I'd like to introduce you to my hammer, Sancho Pound-za

I built it last year, and it has served me well so far, but I feel like I could squeeze a bit more work out of it, hopefully without breaking anything important in the process.

there are three ways I can think of to get more work out of it. In order of how good an idea I think they are:

-add weight to the ram. Right now the weight of the ram, including dies is about 30lb. The anvil weighs about 400lbs, so I figure I should be good to add 10lbs.  I was thinking I could essentially just add a 10lb spacer where the dies clamp on. That way I could remove it if I want a lighter ram weight, like for plannishing armour.

-replace the cylinder thingy on the motor that contacts the tire with a wider one. Right now I've got one on there that's 1.5" diameter (if I remember correctly), and with a motor running 3470 rpm, I get about 4bps. Of course more bps is probably better, but I imagine there's a point where it will put too much stress on the machine.

-increase the stroke length. Right now I have the eccentric point set to 3.5", I believe, but I also have a smaller setting, something like 2" that I use for plannishing armour. I could just pop another hole in that plate and increase the stroke length. Similar to the last option, I'm just not sure at what point i'll be over stressing the machine and risking breaking something?

 

I suppose if there's a risk of over-taxing the machine and breaking something, I could of course just replace or reinforce anything that might break right? Like, is the spring/helve strong enough? I'm using approx 1/2"x3" leaf springs. The helve started life as a much larger stack of springs, so I could fairly easily add more to the stack. I might have to rebuild the top part of the ram, with the rollers, if I want to, say, double up the spring for the whole length.

 

Anyhow, I'd love to get some ideas and feedback on this, and hopefully save myself a bit of trial and error.

 

PS here is a link to a video of the hammer running:

 

 

 

 

Impressive build; I see no excess movement, unlike a lot of home built machines. That was a sizable piece you were hitting on, so it looks like it hits well. How big of a gap is there between the tup and anvil? You might just adjust the turnbuckle out a little to get a harder hit.

How much "snap" are you getting in the stroke---throwing the hammer at the metal vs just moving the hammer up and down?

On 10/4/2018 at 2:24 PM, Steve Shimanek said:

Impressive build; I see no excess movement, unlike a lot of home built machines. That was a sizable piece you were hitting on, so it looks like it hits well. How big of a gap is there between the tup and anvil? You might just adjust the turnbuckle out a little to get a harder hit.

Do you mean turn the turn buckle to raise the ram up a little bit? I think you're right, in this video it looks like it might be a little low. I usually try to leave at least a 1/2" gap between the die and my work piece, when it's in a resting position.

 

On 10/4/2018 at 3:14 PM, ThomasPowers said:

How much "snap" are you getting in the stroke---throwing the hammer at the metal vs just moving the hammer up and down?

Definitely, some. I'm not sure how I would gauge that though. I don't have that much of a frame of reference. I have some experience with commercial machanical hammers, but not a tone. I'm sure there's less snap than an LG gets, but also I think I'm running slower than an LG usually would.

No, I mean the opposite...lowering the ram to hit harder.

2 hours ago, Steve Shimanek said:

No, I mean the opposite...lowering the ram to hit harder.

Not sure I follow you here.  With a mechanical hammer of this type, shouldn't a longer stroke hit harder, but not as quickly?  I think Thomas is on to something with the snap, more a function of the spring tension and stroke as far as I know.

Open up the space between the dies. 

Can you adjust the location of the eccentric? 

I think you could try everything you mentioned. but of the lot of them increasing the travel would be my first move as the ram does not seem to be moving that much.

It's got 7" of travel, not including spring, so it's probably more like 10-11". I think it looks like a small amount because I left lots of room  between the guide and the anvil so I could get a maximum amount of height adjustability, so that I could attach very tall top dies.

I suppose I could increase the travel, and only use that setting with short dies, since I think a larger range would stop me from using my tallest dies.

 

I'm thinking increasing the speed might be the most broadly applicable improvement.

21 hours ago, Latticino said:

With a mechanical hammer of this type, shouldn't a longer stroke hit harder, but not as quickly?  I think Thomas is on to something with the snap, more a function of the spring tension and stroke as far as I know.

I think that a longer stroke would hit harder and give you almost the same BPM, since that comes from the relationship between the drive wheel and the motor, but for each blow the ram would be moving faster since it needs to cover more distance in the same length of time.

 

most of these alterations will require more power.....

1 hour ago, basher said:

most of these alterations will require more power.....

I've got a 1HP motor on there now. I think that should be overkill, at least where I'm at now, right?

standard motor for weight is 5hp per 100WT at normal speed, with a mechanical you can get away with less.

Way too slow.

Number 1 problem.

Leave the stroke alone.

Only make one change at a time or you lose control.

After you nearly double the speed, if you still need more performance, add to the tup weight.

Free space should be at least 1" above the work, not the dies. That is the best way to maximize stroke length and the reason for the turnbuckle on the Pittman arm.