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 TM 210 Dry Friction
 Technical Description

Friction is a key factor in mechanical engineering. Static friction needs to be adequate to fix components to each other, such as parking brakes, self-locking threads and frictionally engaged connections. Dynamic friction needs to be kept as low as possible, such as on bearings, in guideways or in shaping tools. Consequently, great attention is paid to the topic in engineering mechanics, and understanding of it is enhanced by clearly laid-out experiments.
The unit provides a broad range of experiments relating to static and dynamic friction between solid bodies which are in contact with each other and moving relative to each other. Various influences on friction can be investigated, such as surface properties and material pairing.
A support friction surface slides beneath the stationary friction body. The support friction surface is held in a carriage which is drawn along by a motor at uniform speed by a motor. The friction body is connected to a height-adjustable force measuring unit. This ensures that the lines of action of friction force and tensile force are parallel. The force measuring unit is essentially a force gauge which is fitted with an air damper to compensate as far as possible for slip/stick effects and so indicate a mean friction force (with no spiking).
Three support surfaces and two friction bodies are available. The normal force can be varied by adding weights.

Experiments can be performed at two constant speeds. The air damping is adjustable. When it is inactive, slip/stick effects can also be observed.

The various elements of the experiment are clearly laid-out and housed securely in a box.
The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

Learning Objectives / Experiments

- Difference between static and dynamic friction
- Friction forces as a function of
* normal force
* sliding speed (relative speeds of the friction

partners)
* material pairing
* surface properties of the friction partners
* size of the contact area
- Slip/stick effect
- Determination of friction coefficients

 Features

* Fundamentals of mechanical friction1
* Stationary friction body, uniformly moving support

friction surface1
* Force gauge with air damping cylinder

 Available accessories
WP 300.09 -- Laboratory Trolley
 Alternative products
TM 110.01 -- Supplementary Set -  Inclined Plane and Friction
TM 200 -- Fundamentals of Mechanical Friction
TM 225 -- Friction on the Inclined Plane
 Specification [1] Mechanical friction between 2 solid bodies[2] Friction body stationary, support friction surface in a moving carriage[3] 2 friction bodies each with 2 different surfaces[4] 3 support friction surfaces with a total of 4 different surfaces[5] Carriage driven by cable pulley and motor [6] 2 driving speeds via a graduated cable drum [7] Force measuring unit: force gauge and adjustable air damper [8] Force measuring unit height-adjustable[9] Lines of action of friction force and tensile force always parallel[10] Adjustable air damper - with damping: Measurement of a mean friction force adjusted by disturbances, without damping: Slip/stick effects measurable[11] Box to house the components Technical Data Support friction surface- l x w x h: approx. 175x80x6mm- aluminium - PVC / felt- glassFriction body- l x w: approx. 50x40mm- dead-weight force: approx. 1N- smooth / rough (Al), h=20mm- brass / felt, h=5mmDrive- synchronous motor- rotation speed: 100rpm- driving speeds: 23.5cm/min, 47cm/minForce gauge with damper- measuring range: 0...2N, graduations: 0.05NWeights: 8x 0.5N Dimensions and Weight l x w x h: 650 x 150 x 100 mmWeight: approx. 7 kg Required for Operation 230V, 50/60Hz, 1 phase or 120V, 60Hz, 1 phase Scope of Delivery 1 experimental unit1 set of weights 2 friction bodies3 support surfaces1 storage box with foam inlay1 set of instructional material Order Details 040.21000  TM 210  Dry Friction