Tech Tips

Steps in Performing a Leap Frog Alignment

Requirements: Three features that will act as datums. These three features can be geometric primitives on the measured part or conical seats attached to the part with hot glue or magnets. Whether you choose geometric features or conical seats will not matter providing that these features support the stylus of your choice in all three axis X,Y and Z.

Some choices for Datum Features

Geometric features like bores may also work

Notice how the probe is supported in all axis X,Y & Z!

If you choose to use washers, ensure that your probe sits in the washer without touching the part!

   Lets Begin

• Start by choosing your 3 datum features on the part. If you do not have suitable features on your part then glue the appropriate size conical seats or washers to your part. These datum features should encompass all of the parts volume for the best accuracy! Use a piece of paper to sketch the location of your 3 datum features.
• Create your PC-Dmis part program like usual, measure all the features that you can reach with the part in this position.
• We will now prepare for the Leap Frog alignment. Turn off the probe compensation by selecting Insert -> Parameter Change -> Probe Compensation from the pull down menus. While viewing your program in command mode ,ensure the command reads “probecom/off”.

• If the Probe Compensation command reads “ON” then place your cursor on the command and hit the F9 key to bring up the edit dialog and remove the check mark from the “Probe Compensation Active” entry. Hit OK to save this change.

• Open the “Leap Frog” dialog by selecting its icon from the tool bar.

• Select the “Measure 3 Points Sets” option. Leave the number of hits at 5 and select the “Measure All” button. This dialog means that we will measure each datum feature 5 times. This multiple measurement will increase our accuracy by averaging the 5 measurements for each of our 3 datum positions.

•  You will now be prompted to measure hit 1 of 5 for point number 1. Locate datum feature number 1 and ensure that the probe is resting securely in this datum feature. Now measure a point and confirm the measurement for this datum feature.

• Measure 4 more individual hits in datum feature number 1 and confirm each hit.
• Perform the same operation on datum features 2 and 3.

• You can now move either the part or the arm to a location suitable to measure the next group of features.

• 
  With the arm or part in the new location, remeasure the datum features with 5 hits for each feature, in the same order as used in the preious. Refer to the sketch created in the first step  if necessary.
• When the measurement is complete you will again be presented with the Leap Frog alignment screen. Review the results for residual XY and Z error. Select the "Accept" and "OK" buttons to apply the alignment. Select "Yes" to the prompt "Is it OK to insert a Leap Frog Alignment Command?" If you fail to hit the "Accept" button you will lose your alignment!

• As a final step, turn the probe compensation back on in your part program (See steps 3 and 4 for details). You may perform a Leap Frog alignment as many time as necessary to measure the remaining features on your part.