Runner for Crossbar

This is a website for the runner that the crossbar will use to move in the horizontal direction.

http://www.hepcomotion.com/en/psd-screw-driven-linear-actuator-pg-14-get-24

Boom fixings and real mini crane pictures

This post will explore a few methods of fixings and boom development from original sources. The bulldog crane now named 'The Grasshopper' as of now, has to be marketable and innovative. I personally believe that idea number 3 looks like a grasshopper.

Slogans such as "Get the Hopper" and "I need help, I need The Grasshopper" are catchy and have a history of adding lasting appeal to a product and gives it a separate identity, a sort of quirky uniqueness.

fig.1

Above (fig.1) is a picture of a green grasshopper for visual aid. (Idea 3 will be shown at a later date.)

Now moving on to more serious matters...

Below is a crane, it uses a 'cradle' to move the object picked up in the x-direction. The object is picked up using chains and hooks, once secure it is elavated to the desired position.

fig.2

This is an excellent model for us to work from. We can use a inverted T beam for the boom itself. An 'I 'beam will work also but will add unnecessary weight, we will try to avoid it unless the stress calculations require the boom to have extra strength. Remebering idea 3 is supported from both ends and is not wall mounted as this one is therefore should be able to hold considerably more than 500kg.

fig.3

Figure 4. shows how the wheels that allow the cradle to move along the boom are fixed. The wheels are on both sides of the boom. They are fixed in place using a bracket that stops them from moving in unwanted directions or falling off. The wheels can be replaced and the entire cradle removed by unscrewing the bolts. This makes it a separate component from the boom, making it easier to transport.
fig. 4

Talking about portability, the boom will roughly be 4m+ so carrying this around either by man or machine power (landrover defender) is dfficult. So a 'hinge' is in order, and I have one that may suite our needs...wala!

fig.5

We can develop and modify this one to suite our needs. OR the two parts of the boom can be separate but connected with bolts.

Heavy duty materials must be used and an accurate stress test is required to determine most of the positioning of the components and type of fixing required.

This post is designed to develop idea no.3 though a considerable amount of the post can be used for idea no.2 also.

These photos are property of Amardeep Singh Dhillon and can only be used with permission from the owner, me.

Types of electric winch:

Winch example (1)

Found: http://www.liftingonline.com.au/products/JDN603

1000KG X 3M, JDN 'MINI' AIR HOIST

Specifications: (Extensive specifications given in a table on the link above)

"1000KG X 3M, JDN 'MINI' AIR HOIST *Extremely compact at a minimum of weight *High flexibility for varying working places *Few components for easiest operation and maintenance *Ideal as an inexpensive alternative compared to hoists with other driving media *Suitable for lube free operation, no additional oiler required *Suitable for application in hazardous areas *suitable for horizontal pulling *Newly developed braking system with little wear."
Weight: 26.0 Kg


Winch example (2)

Found: http://www.portablewinch.com/en/02.asp

• Portable

There is no fixed link to a vehicle; therefore you can take the winch anywhere. Tether it to any solid object: a tree, a post, a rock or even to the ball hitch of your vehicle.

• Powerful - Up to 2000 kg (4400 lb) of pulling power

The Portable Winch^TM will pull 1000 kg (2200 lb) single line. If you need to pull extremely heavy loads, we offer a snatch block kit including a swing-side pulley and locking steel carabiner. The pulley is attached to the load with the carabiner, and the rope is attached to the winch anchor. This lightweight system effectively doubles the pulling power of the winch to an amazing 2000 kg (4400 lb) pulling capacity!

• Lightweight - Weighs only 16 kg (35 lb)

Both winches have differing merits, the second example is most likely to be the one our group will use during our calculations as it is portable, and could be carried by hand, it will not add significantly to our overall payload, and could be modified to enable it to take a greater weight.


