Omniversal Die

[JNewman]

I got the idea and name for this die that I plan on making from Grant's anvil http://www.iforgeiro...l/page__st__220 . As well as the setup he or Bob designed for the KA 75 of a die inside a die.

I often have runs of 50-100 parts that I need tooling to make the parts efficiently sometimes they have repeats but it can be years between the repeats. Much of the tooling is reasonably simple although some are more complicated, often a flat die is part of the setup and many of the components will likely be common to different jobs.

Making fully machined dies for a run of parts that may or may not have repeats is far too expensive I currently use spring swages and tools that drop into a bolt on hardy hole but often I have to change heavy tools multiple times in the same heat. As well some of the tools need better top bottom registration than spring swages provide.

So I drew up a CAD model of the part and some of the dies I need for some future projects. I plan on getting a 12' bar of 3" square cutting it to 3' or 4' lengths and having the dovetail cut on all of them. I will then have bars I can cut die blanks off of and make tools from with minimal cost and lead time. I am waiting for quotes on machining and will probably be going ahead with it unless the quotes are astronomical. In which case I will have to machine them myself on weekends etc. but I will have to take my time doing it.

This sort of die would probably not be useful on hammers that take small dies, as the usable die area would likely be too small.

[ironstein]

Can dovetails be cut on a long piece of die stock? Somewhere I remember reading that some hammer dovetails taper lengthwise. Just curious what type hammer you're running.
I've been considering buying a stick of s-7 to make 5 sets of dies for my Anyang to have some "blanks" that I could modify and heat treat at my leisure.

[ironstein]

Nice looking drawing by the way! Looks to be super handy. Looks like it would be super handy, looks like you could change tooling quickly. What's holding the die in place?

[peacock]

You can have dovetails cut on a long piece without taper, then cut off short chunks if you use 2 die keys One from each end of the die. this also lets you align the die edges by how deep youdiver the keys on each side. Bradley hammers are made this way, on taper in the male or female dovetail. I do these in a shaper very quick and easy.

[JNewman]

On my hammer the taper is in the female half so the dovetail on the dies are straight. The female dovetails cut in the top of these dies is tapered so the dies that fit into the top will have paralell dies. They will be held in with tapered keys same as the Omniversal die gets held into the hammer.

Dovetails can be cut as long as the X axis of the mill minus the diameter of the cutter. Or the stroke of the shaper if you use a shaper. It could be machined longer but the setup time would be more expensive than any savings in material by going with longer lengths.

[ThomasPowers]

Just like the Cutler's anvils were set up to take dies to do specialized shapes for their work!

[pkrankow]

It could be machined longer but the setup time would be more expensive than any savings in material by going with longer lengths.

Can a "dovetail" profile be ordered rolled as a bar?

Alternately, since these are "small" dies, can you just saw the dovetail on when cutting the die from the parent stock and not have overhang?

Phil

[JNewman]

Can a "dovetail" profile be ordered rolled as a bar?

Alternately, since these are "small" dies, can you just saw the dovetail on when cutting the die from the parent stock and not have overhang?

Phil

I am sure it could be ordered rolled if i wanted to order 4-5000 tons of the material. Custom rolls are not cheap and mills tend to not do custom rolling unless you are ready to buy a lot of material.

If I had a vertical saw I suppose I could sawcut the dovetail but it would not really be accurate enough. I do have to look through the Clifton Ralph videos. He did have a method of forging dovetails for smaller dies. It was quite tooling intensive but it might be worth making for a situation like this.

[ironstein]

I learn so much on this site!

[nonjic]

Looks good John, but its a lot of keys and pegs, Alignment might (errm, will) be a nightmare!

Could you make one dovetail, but much deeper, and have the die inserts in that, like books in a bookshelf ? the 'end dies' (dead side and key side) would need one taper face, the middle dies could just be rectangular blocks. Just one key per dieholder to contend with, and 2 datum faces to worry about registering (top die holder, and bottom dieholder)

You might need a way to tie all the die inserts together, say a 1 1/2" hole through each die insert? you could then 'thread' 3 or 4 dies onto a 1 1/2" dia bar, then key them in as one lump.

If you standardise the inserts from the start it should be do-able, The 'middle' inserts might have a tendancy to 'bounce' a little but for qty's like 200 off forgings (say, 1000 blows of varying intensity) it should not be a deal killer, I would have thought much less hastle than lots of individual dovetails, datums and keys.

[Andrew T]

John,

there is a drawing in the Norwegian book "Klassiskt Jarnsmide" that shows this setup on a mechanical hammer for axe forging.

What alloy and hardness are you thinking of for holder and insert dies?

