Page 1 of 5 123 ... LastLast
Results 1 to 10 of 47

Thread: Largeish Hydraulic Press Build

  1. #1
    Join Date
    Dec 2006
    Location
    Torres Straits
    Posts
    3,471
    Total Downloaded
    0

    Largeish Hydraulic Press Build

    Sometimes you get lucky and end up in the right place at the right time.
    Old time engineer in town, Bill, is selling some of his gear off.
    I managed to pick up what will become a new press for me for about the cost of scrap steel for the frame Bill wanted less but we negotiated up on price!

    I had been wanting to change up from the 20T jobbie that is back bendingly low, wobbly and inaccurate and really just painful! I didnt intend going quite this big but hey you work with what you got!

    Specs are something like this:

    Frame is built largely from 8"x4" Tapered Flange Beam (unsure of weight but lets just say solid)
    Frame stands 2400mm high and is 1300mm between the uprights
    Bed is a pair of 8"x4" with 8" gap - press plate area will be 1300mmx400mm

    Hydraulic ram is double acting trunnion mount
    4.125" piston diameter by 12" stroke
    threaded rod end
    Beam trolley to track the ram left to right will need some work
    Rod chrome is pristine, I have no way of testing seals but the piston travels smoothly.
    I will likely re-seal the piston as a matter of course.

    The project:

    -Rejigger ram trolley so that it moves smoothly at rest and when loaded up the trunnion ring engages force into the press frame. I will use the ram to raise and lower the bed.
    -Source a pump and spool valve to control the ram - power will be via electric motor. (made that sound easy didnt I )
    -Source some heavy plate for the press bed.
    -Paint a sign "Bills' Press" to capture the history of the old girl.
    -Sell the old 20T jigger (blue press in photo)
    -Get back to doing what I should be like building that trailer.

    How can you guys help:

    -I only have a pretty basic understanding/ experience of hydraulics.
    By my calcs the piston contains ~0.69Gal (~13.3sq" x 12" stroke). So as to not make the stroke painfully slow I am thinking something up around 5 GPM flow rate at what I presume will be about 3000psi.
    Soo any recommendations on pumps, hp of motor to drive said pump and spool valve & plumbing would be appreciated. I think I will build it with the hydraulics and tank up top just to keep the floor clear.

    -Also need some idea on the bed support pins. The holes are drilled at inch diameter.
    One pin is an old length of shafting the other is a piece of MS rod which is a little banana like. Thoughts are to source 25mm HT rod or shafting or possibly over drill the holes and use some old axle half shafts I have floating around?

    -Any other good ideas?

    Steve
    Attached Images Attached Images

  2. #2
    Bearman's Avatar
    Bearman is offline TopicToaster Gold Subscriber
    Join Date
    Jun 2006
    Location
    Hay Point
    Posts
    4,042
    Total Downloaded
    0
    That is a ripper of a press Steve. Wish I had one like that, my present one is smaller than the one you are getting rid of.
    Cheers......Brian
    1985 110 V8 County
    1998 110 Perentie GS Cargo 6X6 ARN 202516 (Brutus)

  3. #3
    Join Date
    Dec 2006
    Location
    Torres Straits
    Posts
    3,471
    Total Downloaded
    0
    Should just about do the job eh Brian

    Now more calcs from this site

    I see that a 5hp motor (about the biggest easily obtained single phase) will yield about 3GPM at 3000psi assuming 100% efficiency. So best case would be piston stroke time of 14 seconds. I reckon I could live with that.

    Soooo onto the pump. To ensure the pump is not the rate limiter lets look for a pump that will provide a say 6GPM at motor shaft speed (2800rpm)
    6 Gal is 366 cu inches - so pump capacity needs to be 0.13cuin/rev at 3000psi.
    Seems GPM are usually stated at 1750RPM but on my calcs this unit should work
    Yuken Hydraulic Gear Pump PG0E 210 1GPM 3000PSI Keyed Shaft 2 1cc 13CID SAE NEW | eBay

    Question is though, shaft speed range is 800-4000 so direct drive from 240 motor at 2800 is good, but why do they state them at 1750RPM? is it an efficiency thing or heat load???
    Should I be looking to gear the motor down?

