Well you are certainly making progress, when weather and the dogs allow...

I'm a little confused about your planned hammer die mounting.  Are you planning on putting a threaded post on the non-contact side of the die and locking them to the hammer by screwing it down to the hammer anvil and tup?  I think there may be a number of issues associated with that strategy:

1. No easy way to align the dies
2. No easy way to "lock" the connection
3. If hammer vibrations loosen the attachment, and you make one more solid strike, you will  bork up the threads and have a lot of trouble ever getting it apart again.

Nothing wrong with being innovative, just don't ignore lessons learned by the previous manufacturers of power hammers.

9 hours ago, Latticino said:

Well you are certainly making progress, when weather and the dogs allow...

I'm a little confused about your planned hammer die mounting.  Are you planning on putting a threaded post on the non-contact side of the die and locking them to the hammer by screwing it down to the hammer anvil and tup?  I think there may be a number of issues associated with that strategy:

1. No easy way to align the dies
2. No easy way to "lock" the connection
3. If hammer vibrations loosen the attachment, and you make one more solid strike, you will  bork up the threads and have a lot of trouble ever getting it apart again.

Nothing wrong with being innovative, just don't ignore lessons learned by the previous manufacturers of power hammers.

Well, yeah, this is my first go at a hammer, so I'm learning as I go.  I've seen plenty of bolted on dies, namely Ken's KZ hammers.  I know there are better ways, like dovetails and set screws, but that would overly complicate things. 

I'll be sure to tighten the bolts often.  Thanks!

Bolt on dies will certainly work.  I was afraid that you were centering the bolt under the die itself.  On the side is certainly better, particularly if you do both sides.  If you make oval holes in your die "flanges" you will get some alignment correction ability.  Those welds will be regularly stressed, so make sure you use the right rods and get really good penetration.  If the dies are medium or high carbon you may need to temper the welds.  I recommend relieving the corners on the long side of the dies to at least a 1/8" radius.

 

7 hours ago, Latticino said:

Bolt on dies will certainly work.  I was afraid that you were centering the bolt under the die itself.  On the side is certainly better, particularly if you do both sides.  If you make oval holes in your die "flanges" you will get some alignment correction ability.  Those welds will be regularly stressed, so make sure you use the right rods and get really good penetration.  If the dies are medium or high carbon you may need to temper the welds.  I recommend relieving the corners on the long side of the dies to at least a 1/8" radius.

Haha!  Everything you suggested I was getting ready to ask. I was planning on making the holes bottom flanges a little bigger than the bolt itself so I could fine tune the alignment.  I used 5/32" 6013 rods at 130 amps.  On the bottom seam, I ground out a channel, welded, and ground flat.  As far as good penetration, I'm not a professional welder, so I can only try to mimic what I see on youtube, weaving and pausing at each side, watching arc length and travel speed, etc.  I guess time will tell.  

The dies are 4140 hammer blanks.  What do you think, 400F in the oven for an hour? Speaking of tempering, should I heat treat the top surface of the dies?

I was going to ask about radius on the edges.  Will do 1/8".  

Thanks for the advice!

I don't know if you read through everything, but I posted a quick change die that someone else did, so if my dies turn out to be garbage, I was planning on upgrading anyway.

Sounds like you are on a good path.

Unfortunately I'm not either a professional welder or a power hammer maker, so I can't really speak with authority about proper die welding and heat treatment procedures.  I was just making suggestions based on vague memories of conversations with actual professional welders.  I urge you to do your own research regarding the welding of large 4140 sections to mild.  What I have seen is recommendations for preheating, use of low hydrogen electrodes and post heat treatment to relieve stress.  Depending on how the billet was supplied, you may even want to fully heat treat the die and temper it afterwards (I am not familiar with flame hardening surface heat treatment, so I can't really comment there).  If it were me, I would temper pretty high (650+).

That being said, I have worked in a shop where the owner used mild steel dies that had been super quenched in a hammer significantly larger than yours.  He even used them for some cold forging, and mentioned that they lasted years for him.  I guess the worst that can happen is that the dies deform early and you have to make another set.  What I wouldn't want to see is a weld fail in a HAZ zone and send a sharp piece shooting out.

