Hydraulic circuit design software 9

[frans]

Does anybody in the forum have experience with hydraulic circuit design software. I would like to simulate operating conditions in complex circuits and get results such as flow losses, pressures and temperatures.

 

[PNachtwey]

I think the wall thickness or the pipe to the rod end is .035 but can't say for sure.
You can see ( look at my .pdf above ) the capacitance change due to pressure expanding the cylinder wall very small. It can be ignored.
The pressures in my system are relatively low. My system pressure is 1500 PSI. I will do the calculations on the rod end pipe though.
I admit the rod end pipe is too small because the oil must travel too fast.
Roger the accumulator location and piping. There is a consensus on that.

At this time I am trying to figure out why the damping factor on my system is so much higher than what most text books say the damping factor should be. Most books say the damping factor should be about .05 to .1. My system has a damping factor close to 1 while extending and about .6 while retracting.

 

[jonnycowboy]

Does anybody have a copy of pc_bathfp that they could send me? the website dosen't work anymore.
thanks

 

[HCMechSys]

You can get it from:

http://ca.geocities.com/hchesser@rogers.com/pc_bathfp.zip

its the previous (alpha) version, not the version that everyone is waiting for...

 

[jonnycowboy]

thanks incredibly!

 

[95yukon]

Try this - you can do just about anything but drive the vehicle right out of the screen.

http://www.cat.com/cda/components/securedFile/displaySecuredFileServletJSP?fileId=96607&languageId=7

If this is too much, Hysan from Hydrasoft is something I've used in the past that allows you to model components / systems.

I'm not aware of hydraulics simulation software that individuals can afford - they are very costly to develop.

 

[PNachtwey]

We just bought a copy of 20sim. It has saved us a lot of time because we can simulate so many different sizes of hydraulic servo systems. We can even simulate the whole machine shaking as it moves because the machine is not bolted to the earth. It would have cost me much more to write anything approaching 20sim so I think it is a bargin.

http://www.20sim.com/

 

[EdDanzer]

Did you get Standard or Professional?
How easy is it to learn?

 

[Gkranz]

Quote: "Actually I do not think there are too many people who can design a proper hydraulic circuit at all."

Another quote: "I have up to now used so called hydraulic specialists working for the big hydraulics suppliers to do the hydraulics for my designs and boy more often tham not I have problems, ranging from overheating to functionality issues."

This subject comes up every so often and we get the same answers in the posts. Correct answers;

Stop trying to get FREE designs by purchasing components, and then complaining about poor designs. Second, there are very good hydraulic designers out there working, but you know what, they do not charge for the design, then give you free parts?

Hydraulic simulation software - I have used most including Easy5, and again without expernice and knowledge, correct inputs of data and knowing how to interpet the results. These packages simply get you to the wrong answer faster than without them.

Software for dummys is what most people are looking for, and we are not there yet. "We can even simulate the whole machine shaking as it moves because the machine is not bolted to the earth." I really like this one, only Peter could come up with a statement like this, gotta love this guy?


Westerndynamics.com

 

[frans]

Obviously it touched a nerve with you Gkranz. Fact is, component suppliers offer to do the design - it is part and parcel of their offer: They claim to employ design engineers, they offer to quote on what you need, they provide you with a hydraulic circuit schematic listing the required components - they are doing the design. It is not about free or not free - you pay for it in the price of the components for sure.

Rest assured, I do not mind paying and in fact I have now found an independent that I use (and pay).

I agree with your notion about garbage in and garbage out in relation to software for dummies. I am irritated with the hydraulics component suppliers because they do not deliver to me what they promised. By own admittance I am not an expert, I do not have the time or potential immersion to become one either. I am not talking about reading a circuit - I can do that too - I am talking about the type of experience only a professional in an industry can have. I have an obligation to my customers to make sure what I build works and continues to do so.

 

[Gkranz]

Dear frans,
Didn't bother my nerves at all. I think your kidding yourself about suppliers offering to do design.

First you never see a seperate line item charge for design?

Second, if you take the time to check component pricing, it is the same with or without their help.

Component suppliers are like Wal-Marts, one on every corner and the hook they use is "we can design circuits for you if you buy the parts from us, we are designers?

