Ross Moffett Posted August 18, 2018 Posted August 18, 2018 Hi Y'all! Today I met one of my neighbors (I've recently moved) whose a retired electrical engineer. He was showing me his home built hydraulic log splitter and the some of the parts he'd gotten from an old punch press, long story short, he still had the cylinder from the punch press and he implied I could use it for building my forging press if I wanted to! So my question is if its suitable or not? I only got the rod and bore diameter's, rod is possibly 2 stage/telescoping? Bore size: 22 cm/ 8.66 in. Rod size (smaller): 7 cm/ 2.75 in. I'm estimating the stroke is around 8 inches, maybe less. Thanks in advance! Quote
CMS3900 Posted August 18, 2018 Posted August 18, 2018 Thats's a really good cylinder if it is in good working order. Quick math at 3000 psi put's it around 88 ton. I would try to figure out what pressure the press ran at and then do the calculations on the amount of gallons per minute it will take to cycle at a speed you want. Some people have issues with short stroke rams in their press because they affix both sides in one position. you can mitigate the short stroke length by designing the press to have the non-ram side movable if you wanted. Quote
Ross Moffett Posted August 18, 2018 Author Posted August 18, 2018 I was really hoping I'd be able to use it! I'll probably take it to some hydraulic experts and see if they can figure out its specs as it doesn't have any numbering or writing on it as far as I've seen anyways. My calculations say on a 8.2 in bore (I'm accounting for wall thickness) at 16 gpm I'll get 1.2 in per second. Good idea on having the non-ram side moveable! Ross. Quote
Ross Moffett Posted August 20, 2018 Author Posted August 20, 2018 Update* My neighbor said I could take the cylinder and its free of charge! I've been working on a design and I just wanted to run it through for inspection! Note: This is a rough design and open to change/modification. Overall dimensions H 1304 mm (Cylinder included) W 863 mm Th 254 mm All input is appreciated! Ross Quote
Kozzy Posted August 20, 2018 Posted August 20, 2018 Be sure and back-calculate the volume to get a good estimate on stroke speed so you can properly match the pump/motor. One common theme that seems to come up with people planning hydraulic presses on this site is undersizing pumps and motors so the stroke speeds are quite low. That will definitely drive you crazy when using the thing. The price of undersized pumps is sure tempting but in the long run not worth the savings. Quote
Ross Moffett Posted August 20, 2018 Author Posted August 20, 2018 1 minute ago, Kozzy said: Be sure and back-calculate the volume to get a good estimate on stroke speed so you can properly match the pump/motor. One common theme that seems to come up with people planning hydraulic presses on this site is undersizing pumps and motors so the stroke speeds are quite low. That will definitely drive you crazy when using the thing. The price of undersized pumps is sure tempting but in the long run not worth the savings. Thanks for the reply! I''ve been trying to keep all the calculations in mind and I'll probably go for a 19 or 28 gpm pump (2 stage) run by a petrol engine because I don't have suitable power to be able to run an electric motor, the engine won't be under powered. Ross. Quote
the iron dwarf Posted August 20, 2018 Posted August 20, 2018 you could try air to get the stroke measured, if the rod telescopes it will be with much less force as it will be a smaller bore and dont do a full stroke each time, I use limit switches to save time and that means I can do a stroke in less than 1 second Quote
Ross Moffett Posted August 20, 2018 Author Posted August 20, 2018 I'll try that. Some guys I've been chatting too (not on IFI) have expressed their doubt of the cylinder being telescoping but hey, only one way to find out! Any concerns or suggestions for the press design, structurally? Ross. Quote
ianinsa Posted August 22, 2018 Posted August 22, 2018 just connect your cylinder to a compressor and you will see what it is .... no load obviously ! ian Quote
t2harh Posted August 23, 2018 Posted August 23, 2018 In/outlets could be problematic, as a press can operate at high pressure, not at higher rates speed. Hydraulics only cycle as fast as fluid can move thru the restrictions. Not so different from an air cylinder that returns at the same point the supply is, hence the reason air is exhausted close to the port as possible. Good luck! Quote
ianinsa Posted August 23, 2018 Posted August 23, 2018 KE? ..... the OP wasn't sure if it was telescopic thinking there was possibly only one way to find out. to many that would not be the case! i proposed a simple way to discover if it was so, you would not be connecting inlet and outlet you merely want to push some air into the inlet port to push out the piston you might even be able to do it with a bicycle pump(if you are lucky) Ross you'll need a short piece of rubber hose that fits over the thread that has the yellow cap and a hose clamp in the other end you 'll need a reducer , the cheapest will be a plastic(ldpe/hdpe) irrigation one from the local co-op , Build-it ,Mica. (those are in order of cost) probably R7 to R11. the other side to fit your compressor hose probably 6 or 8 mm. if you don't have easy access to a compressor then go to your local tyre fitment shop and ask for an old tyre valve, cut off the bulbous bit and that will give you a 10mm rubber stem to stick into the tube . so all you need is two bits of hose , 3 hose clamps and a reducer if you have the tyre valve you can "test" at your local petrol (gas to our American friends)station. all for less than 1us$ that's R15 for us Ross. if that piston is in good shape it should require less than 1 bar or so to extend it, you are merely testing to see if it is telescopic or not. Good luck Ian Quote
Ross Moffett Posted August 23, 2018 Author Posted August 23, 2018 Thanks for all the replies everyone! Great advice Ian, I will soon have access to a compressor and I'll test the cylinder. Ross. Quote
Ross Moffett Posted September 4, 2018 Author Posted September 4, 2018 Okay, I tested the cylinder using a compressor but it only extended about 3 cm and it was super stiff, I couldn't push it back in or out by hand. I think maybe it not being used in about 10+ years has something to do with this? I'll take it somewhere to have it checked out and maybe have clevis rod ends attached. But by my estimate the stroke is around 10 cm + or -. Ross. Quote
the iron dwarf Posted September 4, 2018 Posted September 4, 2018 punch presses dont need much travel and hydraulic cylinders are meant to be tight, what is the distance between the 2 fittings ( piston can easily be 10cm of that ) Quote
Ross Moffett Posted September 5, 2018 Author Posted September 5, 2018 It's about 14cm from the middle of one fitting to the other. Thanks for the reply. Ross. Quote
Ross Moffett Posted September 5, 2018 Author Posted September 5, 2018 Well.... that could be a problem... Quote
the iron dwarf Posted September 5, 2018 Posted September 5, 2018 I buy new cylinders to get the spec I want, they are cheap these days, the one for the next press build is about 4" bore, 8" stroke and works at 200 bar, 3000 psi. at a rough guess it is 25 tons and it cost about 100 uk pounds about $130 Quote
Ross Moffett Posted September 5, 2018 Author Posted September 5, 2018 I would buy new but the price of hydraulics here is quite expensive, it was about $400 for a new 5 inch bore cylinder. Thanks for the advice. Ross. Quote
the iron dwarf Posted September 5, 2018 Posted September 5, 2018 mine came from germany, it is a pity about the recent large tariff on steel as that adds to your costs it also put up steel prices here due to most commodities are priced in $ so steel from india or china coming here and never going near the US went up 10% recently Quote
Ross Moffett Posted September 5, 2018 Author Posted September 5, 2018 Pity indeed. Well I guess the search continues . I may still have it tested if it doesn't cost too much $$ of course. Quote
the iron dwarf Posted September 5, 2018 Posted September 5, 2018 check sellers in germany on evilbay Quote
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