Moose Forge

Fly Press

Screw press/Ball-drive screw press

A screw press is a type of machine press in which the ram is driven up and down by a screw. The screw shaft can be driven by a handle, or a wheel. It works by using a coarse screw to convert the rotation of the handle or drive-wheel into a small downward movement of greater force. The overhead handle usually incorporates balls as a flyweight. This weight helps to maintain the momentum and thrust of the tool to make it easier to operate.

The screw press was first invented and used by the Romans in the first century C.E. It was used primarily in wine and olive oil production. The screwpress was also used in Gutenberg's printing press in the mid-15th century.

A press is a metalworking machine tool used to shape or cut metal by deforming it with a die. It is frequently used to punch holes in sheet metal in one operation, rather than by cutting the hole or drilling.

If used as a punch, the tool itself consists of a punch and a matching die, into which it very closely fits. Both are usually precision machined and then hardened. The material is introduced between the punch and die, and the machine operated. The punch will cut through the material in one movement by shearing it. The punch and die may be of any desired shape, so odd shaped holes and cutouts may be created.

If used as a forging tool the dies can be many different shapes varying from flat to various shapes that will mold the metal to the desired configuration.

The Advantages of a Fly Press

by Bill Lavelle, Director Foxx Spectrum Ltd.

Its strange that with all the technology around, that a machine that was first produced in Roman times to squeeze juice remains popular today and wanted by black smiths, jewellers, crafts people and professional fabricators.

So what are the advantages of fly press?

Here is a list, you're welcome to put forward more if you know of some.

It's simple to operate.
It requires no utilities to work, No compressed air, no electricity, no gas.
It is ecologically friendly, with no harmful emissions of any nature.
It packs a good punch in small space.
It's understandable technology.
It's robust. Virtually unbreakable.
Its need no expensive sophisticated guarding system.
Tool changing is rapid and simple.
It's very versatile. With the correct tooling, you can punch, coin, tube end form, bend, slot, form, dimple, clinch fasteners, edge fold, rubber form, etc etc.
It's cost effective.
The fly press is an inexpensive solutions to many pressing applications.

Tips on buying a used single sided fly press

by Bill Lavelle, Director Foxx Spectrum Ltd.

If your thinking of purchasing a new fly press then its best to consider the following issues before making the purchase.

What force do you need? The presses are rated normally in tons with the press number usually denoting their capacity. E.g. A Norton #6 can give 6 tons force with two balls on the arm.
What space do I have available for the press? This is important to consider as with some of the larger presses say #6's have a span across the arm of up to 4 foot. (1.3 M) You need space to rotate the arm.
What throat do you need? This is the distance from the centre of the presses ram to the back of the presses frame. If your going to be working on large sheets of metal then you need to know how far in from the edge of the sheet you will be working. If your clinching a nut into a sheet of metal 10 inches in from the sheet edge, then its not wise to buy a fly press with just a 7 inch throat, Generally you want a throat at least an inch more than what you consider to be you maximum working distance from the sheet edge.
What daylight do you need? This is the distance between the end of the slides (that hold the ram in place) and the machined base of the press. It's important to know, as it determines how big a tool you can fit in the press. If you have a die set, that in its closed position has a height of say 8-1/2 inches (over the stub) then you need to get press with a shut height of 9 inches or more. Note the stub {or stem} is the round arbor that fits in to the hole in the ram of the press. You need to remember its there as if you don't take its height into account, you will not be able to get you tool into the press.
What stroke do I need to make the tool work? 95% of fly press applications use a short stroke (less than an inch of travel) but there are tools out there that require more. So you need to consider the stroke.
Do I want it supplied on a table? This is really a transport cost issue, Its some time cheaper to just have the press shipped and for you to make a table yourself.
Do you need a hole in the press base? If your punching metal or cropping metal then you need to consider where the scarp is going?. If you have a hole through the base it will be possible to design your tools so the slugs fall straight through the tool and through the hole in the base. This means you will not have to stop work continually to clear away debris – off cuts.

How to assess the presses general condition?

