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what # flypress do i need?


Rob G

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You need as big of one as you can afford... Thats my opinion.. ;)

60 ton on a jack operated press has very little "cross over" info to what a fly press will do and its all relative anyway.... If you need 60 tons to punch on a jack operated press you very well could punch the same hole on a 8-10 "ton" fly press... Partly because of the amount of heat you loose, but mostly because of inertia and speed of the blow... Think about it this way... it takes 24 tons of mechanical force to punch a 1/2" hole in 1/2" plate cold.... Yet with a 3 pound hammer and a little heat you can do it with the swing of your arm.... There is way more going on than just raw power....

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i guess the force a flypress can deliver depends mostly on the lead of the screw and the weight of the wheel. i'm punching 2.5" holes through 3" thick aluminum. can that be done on a flypress in the size range oldworld anvils offers?

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I hope I am reading your dimensions right but it is impossible to punch a hole through plate that is thicker than the diameter of the hole, for instance you cant punch a 1 inch hole through 2 inch thick plate. Are you pushing a slug out or are you slitting and drifting a hole.

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Kevin your right for steel (cant punch a hole deeper than it is in diameter, or at least not without great difficulty) It might be that aluminum is soft enough that you could...


I dont have any experience punching big holes in aluminum but my guess is your going to need something bigger than a hand operated fly press... That is a massive hole in some thick stuff, even if it is soft...

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Here is what John Crouchet emailed me when I asked him what size he recommends with regards to Old World Anvils...

"I had worked with that model number five a lot at flypress seminars I
taught and it seems to be a well made, well machined, general purpose
press for the professional blacksmith shop. The number six is a fine
press, but pushing that big wheel all day --like when you are veining or
doing tenons or other repetitive work-- will just wreck your body after
five or six hours. I had a really big guy in my last class who mostly
worked 1 1/4 inch stock and needed to do a lot of cold bending and I
advised him to get a number six. For most guys, though,it is just too
much press and they wind up not using it much. I would get the smaller
press that will do 98% of what you need and just go to the powerhammer
with the rest. Most of the time, you are just "bumping" anyway. Also,
remember, a well anchored really heavy flypress table will do a lot to
make a small press perform like a big press."

I still don't have one, should have bought one from a local auction, it sold on the floor for $60 even though I had a proxy bid in with the auctioneer for $300! Local auction company not known for being very well run...

-Tod

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So, are we talking hot or cold here?

Kpotter: Never say "impossible". That's just a rule of thumb for O-1 punches through mild steel and is on the "safe" side. I've exceeded that by 50% with S-5 punches and extra clearance. And I've done 4 -5 times that hot (just dull red).

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I am stretching the limits of memory when I worked with aluminum years ago,but T means tempered and H means hardened. 5000 series aluminum would be a h# and 6&7000 are a t# The first numbers are the alloy and the t or h is the hardness of it, the higher the number the harder it is T0 to T6, 0 being very soft. You should be able to re-temper it if it matters.
Rob

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i guess the force a flypress can deliver depends mostly on the lead of the screw and the weight of the wheel. i'm punching 2.5" holes through 3" thick aluminum. can that be done on a flypress in the size range oldworld anvils offers?


I don't want to get into all the math involved, and I am not an engineer anyway, but I think you need about 25,000# force per inch of thickness x the square area of the die for aluminum, so no, not even remotely. Hot, of course would be a different story. The charring temp of a pine stick, 600F, is slightly below the anealing temp of aluminum, at 650F. However, three inch thick would not be nearly 650 in the center of the metal, when the outside chars a stick.
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Except that, as has been discussed before, a fly-press can deliver multiple blows and keep doing work. It does not stop working after a single blow bottoms out, so it's possible that it could eventually push the punch through. That is why the fly-presses are popular among smiths, if it were the manual equivalent of hydraulic or crank presses they would be too much work.

Aluminum is a much better conductor of heat than steel, so I wouldn't discount the charred stick method. I've forged 3" aluminum using the 'Oh, my sharpie mark disappeared method' and done fine.