44 minutes ago, Latticino said:

I urge you to do your own research regarding the welding of large 4140 sections to mild. 

I asked Grok3.  I should have used 7018, which I have in a vacuum sealed bag with desiccant, but I did other things correctly.  Next time I'll use that rod.

Heat treating is an issue.  I don't have a way to get it up to 1100-1200F other than my coal forge, and I don't think my non-contact thermometer goes that high.

Actually, I have an acetylene torch, but I'm sure I'd run out of gas before getting it that hot.  Small tank.  I think only a proper oven will do, so I'm outta luck.

Maybe I should just find some mild steel chunks and make the dies into hammers.

Not sure this would work for you, but I used the top part of RR track for my dies.  Of course it's a bit of work to cut the webbing, but for me it was a suitable option.   Looks like you're going with bigger dies than I used though.

I saw some railroad track for sale on Craigslist last year.  That just seems like something all of us should have laying around somewhere.   My dies are 3-5/8" long and 1-3/4' maybe 2" wide.  I can't remember, but I'm sure that RR track is wider.

I used Harbor Freight autobody dollies on my air-over hydraulic press (that now sits rusting under a tarp).  They were nicely shaped for drawing out, as is RR track I guess.

Edited April 17, 20251 yr by Mod30
Remove excessive quote

I finished the ram and both dies.  Time to assemble and test-fit. I'm pretty pleased with how things are looking at this point.  The ram and the anvil post are offset slightly front-to-back, but parallel, and spot on side-to-side.  I could run the rear UHMW bearing plate through my planer to move it back a little, but does 1/16" or 3/32" really matter if I can get the dies lined up (which it looks like I can with little problem)?

I need to grind down the inner part of the anvil post a bit, but all I need to do is shim the bottom die mounting plate a little to get the two dies touching all around.  I'll probably stick in the rest of my 3/4" square bar to add some more mass before I button it up.

I'm within 1/4" of my planned air cylinder height, so I'll take that!

My guy at a local metal fab shop is blowing me off.  I've been waiting two days for him just to tell me if he has any 1/4" plate and/or 1x4 flat bar.  I might have to just order those from eBay or a metals website.

I'm calling around trying to locate someone who has a heat treating oven and is willing to bake these things for a reasonable fee. Vevor has a digitally controlled kiln for $300.  My dies will fit inside it, but not much else, maybe a pocket knife blade.

Anyone who can build a power hammer can surely rig together a heat treat oven.  These days PID controllers are cheap (or were last time I checked, who knows now).  You don't need a SCR.  I've made them with contactors or mercury relays and surplus coils from electric duct heaters.

I wouldn't obsess about heat treating the dies.  You are probably fine with the dies as is as long as they have been adequately tempered after the welding.

I've heard bad things about misaligned air cylinders and power hammer rams/tups.  Hopefully you have a linkage that will accommodate a bit of misalignment and vibration.  

Good Morning,

I can't see the edges of the Dies properly. From here they look like they are crying for 'Radius Edges'.  Square edges are setting you up for a huge amount of 'Cold Shuts'. Many broken work pieces.

I would not want to rely on your welded joints making the Dies. I would be patient and visit your 'Welder, in your area' and have them welded correctly with the correct equipment and rods. Your hands, face and body deserve that patience!!

Patience Grasshopper!!

Neil

10 hours ago, Latticino said:

I've heard bad things about misaligned air cylinders and power hammer rams/tups.  Hopefully you have a linkage that will accommodate a bit of misalignment and vibration.  

I bought an alignment coupler.

10 hours ago, swedefiddle said:

From here they look like they are crying for 'Radius Edges'.

I would not want to rely on your welded joints making the Dies. I would be patient and visit your 'Welder, in your area' and have them welded correctly with the correct equipment and rods. Your hands, face and body deserve that patience!!

Patience Grasshopper!!

Latticino suggested a 1/8" radius. That's what I'll do.

