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metalmagpie
05-05-2015, 11:32 AM
Straightforward, but I want to doublecheck my thinking/math before I commit the $$.

I want to make a hydraulic system powered by a 3hp 1750 rpm 182TC motor. I want 3000 psi max pressure. I need to know what pump to buy. I'm willing to take whatever flow rate I get. (I believe that the product of PSI and GPM is proportional to HP thus the larger the PSI rating the smaller the GPM for a given horsepower.)

I figure I should buy a gear pump. They are easy to understand and (I believe) cheaper and for my application should well outlast my lifetime and perhaps a few more. However, I don't fully understand the tradeoffs. Should I be looking for a vane pump or piston pump? Why?

Working through the math, I come up with the result that I should order a gear pump with displacement of 0.19 cubic inches per rev and of course max pressure rating of 3000 psi or above, ideally rated for use at 1800 rpm. Did I get the math right?

There don't seem to be a whole lot of these. Surplus Center has one but it is designed for 3450 rpm not 1750. This one: http://tinyurl.com/mxq9cnz Can I use this pump at 1750 without derating?

Finally, does anyone know a book or Web site that covers these questions and other practical aspects of hydraulic system design, pitched for an average engineer without graduate credentials in mechanical engineering?

Thanks!

metalmagpie

superUnknown
05-05-2015, 12:47 PM
Gear pump: cheap, robust, uses open center valve.
Rules of thumb: 1hp required per 1000psi x 1 GPM; Calculate your GPM requirement and then size the pump and motor accordingly.
If the pump is rated for 3450rpm it'll run just fine at 1750. But why not run the motor with a VFD then ramp up to 3450 RPM? It's almost like double the flowrate for free: the pump displacement is low, so you don't get sticktivity nuissance trips on start up and you can still hit your (intermittent) 3000PSI requirement.
I had a look at your other valve post, so I'm adding these two caveats:
For all that is good and holy, don't forget the relief valve! But don't design the system to go over relief for extended periods, because it will overheat the oil and burn your shop down.
It might be a false economy (especially for a neophyte) to use unknown valves/components. Have you determined if the valve is open center or closed? Is the adjustment a relief valve, or a cross over relief, or an over center, or some sort of load lock... I think this little build will have some interesting and possible oily lessons in store. ;-) Keep us posted!

superUnknown
05-05-2015, 12:57 PM
Your pump is too big for 3hp 3ph motor. If you're using a cap start 3hp 1ph is WAY too big. What viscosity oil are you using, is it in a heated shop or outside?
Will it be flooded inlet or suction? Pressurized tank or open? Return filter?
The problem is start-up. Pumps are sticky, and it needs to "oversized" to handle start up.

Black Forest
05-05-2015, 01:26 PM
What are you going to use this pump/motor for? What type of actuator? Will it be a cylinder or a motor? Will it run continuously or intermittent?

camdigger
05-05-2015, 01:45 PM
In my opinion, you have not supplied enough information for me to comment on design too much. I can make some general comments though.

The speed rating on the pumps is the maximum design speed. Most will function reasonably well at lower speeds. You do have to be very cautious about running a pump too fast, but running at half maximum, no problem whatsoever.

Most hydraulic systems ( in fact, every one I can think of) allow the motor to start in an unloaded state. After the pump is running, the controls apply the loads. This means that the starting friction is not as important as one might think.

Most hydraulic systems operate below the max design pressure 99% of the time. Some systems like log splitters run two stages, low pressure high volume and high pressure, low volume. For those systems the HP requirement is drastically reduced.

I've designed built and used 3 different systems. The loads are different in each case, so the system is different for each one.

There is a specific website ( or was.at one time) called something like "hydraulic Innovations". The website has a guru from a hydraulics supplier for design support. I have some PDF design stuff I could share if you PM me an email ( and I can find it). Last, but not least Princess Auto from Canada and,IIRC, surplus center have hydraulic spreadsheet calculators that can go a long way to getting a system that will work.

Good luck!

metalmagpie
05-05-2015, 04:50 PM
Thank you for your replies and your wisdom. I can see I know less than I thought I did.

First of all, yes, I did have another recent post about hydraulics. However, that was for a different project (an ironworker). This project is going to be a hydraulic press. The valve will have a spring return to an open center, so unless the operator does something really stupid the motor/pump will be unloaded at startup. In a hydraulic press unless it's a forging press, GPM isn't a big deal. High flow rate would be nice for freewheeling the ram up or down, but once it's in its work zone it's pressure and not flow that will make things happen. So although designing for a particular GPS may make sense in general, it doesn't make sense (to me, anyway) in this case.