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Except that, as has been discussed before, a fly-press can deliver multiple blows and keep doing work. It does not stop working after a single blow bottoms out, so it's possible that it could eventually push the punch through. That is why the fly-presses are popular among smiths, if it were the manual equivalent of hydraulic or crank presses they would be too much work.

Aluminum is a much better conductor of heat than steel, so I wouldn't discount the charred stick method. I've forged 3" aluminum using the 'Oh, my sharpie mark disappeared method' and done fine.


Not discounting it, just explaining something. I have anealed 6061-t-6 using the combustion temp of carbon method and then watched it crack when I bent it. By the way, I have two flypresses. I am somewhat familar with them.
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Not discounting it, just explaining something. I have anealed 6061-t-6 using the combustion temp of carbon method and then watched it crack when I bent it. By the way, I have two flypresses. I am somewhat familar with them.

Last time I did some research on AL for a job I was surprised to see that 6061 (which is the most common alloy I run into) is a poor choice for forming. If I remember correctly it has good structural and welding qualities, but poor forming and bending qualities. It's possible that the cracking was caused by the bend being too sharp; for example, my Reynolds Aluminum book recommends 1" as a minimum inside radius for bending 1/4" 6061 plate.

Arftist, I'm not trying to be a jerk, when I see your name on a post I usually pay a little more attention. It bugs me when people throw out numbers and don't explain them. The original poster said that he was working the material hot, so if we assume that he is using blacksmithing methods, rather than a 2" punch and die set, then even a small fly-press might be an improvement.

Rob G, I checked the Forging Industry Handbook and forging temperature is between 700-850 degrees farhenheit for 7075 aluminum. I don't know how you would check that temperature with a stick, but it sounds like you've been working a little too cold.
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Here is what John Crouchet emailed me when I asked him what size he recommends with regards to Old World Anvils...

"I had worked with that model number five a lot at flypress seminars I
taught and it seems to be a well made, well machined, general purpose
press for the professional blacksmith shop. The number six is a fine
press, but pushing that big wheel all day --like when you are veining or
doing tenons or other repetitive work-- will just wreck your body after
five or six hours. I had a really big guy in my last class who mostly
worked 1 1/4 inch stock and needed to do a lot of cold bending and I
advised him to get a number six. For most guys, though,it is just too
much press and they wind up not using it much. I would get the smaller
press that will do 98% of what you need and just go to the powerhammer
with the rest. Most of the time, you are just "bumping" anyway. Also,
remember, a well anchored really heavy flypress table will do a lot to
make a small press perform like a big press."

I still don't have one, should have bought one from a local auction, it sold on the floor for $60 even though I had a proxy bid in with the auctioneer for $300! Local auction company not known for being very well run...

-Tod


I have a #5 from Old World Anvils and like it very much. I got the same information from John Crouchet when I bought mine 2 years ago. I have not done any punching with it though. I looked at a #6 from Blacksmiths Depot and Old World. I decided on the smaller one and my arm still gets tired working it.
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Last time I did some research on AL for a job I was surprised to see that 6061 (which is the most common alloy I run into) is a poor choice for forming. If I remember correctly it has good structural and welding qualities, but poor forming and bending qualities. It's possible that the cracking was caused by the bend being too sharp; for example, my Reynolds Aluminum book recommends 1" as a minimum inside radius for bending 1/4" 6061 plate.

Arftist, I'm not trying to be a jerk, when I see your name on a post I usually pay a little more attention. It bugs me when people throw out numbers and don't explain them. The original poster said that he was working the material hot, so if we assume that he is using blacksmithing methods, rather than a 2" punch and die set, then even a small fly-press might be an improvement.

Rob G, I checked the Forging Industry Handbook and forging temperature is between 700-850 degrees farhenheit for 7075 aluminum. I don't know how you would check that temperature with a stick, but it sounds like you've been working a little too cold.


You are absolutely correct, 6061 is not prefered for bending, but is sometimes chosen anyway for other reasons.

Thanks for the comment, I really apreciate it, and I see your point about an incomlete equation having little value.
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