[lx665]

In a recent article in Pro Mag. Stonehenge referred to a direct read grade rod. What is a direct read grade rod and how is it different from a standard rod?

John

[jwholden]

Pictures?

[Paul]

A direct reading grade rod, has a metal tape that travels on a track in the rod. Most grade rods start from 0 at the bottom and end at say 10'-16' a direct reading grade rod the tape is movable and it reads the from the top down so actual grade reading are given instead of having to do math to figure out what grade you are at. Most plot plans have a elevation number given for the house. this is usually for the ground floor or main floor. you set your rod for that number (lets say it's 306.24) so you set the rod at 6.24 when placed on the main floor. Lock the tape at that measure. Now any where you set the rod it will read the correct elevation of that spot.

[Bill Schwab]

Typically what we would do with a direct grade rod is attatch it to the top front of the pan of a scaper, or at the top front of a dozer blade. The lazer is set on site away from the grading, and a computer in the machine tells it to rasie or lower the blade until 1/10 of spec is achieved. As a general rule, this is way too much technology for most landscape jobs, as the excavtor turned the project over to the owner, and in order for him to get paid, his elevations had to pass spec. So, unless you are doing some serious cutting or filling, this thing is to yuppy for most jobs....

[Paul]

Why attach a direct reading rod to a piece of equipment? We just use a piece of pipe. We do ball field grading and use a slope laser all the time. The grade box is attached to a skid steer or tractor and gives you perfect grades every time. A direct reading rod helps with grade changes in retaining walls, steps in patios, or installing drainage pipe.

[Bill Schwab]

Paul:

The direct read rod is attatched to the machines on board computer which automatically raises and lowers the blade/cutting edge of the machine. Basically all an operator needs to do is steer the machine to make the grade cut or fill, the computer does all the rest, as long as you can trust one of the things to do what it is told....By using a rod, you can't interface with the computer, and you need to work the changes on the machines cutting tools manually. The computers really take the fun out of things, but also run the job more efficiently, until they break, get sick, or just stop working. Then you go back to what has worked 100 years, use your head...lol

[Paul]

We use machine controls on our stuff. But no direct reading rod is needed. We plug in the grade on the laser,(slope) and set a starting point (grade) . Then let the machine do it's thing. All we need is a pipe that holds the 360 degree laser receiver and it gets connected to the on board computer that controls the hydraulics of the machine. You shouldn't need a a rod on a machine just something to hold the receiver. The rod can be used to check slopes or level grade by hand to make sure the machine is doing it's thing. Now a few excavators around us use a power pole on their dozers to change elevation for flat work that way with one laser setup you can grade multiple level grade settings.

A direct reading rod is used to get the base elevation and do away with the math involved in getting to a set grade. If you wanted me to start a wall at say 703.23 elevation I would use the rod to find a hub or starting point( most times taken off the plot plan or survey) that would be my set elevation or hub. I would then find the 703.24 grade for the wall subtract the 1' for may base and buried course (I would set the laser for 702.24) and excavate to that elevation. Next I would set my rod to 702.74 to give me my base height (CA-6) Now I have my base elevation for all my base block unless I need to raise it a level which I can do by just adding in .5 feet to my base (703.24)

[lx665]

The rod I was speaking of is handheld and sounds like the one Paul is speaking of. I use a laser and was looking for something to make taking grade measurements simple.

John

[Paul]

here's a picture of it.

[lx665]

Thanks for the info.

John

[Stonehenge]

lx665 - I'd have posted sooner, but have been out of town for a couple days.

Here's a pic of our unit, not much different than Paul's. The scrolling feature of the tape makes it really handy to use, but it will take a few projects to get used to the feature. Plays with your head sometimes...

[jwholden]

I think it will all make sense the next time I spot one at a tool suppliers place. Until then,

[Paul]

A standard rod is just a measuring tape. If you have a given elevation, say the foundation of a house and you want to be 7 1/2" below it for the first step you need to first shoot the foundation then do the math to find what that elevation will be. A direct reading rod you shoot the foundation and set the tape to that elevation. Then just move the laser receiver up 7 1/2 inches. It now gives you the exact elevation with out any math. This allows you to figure any amount of steps or grade changes that you might encounter over the whole job. Maybe you need to slope a driveway 1' over 30' the plot plan has the curb height set (say 600.25) you set your rod tape at 00.25 at the curb then bring down the receiver 1' (so it reads1.25) drive a stake at the point you want to meet and mark that elevation with a marker on the stake. You've done no math and you can repeat the settings at any time.

[lx665]

Thanks again for the information. This is exactly what I'm looking for.

John

[Will Pacala]

A little off topic,but what are all these new laser things. They are probably really good indoors but outdoors, I don't know.