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Model Engineering and Technology at School -  Team Projects.
A Technical Education can be highly entertaining and at the same time low cost

Teachers/Schools Note - 
Special quantity prices available.


Balsa Wood Bridge Building Projects for small groups -  eg class team at school, parent/teen pair, engineering and technology students, or as a  modellers "2nd model" is always a rewarding activity.

These models are scale models but not made from kits. What we do is take a photo (or drawing) of a real bridge somewhere, draw it on graph paper, measure lengths, cut some balsa sticks, and make ourselves a small scale copy.

A balsa wood bridge construction project is ideal for modelling in schools where a small group of 2 - 4 persons are making the model together over 5 or 6 building sessions. The size and complexity of the bridges can be varied to match abilities from 8-10 year olds all the way up to architecture and engineering degree students.

Materials:The raw material is balsa wood 1 metre strips (planks). Usually the dimensions are 5mm x 5mm x 1M, or 6mm x 6mm x 1M. They cut easily with a scalpel, and cut obliquely with a scalpel, or better still a razor saw/junior hacksaw. A simple mitre box gets the angles of oblique cuts perfect, but is not essential. If you use a balsa strip cutter to cut your own balsa strips from the 100mm wide sheets, the cost is very low, even with over 25% wastage, there is approx 50% saving in material costs.

Standard safety procedures must be taught and used with the cutting tools, scalpel or stanley knife, small saws, and with fast setting super glues.

Glues can be superglue thin viscosity, or (safer) aliphatic wood glue like eg Ponal Express . Modelling pins hold the trusses in place while glue sets.

The finished bridges come to various ends in our experience. Some suitably sized balsa bridges end up in model railway layouts. Others are proud trophies that get put in a place of honour and displayed at home or in the classroom. And many get tested with weights to destruction! Most competitions involve testing, which is an entertaining high point to the project.
The usual test is several house bricks placed on a balsa sheet (which spreads the load at the edge of the bricks). The competition winner is that bridge that weighs the least and carries the most. Another test is a bucket hanging under the bridge (less distance to fall) which is then incrementally filled with sand.
Maximum mass carried before failure / Bridge Mass is the measuring formula.. Don't forget to place some shock absorbing material under the stress testing area to protect floor surface.

You will be amazed how strong a balsa wood bridge can be when it's well made with good joints!

Our BRIDGE BUILDING PACK includes 1 metre lengths of 3mm x 3mm balsa wood, with 100mm width 1 metre sheet of 3mm for decking, roadbed and i-girder construction. Bigger versions are available in 3mm, 4mm, 5mm, or 6mm thick balsawood. These contain more lengths for making lots of trusses. 
You can choose different pack thicknesses to suit your chosen project because thin wood cuts easier (safer) and increases speed and simplicity of building. For wider span and more time available, we recommend thicker parts, eg 6mm balsa wood for making bridges of over 1 metre span, 5mm for 1 metre bridges, 4mm for
3/4 metre bridges at Transition Year, down to 3mm for doing balsa bridges of 480mm span in 1st to 3rd year in secondary schools.
The 5 pupil BASIC BRIDGE PACK contains 25 x lengths, 5 roadbed sheets  of 100mm x 1M per project team/bridge, each pack is sufficient for 5 bridges (assuming 480mm span). 

 

FREE Balsa Wood Bridge Plan Download Here

Student Model Engineer Balsa Bridges   
 


VIDEOS:
Balsa Bridge Testing Fun in Ireland

Bowstring Tied Arch Truss balsa bridge from 5mm strips takes 11 bricks and stands firm !
"Brown" X Truss balsa wood bridge gives up on 9 bricks
Tied Arch Truss Balsa Bridge withstands 11 bricks undefeated
Balsa Wood Bridge destruction !
More balsa bridge destruction, and also a survivor ...
The "sit on it" test! And a "K"-Truss Balsa Bridge survivor
VIDEO:
How To Build a Balsa Wood Bridge

Video clip showing how to take a Photo, draw your bridge, cut the balsawood, make it, paint it.
Free bridge plan to download.

Please feel free to contact us at 01 4928776 if you have any questions about organising a group balsa bridge building project.

 We can offer helpful advice, and ways of potential problem avoidance based on an estimate of the abilities of the students and our knowledge of the tricks and materials.
This helps ensure a pleasurable and successful project for all involved.

Bridge Designer: Virtual Online Bridge Builder & Tester
Truss bridge designs can be "painted" and then tested with a click of your mouse. A great tool for model bridge makers!
Bridge Designer: Tutorial
How to use the software above. He omits adding the horizontal members, so remember to do that too & it works nicely.
  5 Steps to Building a Model Bridge PDF Free guide from the excellent bridge builder website www.garrettsbridges.com


Please call us if Balsa Wood Bridge Packs are interesting to you  ....  phone 01 4928776

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Green Hobby & Model, the R/C source
38 Clareville Road, Harolds Cross, Dublin 6W
Tel (01) 4928776 , Fax (01) 4979946
Sales Norman or Patrick

 

Get your top grade Balsa Supplies
Balsa Wood Bridge Packs
from
Green Hobby & Model
Dublin
Close grain bridge building
balsa available
Semi Flexible Lime Flat Strips available
Tools: balsa strippers, planes, razor saws, etc

Tel 01 - 4928776

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