Final Conclusion

In conclusion to this project I would like to say a few words.

Firstly, I would like to say that this project has been very rewarding. I have learnt a lot about many different kinds of crane systems & what it takes to build one. The team have worked together from day 1 and we worked really well together. We all had our advantages and strengths to make this project come to life.

The group had met up definitely a day a week and sometimes we would meet up on the odd day as well.

Rajan Sudera

Our Presentation.

Final Product

The following displays our final product, costs, materials and stress calculation results.

The Product:

The above image shows our crane. It is a gantry crane, the beam itself is 5m long, the legs are 1.5 metres long and the leg struts are 1m long.

Lifting Mechanism:
Clarke CNP 1250 Heavy Duty Power Puller

This winch was chosen because:
Lifting loads of up to 1250kg
Cable length of 3070mm
Cost = £21.14 including VAT
Limited parts so less can go wrong
Simple to use
No need for external power supply (fully manual)

Transport Mechanism:

This roller mechanism was chosen because:
Price = £46.98
Suitable for all winches and loads of up to 5440kg's
No need of external power supply

Chosen Beam Structure:

Hollow square cross section beam
Chosen because:
Can withstand vertical and horizontal shear and bending which would suit the purpose of this crane as load will be swinging so load not only in the vertical direction. Allows for worst case scenarios.

Stress calculation results:

Maximum deflection at worst case on the beam (center, 2.5m) is 4mm.
Buckling in the leg structs would occur at a load of 37730.61kN
The load at which the legs would start to plastically deform is 4000kN

All these results show that our crane can cope under the 1000kg load.

Material:

We have opted to use aluminium instead of steel for our crane as:
Aluminium is lighter
Although aluminium isnt as strong as steel, it is still strong enough for our purposes

Costs:

Aluminium structure = £333.91
Beam Supports = £100 approx
Joints = £55.74
Winch = £21.14
Roller system = £46.98

Total = £557.77 excluding labour costs

Final thoughts of Project

I personally have found this project challenging and interesting as it has increased my knowledge about materials and static mechanics in practical situations.

Throughout this project, the group have not been working well however. 3 out of the 5 of us did the minimum amount of work and i believe at without myself and Will the project would not have been finished on time. I have not enjoyed working with this group and i would not work with any of them except for Will in a group project again.

Stress analysis for hollow square cross section

Below is the stress analysis for the hollw square cross section beam.




As you can see, the steel beam was deflecting in the centre of the beam by approximately 115mm. This value is to large so a different material was tested to see if it would produce a smaller deflection.


Aluminium provided a great substitute for stell as it is lighter and thus gives a much larger structure for the same weight as a the steel beam. After much trial and error, the ideal structure dimensions were found and a maximum deflection of 4mm for found in the centre of the beam when the load was applied. This is a much more reasonable value and is within british standards for this structure.

Below is the buckling calculations for the legs and the connecting leg to beam strut.

Financial Evaluation

once we had finalised the design we needed to do the stress analysis to determine exactly what the dimensions were for each component. after researching into the different types of metals and dimensions we were then able to find prices for the specific material. we obtained these prices from www.aluminiumwarehouse.co.uk

Metal Structure = £333.91
Roller System Mechanism = £46.98
Winch = £21.14
Beam Joint Supports =£100
Connection Pieces =£55.74

Total =£557.77

Wheels

A possibility to add to the crane is wheels for the bottom of the legs. The groups had a meeting and I decided to do some work on advantages and disadvantages of wheels. We would need special industrial crane wheels (as shown above) for our crane. It would need to be designed to withhold the rough terrain that is required. A major disadvantage for wheels is their stability. It would be very difficult for them to keep still whilst the 1 tonne load is being lifted. However, if a braking system was to be installed then the stability problem would be gone. Still, this accessory would not be appropriate. The rough terrain caused by the Haiti disaster would most likely damage the wheels. If this happens then it would be even more of a hassle in getting it repaired.

Rajan Sudera

Chosen Roller System

The chosen roller system we have chosen is a heavy duty roller fairlead. we have chosen this product because it is more than capable of supporting the load. infact it can cope with 5440kgs. it has galvanised rollers for durability and to prevent corrosion. This product is shown below.


this product can be purchased from from a company called machine mart. the details are on http://www.machinemart.co.uk/