I've already ordered 2x2 mild steel bar to make a new set of dies. I took the 3/4" base plate with the two main posts and gussets tack welded in place.  When asked, they told me they did not preheat the plate, which I thought was required for such a big chunk of steel.  But the welds look good.  The base plate is also no longer flat, but slightly concaved.  That might be unavoidable? I don't know.

But with these dies, I don't think they'd bother doing what I did to keep the flanges flat, and I would expect to get a block of 4140 with upswept mild steel wings and very nice welds.  Would still have to temper the welds, too.

I'll just use them for setting up the pneumatic system and be sure to put a block of rubber or wood in between.  

There has to be a company out there who can make me some custom dies.

10 hours ago, Latticino said:

I wouldn't obsess about heat treating the dies.  You are probably fine with the dies as is as long as they have been adequately tempered after the welding.

I meant tempering, not heat treating. 

Depending on how you plan on using the hammer, it can be helpful to have dies with different crossections for different tasks.  Flat dies like you have now with a 1/8" radius are pretty good general purpose and allow use of hand held tooling to cut, flatten, isolate mass, punch holes, tennon, spread...  I have a smaller hammer (Anyang 33) and find that I most often use drawing dies in mine (which have more of a crown to the top).  One of the nice things about being a smith is the ability to make equipment and tooling changes, as required.

If you are just tempering, why not use your kitchen oven?  Most likely it will get up to at least 500 deg.

For steel stock, check and see if there is an Alro Metals Outlet or service center near you.  I know there are a bunch in Florida.  I have found their prices and selection of "drops" in the outlet near me are quite good (and you can always order "virgin" stock as well).

10 minutes ago, Latticino said:

If you are just tempering, why not use your kitchen oven?  Most likely it will get up to at least 500 deg.

For steel stock, check and see if there is an Alro Metals Outlet or service center near you.  I know there are a bunch in Florida.  I have found their prices and selection of "drops" in the outlet near me are quite good (and you can always order "virgin" stock as well).

I use our kitchen oven for tempering knives, punches, etc, usually at 400F for an hour or so. From what I've read and what Grok3 states, post weld heat treatment requires much higher temperatures, 1100-1200F. The $300 Vevor kiln can go way higher and is programmable.  I'm tempted.

The door lock function on the oven recently broke when on a self-cleaning cycle, so unfortunately, I can't bake the 7018 rods that are sitting in my shop, but I have fresh ones on hand.

I think I need to just redesign my dies.  Instead of doing wings or flanges welded to the side, I need to do it like on Ken's KZs.  I was so concerned with warpage that I wound up just doing a series of tack welds instead of a complete, unbroken bead.  It would be better to do a deeper bevel and weld the entire perimeter (with 7018).  I can give the welding shop an assembly that is clamped onto a thick steel backer.  All they'll have to do is run the beads. Won't even have to unclamp it.

If it were me I would find a cheap toaster oven at a thrift store for baking those rods and tempering.

I was just about to order $150 worth of steel when I remembered I had this thing sitting under a tarp for a year.  Now, can I make the 2" x 4-3/4" x 3/16" C-channel as rigid as 1" flat bar?  I've only got 33" of 1/2x4 bar left, but I could weld the C-channel to a piece of that flat bar then do some diagonal gussets as planned with the 1x4 flat bar.  I think that might work.  Thoughts?

33 minutes ago, LeeJustice said:

If it were me I would find a cheap toaster oven at a thrift store for baking those rods and tempering.

I've had no smelly issues with tempering knives, etc, in the oven.  The wife doesn't even notice.  I'm aware of the potential stink that may come off a 7018 welding rod, but I haven't done it yet because of the broken door lock that prevents it from doing the self-cleaning cycle, which would meet the required 650F to 800F to rebake the rods.  A toaster oven wouldn't even come close for that task, but would do fine for 400F tempering.

It's probably not even worth the trouble and who knows what gasses might be released.  I just bought a new bundle of 7018 for $16.  I keep them vacuum sealed with desiccant inside.