You need to consider, if there are any cracks in the frame or arm? Are the tee shots in good condition? Is there play back in the screw/ram? Is there excessive play in the ram slide? Has the arm ever been welded after it broke? How can I get the press into my place? Even the small #1 & #2 fly presses have bit of weight in them. You certainly would not want to drop one on your foot. Above the #2 models weight starts to shoot up. A #6 press for instant can weight 500Lbs. You need to give careful consideration therefore how you're going to handle the press on arrival. Don't try and muddle through when taking delivery of the press, get friends to help or even bring professionals in to put the press in place. If you get it wrong the press can fall, and as the frame is cast iron it could crack. Worst still someone could get seriously hurt. That my tips for buying a single sided fly press hope it helps!

To understand the terms used better, see the photo to the left.

Important tips on extending the life of your fly press from Old World Anvils

Note: The bottom half of the tenon die
can be attached to a user supplied piece
of plate steel as seen in the photo above.
Cutting a hardy hole in the plate that is
the same size as the hole in your anvil
will allow you to use your existing hardy
tools with the fly press.

When making up tooling for the fly press tooling hole all tools should:

Have a shoulder on your tool to distribute the force of the tooling hitting the workpiece. This will prevent the tool from being driven into the top of the ram tool hole. Over time this could do damage to the top of the tool hole in the ram and might upset a tool in the ram making it difficult to remove.

A good solution to this is to go to the local farm store and buy some mild steel bolts with hex heads. The shaft of the bolt should be slightly shorter in length than the ram hole. Chamfer the sides of the bolt shaft that goes up into the ram tooling hole with a grinder. You can weld your tooling onto the hex head of the bolt. Add a couple of washers to the hex head screw shaft and this will transfer even more of the stress to the ram face. The ram has a set screw that allows you to tighten the bolt in the ram. Tooling can include, but is not limited to the following:

chisels
punches
fullers
drifts
side sets
tenon dies

You can add more shoulder area to the hex head of the bolt if desired. Take a piece of hot rolled mild steel that spans the ram face but doesn't hit the guides and heat it up to a yellow-white heat. With a bolt shaft up in the ram tooling hole, tighten the set screw , Bump the bolt head in the ram into the hot steel. This should sink the bolt head into the hot steel so the bolt head is flush with the hot steel. Now you can clean up this hole and weld it to the bolt head. You now have more surface area that spans the ram face and you can weld your tooling onto this piece of steel. This helps to distribute the rebounding force of the tool in the ram over more of the ram face and not the tooling hole in the ram. An even easier way to do this is to just add 2-3 washers to the bolt shaft and this will transfer more stress to the ram face.

Always work with as much of the ram up in the guides as possible. This gives the ram the most support in the guides and prevents any slop when the ram is at it's full length. To do this, just raise your workpiece with a piece of steel under it, so that the ram stays up in the guides as much as possible. I use a piece of 1" cold rolled plate that I bought at the scrap steel yard and used this as the basis for the fence in the photo above. I also add a piece of 1"thick X 3"wide piece of hot rolled to raise the workpiece up to keep the ram in the guides, as much as possible.
Do not use grease on the fly press. Use a light weight motor oil, i.e.: 10W, 5W.
If upon arrival the fly press doesn't spin down easily, you can control the ease with which it spins by the the interplay between the two nuts above the ram on the screw. Try loosening them and you should be able to set the fly press to spin down when you let go of the handle or if you tighten them you can set the handle at a certain position and it will hold that position. This is very handy if you need to change tooling with the ram up in the guides. The photo above shows the ram and screw with the two nuts on top of the ram. The writing on this photo is in yellow.
You have to tighten up the screw on the check nut if you are going to use it as a vertical stop. If the check nut is left loose you can damage the threads on the check nut when used as a vertical stop.

Additional sources of information:

I've borrowed liberally from a number of sites for this information since I knew nothing about fly presses, other than that I wanted one, so if the write-up is yours and you want me to delete it, email me. Below I've provided what I consider an extensive list of sources for additional information and inspiration. Enjoy learning and doing.

Gee Mom, look what else I've found!

Wisdom of my father: "It takes more of a man to walk away from a fight than to stay and fight."