Here is a video showing a friction press a little smaller than the one I had in my shop forty years ago. I worked the metals cold (SS 304 and 1018).
A friction press
- Thread starter johnnielsen
- Start date
John, is there an advantage to a friction/screw press over other types of presses, or are they considered outdated completely now? I saw a program on TV a while back and inside a pretty modern factory they were still using screw presses. That tells me either the things last forever (likely) or there is some economic/production advantage they must still have.
historicalarms
Ultra Member
because of their accuracy, modern rifle barrel manufacturer's still use an "un-motorized", manual hand -wheel screw press to straighten rifle barrels that have warped for some reason through the drilling-boring-heat treating or contouring procedures that cause a heat/stress warp.
The highest paid craftsman in the plant will be the "straightener guy" because of the skill needed to excel at the job
The highest paid craftsman in the plant will be the "straightener guy" because of the skill needed to excel at the job
Tom Kitta
Ultra Member
You can get these from China for around $1000+.
https://www.aliexpress.com/item/400...68#1000022185#1000066059#0_668#3422#15392#725
For $150 you get 2.5kw unit.
You can go much cheaper for say 1kw and you supply power.
To heat a 1/2" bar that is say 6" long in 1.5kw heater takes over a minute as per youtube.
This seems to have niche actual usefulness - for smaller ones it seems they are great at heating quickly rusted bolt heads. For bigger ones use would be as per video. Some people use bigger ones to melt small amounts of metal (like say silver). You would need rather huge unit to melt larger amounts of metal.
They are very fast and are still used in Sheffield England to polish expensive cutlery with a single hit. They were very common before variable stroke length and stroke position punch presses were popular.
The one I had was used to flatten 3/8" 1018 steel for 4" to a 1/8" thickness with a 2" stroke. I was making MULTI SECURITY four way deadbolts that had a lockset in the middle of the door and 4 rods that would move up-down-left-right directions to lock the door securely. They were invented by the Israelis to secure doors against terrorists.
I also used it to forge stainless eyebolts to secure refractory material to steel shells for high heat applications and to fasten marble and granite sheets to the outside of tall buildings like the Bowlen Building (courthouse) and the TD building downtown.
It was a Schuler 100 tonnes pressure capacity that stood almost twelve feet tall and weighed 4 to 5 tons.
Interesting fact. I tried running the ram up and down without the stops being set and it would walk around the shop.
The one I had was used to flatten 3/8" 1018 steel for 4" to a 1/8" thickness with a 2" stroke. I was making MULTI SECURITY four way deadbolts that had a lockset in the middle of the door and 4 rods that would move up-down-left-right directions to lock the door securely. They were invented by the Israelis to secure doors against terrorists.
I also used it to forge stainless eyebolts to secure refractory material to steel shells for high heat applications and to fasten marble and granite sheets to the outside of tall buildings like the Bowlen Building (courthouse) and the TD building downtown.
It was a Schuler 100 tonnes pressure capacity that stood almost twelve feet tall and weighed 4 to 5 tons.
Interesting fact. I tried running the ram up and down without the stops being set and it would walk around the shop.
I have a four start square thread ram and nut that I plan to make into a baby version called a flypress. It should deliver about a 2 to 3 ton hit. One full rotation of the thread moves the ram 3 to 4 inches.
They are very versatile. With appropriate tooling you can do deep drawing, forming, punching holes, straight bending or progressive bending by bumping.
Grizzly Adams
Member
Stupid Question. What rewinds the press ?
A fly press has to be retracted by turning the screw backwards. It is not a big deal as often you only use a 1/2 to 3/4 turn of the screw to do a bend, forge or forming. The screw moves 3 to 4 inches in one turn due to the very coarse 4 start thread. There is almost always a collar on the screw to regulate the exact point where the down stroke ends.
A powered (friction) press will have upper and lower stops to reverse the rotation upon hitting the lower stop and stopping the reverse rotation of the screw upon hitting the upper stop. This leaves the screw in a detente position ready for another down stroke.
A powered (friction) press will have upper and lower stops to reverse the rotation upon hitting the lower stop and stopping the reverse rotation of the screw upon hitting the upper stop. This leaves the screw in a detente position ready for another down stroke.