Incidentally, I make homemade natto (fermented soybeans) that everyone in the house says stinks to high heaven, but I prefer to call it an "earthy" smell. 

It took a while for Grok3 to teach me the correct terminology for describing a U-channel, and the difference between U-channel and C-channel.  It also took several attempts for me to accurately and succinctly describe to it what I was wanting it to calculate and compare, but eventually, it did the moments of inertia for a 1x4 flat bar and a composite assembly consisting of the U-channel and 1/2" flat bar welded together as shown in the picture.  The composite assembly is significantly stiffer.  Saved myself $150. 

My gut feeling was that just the U-channel and some 1/4" plate gussets will be stiff enough to handle the reciprocating 66 lb tup.  If not, I can easily add a 1/2 x 4 bar above it.  We'll see.  I wanted to save the last of my 1/2x4 flat bar for making die plates.

I played Whack-a-Mole with the adjustments, but finally got it as close to perfectly squared and aligned as possible.  I do have an alignment coupler as well that I planned on using.

I'm pretty much done with the welding, except for the parts that will hold the roller lever switches.

Bought time to make a plan for how you are going to lag it down.  Otherwise you may find it dancing around the shop.

The Air Line will be the Leash. LOL maybe.....

Neil

10 hours ago, Latticino said:

Bought time to make a plan for how you are going to lag it down.  Otherwise you may find it dancing around the shop.

Yes.  I just discussed that with my unimpressed and equally uninterested wife when I showed it off to her.   Option 1 is the easiest and quickest:  using concrete anchors. The name escapes me, but it's the type that is like a barrel nut with a wedge at the bottom you hammer in place with their set tool.  Bolts go in from the top.  Option 2 is cutting out out the 4" slab and pouring an isolated, rebar enforced deep footer with J-bolts set in the concrete.  Less desirable due to labor involved and having to get the thing up and onto the J-bolts by myself (I'm used to working alone, so I have my tricks).

I'm going to try Option 1 first and see how that goes.

8 hours ago, swedefiddle said:

The Air Line will be the Leash. LOL maybe.....

Neil

Do you mean limiting factor?  I don't think it will be.  I have a 3.7 HP 60 gallon compressor and the 80 gallon tank from my previous compressor that I'll hook together, giving me plenty of compressed air at 100 psi.

I do have a a couple of minor issues. 

This sucker is going to be loud and it's pretty close to the property line.  For over 20 years, this neighbor has had nearly weekly weekend parties.  Practically every weekend there'd be 10-15 cars parked all over the place.  These parties would turn into late night/early morning slurred speech drunken shouting, revelry, and music.  We routinely get woken up at 1 or 2 am.  It's been like living next to a frat house.

When they don't have parties at home, they take their big pontoon boat out and party on a beach in the sound. One of the most entertaining things for me to watch is him trying to back this huge trailer in between a row of pine trees as his wife shouts instructions at him.  Well, funny until he hit my mailbox.  We are friendly with each other.  It's no fun having neighbors you don't get along with.  I just try to tolerate it as best as I can.

My blacksmithing usually stops at 3 or 4 pm, but I still want to dampen the sound of the blows.  What do you guys think about a piece of 3/4" plywood or maybe horse stall mat in between the concrete and hammer?

The second minor issue is the base plate is now cupped up slightly.  I'm thinking I should cut out some steel wedges/shims and hammer them under the base after it's bolted down.  Any other suggestions?  Hard curing epoxy?

BTW, my neighbor on the other side of me moved away, and the house was bought by a mid-20s Ukrainian man who immediately turned it into an AirBnB.  It has been such a nightmare.  I've had to call the sheriff on the occupants several times for noise complaints or heated arguments at 2 in the morning, and once during the day.  They were playing their rap/hip-hop music so loud that I couldn't even hear my TV on my back patio.

So, if I were to build a new smithy on that side of the yard next to the property line, how could I make the hammer even louder? Nothing drowns out rap music and the drone of a subwoofer like the rhythmic thumping of a power hammer. 

He was referring to the air line being the leash when it goes for a walk.