I totally don't understand the statement "Your pump is too big for 3hp 3ph motor." But let's say it's true. OK. Given a 3hp 3ph motor and the fact that it will always start unloaded, what pump would you (superUnknown) recommend? I'm more or less copying a design I saw online (no details though) which has a 3hp 1750 rpm motor running a pump and getting 3000 psi out of it, so I know it can be done.

For the guy who cautioned me to not forget the relief valve, don't worry, I won't, thanks!

As far as powering the motor through a VFD, I don't see that adding enough value to be worth the added cost and complexity. I'm much MUCH better at electrical/electronics than I am at hydraulics, and I've designed a couple of VFDs into other machines so I know about them.

As far as the rule of thumb cited above, I think it's a little conservative. These are the design equations I used:

HP = GPM X PSI X .0007 ;; OK, this is another rule of thumb
PUMP GPM = RPM * PUMP DISPLACEMENT / 231 ;; because there are 231 cubic inches in a gallon
rewriting,
DISP = 231 X GPM / RPM

My HP is 3, my PSI is 3000, and my RPM are 1750. That's how I came up with needing a pump with displacement of 0.19 cu. in./rev.

The Surplus Center calculator appears to support my calculations. The site http://www.hydraulicinnovations.com has passed into history, sadly. I visited the site the way it used to look (using archive.org, a handy resource) and poked around. Maybe it was just me, but I didn't see anything all that relevant.

Thanks!

metalmagpie

superUnknown
05-05-2015, 06:29 PM
"I'm more or less copying a design I saw online (no details though) which has a 3hp 1750 rpm motor running a pump and getting 3000 psi out of it, so I know it can be done."
You are missing a very important piece of data.

You asked. Unloaded, sure, sure, what's the rotating mass of the rotor, coupling, pump and 100-200 PSI of line loss, especially when the oil is cold, right? How fast does it need to come up to speed to prevent the overloads from tripping? You won't mind cracking the oultet hose everytime you need to start it, right?
As you say, your calcs confirm everything you need to know. Happy building!

Blackfoot
05-05-2015, 07:38 PM
There are always reasons for a specific design. For example, why are you needing a 3000# system? Lower pressure = lower component cost, safer operation, fewer leaks, greater number of available components, less consideration for noise and heat generation, and longer component life with lower maintenance. Will you use a fixed displacement pump or a variable volume, or maybe a 2 stage "hi-low" type pump, and why? What will be the duty cycle of this system? What "fail safe" features will be required? Will this system be using conventional hydraulic oil or a "fireproof" type hydraulic fluid? How large will the oil supply be? Will it be temp. controlled with a heat exchanger?

I am retired now, but I have had 40+ years experience designing, building, and working with hydraulic machinery. All the above is very basic.

Good luck.

gundog
05-05-2015, 07:40 PM
I built a press some years ago and got a lot of help here from people if you do a search using my moniker and press it will bring up several threads with some good engineering info in it. I also had a few pictures of the build. I think the formulas are there also that were shared with me.

One of the things that helped me was thinking about it in the right terms I had some parts and was trying to build around those parts it was pointed out to me I needed to start withe the required work to be done in my case I wanted 30 tons. We started there and worked backwards it turned out the parts I had were not suitable for what I was trying to accomplish. The next thing after the ram was determined was how fast I wanted it to travel I did not want it to slam shut or wait for 10 minutes to complete one stroke the pump was then chosen and last the motor to drive it.

Mike

Arcane
05-05-2015, 08:01 PM
metalmagpie, a self contained PTO powered pump and reservoir used to provide hydraulic power to truck hoists like you find on gravel trucks or farm trucks would be ideal for what you need. This is what the power pack on a friend's recently acquired press is and it was ran by a 3 phase motor 3 hp @ 1725 rpm via chain and sprockets. They have a max of 1000 rpm and will put out up to 5000 psi and come with the control valve and adjustable pressure by pass built into them too and would fit in a 1' x 1' x 2' space.

cijuanni
05-05-2015, 09:31 PM
Your calculation of 0.2 cu/rev is correct.
I would look at a SpeeCo 8gpm 2 stage log splitter pump, rated to 4000psi, with a displacement around 0.2 cu/rev in high pressure mode. It is one of the few 2 stage pumps rated for 4000psi.

