There's a lot of focused content in the forum at the moment, so I thought it would be good to add something to this thread. Different way of doing the same thing ... but I would appreciate the feedback.
This is the basic frame - bolted to the floor. Clamps allow for change in centre of the ski, when commercial skis are measured. I regret not creating a longer rail for the shuttle, but it was going to be tricky to achieve:
The shuttle is moved up and down the rail using a hand-drill - it sits on a platform, so as not to stress the thread and twist the shuttle.
The position of the shuttle is referenced against this paper scale which is stuck to the base (double sided tape)
The test starts with the force cell in place and readings are taken:
- no force applied
- force required to neutral position
- 10 kg
- 15 kg
- 20 kg
- 25 kg
Rest 0kg 0mm Total Displacement
Neutral 3.8Kg 7.48mm Total Displacement 7.48 Change in mm
10Kg 18.86mm Total Displacement 11.38 Change in mm
15Kg 29.1mm Total Displacement 10.24 Change in mm
20Kg 37.29mm Total Displacement 8.19 Change in mm
25Kg 45.8mm Total Displacement 8.51 Change in mm
What's interesting is the none liner relationship between force and displacement.
The force cell is then removed - no point leaving it under pressure and measurements are taken every 10mm
The shuttle is relatively simple - held in place using plumbing parts and plastic edging strip
Accuracy level appears good - as the results are repeatable to within +/- 0.05mm
This is what I have set up for focused tip deflection force cell is not in place in these photos:
What's interesting about the results I am getting is they are based on the same ski built differently, so the results compare these changes e.g. 20 cm more CF, an addition 0.1mm in overall height of the core or capped v.s sandwich.
The machine is four processes within the one frame - I would think it could have been made more simply, hopefully it will offer a few ideas to others.
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