Perkins Fly Presses

[J.P. Hall]

Hi all, I'm looking for information on Perkins fly presses. I'm considering buying a #3, but haven't found much in the way of dimensions or what its capabilities would be. It seems that Perkins' presses run a bit bigger than other brands of a given number size (I understand the numbering system is manufacturer-specific). This video shows a #4 which looks to be pretty hefty. I was hoping to hear from somebody who's seen a #3 and might know how much of a difference there is between the two sizes.

 

[J.P. Hall]

I should also mention that the one I am looking at is actually a model 3K, not just a 3. I'm not sure yet what the "K" distinction means.

[Frosty]

Keep us posted please. From skimming the Commercial site I linked, said the number is usually tonnage. 3ton, 4ton, 10ton, etc. 

Frosty The Lucky.

[J.P. Hall]

I ended up getting the press. I haven't found any more information online, but I found this in a Perkins catalog for power presses.  the "K" just denotes that it's a hand screw press. I'll try to get pictures, but here are some general measurements. It's a fair bit smaller that the #4 in the video above, but I think it'll still be pretty capable. The ram has about 6" of daylight, and the press is about 5'5" with the ram fully raised when sitting on the 2' tall stand. The footprint is about 26" square and the bar holding the handle and weight is 32" long

 

[Frosty]

Congratulations! I look forward to all the pictures you are going to post. We LOVE pictures you know.

Frosty The Lucky.

[J.P. Hall]

The press:

Made in 1956:

 

The screw:

The split nut. This seems to be different than on other presses. Examples I've seen from other manufacturers generally have a split nut and a lock nut, but on this press it's just this one that is threaded into the ram and held in place with a set screw. The set screw presses a copper slug against the threads to protect them. There are 4 holes in the collar, two on each half, presumably for a spanner. The cavity in the ram has a flat washer for the bottom of the screw to spin against, which sits in a bit of oil.

 

The base plate on the press. The outermost holes are 1/2" and  attach it to the press body from underneath. The other two sets of holes are 5/8" and 5/16". The plate has a crack on the left side that goes through both threaded holes. The previous owner said it had never been an issue for them, so I have no immediate plans for trying to repair it. The tooling hole in the ram is 1-1/2" and has an adapter for 3/4" tooling shanks. The ram also has a hole that connects with the tooling hole, which may have been for knocking out parts that were being punched.

 

So far I've made a flat die and a 5/8" fuller/drawing die. I'm working out how best to make a mounting system for bottom tools and then I'll make matching bottom dies.

[Frosty]

Oooh PICTURES!  

A couple thoughts to start. Have you looked at the patent drawings? They're available from the USG patent server, if not here look at the ones from the country of origin. They usually have detailed drawings, often blue print quality drawings. You have the serial and model number to go with company name and only have to delete your way through the adds. 

 In drawing 1 it looks like the mounting bolts and the bottom of the die table aren't on the same plane, any gap under the bottom die(?) "feet" would cause flexing through the mounting bolts, the hammer isn't going to flex so metal fatigue stresses would build to failure. . . Somewhere, maybe the broken bolt holes?

I don't get how parts would get stuck IN the ram to require a wedge to knock out. In all probability it's to knock out tapered shanks as is the Morse #2 taper in the tail stock of machine lathes. The main hole in that thought being using a taper coupler with repeated impacts through it. 

Frosty The Lucky.

 

 

[J.P. Hall]

I hadn't thought to check patents, that's a good idea. I'll see what I can find there. I had imagined the base of the press underneath the die table was thick enough that it wouldn't be flexing, but I wouldn't be surprised if that was the case. I think it's also possible for it to have cracked some other way, like if a piece of debris was underneath the die table when it was bolted on, that could have also caused flex and eventually failure-- just an idea.

You're probably right about the cavity in the ram. It could be that it was simply to prevent tool shanks from bottoming out, upsetting, and getting stuck.

[Frosty]

I had a sky balling kind of thought after sending that post, perhaps because of the direction the weight turns there is more shock loading on the left side. Or maybe more likely, those screws tend to work loose. Loose screws are stress risers though it's often a screw other than the loose one that suffers. 

Did a long wedge come with the it? Does anything that fits the shaft look like the pic below? These are Morse taper sleeves, they adapt a smaller tool to a larger Morse taper. I have no idea what the numbers in the pic mean, it just came up in a search and didn't have a commercial link.

The rectangular section at the top of the taper stops about 1/2 way across the rectangular opening in the taper sleeve it couples to and REQUIRES a wedge to release. The tapers are long and slight, less than a degree do NOT quote me on that, I didn't look at or copy and post one of the morse taper charts here. Nor did I see a pic of a wedge. I'm sure they're out there but all sleaves and couplers work just fine with the wedge. One caveat to that last statement, drive wedges are matched to the taper so a #2 morse taper drive wedge won't be very effective in a #1 taper sleeve, etc. 

Frosty The Lucky.

 

[J.P. Hall]

Nothing like those sleeves or wedges, but it did come with a box of punches and dies for punching various shapes in sheet metal. As far as I can tell, the tool hole in the ram isn't tapered. The shank of the adapter is straight (as far as I can tell) and there isn't the slightest bit of play between the two. It's possible that it's a percentage of a degree, but it doesn't seem like it. I also haven't noticed any wedging between the two when trying to remove the adapter-- it's a tight fit but it spins freely even after heavily using the press.

[Frosty]

Is there ANY rust or dirt on the shank? Mic it to be sure if it's a taper, there is only a few thousandths top to bottom on most. Okay there's more taper than I thought, chart below. 

Frosty The Lucky.

[J.P. Hall]

the shank does have some surface rust about on par with the rest of the adapter in the last image. I'll have to mic it next time I'm in the shop as it's a bit of a hike. Are morse tapers common for presses? I'm not discounting the possibility but this use case doesn't make much sense to me, though I might just be showing my ignorance. To me, a taper with such tight tolerances seems like a good way to get it hopelessly stuck in the ram, if not split the cast iron if too much force is applied. I've also never seen one used with a set screw.

[Frosty]

Tapers are amazingly strong couplings, I've never heard of a properly maintained and seated one splitting the sleeve or being harder to tap out. I'm sure you can find explanations online, I've pretty  much hit the limit of what I know even though I've used the things for years. 

Frosty The Lucky.

 

[J.P. Hall]

The shank of the tool adapter was too large to fit in my micrometer, but its entire length was right on 1.5" according to my calipers, give or take a couple thousandths

I finally got around to making a system for bottom tooling-- I found a 1" cast iron plate and drilled/filed a 3/4" square hole, and then filed in some more corners to index tooling at 45 degrees. I then realized I didn't have 3/4" stock, so I made another thin plate to hold a 5/8" square shank. I started with some drawing/fullering dies and I've already got a flat top die. I think next I'll make some punches and drifts and butchering dies. Some proper clamps are also on the list.