[JNewman]

You make a good point John but I hope if I get the holder die properly lined up from the start it should help. I have told the machine shop that before they machine the bottom dies female dovetails I need to test fit the holder. I will then ensure everything is lined up and if necessary provide them datum points to machine to so the top and bottom dies are perfectly aligned as far as any twist and meet perfectly in the horizontal plane. I was going to use 1/2" bolts with the threads cut off as pins with slots in the bottom of the small dies aligning on the heads. I can then make offset pins if necessary. Most of the time only one of the 3 dies really needs to be aligned really well in the x,y axis the others would often be taper dies or flat dies with an offset to provide a stopper. I think the trickiest part of lining them up is when installing the holder dies. I may have to make up a set of small dies with dowels to line up the holder dies while installing them.

If i were to do something like your loaf of bread setup I think I would only dovetail one side of the die but dovetail all of them and then then use set screws rather than keys to hold the dies in. I think Grant mentioned using something like this on a steam hammer back in Keenjunk or an old Anvils ring. My concern with the non dovetailed center blocks is they cannot be used on the ends with a different setup. i would want them all able to be used with any other tool.

The plan is to use 4340 for the holder and 4140 for the smaller blocks both hardened to 50-55rc I would rather go 4340 all around but I can get the 4140 as 3" cold rolled square the 4340 has to be saw cut from plate or be forged of machined from round. .

[Patrick Nowak]

John,

I have dies for my Bradley already made just as you've drawn along with maybe 10 sets of insert dies. These came from a shop in Cinncinatti that made tools for Mac Tools. In their design they made the little die pockets with a single dovetail. They're drawings called for S7 material.

If you want to forge dovetails it does not have to be tooling intensive. I've done it several times. Start by forgings a bar that is just narrower than the top of the dovetail with the key in place. the bar should be a fair bit taller than the depth of the dovetail slot. Put a half round bar in the dovetail slot with the round facing up. Heat your material as hot as you dare, then place it in the slot on top of the half round and drive it down hard. Be sure the key is in place when you do this. Knock everthing free and trim or torch the flash from the top of dovetail section you're forging. Re-heat and repeat, but this time leave the half round out. If you do this right your should get a fairly serviceable dovetail blank that you can weld other shapes and forms to. I've made serveral dies this way and it has worked pretty well. It's not as good as machining, but it does work.

Patrick

[peacock]

A word of caution Patricks method works well in a mechanical hammer I have used it more than once. Don't try this on an air hammer. You run a great risk of bottoming out the ram and costing yourself way more than a set of dies will cost.

[r smith]

Please explain the half round bar a bit more, I am not clear on its use or orientation.

Thank you
smith

[JNewman]

Good to hear from Andrew and Patrick that this is something that has been used before. I got a preliminary price on the machining and at about $5000 for the machining of the holder dies and $1000 each set for the 4 sets of small dies. So I have figured out another way to do the job that was the impetus for this project. I am going to get pricing from another machine shop to cut the base die and rough out some small dies. They could not do the 3d machining needed to do the dies for the project I am working on but will hopefully be much cheaper for the machining of the holder dies.

I am eventually going to build the holder dies but it may have to be a multiple weekend project on my little Excello mill unless the second machine shop comes in with a better price.

Thanks for the method of forging the dies Patrick. When I get around to making the holder dies one of the first small dies will have to be a die with a dovetail the size of the dovetail with a key in it that way I will have the height to forge the dovetails safely and I don't have to worry about the key moving. I still want to find Clifton's method, if I cannot find it on the video's, hopefully I can make it to quad state this year and ask him there. One advantage of forging the dies is I can use 4340 instead of 4140.

RSmith the round bar is to act as a fuller and force material into the corners of the dovetails.

[r smith]

Thanks for that.

[nonjic]

If you can find someone with an 'old school' planer they should be able to make you that 12' stick of dovetailed bar in a shift.

Im on the final stages of installing a planer with 12' x 4' table, there are so many jobs on forging machines that a cheap planer can do better than a million bucks worth of Elgamill. Dovetails, and slide 'v's on hammers mainly! especially when there are multiple 'v's on each slide like this..

|VVV|

often you could not mill them as there is no cutter clearance on the opposite face from the one you are cutting.

If you have access to a mill with a head that can be tilted, and a quill that can be extended I will show you my '10x quicker than using a dovetail cutter method' of cutting dovetails I worked out.

[forgemaster]

Too true John, sometimes newer is not better or quicker. I could not exist without my trusty old shaper, it's so easy to machine new dies, to fit. No expensive tooling just a single point tool, and a grinder and I can machine any profile I want (almost).