Laser grading hydraulic valve issue.

[jenkinsph]

And after you find out everything you need to know from the forum that glastron suggested, you'll bring your buildup and knowledge back here, right? You did already bait me in when you mentioned it before, so I'll take that as a promise.

I have been working on this set up for a while, just gathering money for the stuff. Putting in the irrigation pipeline on a job now, almost done with it and will use the proceeds to buy more electronics. I am taking pics of the build and will post when this is operational. I just felt that most people didn't wan't to wait while I ground all of this out, most would wan't a quick group of pictures and short synopsis.

 

[Complete Turf Care]

I have a Trimble GL422 Dual slope laser package.


The receiver is a Trimble LR50 and the control box is a Trimble CB25


This picture is of the valve and solenoid mounted on my 8' Landscraper blade.



And, the pics below are of the new solenoid or coil that I have not mounted yet. I'm going to use the one already on the blade until it goes out completely before mounting this new one. I looked on the shipping invoice an the part number listed for this is MTA6157B4032.

I purchased the entire system from Quinn Equipment and their web site is Survey Construction Lasers | Dual & Single Grade Lasers | Rotary Surveying Lasers However, everything was shipped from MidTech Services in New Hampton, Iowa, but I don't have a web address for Mid Tech.

 

[jenkinsph]

Thanks for posting the pics, how well do you like it other than the solenoid problems. How fast can you operate this with accuracy?

 

[Complete Turf Care]

Thanks for posting the pics, how well do you like it other than the solenoid problems. How fast can you operate this with accuracy?

I like it, but I don't really have anything to compare it to. I've never used any other equipment. The control box has a few settings that can be adjusted.

I can adjust the 'dead zone' on the receiver, and I can also adjust the reaction time.

The 'dead zone' is an area on the receiver that is dead. This means that if the dead zone is 2" for example, and the laser signal is within that 2", the blade will not change height. I usually set the 'dead zone' to about 1.5" when I start a job, and reduce it down as I get it more level, and eventually get it down to about .25" to finish the job. Soil type will affect the amount of accuracy you can achieve. Pure sand will be easier to get to within .25" than will a clay soil.

I can also adjust the reaction time, which is the time that the laser gets out of the 'dead zone' to the time that the control box commands the blade to move up or down. Again, I start with a slower reaction time, and adjust it to be faster as I get closer to finished grade.

As far as how fast I can operate, it's just a matter of a comfortable travel speed. Most of my work is on football fields and my tractor is hydrostatic, so I constantly change travel speed. I would say I usually travel between 2 and 6 or 7 mph.

 

[jenkinsph]

Thanks for the information you provided.


In my locale (New Mexico) the river bottom land is mostly sandy loam and works easy enough. I am a native of NOLa and can see the issue with the spongy soil there. I built a roller to use for this work to provide some compaction and hope this will aid in getting a uniform surface. I am converting my Gannon box blade to work with the laser set up and should be able to use it in both 3ph and pull type.

 

[jenkinsph]

Back to your issue I would have assumed you could have a power beyond circuit for the tractor. I know on my 110 tlb I have the PB circuit and the 3 curcuit diverter with 3 front circuits for the fel and 3 rear circuits. The 5740 is a very nice tractor and is available with a good hoe, isn't this hoe set up with a PB circuit? Maybe someone more familiar with this tractor can enlighten me.

While you can raise the vent higher as you mentioned above that still doesn't help with the air entrainment issue. With a 12 gallon reservoir capacity and a 10 gallon flow rate the fluid is being changed in about 72 seconds. I think it will be important for you to be able have the return oil to the sump in a lower location.

 

[Complete Turf Care]

Back to your issue I would have assumed you could have a power beyond circuit for the tractor. I know on my 110 tlb I have the PB circuit and the 3 curcuit diverter with 3 front circuits for the fel and 3 rear circuits. The 5740 is a very nice tractor and is available with a good hoe, isn't this hoe set up with a PB circuit? Maybe someone more familiar with this tractor can enlighten me.

While you can raise the vent higher as you mentioned above that still doesn't help with the air entrainment issue. With a 12 gallon reservoir capacity and a 10 gallon flow rate the fluid is being changed in about 72 seconds. I think it will be important for you to be able have the return oil to the sump in a lower location.

I will try calling a different Kubota dealer to see if I can talk to another mechanic about this. It just seems to me that there would be a more simple solution to this issue. The guy who sold me the system said it would work on this tractor, but it's not working, so is there a different valve/solenoid/coil that I could use that would work?

 

[jenkinsph]

I think you will need an unobstructed fluid path on the return line for all of them to work well. A PB circuit would provide that for you, I plan on using a 3/4" hose for the valve loop for less restriction too.

 

[J_J]

Correct me if I am wrong, but didn't you run the OUT of the grader valve directly to tank.

Some one also mentioned about PB, and I thought since you were using the grader, that problem was sorted out.

That should have given you unrestricted flow to the reservoir with little or no backpressure.

As far as blowing stuff out the vent cap, they must not have put the out flow tube far enough in the tank.

You are simply adding fluid to the tank at what the pump is supplying.

You should be using the same amount of fluid going into the valve as the fluid passing through, so the level should remain fairly level.

You might check to see if the solenoid can handle constant movement of the spool.

For instance, is the sensitivity in level set to fine.

Did you ever say what flow the valve was capable of?

 

[Complete Turf Care]

JJ, I have not started using the system yet, but I plan to in the next few days.

I have run the OUT flow back to the tank unrestricted, but it dumps into the fill cap as you can see in the 3rd picture in post #77. The oil is not dumping directly back into the oil in the tank and many have suggested it should be.

There is no way to extend a tube down into the oil from the fill cap because there are metal parts just inside the fill cap.

My concern now (as many here have suggested) is that dumping the oil above the oil level in the tank will cause air in the oil and therefore cause heat problems.

I plan to contact a different Kubota dealer to see if there may be another mechanic who can help me with this issue.