Alternative websites also viewed:

http://www.northerntooluk.com/winches-and-hoists/electric-hoists/?sortby=priceascending&cm_ven=Performics&cm_cat=PPC&cm_pla=Google&cm_ite=electric%20chain%20hoist

http://www.winchsolutions.co.uk/

http://www.nextag.com/Master-Lock-Co-2953AT-506261517/prices-html?nxtg=26900a1c0512-35D7477F7F5880CA

http://www.nextag.com/portable-winch/compare-html

Types of Bearing

When considering bearings, the main factor to consider is the type of load required for the bearing to withstand, the two main types are radial and thrust.


For use in the turning mechanism of the crane, a large thrust load and very small radial load will be applied to the bearing.

Plain Bearing


This is the most simple type of bearing, which simply consists of two surfaces that move past each other with no other mechanism. Often one or both of the surfaces is coated in a non-stick layer as well as being lubricated to further reduce the friction. This type of bearing has a very high load carrying capacity but also creates a lot of friction. They have a fairly high radial and relatively low thrust capacity.


Ball Bearing


Ball bearings have both a high radial and thrust capacity, and are found in a large range of applications where the load is small. Any load applied is focused onto a very small area, which makes it run smoothly and quietly, however this creates high internal pressures which may deform the balls should the bearing be overloaded.


Roller Bearing


Roller bearings are similar to ball bearings in the way they are made, having the key difference that they contain cylindrical rollers instead of balls. The rollers distribute the internal forces over a larger area, which reduces the internal pressure, making the components less likely to deform and vastly increasing the radial load capacity. Although the radial load performance is increased, this type of bearing has a very low thrust load capacity comparatively.


Magnetic Bearing


Magnetic bearings are ideal for high speed applications as they support the load using magnetic levitation which has zero friction and requires no maintenance. These bearings require a constant power supply as well as a sensor circuit to keep the inner and outer rings at a constant distance. This means that often a set of backup bearings is required in the event that a power loss to the device occurs. They have a relatively low radial load and extremely low thrust load capacity, and are most suited to continuous low load applications such as power generation or machine tooling.


Ball/Roller Thrust Bearing


This type of bearing is similar to ball and roller bearings in the way which they work, however the layout of the components allows a far greater thrust load capacity. This type of bearing is well suited to high thrust load applications, where radial load requirements are low. Rollers have the benefit of increased total load capacity, while ball bearings are smoother and run a lot more quietly as a result of decreased friction.

Beam Dimensions

This is a website for the standard dimensions of I-beams, rectangular hollow section beams flanges etc.

http://www.roymech.co.uk/Useful_Tables/Sections/steel_section_index.htm#tables

Hand Winches

Gear Ratio

One person can't lift 1000kg using a hand winch without a gear ratio of at least 14:1 so that to the person using the winch it would feel like lifting 71.4kg. This is because the amount that an average man man weighs is 60-70kg and the maximum most people can lift is their own body weight.

Maximum Capacity

The winch needed for this design would have to have a maximum capacity of 1000kg or 2200lbs.

Weight

The winch needs to be a suitable weight so that it can be transported manually from the 4x4 vehicle to the disaster area.

Brakes

As the maximum load to be lifted will be 1000kg the winch needs to have a brake so that the person using the winch has time to rest and when the load is at the required height the winch can be locked.

These are the sites of suitable hand winches:

http://www.winchsystems.co.uk/sf-2200-hand-winch.php
http://www.winchsystems.co.uk/sf-5000-hand-winch.php

Pay-load for a Landrover Defender:

The website I found the following information on:

http://www.landrover.com/gb/en/lr/defender/explore/defender-professional/

"Dropsides

The Defender 130 Dropside in either Single or Double cab format provides huge load carrying capacity and a whole lot more. The corrosion resistant body is constructed from aluminium with zinc plated catches and corner pillars. The totally flat, wheelarchless load floor with hinged removable side boards, back boards and corner pillars all make for fast and easy load management. With a payload of 1200kg through, class-leading towing capability of up to 3500kg and optional tipper functionality, this is a truly remarkable load carrier."

This is relevant to the group becasue it gives us a maximum weight for our crane structure when it is dis-assembled for transport.

Types of Cranes Research

The different types of cranes available was researched to give a broad idea of the different designs currently in use.