1.31.2013

A-Silicone or PU Tires?

Tested polyurethane rubber with the surface of the dohyo, with 32-07 Monitor/Slip and Friction from Testing Machines Inc.
Introduction:
Slip and Friction testing aids in the evaluation of chemicals and additives used to create or minimize the degree of friction between two contacting test specimens.

Applications:
Paper, Flexible Packaging, Foils, Rubber, Plastics, Wood,
Linoleum, Metal, Printing, Coatings, Composites

Specifications:

  • Selectable speed from 5 to 43 cm/min (2 to 17 inch/min)
  • Selectable travel distance from 2.5 to 30.5 cm (1 to 12 in.)
  • Meets TAPPI T816, T549, and ASTM D1894

Features:

  • Digital display, storage and editing of up to 100 readings, and selectable units (COF or grams)
  • Settable limits
  • Statistics-average, standard deviation, high/low results.
  • Report printout with built in printer
  • RS-232
  • Static and kinetic coefficient of friction calculated in one operation.
  • Direct drive arm with unique skid control.
  • Sled-connecting mechanism ensures level pulling action.
  • Easily interchangeable sleds.
  • Full color easy to read Display

Instrument size:
Depth: 495 mm (19.5 in.)
Height: 508 mm (20 in.)
Width: 515 mm (20.3 in.)
Weight 25 kg (55 lb)
PDF product sheet:
Monitor/Slip and Friction

Product Video:

Brief test results:
* TEST REPORT *
Test Name: SL
Date: 31 Jan 2013

Sample ID: -
Sled Type: B - 200g (.44Lb)
Sled Info: -
Speed: 10cm/min
Travel: 20cm
Unit: COF

Total Meas.: 3
Rejected: 0
Static:
 -> Mean: .654
 -> SD: .089
 -> Lo: .601 (#1)
 -> Hi: .758 (#2)
Kinetic:

 -> Mean: 1.536
 -> SD: .210
 -> Lo: 1.410 (#1)
 -> Hi: 1.780 (#2)

Reading #: S K (X=reject)
 1: .601 1.410
 2: .758 1.780
 3: .604 1.420

* END *

Conclusion:
Graph bellow is found from motor parameters, by ramming the robot to the wall.
  1. As expected, static is lower than kinetic friction coefficient.
  2. These aren't final results, because 3 measurements at one speed means nothing.
  3. It is essential to conduct full experiment at different speeds and normal loads, in order to achieve force vs speed load graph and compare with DC motor load graph.
  4. Next: Full experiment conduction with PU and silicone rubbers.


Useful links:

2 comments:

  1. Really cool, where did you find this machine?
    Isn't static friction higher than kinectic?
    Great job with your robot!

    ReplyDelete
  2. This machine was ordered by Klaipeda University's department of thechnological processes. On of master mechanics told me about this machine. So I tested it out.
    PU is not an ordinary material, especialy on plastic surface. It slips at the begining and builds more thrust, when it slips more, thats why the static is lower than kinetic at this situation.
    Thanks for comment, I try my best to share.

    ReplyDelete