Learning Center

Set blade height

Blade height is how high the cutting edge sits off the ground with the implement raised in transport. The app takes it off every survey point. How to measure it by hand or with Auto Measure, where to change it, what the orange chip means and what a wrong value does to your design.

  • Full Automation Kit
  • Guidance Only Kit
  • Ditch Assist Lite

In the app Settings › SURVEY › Blade Height

Blade height is how high the cutting edge sits off the ground when the implement is raised in transport position. You survey with the implement up, so the antenna is higher than it will be when you grade. The app takes the blade height off every survey point so the survey records the ground, the same way the antenna sees it when the edge is down and cutting.

It is not the distance from the antenna to the cutting edge. That distance never changes and calibration and grading take care of it.

What blade height measures Two side views of the same pull-type implement with the GPS antenna on a mast. 1, survey: the implement is raised in transport position, so the cutting edge is off the ground; that gap is the blade height, and the app takes it off every survey point so the survey records the ground. The antenna rises by the same amount. 2, calibrate and grade: the implement is lowered so the cutting edge rests on the ground, and nothing is taken off. Bottom: Auto Measure takes the reading with the implement up, minus the reading with it down, and that difference is the blade height. What blade height measures 1 Survey: implement raised Blade height Taken off every survey point 2 Calibrate and grade: edge down Nothing taken off Auto Measure: UP − DOWN = blade height
Blade height is how high the cutting edge sits off the ground with the implement raised. The app takes it off every survey point. For calibrating and grading the edge is on the ground, so blade height isn't used. Auto Measure finds it for you: the reading with the implement up, minus the reading with it down.

Before you start

  • About 5 minutes, with the implement you'll survey with hitched up
  • A tape measure, or (for Auto Measure) the tablet connected with RTK Fixed (Connect)

When it matters

Used

Every route survey you record on the Survey screen, Drive or Shots (Ditching, Simple Grading, Tiling, Terracing and the rest), and the Grade Check readout while surveying. Designs built from those surveys inherit it.

Not used

Calibrating to a benchmark (the edge is on the ground), grading, imported Land Forming designs, Field Survey (the whole-field mapping for Levee and contours, which records the antenna's elevation), and the DIG™ Kit, where the DIG module already reports the bucket tip.

A wrong value moves the whole survey up or down by the error, and the design with it:

Blade height enteredSurvey records the groundWhen you grade the design
Too bigLower than it isYou cut too deep, by the error
Too smallHigher than it isYou cut too shallow, by the error
0 (skipped)At antenna height: higher by the full blade heightThe design sits far above the ground

Measure it by hand

  1. Park on level, firm ground

    The implement hitched as you'll survey with it, tyres at working pressure.

  2. Raise the implement fully, as you drive it when surveying

    All the way up into transport position.

  3. Tape from the ground to the cutting edge

    Measure straight down under the edge, where the edge would touch the ground. Write it down in inches (or centimetres if the app is metric).

Enter it

The Set Blade Height window opens by itself the first time you open a Survey screen with no blade height set.

  1. Tap Enter Manually

    The button on the left. A box appears and the number keys open.

    Set Blade Height window with Enter Manually on the left, Auto Measure on the right and Skip for Now below 1
    1. Enter Manually.

  2. Type the height you measured

    In the app's units: inches here (centimetres if the app is set to metric). Typing on the tablet.

  3. Tap Save

    The green button right of the box. It's stored until you change it.

    Set Blade Height with 36 typed into the box, the unit in, a green Save button, and Skip for Now below 1
    1. Save. Right of the box.

Or let the app measure it: Auto Measure

Auto Measure records the RTK elevation with the implement up, then again with it down on the ground, and takes the difference. You need a connection and an RTK fix.

Tap Auto Measure

In the Set Blade Height window, tap Auto Measure, the button on the right. (Later you can also start it from the Auto Measure button next to Blade Height in Settings: see Change it later.) A window called Auto Measure Blade Height opens at Step 1: Transport Position.

Set Blade Height window with Enter Manually on the left, Auto Measure on the right and Skip for Now below 1
  1. Auto Measure. The right-hand button.

Check both rows are green, then raise the implement

Park on level ground. At the top of the window, Controller: Connected and RTK Fix: RTK must both be green. Then raise the implement all the way up, as you drive it when surveying. On a Full Automation Kit the green Raise and red Lower buttons in this window move it; otherwise use the tractor lever.

