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6:11 pm
NWBA Member
April 22, 2010
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Die Misalignment?
I actually probably know the answer to this question, but I wanted to consult those that are smarter, and more experienced than me.
I have flat dies on the power hammer, which is a smallish Anyang self contained.
It is a two piece hammer, with a separate floating anvil, like a bigger nazel or chambersburg would, so the anvil is located in respect to the hammer base with wooden wedges.
When I forge flat bar thinner, or use one of Grant's single sided texturing tools, the flat bar always curves, always in the same direction.
My theory is that this means the two dies are not parallel to each other- that the top die is slightly off from the bottom die, somehow.
Does this sound like the culprit?
Then, of course, the question is how do you make them more parallel?
I could, I suppose, take the whole hammer apart, and grind or shim the base of the anvil (it weighs around 1300lbs) then put it back, check it, take it apart a few more times, repeat, until its better. Days of work with the forklift, and big wrenches. Its small, but it still weighs about 3500 lbs all up, and is a pain to take apart and put back together.
I suppose I could also attempt to measure it very accurately, then just re-mill the face of the bottom die on the milling machine, shimming it a bit to make it match the top die?
First thing to do, anyway, is remachine both dies flat- its just vaguely possible that a couple of years of hammering since the last time I took twenty thousandths off has left one or the other more worn on one side than the other.
Ideas?
6:36 pm
NWBA Member
March 17, 2012
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The simplest method would be to check the dies for parallel/square and then adjust the shims in the dovetails.
If the dies are square, then look to the dies surfaces. Sometimes folks forget that dies deform/wear (instead of demo-ing using a two by four, you let the dies clack together once or twice... "It was only once or twice..." but over time that can add up.) and maybe all you need to do is a little surface work to restore them.
6:42 pm
January 18, 2011
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Smarter? I know not..:confused:...First thing I would try is a digital level (one tenth of one degree is sweet), zero it on the bottom die and then see if the ram is at 90*in relation to it. If it's more than .3 of one degree it's getting dicey. If that's ok then have a look at how the dies line up visually the go around the perimeter with a feeler gauge(s) in between the dies. If that's off mic the die heights.....
"Be who you are and say what you feel, because those who mind don't matter, and those who matter don't mind."
— Dr. Seuss
9:34 pm
May 13, 2010
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Sounds to me like something has shifted or the dies have worn. I assume you have checked that all your wooden wedges etc. are all tight. Being winter they would be drier therefor looser here, I don't know if that applies out there on the Wet Coast.
I would take your skim cuts to make sure the dies are parallel and then check with feeler gauges etc. The one method I have used to check dies is to put a piece of paper between the dies and hit it with one blow. You should be able to see where the dies are hitting by looking at the paper. I like making any cuts out of parallel on the top die rather than the bottom. My bottom die is level and I like to keep it that way.
The last time I set up a set of dies I cleaned up the bottom parallel die then lightly oiled the face. I then put the top die in the hammer and with the hammer on put a couple of dollops of bondo on the bottom die. I then turned the hammer off. After the bondo hardened I removed the top die and clamped the die to the mill with the bondo face down. I then put a couple of dollops on the top of the dovetail which I milled down most of the way to the dovetail after it had hardened. You now have the 2 faces parallell. You can flip it over now and clamp it down. You can then take a cut off the face and it will be parallel to the bottom die. You will either have to use toe clamps or move your hold downs to finish the cut. This actually goes much quicker than it sounds and you don't have to mess around with all sorts of shims. When you are done you clean the bondo off the dovetail with some heat or a sanding disk.
10:24 am
September 6, 2010
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Place a piece of carbon-paper and a piece of white printing paper between the dies and strike a blow. You will be able to see all the points of contact.
