Laser grading hydraulic valve issue.

[J_J]

Superior Instrument - CT's Source for Sales and Service of Construction Lasers, Machine Control and Surveying Instruments

PT HYDRAULIC VALVE PKG


This hydraulic system utilizes digital-proportional valve bodies for greater accuracy and reliability than other systems on the market.

 

[Complete Turf Care]

I wanted to buy my system from this guy last year, but he had shut down for 3 months because of an injury. His web site used to show the same blade I have. It looks like he has downsized a lot in the past year.

Laser Grade Company

 

[Industrial Toys]

My God! I checked around for information. Such a system costs $20,0000 and I don't believe that even covers the laser and tripod!

And yet the sites don't give you any precious information. I'm still just as stupid when it comes to proportional valves. I went on that above site, before you posted it and was rather disappointed. Looks like more of a site to sell a plastic dog dish then a $20,000.00 system!

My very first thought when I first encountered this thread was "HEAT". Apparently it is an issue and your particular manufacturer speak of manifolds for open centre systems, but in such cryptic language that I still don't know what is what.

I hope you have your problem on the way to be sorted out, but my gut feeling says no. By the way,what is that bright colored protrusion mounted on the valve body on the opposite side of the servo valve?

 

[Complete Turf Care]

By the way,what is that bright colored protrusion mounted on the valve body on the opposite side of the servo valve?

That is to manually operate the hydraulic cylinder

 

[oldnslo]

My God! I checked around for information. Such a system costs $20,0000 and I don't believe that even covers the laser and tripod!

And yet the sites don't give you any precious information. I'm still just as stupid when it comes to proportional valves. I went on that above site, before you posted it and was rather disappointed. Looks like more of a site to sell a plastic dog dish then a $20,000.00 system!

My very first thought when I first encountered this thread was "HEAT". Apparently it is an issue and your particular manufacturer speak of manifolds for open centre systems, but in such cryptic language that I still don't know what is what.

I hope you have your problem on the way to be sorted out, but my gut feeling says no. By the way,what is that bright colored protrusion mounted on the valve body on the opposite side of the servo valve?

Industrial,
a) A simple fact in hydraulics is that proportional valves create heat by design. The way a proportional valve works is the control flow via pressure drop. Pressure drop equals heat generation.

b) Depending on the style of proportional valve the coils may not be sold as seperate item since they are "tuned in" at the factory. This is nothing new or revolutionary in the proportional class of valves.

c) I am not surprised the webiste does not provide detailed operating information or schematics. This is a semi proprietary system with it's own slight variation on how it functions.

d) Open center systems: These have a fixed displacement pump which produces oil flow flow when ever the pump is turning. This flow must be directed some where at low pressure (open to tanK) or the system will over heat quickly if allowed to dump across the relief valve.

e) Closed center systems: These use variable volume pumps and the flow can be blocked (closed from tanK) with very little heat generation.

 

[Industrial Toys]

Thanks for the information. I didn't expect detailed information, but something a little better then what they had. But then I've seen that all these systems mostly talk about all the neat stuff you can do, but never speak of the hardware itself.

What makes these things so expensive? I have so many questions about these systems, I should start a thread rather then hijack this one. For one, I am curious is there is a position sensor on the cylinder? Most computer controlled systems like a CNC machine has a feedback loop indicating position or speed.

 

[aczlan]

Thanks for the information. I didn't expect detailed information, but something a little better then what they had. But then I've seen that all these systems mostly talk about all the neat stuff you can do, but never speak of the hardware itself.
What makes these things so expensive? I have so many questions about these systems, I should start a thread rather then hijack this one. For one, I am curious is there is a position sensor on the cylinder? Most computer controlled systems like a CNC machine has a feedback loop indicating position or speed.

No feedback on the cylinder, it uses the laser detector on the "stick" to tell where the blade is in relation to the ground and to know how far up/down it needs to go.

Aaron Z

 

[Industrial Toys]

Thanks again. Just two more questions and I won't have to start a thread.

How wide an area does the stick "see" and what happens if you loose the laser as in going too high or too low? Do you have to basicallly be within grade to a certain extent before you can employ the laser grading?

Q # 2 I see many systems with two receivers on each side of a blade. Is that just like having two seperate systems?

 

[aczlan]

Thanks again. Just two more questions and I won't have to start a thread.

How wide an area does the stick "see" and what happens if you loose the laser as in going too high or too low? Do you have to basicallly be within grade to a certain extent before you can employ the laser grading?

Q # 2 I see many systems with two receivers on each side of a blade. Is that just like having two seperate systems?

A1: It depends on the stick and how many receptors were put on it. Wider range = more expensive.
A2: That allows the system to grade a slope (ie: make the crown of a road while driving down it) and they will generally be hooked up to tilt the blade from side to side.

Aaron Z

 

[oldnslo]

Not sure if the technology has improved but Spectra Physics used to guarantee 1/4 inch accuracy over 1,000 ft. This was 20 years ago so technology has probably improved this accuracy.