thirteen Posted March 24, 2013 Posted March 24, 2013 i bought a multipower cylinder off ebay that can press 8460lbs at 150psi max i just need to build a stand for it but i dont deal with metalworking
BlastFromThePast Posted March 24, 2013 Posted March 24, 2013 (edited) Well how much metal working are you willing to undertake. If you don't have a welder, which I"m assuming you don't, you can always go with angle iron steel that is perforated with holes all along the metal. This is commonly used in metal framed desks. What are the dimensions of your pneumatic cylinder, height wise? Edited March 24, 2013 by BlastFromThePast
thirteen Posted March 24, 2013 Author Posted March 24, 2013 its like 6" tall with a 2" stroke its got mounting holes on the base 2 holes on each sidehttp://www.televisionary.net/ebayimages/032312_0331.jpg
BlastFromThePast Posted March 24, 2013 Posted March 24, 2013 (edited) If I were you I would take a look at some mounting designs of commercially made presses. H-frames are probably the way to go but if you want to get creative, one thing you might want to consider is mounting it to the underside of a drill press table. Do you have a drill press? If you do, and decide to mount it, you'll have a variable height press and won't have to worry about a max working height. Edited March 24, 2013 by BlastFromThePast
thirteen Posted March 24, 2013 Author Posted March 24, 2013 (edited) fabco makes an aluminum frame for this cylinder but its a little pricey i only paid 100$ for the cylinder Edited March 24, 2013 by thirteen
BlastFromThePast Posted March 24, 2013 Posted March 24, 2013 Well if you don't want to dish out for the frame, then I would try to mimick the frame with the right angle steel
thirteen Posted March 24, 2013 Author Posted March 24, 2013 i think im gonna have a frame priced for me i just gotta figure out what height would be needed for 1lb tooling
Bobosan Posted March 24, 2013 Posted March 24, 2013 I built this press for 1oz motors and works well with nozzles and fuel in spiral wound tubes. The cylinder is 38mm x 12" stroke. Might give you some ideas.
Zingy Posted March 25, 2013 Posted March 25, 2013 (edited) Steel channel makes a nice stiff structure, with a one sided flat surface, like used in Bobosan's press. You will want to obtain airline filter(s), to remove the moisture. When water mixes with petroleum fluids, (hydraulic fluids, oil, brake fluid), it becomes foamy and opaque, like phlegm, or snot. This would require you to replace the hydraulic fluid. It would eventually work it way into a pressure gauge, if attached. I use a separate pressure gauge and let the airline pressure regulator apply pressure uniformly, between identical work pieces. Edited March 25, 2013 by Zingy
dagabu Posted April 8, 2013 Posted April 8, 2013 Gee, you SURE you want to use air? Air power is a spring, the compressed air stores energy while hydraulic pressure is almost all static. Imagine if you will tensioning a steel rod and a rubber bungee to 8000 flbs. and then let go. The steel rod will wiggle and ring but it will hardly move, it is holding the energy statically. Air is like the rubber bungee, if it lets go, the energy is transferred to the piston, tooling, etc and makes a missile out of them. It's your decision but the likely hood of an injury with 8k of air-power is an almost given. Make a damn good shield!
thirteen Posted April 9, 2013 Author Posted April 9, 2013 i think i get what your saying but the rod moves so slow and with a pressure regulator its a steady psi. as long as everything is sitting flat and even i should be fine
dagabu Posted April 9, 2013 Posted April 9, 2013 i think i get what your saying but the rod moves so slow and with a pressure regulator its a steady psi. as long as everything is sitting flat and even i should be fine I'm sorry but that is not what is going to happen if the ram gets sideways or your blocks tilt or you misaligned something. There is stored energy that you cant see until it releases it. The entire cylinder is filled with compressed air when under pressure, even though you see it moving slowly as the pressure builds, it is the stored pressure that will bite you. I'm just trying to save you a trip to the emergency room or the worse yet, the ME's slab.
nater Posted April 9, 2013 Posted April 9, 2013 ... as everything is sitting flat and even i should be fine Easier said than done, especially if you build at events or with other people. It is very easy to get a little powder pressed around the spindle uneven causing issues. Please be careful. Also, is a 2" stroke length going to be enough?
thirteen Posted April 9, 2013 Author Posted April 9, 2013 does anyone here have any experience with this. i just wanted something faster than manual hydraulics i couldnt afford to build a powerpack type machine
nater Posted April 9, 2013 Posted April 9, 2013 I have an air assisted hydraulic jack on my press. It is much cheaper than using a ram with a powerpack and faster than cranking the jack by hand. However I end up using it manually more than anything. It can be a pain to lug the compressor around and find an outlet at events.
