# DIY Hydralic cylinder for my press ??



## ksor (Aug 29, 2013)

I want to make a hydralic cylinder to my press and I need some ideas and theory or calculation concerning the dimensions of the cylinder.

 I plan top and button in the cylinder to be a thick plates connected with 5 or 6 Peaces 16mm threaded rods. 

 I need about 300-400mm operation room or what it's called in English - the length the pisten can travel !

 I HAVE a pump with motor and - I think - 40-50 liters tank for the oil - but how can I find out if this pump is any good for this project ?

 Any links for some "hydralic BEST PRACTICE" ?


----------



## canadianhorsepower (Aug 29, 2013)

ksor said:


> I want to make a hydralic cylinder to my press and I need some ideas and theory or calculation concerning the dimensions of the cylinder.
> 
> I plan top and button in the cylinder to be a thick plates connected with 5 or 6 Peaces 16mm threaded rods.
> 
> ...


 
you should find this interesting all the math calculation or identical rom
pneumatic to hydrolic 

View attachment 391127_PNEUMATIC_CYLINDERS.PDF


----------



## rcfreak177 (Aug 29, 2013)

HaHaHa funny that,

I have just finished my training course with Atlas Copco in advanced hydraulics #4.
been working with very high tech hydraulic systems for over 15 years now.

If you PM me your email address I will send you the info that you will need,

Personally I would stay away from a tie rod type cylinder, they are not suited for high pressure situations in my opinion.

Another thing to ensure is that the pump you have has a pressure relief to limit the max working pressure, if not I would advise having one in the circuit.

Also be well aware of the dangers involved, high pressure oil injection is very nasty and usually ends up with amputation of limbs to avoid infection.

I do not intend on scaring you but when designing, building or repairing hydraulic systems there is a high level of awareness and knowledge required.

Stroke is the term for the travel of movement, (for reference) and Pascal's law is the formula used for force and pressure calculations.
http://www.antonine-education.co.uk/Image_library/GCSE/Hydraulic_2.JPG
http://www.grc.nasa.gov/WWW/k-12/WindTunnel/Activities/Pascals_principle.html



I will be happy to help you out.

Baz


----------



## gus (Aug 30, 2013)

May I speak up.
1.All pipe and fittings must be rated for the maximum working pressure. Refer to
  manufacturer literature. All high pressure fittings have max.W.P. stamped on.
  DIY fittings  banned.While in China,was short of a 5000 lb coupling. Customer gave
  me a local 'Made in China' coupling and claim it is rated for 10,000 psig.Turned out to 
  a dud when I pressed for supporting docs.
2.All fitting joints must be sealed and tested for leakage. On no point use hands to
  to look for leaks. Pressurised hydraulic fluid will go through hands fingers etc.
  And good by fingers and hands.
3. All relief valves must show factory pressure rating and setting and capacity.Pressure
    setting wire/lead sealed.

Spent 20 years building 100------500 ton hydraulic presses with Ingersoll-Rand,Simgapore
Compressor Plant. Till today I get nervous when starting up 5000psig air compressors.
No bystanders,no unqualified helpers including customers.


----------



## MachineTom (Aug 30, 2013)

If you are set on using the pump motor you have, you need to first figure what is the pump rating, Pressure and volume. Normal Porta-power type units run 10K psi they use a very small volume of oil around a couple of liters and a 3/4hp motor, the pump in mine is a two speed version, first 1000ps use 2 cylinders and pump 4 times the volume, then only one cylinder up to 10,000 psi, the cylinder is about 2.5" diameter and yields 25 tons. 

These are piston pumps at this pressure, gear pumps top out at around 3000 psi, and centrifugal pumps are not used for normal as they end at 300PSi.

For a long stroke as you want, I would look for a used cylinder from an excavator as those machine tend to high pressure 5-10K, where a backhoe, or bulldozer tend to the 2-3000. It would be project to bore and hone a heavy wall seamless pipe to size and fit the packings good for 10K psi. The rod end is another issue, ground and chrome plated rods, and packings that need some reverse engineering to be right.

Just ideas.


----------



## ksor (Aug 30, 2013)

Thx to all of you - I got the Picture, I think :fan:


----------



## Wizard69 (Sep 6, 2013)

ksor said:


> Thx to all of you - I got the Picture, I think :fan:



Good luck with your endeavor, but think twice about doing this if you lack the engineering skills.  Even if you do a reality check with a practicing engineer is in order.  That is verify the critical equations with somebody that has the experience.   The failure of high pressure systems is extremely dangerous.  

I realize this has already been pointed out but the tiniest leaks in a high pressure system will result in severe injury to fleshy humans.   Think about how water jets cut steel and a host of other materials.   

To give you a data point, some time ago in the plant I work in a guy in another department either inadvertently or on purpose (don't know the details and didn't ask) had part of his hand come into contact with a hydraulic leak.   These really where high pressure systems like some work on but rather running at less that 2000 psi.   Those eating a daily meal might not want to read further.