If you didn't want 2 stage and want a constant slow extension and retraction look at the MTE 4000psi rated pumps.
Surplus # 9-8401-192.
I just used one of these, a 0.129cu/rev version to build a broaching press with a 1.5hp, 1725 mtr. I set the PR valve to 2750psi and it easily makes it.
I have a 3500 psi rated cylinder and 3500psi rated directional valve, so I should be able to get 3000 psi out of the motor if I need it.

http://i56.photobucket.com/albums/g164/cijuanni/DSCN10671.jpg (http://s56.photobucket.com/user/cijuanni/media/DSCN10671.jpg.html)

What is the psi rating, bore and stroke of your cylinder?
Be sure and use an in tank strainer and a return line filter.

On Ebay you can buy college entry level hydraulic textbooks for cheap.
They will give you lots of info that is easy to digest.

metalmagpie
05-05-2015, 10:22 PM
There are always reasons for a specific design. For example, why are you needing a 3000# system? Lower pressure = lower component cost, safer operation, fewer leaks, greater number of available components, less consideration for noise and heat generation, and longer component life with lower maintenance.

You want high pressure on a hydraulic press. Sure, I could buy a cylinder with 8" bore, but that would break the budget to smithereens. I'm just trying to design a press that can develop between 25 and 30 tons.


Will you use a fixed displacement pump or a variable volume, or maybe a 2 stage "hi-low" type pump, and why?

My original question was basically what pump to buy. Now it's been turned back on me to defend my choice. I don't know that much about hydraulics. What I need from this audience is good clear explanations of what my options are, and why I'd want to do this versus that. My initial thought was to use a fixed displacement gear pump. They are simple enough so that I can understand them, and robust enough and cheap enough for this project. After some thought I'm leaning towards the 2-speed design, though. Frankly, I don't understand variable volume pumps. I'm looking for a place that explains them in language I can understand. So I'm ruling those out, but were I to come to a deeper understanding, that could change.


What will be the duty cycle of this system? What "fail safe" features will be required?

I think a hydraulic press will get used at most a few times a month. Each time I might cycle the cylinder 4 or 5 times max. The duty cycle is going to be super low. I plan to incorporate an adjustable relief valve which ports back to the reservoir, but other than that and sound fabrication procedures and common sense, there isn't any other fail safe.


Will this system be using conventional hydraulic oil or a "fireproof" type hydraulic fluid? How large will the oil supply be? Will it be temp. controlled with a heat exchanger?

I had never heard of a fireproof type hydraulic fluid. I suppose the oil supply will be on the order of 2-3 gallons. I tore apart the hydraulic unit from an old tracer mill yesterday. It has an overtemp sensor which feeds a switch which was wired into the off/on switch. I may decide to use that. The design I'm loosely following has a thermometer visible from outside the tank and the guy said it had never gotten warm in all the years he'd used his press, so I don't see this as a big deal.

I appreciate detailed questions like this. Frankly, though, I'd appreciate more guidance rather than criticism. Nobody is born understanding hydraulic system design, after all. I really don't want to offend anyone or get into some flame wars about defending something that I just suggested, asking for input on my suggestion.

metalmagpie

camdigger
05-05-2015, 11:09 PM
Now that we know what you're trying to do, we can discuss some details.

For a press application, speed on retraction is nice, but control of adequate force on the work stroke is much more important. For this reason, I would shy away from a system that automatically changes speed like a "two speed splitter pump.

It might be nice to have control over the power stroke to log, etc, but have an auto retract type control valve to retract the cylinder and kick off when fully retracted. This is exactly what auto kick off log splitter valves do.

For general press info, look up Keith Fenner's press talk on YouTube. A good way to spend a half hour or so to get some general info on hydraulic presses.

If I were building a press, I would include a pressure gage to keep track of the force applied on occasion. Sometimes, you can source a gage that has units that correspond directly to cylinder force. By doing some voodoo on the F=p x A equation, you can cipher force units to piston area and may be able to get a gage that would read almost directly in tons. Don't shy away from odd pressure units to make this happen. You may end up with a bar per ton, for example ignoring the fact that the gage is in bar, you may be able to read directly in tons.... Some playing around with the force/ pressure relationship and an online converter may lead to some satisfying results.... If nothing else a laminated printout of a pressure vs force cigaret on the wall beside the controls can be handy.