Auto Measure Blade Height, Step 1: Transport Position. Controller Connected, RTK Fix RTK. Park on level ground, raise the implement all the way up, keep the machine still. A blue Measure UP Position button 1
  1. Controller and RTK Fix. Both green before you start.

Tap Measure UP Position

Tap the blue Measure UP Position button in the middle of the window. The 10-second reading starts.

Step 1 of Auto Measure with the blue Measure UP Position button 1
  1. Measure UP Position. Starts the reading.

Keep still for 10 seconds

Measuring transport position... The app takes a reading about five times a second for 10 seconds. Don't move the machine or the implement.

Auto Measure Blade Height: Measuring transport position..., 6 samples collected, Keep the machine still... 1
  1. Samples collected. Counts up while it measures.

Lower the implement onto the ground and tap Measure DOWN Position

The window moves to Step 2: Ground Position and shows the UP elevation it recorded. Lower the implement all the way down so the cutting edge rests on the ground. Then tap the blue Measure DOWN Position button and keep still another 10 seconds.

Step 2: Ground Position. UP elevation 811.65 ft, and a blue Measure DOWN Position button 1 2
  1. UP elevation. The first reading, for reference.
  2. Measure DOWN Position. Second 10-second reading.

Check the result and apply it

The card shows both readings and the blade height. Measurement Complete in green: tap Apply … Blade Height.

Measurement Uncertain in orange means the RTK readings wandered more than an inch during one of the two readings (after the 5 highest and 5 lowest are thrown out). Tap Retry Measurement, or measure with a tape and use Enter Manually. The app still offers Apply: use it only if the number matches your tape.

Result card: Measurement Uncertain, RTK readings showed more than 1 inch fluctuation, Transport UP 811.648 ft, Ground DOWN 811.889 ft, Blade Height 2.9 inches, Retry Measurement, then Apply 2.9 inch Blade Height and Discard 1 2 3 4
  1. Measurement Uncertain. Readings jumped more than 1 in. (This one is from the simulator, so the number means nothing.)
  2. Blade Height. UP minus DOWN.
  3. Retry Measurement. Start again from step 1.
  4. Apply … Blade Height. Saves it. Discard throws it away.

Change it later

  1. Tap Settings

    The gear button in the column down the right-hand side of the screen.

    Home screen with Settings, a gear symbol, fourth in the right-hand column
    1. Settings.

  2. Scroll down to the SURVEY box

    Slide your finger up the page (how to scroll) until you see SURVEY, about a third of the way down.

  3. Tap the Blade Height number

    Tap the number on the Blade Height row. The number keys open along the bottom of the screen. Or tap Auto Measure beside it for the steps above.

    Settings scrolled to the SURVEY box: Recording Interval 10.0 ft, Blade Height 36.0 in with an Auto Measure button, Benchmark Offset, RTK Filter and RTK Sensitivity
    1. Blade Height. Tap the number to change it.
    2. Auto Measure. Measure it with RTK.

  4. Delete the old number and type the new one

    Tap the delete key (an arrow with a cross) until the box is empty, then type the new height. It's saved as you type: there's no Save button. Typing on the tablet.

  5. Hide the keyboard

    Tap the tick key on the number keys, or the tablet's Back button (Back button). The new value stays.

If you skipped the prompt, the orange chip Blade Ht 0 — antenna level sits under the badges on the Survey screen until you set it (it hides while you record). Tap it to open the prompt. First launch.

One value: re-check it when the machine changes

The app holds one blade height. Set it again whenever the answer changes:

  • You move the kit to another implement or machine (Move the kit).
  • You change the antenna mast, the hitch height or the tyres.
  • Ditch Assist Lite: the Reach rides on the blade, so it's measured the same way: blade raised as you survey, edge to ground.
  • DIG™ Kit: the app ignores it. If the prompt appears, any value will do.

If something goes wrong

  • The design sits above or below the ground by about the same amount everywhere: blade height wrong when you surveyed. Grade off on my own survey
  • The prompt keeps coming back: Blade height prompt
  • Auto Measure says Auto Measure requires a controller connection for RTK GPS data.: connect first (Connect)
  • Survey won't start or points aren't logged: Survey problems

Related

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