Bobosan Posted April 9, 2013 Posted April 9, 2013 I've been looking at the HF air assist jacks. @nater - for at shop use only, would air assist hydraulics be worth the extra money? Do you still have to manually release the pressure?
nater Posted April 9, 2013 Posted April 9, 2013 (edited) If you have a large compressor and don't plan on moving things around, the air/hydraulic jacks are nice. The one I have from HF has return spriings, which is nice no matter how you use it. You do have to manually release the pressure. I think a totally manual jack would be fine for pressing stars and comets. For rockets and gerbs, the air assist saves the fatigue on your arms. I will add, that after I have used one, a press with a hydraulic power pack is the best way to go for building a lot of rockets. That is a pretty big investment though, but the consistency using a pressure relief valve and ease of pressing is nice. Edited April 9, 2013 by nater
dagabu Posted April 9, 2013 Posted April 9, 2013 (edited) does anyone here have any experience with this. i just wanted something faster than manual hydraulics i couldnt afford to build a powerpack type machine Yes, I have certs in pneumatics and hydraulics, I am a Physical Plant manager now and have been an engineer at two other manufacturing plants starting out in maintenance 20 years ago. I probably have 20-30 Bimba pneumatic cylinders in the garage and still use a few for jigs and layout but never for what you will be doing called "stack compression". Consider this: Just an emergency room visit with simple stitches will run $2000.00 here in Minnesota. lets say you have great coverage, right? Whats your share of the co-pay? Is $700.00 to $1000.00 really that much more than what you have in mind? Compressor, air hoses, cylinder, frame, stack pucks, etc. I think you will be within $400.00 - $500.00 of a full powerpack hydraulic system from there. $750.00 complete: Edited April 9, 2013 by dagabu
Bobosan Posted April 9, 2013 Posted April 9, 2013 Are the hydraulic powerpacks you guys talking about like the ones EMS/Fire crews use? a.k.a. jaws of life.
dagabu Posted April 9, 2013 Posted April 9, 2013 (edited) They can be, the jaws of life power packs are single acting, valving can be used to use a single acting power pack on double acting cylinders without much monkey business. http://www.jawsoflife.com/Uploads/Images/Large/3689.jpg I actually use a snow plow power pack, THIS ONE on ebay but I got a rebuilt one for about $300.00. Just saw one for $288.00 on the bay, HERE I'm getting one for a portable, all-in-one. WHOOT!! Better yet!!! Florida Hydraulic has a beautiful DA pack for $365.00 Edited April 9, 2013 by dagabu
Bobosan Posted April 9, 2013 Posted April 9, 2013 Yeah, those hydraulic powerpack things are used for automotive winches and plows. ( he said, while browsing the pages of Surplus Center catalog)
pyromagi Posted April 14, 2013 Posted April 14, 2013 Yes, I have certs in pneumatics and hydraulics, I am a Physical Plant manager now and have been an engineer at two other manufacturing plants starting out in maintenance 20 years ago. I probably have 20-30 Bimba pneumatic cylinders in the garage and still use a few for jigs and layout but never for what you will be doing called "stack compression". Consider this: Just an emergency room visit with simple stitches will run $2000.00 here in Minnesota. lets say you have great coverage, right? Whats your share of the co-pay? Is $700.00 to $1000.00 really that much more than what you have in mind? Compressor, air hoses, cylinder, frame, stack pucks, etc. I think you will be within $400.00 - $500.00 of a full powerpack hydraulic system from there. $750.00 complete: I'm having a little bit of trouble understanding what setup that is, hydraulic or pneumatic?
dagabu Posted April 15, 2013 Posted April 15, 2013 Hydraulic= Water or fluid, in the above case, its hydraulic fluid. Pneumatic= Air. Fluids do not really compress, air can compress to hundreds of PSI.
pyromagi Posted April 15, 2013 Posted April 15, 2013 (edited) Hi,So you suggest hydraulic press instead of pneumatic?I was also thinking of bulding a star plate press, and would like to get a fast process, so i don't whant to press manually.This is what i aim for: https://www.youtube....h?v=hkjkb9bAHQc What kind of pressure would suffice for making a 3/8" star? Kind Regards Edited April 15, 2013 by pyromagi
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