Depending on where you are, you may be able to get hoses custom made while you wait. This is a good time saver. Sometimes the hoses are made by the vendor's hyd guru. Other times, it may be a cashier, or pimply faced stock boy.... Sometimes, you can get some good tips if the right person is making hoses that day....

With such a low duty cycle, you can keep the tank size small. As previously posted, there are self contained power packs that could give you all you need in a small package. If economy is important, you could search truck wrecker yards, or maybe find something off a agricultural machine at a tractor wrecker.

cijuanni
05-05-2015, 11:20 PM
My original question was basically what pump to buy. Now it's been turned back on me to defend my choice. I don't know that much about hydraulics. What I need from this audience is good clear explanations of what my options are, and why I'd want to do this versus that. My initial thought was to use a fixed displacement gear pump. They are simple enough so that I can understand them, and robust enough and cheap enough for this project. After some thought I'm leaning towards the 2-speed design, though. Frankly, I don't understand variable volume pumps. I'm looking for a place that explains them in language I can understand. So I'm ruling those out, but were I to come to a deeper understanding, that could change.


Because because of cost, simplicity of your system and low duty a fixed displacement gear pump or 2 stage version is the best option.
These types of pumps in the past were noisy, and due to the fluid being compressed at basically 1 point (unbalanced) where the gears mesh, so the forces are directed to one side of the relatively small bearings and shafts. With current computer gear design, better gear finishes, better bearing design and FILTERS it no longer is the issue it was.
And for $100 you can get a good pump.

Vane pumps were designed to overcome the shortcomings of gear pumps by balancing the forces so the shafts, bearings and gears didn't cause so much grief. And they are less noisy if it is running constantly, less so with modern gear pump design.

Variable displacement is usually reserved for use with hydraulic motors, hydrostatic transmissions etc where the volume of fluid can be changed w/o changing the rpm of the pump. With a fixed displacement pump you might only need a small amount to rotate a motor slowly and all that excess fluid gets pumped through the pump, valves and back to the tank creating heat and wasted horsepower.
However they are far more complicated requiring some type of system to sense the required volume and make the adjustment.
Probably in the $1500 range for a pump.

I bought > Using Industrial Hydraulics by T.C. Frankenfield, off Ebay for a few bucks and it is a good basic textbook for hydraulics. I am always grabbing it and looking up something.
http://www.ebay.com/itm/Using-Industrial-Hydraulics-Rexroth-Worldwide-Hydraulics-Acceptable-Book-/231546019886?pt=LH_DefaultDomain_0&hash=item35e937e02e

I would suggest the pump I listed in my above post, Lovejoy couplings, an in tank strainer, return filter and adapter, and a open center valve with built in PR valve. You can get all that from Surplus Center. I would use common JIC 8 fittings for the hoses and 1/2" hose which is plenty big. A couple of 1/2"NPT bungs. I usually buy the fittings and premade hoses from Discount Hydraulic Hose, http://www.discounthydraulichose.com/Hydraulic_Hose_s/84.htm?Click=3
I don't like SC hoses, way too stiff for the same pressure rating.

I would make the 3 gallon tank out of rectangular tube steel, 10x10 or 12x12, 3/16" or 1/4" wall if you have the ability to weld it up.
Most commercial tanks are thin, the threads strip out easily in the thin metal and they leak fluid because of the open top design.
That and they have too many things you don't need like a manifold, temp and fluid level gauges, that leak. I am going to notice a big puddle of oil on my shop floor so I don't need any of that.
Plus they fit all and fit nothing. I would put the tank, pump and motor at the top of the press and away from valuable floor space.

1-800miner
05-06-2015, 12:25 AM
I would stick with a single speed pump.
You don't want the thing shifting gears suddenly when you are least expecting it.
It does not sound like you are running a production shop and need fast cycle times.
Keep it simple.

I just built a four post unit and used two 4" rams sharing a common cross member.
A 1/2horse single phase on a gear pump smaller than my fist(dunno what the displacement is)
twentyfour inches of travel in less than thirty seconds and it pumps up to 3200psi
I never have figured the tonnage on it . but nothing has stopped it so far.
I have used it all day and the tank gets luke warm.
It has a return filter and a pressure gauge.
How ever your gauge is calibrated,get in the habit of watching it.