In any event the oil got injected into the hand from what I understand.   This apparently only took a fraction of a second.   In any event at the hospital they had to skin the guys arm back to the elbow to effectively clean the oil contamination away.   I could go on with more details even if they are getting foggy but I won't.    The reality is it gets ugly and the guy was never seen again in the facility.

Now I'm not trying to scare you off the idea, but I'm trying to scare you to the point that you do the research first.   The reality is people build hydraulic devices every day, be it log splitters, presses or what have you.   Just don't jump into it without knowing the proper way to deal with things like leaks.


----------



## gus (Sep 7, 2013)

Wizard69 said:


> Good luck with your endeavor, but think twice about doing this if you lack the engineering skills.  Even if you do a reality check with a practicing engineer is in order.  That is verify the critical equations with somebody that has the experience.   The failure of high pressure systems is extremely dangerous.
> 
> I realize this has already been pointed out but the tiniest leaks in a high pressure system will result in severe injury to fleshy humans.   Think about how water jets cut steel and a host of other materials.
> 
> ...



Hi Wizard,
Your write-up is  very educational for folks who are about to mess with high presssure fluid or gas. The surgical cleaning operation to save the limb was very interesting.
The very first time I was asked to start up an Ingersoll-Rand,Model 223 High Pressure, 3,000 psig Air Compressor ,my hands shivered.
To make it worse,the high pressure stainless steel tubing was done by a sub-contractor who claimed to be a know all. Fine! The tube and fittings were "Swagelock" but the coupling was given more than the mandatory 1 1/4 turn from the initial bare hand/finger tightening. The stainless tubing came flying out and the 3000 psig compressed air blew a 2" Dia x 1/8 deep hole in the prehardened industrial flooring. Sub-contractor Wong was so amused to see that hole and was laughing away. That was his last laugh and last job with us.


----------



## Wizard69 (Sep 8, 2013)

gus said:


> Hi Wizard,
> Your write-up is  very educational for folks who are about to mess with high presssure fluid or gas. The surgical cleaning operation to save the limb was very interesting.


I'm not sure whatever happened to the guy, I know the struggle to save the arm went on for months.  What people need to realize is that this happened in the blink of an eye, some place about the hand, however the whole arm was at risk.  If people question the dangers of fluids under pressure I just explain to them how a water jet works.  


> The very first time I was asked to start up an Ingersoll-Rand,Model 223 High Pressure, 3,000 psig Air Compressor ,my hands shivered.


There have been more than a few machines that have made me nervous over the years.   I can remember working on a huge vertical hydraulic broach where one of the mill style limit switches was out of position, that machine sheared the switch off and dropped it at my feet without even a glitch.    


> To make it worse,the high pressure stainless steel tubing was done by a sub-contractor who claimed to be a know all. Fine! The tube and fittings were "Swagelock" but the coupling was given more than the mandatory 1 1/4 turn from the initial bare hand/finger tightening. The stainless tubing came flying out and the 3000 psig compressed air blew a 2" Dia x 1/8 deep hole in the prehardened industrial flooring. Sub-contractor Wong was so amused to see that hole and was laughing away. That was his last laugh and last job with us.



I'm fortunate to say I haven't experience that sort of failure, broken plant air lines put enough of a scare into one as it is.   In any event I hope people take these stories to heart, it is way to easy to make a mistake even if you have heard about the dangers.    It pays to step back and do a context switch when approaching a hydraulic problem especially if it is a leak.   Context switch is a phrase related to computer operating systems when switch from one job to a completely different job.   It fits here because you need to operate under a different set of rules, for your own safety, when working with hydraulics or really any high pressure system.    If not some of the ugliest and most gruesome industrial accidents can happen.


----------



## kvom (Sep 9, 2013)

Why not use a commercial bottle jack?  There are some that support air over hydraulic if you need that.


----------



## ksor (Sep 10, 2013)

kvom said:


> Why not use a commercial bottle jack?  There are some that support air over hydraulic if you need that.


 
What do you mean by "air over hydraulic" ?


----------



## gus (Sep 10, 2013)

kvom said:


> Why not use a commercial bottle jack?  There are some that support air over hydraulic if you need that.




Hi Kvom,

Shared the same idea. Put 4 nos x 5 ton jack to power dished end die tool for
blank clamping and dished end removal. Used female die dead weight to power retract. The seals lasted 5 years. Had to use a separate power pack.
Spring power return not employed. Will try digging out some old fotos.From 1987--------2001 build 6 dished end deep draw die. 3----8mm
thick. 
Over travel is prevented by a air hole by manufacturer.


----------



## kvom (Sep 11, 2013)

Air over hydraulic is a hydraulic jack that allows you to use compressed air to operate the jack, rather than pumping a handle.


----------

