Building a press

Discussion in 'The Forge' started by Bruno, Nov 26, 2018.

  1. Mike Blue

    Mike Blue Member

    I have a lot of funny stories to tell about Ed's forge and his press (any smith who uses a vertical forge and long welded rods to hold the work). I disagree with his tools but I can make them dance too and I've done a lot of productive work on tools I would not buy or build. I think it's better to be able to use any tool than to be limited because I don't prefer something.
     
  2. Bruno

    Bruno Administrator Staff Member

    True.

    Most of the things I have here are extremely simple. The kind of 'temporary' stuff that becomes permanent. My burner is held in place by a pair of vise grips that haven't come loose in 2 years :D
     
  3. Mike Blue

    Mike Blue Member

    I can admit to that too. Some thing gets jury-rigged and works and then finishing the job drops off the radar.
     
  4. Bruno

    Bruno Administrator Staff Member

    By 'not moving' I take it you mean it should be locked in place on all 4 side?
     
  5. Bruno

    Bruno Administrator Staff Member

    Btw I pulled the trigger after a last minute addition.
    I requested a ball valve at the high flow pump, after discussing the options with the vendor.
    With the valve, I can close the pump with the biggest flow.

    In that setting, I only have the slow, high pressure pump. The reason for that option is that if I do something like finalizing a razor hollow or aligning the different parts of a chef knife, I want a controlled motion. Having the ram move at 10 cm per second would make that process pretty difficult to control. Sure, I could work with spacer blocks to stop at the right thickness or so. And that will probably work in most scenarios.

    Maybe I'll never need it. But at this point it seemed like the perfect idea to at least add the option. Because once the unit is here, jerry rigging stuff is going to be more difficult and annoying.
    For now I have no other uses in mind, but frankly, once you have a hydraulic unit like that in your shop, it's not going to be that big a project to e.g. create a rolling mill :p
     
  6. Mike Blue

    Mike Blue Member

    Yes, the ram should only move up or down, never sideways in any axis.
     
  7. Bruno

    Bruno Administrator Staff Member

    Right before paying this weekend, I noticed something which cost me another couple hondo's.
    The mains plug was a standard 3phase 32 amps one. The motor should use far less, but I wanted to double check.
    At 3 phase 400, indeed the motor uses only 12 amps, but a 10HP motor has quite a surge current when starting up.
    I checked with the vendor and indeed, you need a 32 amp circuit to prevent tripping the breakers OR hook the motor to a soft start protection circuit.

    So the soft started was added. It's better anyway to have one, and in this configuration they add a 16 amp mains plug, and do startup testing to verify it won't trip a 16 amp breaker.

    It's more money, yet again, but on the flip side, these guys assemble and test everything before shipping so if you are not a hydraulics guy, you can know for sure that a) you're working safe, and b) everything works as expected.
     
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  8. Bruno

    Bruno Administrator Staff Member

    I have a frame in mind, based on pictures and youtube videos, and information from Mike and Ed.
    In a rare stroke of intelligence, I have decided to make a small scale version of my frame in wood, just to get a feel for how everything will fit together in reality.
    Usually I'm a 'well figure it out as we go along' kind of guy when it comes to tools, but in this case it seemed prudent to double check my plans before I start ordering steel.

    As expensive as this thing is going to be, it'll probably come out at half the price of an off the shelf anyang press.
     
    Last edited: Dec 4, 2018
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  9. Bruno

    Bruno Administrator Staff Member

    @Mike Blue what is your opinion about ram moving up or moving down?
     