A word of warning: Be very particular that every thing is built square and plumb.
When you start pressuring up on something that is even slightly cockeyed it will be coming out sideways violently.Or should I say...VIOLENTLY

metalmagpie
05-06-2015, 11:46 AM
Single speed pump sounds good to me. If I decide I need more GPM to make the ram travel more quickly I could move up to a 5hp motor. That would let me use a pump with larger displacement. However, I already have a 3hp motor which has a C face, and budget is (always) an issue.

Really appreciate all the good advice. I ordered the book suggested above. That should help clear things up for me.

metalmagpie

camdigger
05-06-2015, 11:51 AM
Magpie

if you use a auto kick off o the retract cycle, the cylinder retraction won't be such a big issue. In addition to the book, I encourage you to watch Keith F's press talk on youtube.

Cam

Black Forest
05-06-2015, 12:45 PM
How big of a cylinder are you going to use? What is the bore diameter, stroke and the rod diameter? If you tell me that I will tell you how fast your cycle time will be.

metalmagpie
05-06-2015, 05:27 PM
How big of a cylinder are you going to use? What is the bore diameter, stroke and the rod diameter? If you tell me that I will tell you how fast your cycle time will be.

Mr. Black Forest, I once had a memorable experience or two in Freiburg. But those will wait for another day. I haven't bought a cylinder yet, and I know about this calculator:
http://www.surpluscenter.com/Tech-Help/Hydraulics/Calculators/Cylinder-Force-Speed/

But thanks anyway! By the way, do you know anyone who works at ITT Intermettal?

metalmagpie

metalmagpie
05-06-2015, 05:29 PM
.. I encourage you to watch Keith F's press talk on youtube.

I have, actually. That's pretty much what inspired the whole thing. - MM

Black Forest
05-06-2015, 05:33 PM
Mr. Black Forest, I once had a memorable experience or two in Freiburg. But those will wait for another day. I haven't bought a cylinder yet, and I know about this calculator:
http://www.surpluscenter.com/Tech-Help/Hydraulics/Calculators/Cylinder-Force-Speed/

But thanks anyway! By the way, do you know anyone who works at ITT Intermettal?

metalmagpie

Off hand I don't think I know anyone at ITT Intermettal.

kmilner65
05-07-2015, 02:00 AM
Have you looked into 110V porta-power units? I bought mine from Catapillar for $375.00 about two years ago. I use it to drive up to 50 ton rams and lift D11 dozers off the ground

kmilner65
05-07-2015, 02:25 AM
Another consideration to help keep cost down is forget the hydraulic return, I have used a huge number of presses and made a few, I just stole the springs from the neighbors trampoline and built a collar that grabs the ram and the springs return the ram to the retracted position when you open the valve. The last two I used a solenoid and a momentary switch to jog and run the ram into the power position

davidh
05-07-2015, 10:02 AM
i agree with the spring return. and for the power unit, i have an Omega air / hydraulic pump that puts out 10,000 lbs if required, to a 4" cylinder. the pump was less than $200 and no filter // control valve // strainer was needed. I'm surprised no one suggested it in all the reply. and its small besides.

gary hart
05-07-2015, 10:02 AM
Had a small broaching press that used air compressed in the lower part of the cylinder for the return. On a small diameter long stroke cylinder, it worked good, and seldom needed recharging.

metalmagpie
05-07-2015, 02:52 PM
Another consideration to help keep cost down is forget the hydraulic return, I have used a huge number of presses and made a few, I just stole the springs from the neighbors trampoline and built a collar that grabs the ram and the springs return the ram to the retracted position when you open the valve. The last two I used a solenoid and a momentary switch to jog and run the ram into the power position

I understand the spring concept, it's just like on an imported hydraulic press. What I don't see, though, is how using springs helps keep costs down.

I don't quite get the solenoid deal, though. I understand what a solenoid is, and a momentary switch. It means you stand there holding an electrical switch until the ram is where you want it, right? OK, let's consider a lever-actuated hydraulic directional valve. With that you stand there holding the lever until the ram gets where you want it. How does that benefit?

metalmagpie

metalmagpie
05-07-2015, 02:54 PM
Have you looked into 110V porta-power units? I bought mine from Catapillar for $375.00 about two years ago. I use it to drive up to 50 ton rams and lift D11 dozers off the ground

I own a 110V hydraulic power unit. It doesn't have anything like the fluid capacity I'd need. Can you post a pic of yours?

metalmagpie

metalmagpie
05-07-2015, 02:59 PM
Had a small broaching press that used air compressed in the lower part of the cylinder for the return. On a small diameter long stroke cylinder, it worked good, and seldom needed recharging.