    More I think about it - it is most likely due to pumping inefficiencies. I should just get a pump rated to say 4 or 5 GPM at 1750 - whack a motor on it and see how it goes!

    Any clues or ideas????

    Steve

  4. #4
    Join Date
    Oct 2012
    Location
    FNQ
    Posts
    1,723
    Total Downloaded
    0
    Clues or ideas? Yep forget about the press just swop for a gearbox also keep the small press as a large press takes no prisoners

    Noel

  5. #5
    Join Date
    Dec 2006
    Location
    Torres Straits
    Posts
    3,471
    Total Downloaded
    0
    Hmmm, I would be lying Noel if I said your offer of a swap was tempting!!!!
    Im hoping when it is done that prisoners could be reformed inside the press!

    S

  6. #6
    Join Date
    Jan 1970
    Location
    under a rock, next to a tree, at Broadmarsh
    Posts
    6,738
    Total Downloaded
    0

    pressing the point

    That 1750 RPM sounds like the pump is designed to be driven by a engine crankshaft.

    Maybe you should look at having the pump driven though a pulley and vee belt arrangement, sorry if you have already stated this.

    Personally I prefer the two hand pump system, with the high volume pump for locating the ram, then a high pressure - low volume pump to create the force required for the pressing operation.
    I particularly like the feedback you get back through the handle and being able to feel how the press is performing while it's working.
    .

  7. #7
    Join Date
    Dec 2006
    Location
    Torres Straits
    Posts
    3,471
    Total Downloaded
    0
    Arthur,
    Im a little sick of hand pumping
    Having seen Keith Fenners' press in action both on the u-tube and in person I seriously want a spool valve controlled hydraulic motor driven press!

    Why upgrade unless you go large?

    I do like the threaded portion of the rod end, I can see me turning up a few attachments which enable me to use the threads to locate a part with minimal pressure and then step back and let the hydraulics have at it.

    Obiously the cheap/easy option is to use a hand pump with return circuit and some springs to pull the cylinder back up... but this is not the sorta press to cheap out on in my opinion

    S

  8. #8
    Join Date
    Apr 2009
    Location
    Crafers West South Australia
    Posts
    11,732
    Total Downloaded
    0
    Old front McPherson struts (e.g.all Commodores) have hard chromed tough steel shafts which when cut off make good steel bar stock for all sorts of things, including press pins. About 22mm diameter.

  9. #9
    Join Date
    Dec 2006
    Location
    Torres Straits
    Posts
    3,471
    Total Downloaded
    0
    Thanks BeeUtey
    22mm might be a touch sloppy and last time I check a commo wont have 450mm of travel which would be the length of pin that I need?
    But it is a good line of thought - I reckon a couple of truck dampers likely have long enough shafts of the roght diameter... Thanks

    S

  10. #10
    Join Date
    Jan 1970
    Location
    under a rock, next to a tree, at Broadmarsh
    Posts
    6,738
    Total Downloaded
    0
    Quote Originally Posted by roverrescue View Post
    Arthur,
    Im a little sick of hand pumping x2
    Having seen Keith Fenners' press in action both on the u-tube and in person I seriously want a spool valve controlled hydraulic motor driven press!

    Why upgrade unless you go large?

    I do like the threaded portion of the rod end, I can see me turning up a few attachments which enable me to use the threads to locate a part with minimal pressure and then step back and let the hydraulics have at it.

    Obiously the cheap/easy option is to use a hand pump with return circuit and some springs to pull the cylinder back up... but this is not the sorta press to cheap out on in my opinion

    S
    I will see if I can get a photo of a chap's 50 ton workshop press, it's a forty year old 'Servex' brand.

    Never mind, here are some of a similar type of press that's for sale.

    Ref; Used Servex 60 TON HYDRAULIC PRESS Hydraulic Presses in Murarrie, QLD Price: $4,680 <66369>








Page 1 of 5 123 ... LastLast

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Search AULRO.com ONLY!
Search All the Web!