  10. MotoMike

    MotoMike New Member

    I had wondered about a soft start on those systems. 3 phase is not an option here, prohibitively expensive to get it if it can be gotten. The factory where I work part time has some 3 phase equipment, and there is a surcharge for the service. is the 32 amps your locked shaft current? wondered if the system would start easier if it weren't pumping hydraulic. say a bypass piping circuit that took the pump output back to the reservoir without making it do any heavy work would be less start current than one that had to come on line turning max load. A moot point I guess since you have the soft starter. 10 horse should be good for a pretty serious system. I've looked at some good working systems that are running 3 or 4 horse. sure anxious to see this project unfold
     
  11. Bruno

    Bruno Administrator Staff Member

    The big issue is that any AC motor only creates impedance (one form of resistance for AC circuits) when the axle is spinning. The very fraction of a second when you power it on and the axle is standing still, it is essentially a short circuit until the magnetic field build in the coils and the axle starts moving.

    So even without load, this 10 HP motor would pull 32 amps at 400 volt or more.

    I have 3phase 400V mains, 20 amps per phase.
     
  12. 32t

    32t Member

    Are you talking about the hydraulic cylinder being over or under your working area?
     
  13. Bruno

    Bruno Administrator Staff Member

    Yep. I've seen many presses by people like Ed Schempp which have the cilinders onder the working area, and they press the die up.
    This has the advantage of keeping the press reasonably sized. You want the work area to be more or less chest height.
    the flip side is that the piece of steel is also moving while you are holding it in tongs.
     
  14. 32t

    32t Member

    My first impression is that being under would be dirty on the moving parts.

    Very high maintenance.

    Why would you want your work chest high? that would feel very uncomfortable to me.
     
  15. Bruno

    Bruno Administrator Staff Member

    Because you want to have a very clear view on exactly what is happening. If you are making complex damascus and mosaic damascus, you need to have a good control on how length, width and thickness change when pressing. There is a need to maintain ratio of deformation and such. Doing that at anvil height is harder, or so I am told.

    Power hammers are much lower because they are very violent and you don't want your face near the place where pieces may start flying around. But for a press, that is less of an issue and the added visibility is an asset.

    The only moving part that is going to be underneath is the actual cilinder.
     
  16. 32t

    32t Member

    I can now see why it was mentioned earlier to protect the hydraulic lines well.

    You wouldn't need a very long cylinder from what I see so if you are buying new a shorter one wouldn't add a lot to the height if put on top.
     
  17. MotoMike

    MotoMike New Member

    Bruno, I've considered a press for a while and like you wanted the height to be reasonable. I'd considered something like the attached image where only the heighlighted part moves while the cross hatched part remains stationary. this would create a low center of gravity, keep the bottom die stationary and in the configuration I show, put your seals down where they are less likely to get debris on them and or slag hitting the smooth finish of the ram. I had also considered putting a skirt on the bottom of the cylinder, maybe an inch or so to further protect it. though more complex than other designs, I don't think it is unduly so. forge241.jpg
     
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  18. 32t

    32t Member

    Interesting idea. To me it does look a little more complicated than need be.

    Has anyone seen a horizontal design like a standard log splitter?

    I will now have to look this up!:)
     
  19. Mike Blue

    Mike Blue Member

    my press moves the ram, aka tup, downward onto a fixed sow block. My sow block is about waist height. I hold all hot items with Tongs, not welded rod handles because I have a horizontal tube forge. Holding things at waist height is more ergonomic with me as I can rest the "weight (usually 7-10Kg)" on my hip and move from there.

    Ed's press moves the sow block and frame up into the tup. He uses welded rod handles because his forge is a Fogg stylee vertical tube. His moving sow block is about shoulder height. I have entertaining stories about heavy billets and trying to get work done.

    Each method will work, you'll adjust to the tool you make.
     
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  20. Mike Blue

    Mike Blue Member

    The original designs that bladesmith/knifemakers developed (Knickmeier) were simply horizontal log splitters turned vertically with the obligatory die changes to make it work.

    A horizontal forging press will require contact with the metal frame that will suck heat from the billet and change the forging time/dynamic. I think its easier to rest the hot billet on a hot working die if contact is needed at all. But even then I generally do not "rest" the hot billet on the bottom die as that sucks heat from the work piece too. If you watch a very good video of Japanese swordsmiths/tool smiths you will see this technique ritually.
     

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