How to Choose a VTube-LASER System for Measuring Aerospace Tubes
Discover key factors for selecting the ideal VTube-LASER system for aerospace applications.
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Table of Contents
First: About the Idea of Leapfrog
Second: Arm Length for Avoiding Leapfrog at All Costs
About the Typical Aerospace Tolerances for Tube Shape Qualification
Table System: iMC 3500 Lite
Using Shorter Arm Length on a TRAX
1 - With the shorter arm and the TRAX, the reach is huge with a Leapfrog.
2 - With the shorter arm, accuracy improves.
3 - The 2.5-meter arm is much more nimble for measuring smaller parts.
4 - The 2.5-meter arm is significantly less expensive than the 4-meter arm.
About Ceiling Height Requirements for Arms
Conclusion - Purchase the shorter arm mounted on a 12-foot TRAX.
Please Contact Us with Questions!
The information will serve to build a foundation for making a good decision. To write this article, I am going to make some assumptions that fit aerospace well.
- Assume that none of your parts exceed 10 feet in width after bending.
- Assume you have 5000 part numbers to manage, and that 98% of them are 6 feet wide or shorter.
- This means you have 100 parts in the 6-foot to 10-foot range.
- This means you have 4900 parts in the 6-foot-or-under range.
With those assumptions, if I were to boil all the information down to an executive summary, it would read like this:
“You can choose a longer, heavier (slightly more cumbersome) 4-meter-long arm and never leapfrog, or choose a more nimble 2.5-meter arm and leapfrog 2% of the time.”
The rest of this article explores the ramifications of those assumptions.
First: About the Idea of Leapfrog
I am going to start with this concept because it heavily affects which arm length you choose. Leapfrog allows you to measure much longer tubes with shorter arms. You can purchase a more nimble and lighter shorter arm that guarantees a higher accuracy, then use a leapfrog like the video I show on this page: https://advancedtubular.helpjuice.com/vtube-laser/vtube-laser-leapfrog
To determine whether Leapfrog is acceptable, consider the percentage of your parts that will require a Leapfrog process. For example, if 2% of your parts are longer than 6 feet wide (bent), then you might want to use a shorter 2.5-meter arm with the leapfrog system with our TRAX rail. This will save money and increase accuracy for most of your parts.
As you can see in the video on the page above, the leapfrog process is not a show stopper if it is only required for a minority of parts. If you use it all the time, then it becomes annoying.
Second: Arm Length for Avoiding Leapfrog at All Costs
This is the webpage I refer to when determining a good articulated arm length for the aerospace application:
If you want to avoid leapfrog at all costs, then you would need the HEXAGON 8340-7. The "83" is a model number, and the "40" means "4 meters". The "-7" means 7-axis, which is the only way to go with a LASER scanner. The 8340-7 can scan an 11.1-foot tube from left to right or right to left without leapfrogging.
If you look through the grid in the page above, you will see three models: 83, 85, and 87. Each represents a guaranteed accuracy level. The accuracies in that table are LASER scanner accuracies (which are less accurate than the ball probe accuracies). I am sharing with you the numbers representing the lowest accuracies for these scanning systems.
- The 8340-7 is accurate to 0.0048" (the thickness of paper).
- The 8540-7 is accurate to 0.0036".
- The 8740-7 is accurate to 0.0032".
The estimated price jump grows exponentially as you move up in model numbers. For example, moving from an 8325-7 to an 8525-7 results in an estimated 5% price increase. Moving from the 8525-7 to the 8740-7, the price jump may be something like 20%.
About the Typical Aerospace Tolerances for Tube Shape Qualification
In aerospace, a typical goal for envelope tolerance is 0.039 inches.
See this page:


Note: Military applications have been using a 0.030-inch tolerance envelope for newer platforms. However, I think that this lower tolerance is not necessary for most aerospace applications.
Table System: iMC 3500 Lite
Because your longest tube is 10 feet, I would at least recommend a 12-foot table like the iMC 3500 Lite.

Or, for an additional $14K, you can opt for the iMC Select table.
Or, you can supply your own table and purchase a separate TRAX rail from us. See the 12-foot TRAX at our store.

Using Shorter Arm Length on a TRAX
The articulated arm you see in this photo is the HEXAGON 8325-7 on a TRAX rail included in the iMC 3500 table system.

1 - With the shorter arm and the TRAX, the reach is huge with a Leapfrog.
With the TRAX rail, it is possible to leapfrog a 2.5 meter (with a part reach of 6.2 feet) arm so that you can scan a 17.7 foot long tube. As I mentioned at the top of this article, you must use Leapfrog on longer tubes to make it happen.
2 - With the shorter arm, accuracy improves.
If you choose the same arms I have in our offices (the 8325-7), accuracy improves too. See these values:
- 8325-7: 0.0027 inches (more accurate and less expensive than the 8340-7)
- 8525-7: 0.0019 inches
- 8725-7: 0.0017 inches
3 - The 2.5-meter arm is much more nimble for measuring smaller parts.
I would not want to regularly measure a 1-foot part with a 4-meter arm, when the experience is much better with a 2.5-meter arm.
4 - The 2.5-meter arm is significantly less expensive than the 4-meter arm.
For every ½-meter change in model length, the price changes by $4,000. So the price difference from a 2.5-meter to a 4-meter arm is $12,000.
About Ceiling Height Requirements for Arms
In some cases, customers put their measuring equipment in an enclosed air-conditioned space. In that case, you would need to consider the required ceiling height.
According to my ceiling height calculator on the arm reach page above:
- 4-meter arm: Requires a ceiling height of 8.2 feet
- 2.5-meter arm: Requires a ceiling height of 6.1 feet
Conclusion - Purchase the shorter arm mounted on a 12-foot TRAX.
My recommendation, given the above assumptions, would be to purchase a 2.5-meter arm with a TRAX mounted to a 12-foot table.
Please Contact Us with Questions!
After having studied all of the above, please send your questions to support@advancedtubular.com. We will be happy to clarify any questions you have.
Thanks for the opportunity!