but i dont know how to post it here.

[Frosty]

Nice it sounds pretty good to me but I only have the one 50lb. Little Giant for experience and I couldn't tell you what it's stroke length is.

The easiest and least bandwidth hog method of posting videos is post them to Youtube and post a link here. That saves folk who only have dial up and pay by the minute from having to download it automatically when they open the post. 

Before my accident I was planning on making a mechanical hammer with a Scotch Yoke rather than the traditional crank plate, link arms, etc. to eliminate all the lateral reciprocating weight. My LG would go walk about anytime I used it if it wasn't pinned to a gozinta in the floor. With a Scotch Yoke the ONLY thing moving horizontally is the crank pin and counter weight, everything else goes straight up and down. 

Frosty The Lucky.

[Ed Steinkirchner]

i considered alternative things to the crank that would eliminate the side to side movement but after alot of figuring i couldnt settle on a way that was strong,buildable with my equipment,  and didnt exceed my headspace and footprint limitations.  i figured that the problem witha scotch yoke is in that the yoke needs its own linear guide because the spring decouples it from the ram guide, and that would add too much height. outside of the height limitations i cant see any reason it wouldnt work

[Frosty]

Did you look at Scotch Yokes? They're really robust and simple. The only "engineering" I was having to design for was an inline spring and guides. I'd settled on a telescoping section and spring similar to a suspension strut. 

Of course it's not enough of an upgrade to tempt a guy to replace a working system or my LG would have a Scotch Yoke.

Frosty The Lucky.

[Ed Steinkirchner]

aaaah i hadn't thought of the "pogo stick" type of spring assembly,  that would get rid of the need for an additional guide for the yoke

last group of pics, here before the guard was added, showing the details better.  also ishould mention the 1 inch socket to the left of the bottom die to facilitate holding swages and such

[Frosty]

Exactly. I was thinking about making the outside section part of the tup to minimize the reciprocating weight that wasn't hammer.  Another thought I had was using aluminum for the crank plate, it doesn't take the kind of impact a LG does. That didn't go anywhere but back of the brain thoughts though. 

I survived a severe TBI 10 years ago (yesterday in fact) and am just not up to welding decent beads or keeping on task well enough to actually build the thing. I have all the stuff, trailer spindle for the tire / crank, a rubber wheel to run on the crank plate, in the yoke, plenty of materials, etc. Then a birch tried to kill me and it's all just sitting in the shop. <sigh> 

Frosty The Lucky.

[JHCC]

That's a very interesting idea!