Well, hello, Gary, I remember you from r.c.m. - you've been around quite awhile. I'm a bit north of you in Seattle.

So you'd just trap pressurized air beneath an extended piston by plugging the second cylinder port? That would act like a spring all right. Pretty cool idea, really. It would be just my luck to not use the press for awhile and come over only to find the air had leaked out and now I'd have to work on the damn press to get my job done. That ever happen to you?

metalmagpie

gary hart
05-07-2015, 05:57 PM
Was lucky the cylinder had didn't loose much air. Was easy enough to put more compressed air back in as it had tire stem valve for filling.

gundog
05-07-2015, 06:17 PM
What are you going to do with this press? Do you plan to do any press brake work where you need precise repeatable bends?

cijuanni
05-07-2015, 07:40 PM
I understand the spring concept, it's just like on an imported hydraulic press. What I don't see, though, is how using springs helps keep costs down.


Double acting cylinders are a lot more common than single acting, so if you are going used or surplus I doubt you would save much over a double.

Arcane
05-07-2015, 09:38 PM
If you use a double acting cylinder you can rig it to raise the table.

lakeside53
05-07-2015, 09:40 PM
You can also use it to pull on things... not just push.

metalmagpie
05-08-2015, 12:57 AM
What are you going to do with this press? Do you plan to do any press brake work where you need precise repeatable bends?

That's a little like me asking you what you're going to wrench on with your 9/16" open end wrench. I'm not building this to do any specific thing, but I'd like to build in a lot of capability. I bend things, yes. "Precise" is defined in the mind of the person using the word. A lot of the things I build I call it good enough if you can't see a difference by eye.

metalmagpie

Black Forest
05-08-2015, 02:09 AM
I want to know what you did in Freiburg? :eek:

metalmagpie
05-08-2015, 10:20 PM
Speaking of Keith Fenner, his press and his videos "Press Talk 1" and "Press Talk 2", there's something in what he says that doesn't quite add up to me. Towards the end of PT2 he shows the press operating, pressing on a crimping die. You can estimate the ram extend speed. To me it looks like at least 1" per second. Also, he says in several places that his motor is 3 horsepower. Well, if he has a 3hp motor and a gear pump and 1" per second travel speed on a 5" cylinder, he's up around 4 gpm give or take and that means he sure as heck isn't developing 3000 psi with that press. He kind of cavalierly tosses off "That's a 3000 psi pump" as though the working pressure rating on a pump is what it's actually delivering. An actual pump driven by a 3hp motor at 1750 rpm, to get 3000 psi it only would put out about 1.4 GPM. Which corresponds for a 5" cylinder to only a 0.3" per second extend rate.

It looks to me like that's at most a 15 ton press, despite its mass and bulk.

metalmagpie

Black Forest
05-09-2015, 01:08 AM
Speaking of Keith Fenner, his press and his videos "Press Talk 1" and "Press Talk 2", there's something in what he says that doesn't quite add up to me. Towards the end of PT2 he shows the press operating, pressing on a crimping die. You can estimate the ram extend speed. To me it looks like at least 1" per second. Also, he says in several places that his motor is 3 horsepower. Well, if he has a 3hp motor and a gear pump and 1" per second travel speed on a 5" cylinder, he's up around 4 gpm give or take and that means he sure as heck isn't developing 3000 psi with that press. He kind of cavalierly tosses off "That's a 3000 psi pump" as though the working pressure rating on a pump is what it's actually delivering. An actual pump driven by a 3hp motor at 1750 rpm, to get 3000 psi it only would put out about 1.4 GPM. Which corresponds for a 5" cylinder to only a 0.3" per second extend rate.

It looks to me like that's at most a 15 ton press, despite its mass and bulk.

metalmagpie

I didn't watch the video so take this with a grain of salt. On the one inch per second travel is that under full load or just approaching the work? Just curious.

metalmagpie
05-09-2015, 07:46 AM
Oh, the videos are worth watching. The travel is with the ram just approaching the work. - MM

PT1: https://www.youtube.com/watch?v=q79P0r66SG8
PT2: https://www.youtube.com/watch?v=qzmO2VI9l6E