Load Cell Testing recovery situations and techniques.

[Metcalf]

I recently was able to add a 25k load cell to my capabilities for the testing and evaluation of recovery gear products and their development.

What concepts and techniques would you like to see tested and validated in the field?

Note: This isn't going to be used for 'breaking' stuff.....that has to be done in a more laboratory setting with more layers of safety in my opinion.

 

[toddz69]

Cool - just saw your post on this tool on IG. I guess I would have a similar request to what John Cappas was asking you in the comments of your IG post - what kind of winch loads do you see when you're trying to pull someone up over a shelf or a rock - the initial (impulse?) loading before things start moving, so to speak. Or something along the lines of loads you see before the 'suck' of a mudhole is overcome.

Thanks,
Todd Z.

 

[Metcalf]

Cool - just saw your post on this tool on IG. I guess I would have a similar request to what John Cappas was asking you in the comments of your IG post - what kind of winch loads do you see when you're trying to pull someone up over a shelf or a rock - the initial (impulse?) loading before things start moving, so to speak. Or something along the lines of loads you see before the 'suck' of a mudhole is overcome.

Thanks,
Todd Z.

Some of that will be pretty simple to test, some of that is going to go FAR into the weeds....

I would propose finding a ledge ( hopefully something like a 90 degree concrete step ) that is as tall as the loaded radius of the tire. Use some cribbing to be able to adjust the height of the step for a series of tests. Use a winch on the vehicle connected to the load cell to pull the vehicle up the step at increasing heights. We should be able to see a trend vs vehicle weight. At some point ( probably close to axle centerline ) you won't be able to 'pull' the vehicle 'up' the step any longer no matter how much force you have.

Doing this with the vehicle in neutral (not helping) is going to give us the best data, but isn't going to be very representative of how things go in real life as usually the vehicle would be helping as much as it could. The vehicle not helping is worst case though and all the data should still scale.

Tire pressure will greatly come into play also. I would bet that a reduction in tire pressure greatly reduces the loads, but that will be counteracted by the reduction in rolling radius of the tire as the ledge grows. That would be a very interesting thing to test.

'Impulse' probably isn't the best word for the load in this case. We generally just care about the peak load needed to overcome the obstacle.

I'll do some scouting around for a location.

 

[toddz69]

Some of that will be pretty simple to test, some of that is going to go FAR into the weeds....

I would propose finding a ledge ( hopefully something like a 90 degree concrete step ) that is as tall as the loaded radius of the tire. Use some cribbing to be able to adjust the height of the step for a series of tests. Use a winch on the vehicle connected to the load cell to pull the vehicle up the step at increasing heights. We should be able to see a trend vs vehicle weight. At some point ( probably close to axle centerline ) you won't be able to 'pull' the vehicle 'up' the step any longer no matter how much force you have.

Doing this with the vehicle in neutral (not helping) is going to give us the best data, but isn't going to be very representative of how things go in real life as usually the vehicle would be helping as much as it could. The vehicle not helping is worst case though and all the data should still scale.

Tire pressure will greatly come into play also. I would bet that a reduction in tire pressure greatly reduces the loads, but that will be counteracted by the reduction in rolling radius of the tire as the ledge grows. That would be a very interesting thing to test.

'Impulse' probably isn't the best word for the load in this case. We generally just care about the peak load needed to overcome the obstacle.

I'll do some scouting around for a location.

I agree on your methods - you're obviously thinking on how to do this with a nice set of variables that doesn't go too far into the weeds.

And yes, peak load would be a better descriptor.

Todd Z.

 

[emtmark]

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[Metcalf]

Congratulations on acquiring a new load cell for testing and evaluating recovery gear products! Here are some concepts and techniques you may consider testing and validating in the field:

1. Load Capacity: Determine the maximum load capacity of recovery gear products such as straps, shackles, winches, or snatch blocks. Test them under controlled conditions, gradually increasing the load until failure or deformation occurs. This will help establish their safe working load limits and ensure they meet industry standards.
2. Strength and Durability: Assess the strength and durability of recovery gear by subjecting them to repetitive loading cycles or prolonged stress. This can simulate real-world usage scenarios and help identify potential weak points or areas prone to fatigue or failure.
3. Material Testing: Evaluate the performance of different materials used in recovery gear, such as nylon, polyester, steel, or synthetic fibers. Test their tensile strength, resistance to abrasion, and other relevant properties to determine the most suitable materials for specific applications.
4. Compatibility: Verify the compatibility and effectiveness of various recovery gear combinations. For example, test different combinations of straps, shackles, and winches to ensure they work together seamlessly and provide optimal performance during vehicle recovery operations.
5. Field Conditions: Conduct tests in real-world field conditions to simulate the challenges and variables encountered during vehicle recovery scenarios. Test recovery gear in different terrains, weather conditions, and vehicle weights to assess their performance under diverse circumstances.
6. Impact and Shock Testing: Evaluate the recovery gear's ability to handle sudden impacts and shocks during recovery operations. This can involve subjecting the gear to drop tests, simulated vehicle collisions, or sudden load releases to determine their resilience and shock-absorbing capabilities.
7. User-Friendliness and Ergonomics: Assess the usability and ergonomics of recovery gear, such as ease of installation, adjustments, or disengagement. Consider factors like intuitive operation, quick setup, and compatibility with various vehicle types to ensure user convenience and safety.
8. Environmental Factors: Evaluate the performance of recovery gear in different environmental conditions, including extreme temperatures, humidity, or exposure to saltwater or corrosive substances. This will help assess their resistance to degradation and ensure longevity.

Remember to document your testing procedures, observations, and results systematically. This will aid in comparing different gear, identifying areas for improvement, and providing valuable data for product development and customer education.

1-4 are best done in a 'lab' setting, you don't want to field break gear to find limits. That is very dangerous without any of the associated safety umbrella when knowingly breaking parts.

5 is always going to be subjective to a degree and doesn't require a load cell, but I would love to share more information in that area.

6 is also going to have to be done in a 'lab' setting under a safety umbrella and protection if you are expecting gear to actually fail.

7, see 5 note

8 is similar to 1-4 and 6.

Thank you for the feedback.