5:13 pm
NWBA Member
March 17, 2012
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The paper trick is a pretty good one, not so different than a dentist checking for bite alignment. I would have eyeballed it and went back to hammering... 😀
5:37 pm
NWBA Member
November 1, 2010
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I think just for grins I would spin the bottom die 180 degrees and see if the stock curves the opposite way or it just may fix the run out. Make sense? It would be simple to try. I do this when checking a square or level for accuracy.
Good luck anyway. Mike
6:56 pm
NWBA Member
April 22, 2010
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Just as I suspected- you guys are all suggesting actual WORK. As a diehard maynard g krebs follower, I tend to avoid that.
If I go to the trouble of popping off the die, I will throw it in the mill anyway, and give it a nice fresh flat surface, then check the result with feeler gages, or maybe that nifty carbon paper trick.
I tend to use a LOT of swage tooling, which is almost all 4140, harder than the dies themselves. So I kinda doubt that the dies hitting each other because of not using a wood block could possibly do more damage than I do in fifteen minutes of ordinary hammer work.
I am actually pretty amazed at how long my cheezy chinese dies have held up, and how well.
5:34 pm
NWBA Member
March 17, 2012
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Well, if you're going to bother to take off the die and mill the surface, you may as well lift up the anvil and make sure it's shimmed and square too...with the die off it won't weigh as much.
5:29 pm
NWBA Member
April 22, 2010
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The die weighs maybe ten pounds. The anvil weighs 1300. And to take off the anvil, you need to first disconnect the power, then the motor drive belts, then remove the motor stand, then unbolt the hammer from the floor, then move the other things in the shop out of the way, move the forklift into place, lift the hammer up (2500lbs) several feet to clear the anvil, then put the hammer down somewhere- then, you have access to the 1300lb anvil.
Its a half day, minimum, to get it out.
6:44 pm
NWBA Member
March 17, 2012
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You could have said "Are you kidding?" Then I'd have to admit I left out a smiley face, but couldn't find one that was "tongue in cheek."
6:56 pm
NWBA Member
April 22, 2010
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the thing is, I have been considering it.
Its probably the right way to deal with it.
I just dont want to.
12:33 am
May 14, 2010
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Using paper to see what is hitting what is a great idea. Also, I really like the suggestion to just turn the bottom die around and see what happens. That is about the quickest way to see what is going on.... It may even take care of your problem...
Grandkids and blacksmithing... Joy Joy Joy..............................YouTube Channel: djhammerd
4:24 am
March 22, 2010
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Ries;17451 wrote: The die weighs maybe ten pounds. The anvil weighs 1300. And to take off the anvil, you need to first disconnect the power, then the motor drive belts, then remove the motor stand, then unbolt the hammer from the floor, then move the other things in the shop out of the way, move the forklift into place, lift the hammer up (2500lbs) several feet to clear the anvil, then put the hammer down somewhere- then, you have access to the 1300lb anvil.
Its a half day, minimum, to get it out.
Half a Day? I could pull the anvil on my 4B in about 45 minutes :wavespin:
Whatever you are, be a good one.
Abraham Lincoln
5:20 pm
NWBA Member
April 22, 2010
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You probably dont have as much stuff in the way.
I have to move a lot of stuff just to get the forklift in there.
And because my ceiling is pretty low, picking the hammer is tricky.
When I took the hammer to the Mt Vernon Conference, it took me maybe 4 hours to get it running again, from picking the first piece up with the forklift, to turning it on and hammering.
But also, practice makes perfect- I bet you have done it more times than I have.
4:59 am
NWBA Member
February 25, 2012
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Ries;17527 wrote:
When I took the hammer to the Mt Vernon Conference, it took me maybe 4 hours to get it running again, from picking the first piece up with the forklift, to turning it on and hammering.
Thanks, btw, for taking the trouble to bring it to Mt Vernon. I learned a lot from that demo!
5:42 am
March 22, 2010
Offline
mmm tis true. There have been days where I had the hammer in and out half a dozen times in the same day.... Not a fun or good thing...
Whatever you are, be a good one.
Abraham Lincoln
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