When something does not work, the warranty is limited to component replacement or repair, never design. Generally it is the way you used or put "their" design together that comes out of their mouth when circuits do not work.

Do you have any performance contract, who owns the design when it is given to you, are we free to pass it around to your customers, who pays when the circuit does not work, and have you provided an out line of what and how the circuit should work.

"I am irritated with the hydraulics component suppliers because they do not deliver to me what they promised." With all due respect, it was your nerve that is hurting not mine.

I do not know your location, but out West (Oregon, Washington) suppliers do manifold designs for customers, only one small problem though. None of them will give the customer a copy of the manifold drawing, just a circuit drawing, that way no one can shop the price around and you are locked into them for more manifolds.

Nothing wrong with component suppliers, if you use them for their intended purpose, selling parts. Well anyway, hope things work out better for you and your customers.
Best Regards,
Gkranz




Westerndynamics.com

 

[PNachtwey]

"Did you get Standard or Professional?"
We got the standard. 1 seat.

"How easy is it to learn?"
It didn't take too long to get the basics. It has its own programming language. You should know how to program if you want to create your own projects.

There are demo versions at 20sim. Try it. We are going to make an example hydraulic servo actuator project that those with the demo version of 20sim can load. Unfortunately there will be a lot of parameters to modify. I will post it on our FTP site when we are done. That way those with BathFP can compare.

"These packages simply get you to the wrong answer faster than without them."

Yes, and you must know enough to sanity check the results.
Simulators will not think for you. You must still understand the physics of hydraulics to design a good system. However, the simulator will show flaws is designs faster if you can interpret what you see correctly.

"Software for dummys is what most people are looking for, and we are not there yet."
We never will be. The dummys must get smarter.

""We can even simulate the whole machine shaking as it moves because the machine is not bolted to the earth." I really like this one, only Peter could come up with a statement like this, gotta love this guy?"

Have you ever been in a saw mill where the machine are mounted on steel frames in the air instead of bolted to the concrete below? The whole frame shakes when the actuators move heavy loads like logs and saws quickly. When the whole frame shakes it is absorbing energy that should have gone to moving the actuator and load. This is a problem since we are trying to move actuators accurately and not the mill. The more compliant the foundation is the more energy it will absorb.

A lot of what I do deals with how energy is moved from one point to another and how quickly it can be moved or removed.
If takes a LOT of power over short periods of time, to compress oil rapidly.

 

[HCMechSys]

"We are going to make an example hydraulic servo actuator project that those with the demo version of 20sim can load. Unfortunately there will be a lot of parameters to modify. I will post it on our FTP site when we are done. That way those with BathFP can compare."

Sounds good, I'd like to give it a try with BathFP...

 

[Gkranz]

Quote - "Have you ever been in a saw mill where the machine are mounted on steel frames in the air instead of bolted to the concrete below?"

And Peter, these steel frames just float in mid air not conected to earth? I always get a kick out of cutting logs down to 0.0005, when I go to buy 2x4, cannot find any two the same size. And the saw filer sharpens the saws +/- 1/8 of an inch.

Quote - "A lot of what I do deals with how energy is moved from one point to another and how quickly it can be moved or removed."

And we call that hydraulics Peter?
As always Peter, take care old buddy.
Best Regards,
Gkranz






Westerndynamics.com

 

[PNachtwey]

"And Peter, these steel frames just float in mid air not conected to earth?"
Sometime not well enough.

" I always get a kick out of cutting logs down to 0.0005, when I go to buy 2x4, cannot find any two the same size. And the saw filer sharpens the saws +/- 1/8 of an inch."

At least the hydraulics controlled by our controllers aren't responsible for that.

"And we call that hydraulics Peter?"
I wish more hydraulic designers did. You know as well as I do that the text books you and I have deal with constant or steady state velocity calculations, not acceleration or jerk which involve moving energy in and out of the system. The best most can do is calculate F=m*a with the assumption force and acceleration don't change. Required power is just Force*velocity. Never have I seen Pcap(t)*Acap-Prod(t)*Arod - friction(v) = m*a(t) except in hydraulic modeling software.

 

[Gkranz]

Ha, Ha. I agree with you, I just like giving you a hard time.
Best,
Gkranz

Westerndynamics.com