3D printing a bridge
3D Print Batemans Bay Bridge replacement model
Transport for NSW (Transport) is currently delivering the replacement of the Batemans Bay Bridge located on the south coast of NSW. The new bridge will provide better connections for motorists, cyclists, freight, river users and pedestrians. Work started in early 2019 and is planned to be completed in 2023.
As part of the Batemans Bay Bridge replacement project, Transport engaged Cammpro to 3D print a scaled model of the bridge to assist with future community and stakeholder engagement opportunities held throughout construction.
Part of the brief from TfNSW involved scaling the bridge model into a scaled length of 1.6m. The scale factor used was 1:250 or 0.004%
Before scale (sizes in mm): approx 400m long
After scale: (sizes in mm):
The difficulty with drastically scaling a part, is that the wall thickness becomes unprintable as seen below:
Cammpro have the software to overcome this problem. Autodesk inventor has the capability to “wrap” 3D models, giving the model a watertight coating of selected thickness, similar to cling wrapping an item with a thick wrap.
Now the file is 3D print ready. At 1.6m in length there are not many 3D printers capable of printing such long parts. One printer capable of printing at 1.6m is the Builder Extreme 2000 PRO, which has a massive build volume of over 1.6m. The Builder Extreme 3D printer range has 3 options of build volume:
|x (mm)||y (mm)||z (mm)||Total (cm³)|
The Builder 2000 is the largest of the range at 1.7m tall:
Unfortunately there is only one Builder Extreme 2000 PRO in Australia at present, the 3D printer used at Cammpro is the Builder Extreme 1500 PRO so the next task is to split the model in 2 pieces.
The best option for splitting 3D printing models for print, is to use a “dove tail” joint. This will give the best result when re-attaching the models for strength and for aesthetics. Cammpro decided to split the model down one of the piers of the bridge for added strength when re-attaching:
Now time to 3D print. Orientation with this model is very important. The road is obviously the most important feature so this is the area that requires the highest surface quality, therefore this will either be the top or side surface.
Printing with the road parallel to the bed of the Builder Extreme 1500 PRO would give the best result, but would use the most support material as shown below:
Therefore, the best option would be to print on the side, this saves 30% of support material and time:
The part was then 3D printed with BASF PRO1 filament, this gives superior strength and quality compared to other brands.
Below is a photo of the print just completed in the machine, with the support structure still attached.
The benefit of using the Builder extreme, with the software Simplify3D and BASF Pro1 material, is the support structure can be easily worked for ease of support removal, giving a clean quality finish with hardly no need for post processing.
As soon as the support material was removed, the 2 pieces slid together to complete the 1.6m bridge model:
Cammpro is the exclusive Australian representative for Builder3D. Let Cammpro take care of all your 3D printing needs, whether it be 3D Design, 3D Printing, Small Batch Manufacturing or if you are looking for your own 3D Printing Machine, large or small.
With over 10 years 3D Printing and Engineering experience, Cammpro has the expertise to provide solutions for your manufacturing requirements.
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http://www.cammpro.com.au/products/3d-printers/ Builder 3D Printers