Laptop Stand Project

1/22/2014

Engineered | Project

MAKER LAPTOP STAND

Engineering

The pintle is an inclined surface formed from tubular steel components

and designed to become rigid when contacting surfaces are subject to a

clamping action, it is desired to develop sufficient friction force

between the component surfaces to restrict motion up to a design

maximum load. In the locked or static state slippage is undesirable

but if the surface threshold for friction breakaway is overcome by

torque loading, slip occurs and the system fails.

1

Engineering

CONTACT SURFACE Using static friction as a minimum angle limit for free release

Free release angle

Pintle contact surface is formed from tube with an outer diameter of 22.23mm, Wall Thickness =0.003m Size of contact surface at abutment

Mean diameter

Radial height

Using design angle of 15 degrees (for free release) Tangential Length

Slope Length

Curved surface area (mean diameter)

lateral surface area of contact

2

Engineering

DESIGN LOAD

For rotational equilibrium, the sum of the torques must equal zero.

,

Considering a worst case configuration

Load Case 1

When R =0.0095m, β= 0°, d = 0.33m, W2=3kg, w1=2.5kg,

Considering a functional configuration

Load Case 2

When β= 60°

Using Factor of safety of 2.0 with Load Case 1 values

Requiring torque capacity of

fbd

3

Engineering

CLAMP CAPCITY

Clamp action generates an axial load driving the contact surfaces

together. Since the normal force acting on the friction surface is

The equation for torque may be written as

Design torque capacity

SURFACE FRICTION

Upon clamping deformation in the components creates limited slip and a

corresponding friction opposing motion, thus requiring additional

force to lock the joint

FREE RELEASE

The surface angle is greater than that of static friction for free

release however should reluctance to disengage be encountered

an axial release force must be provided.

Disc Spring

Selecting a disk spring with a force of 697N at 50% deflection

(0.178mm) we require 2 units stacked in series

Manufacturer:Bellville OD 16mm ID 8.2mm t 0.9mm

4

Engineering

Axial force required for lock (zero acceleration)

Clamp

Selecting a cam action clamp proportional to tube size and a stroke of

1.5mm. Manufacturer:Kipp, Model:201108 Series K0005 Size 8kN (M8)

Pressure intensity

Load limiting

We can limit only by changing the face width while still retaining

free release geometry

limiting to 12 N/mm2

The computations reflect a single pintle interface but values are

accommodated at 2 locations in the design

The design provides for two friction surfaces, each with a slope

length of 8mm and is acceptable

5

ITEM NO. Part No. Description1 QTY.

1 02-01 DrawBar 1

2 02-02 Nut 1

3 02-03 Seat 1

4 PURCHASED Dowel Nut 1

5 02-05 Lever 1

3

4

12

5

371

85

DWG. No.MATERIAL:

X.XXX

DEFULT DIMENSION TOLERANCE

DESIGNER:

Graphics

ANGLES

DRAWN BY:

DATE:

SCALE:

TITLE:

±0.08

LAPTOP STANDPROJECT.

X.X

±1

Ideas in Ink

Technical

X.XX±0.025

±0.13

a Maker Projectopen source

design

2/2/2014

NTH

QTY. REQUIRED: 2 PCS

Clamp

NA

1:2

WEIGHT: 230.47 GRAMS

SUB ASSEMBLY 02

01-02

363

15 17

M8 x 1 THREAD

DESIGNER:

Graphics

±0.025

Maker Project

X.XXX

beautiful

TITLE:

SCALE:X.XX

DRAWN BY:

DATE:

ANGLES

DWG. No.

Ideas in Ink

LAPTOP STANDPROJECT.

X.X

±1

DEFULT DIMENSION TOLERANCE

Engineerd

±0.13±0.08

Technical

MATERIAL:

QTY. REQUIRED: 2 PCSDrawBar

02-01

A307

2:1

NTH

WEIGHT 140.43 GRAMS

2/2/2014

SUB ASSEMBLY 02

Plain Carbon Steel

ITEM NO. PART NUMBER StockSize QTY.1 02-01 8 x 400MM ROD 1

SCALE:

DESIGNER:

Graphics

X.XXX

beautiful

LAPTOP STAND

Ideas in Ink

DWG. No.

±0.025

DATE:

ANGLES

DRAWN BY:

Maker ProjectEngineerd

PROJECT.

X.X

±1

DEFULT DIMENSION TOLERANCE

TITLE:

X.XX±0.13±0.08

Technical

MATERIAL:

Nut

02-02

2014-T6

2:1

2/2/2014

QTY. REQUIRED: 2 PCS

WEIGHT 24.35 GRAMS

NTH

SUB ASSEMBLY 02

ALUMINIUM

ITEM NO. PART NUMBER StockSize QTY.1 02-02 1.125" x .75" ROUND 1

R14.3

12 6.800 14

M8 - 6H

R7 -6 PLACES

EQUI-SPAC

ED

A

A

12°

5

17

22.5

R1

1

SECTION A-A 2

4

28.6

9

1

22.5

ITEM NO. PART NUMBER StockSize QTY.1 02-03 1.125" x 0.5" ROUND 1

DWG. No.

SCALE:

DESIGNER:

beautiful

LAPTOP STANDPROJECT.

Engineerd Maker Project

Graphics

ANGLES

DRAWN BY:

DATE:

X.XXXX.XXX.X

±1

DEFULT DIMENSION TOLERANCE

TITLE:

Ideas in Ink

±0.025

±0.13±0.08

Technical

MATERIAL:

SeatQTY. REQUIRED: 2 PCS

1020

2:1

2/2/2014

NTHPlain Carbon Steel

WEIGHT 38.68 GRAMS

SUB ASSEMBLY 02

02-03

8.200

16 D

DSECTION D-D

R11

.11

5

8.2

20

R4

R8

42 3.9

DWG. No.

SCALE:

DESIGNER:

beautiful

LAPTOP STANDPROJECT.

Engineerd Maker Project

Graphics

ANGLES

DRAWN BY:

DATE:

X.XXXX.XXX.X

±1

DEFULT DIMENSION TOLERANCE

TITLE:

Ideas in Ink

±0.025

±0.13±0.08

Technical

MATERIAL:

02-05

2014-T6

1:1

2/2/2014

NTH

Lever

WEIGHT 18.11 GRAMS

QTY. REQUIRED: 2 PCS SUB ASSEMBLY 02

Aluminium

R11.11

R8

11

4 70

2°

9.6

51 14 1.

5ST

ROKE

ITEM NO. Part No. Stock Size QTY.1 02-05 0.75" x 4" BAR 1

ITEM NO. PART NUMBER DESCRIPTION QTY.1 01 Axis 22 05 Tray 13 03 Leg 14 Weldment1 25 02 Clamp Clamp 26 ORing_214 Parker 4

±0.025

Graphics

DESIGNER:

Laptop Stand

Technical

Ideas in Ink

DATE:

ANGLES

DRAWN BY:

X.XX

PROJECT.

SCALE:

DWG. No.MATERIAL:

X.XXX±0.08

X.X

±1

DEFULT DIMENSION TOLERANCE

TITLE:

±0.13

a Maker Projectopen source

design

NTHNA

1:5

00-012/4/2014

WEIGHT:4495.12 GRAMS

QTY. REQUIRED: 1 PCS ASSEMBLY

1 371

294

358

219

3

25

4

6