Pumpy LEGO parts
The best way to view the pumps and see how they are assembled is by using Lego Digital Designer. This is a 3D application designed by Lego to help people design their own models before building them. We have created several different models for you to view in our Files sections.
There are several alternatives to Lego Digital Designer as well, each with different strengths and weaknesses:
The pumps can either be built as stand-alone pumps or they can be multiplexed as an array.
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The file Single pump.lxf shows a single pump that can be used as is.
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The file Four multiplexed pumps, no top cover.lx shows four of the simple pumps which have been arranged as an array. The major difference is that a few support plates were added which allows the pumps to be rigidly attached to each other.
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The support plates are shown separately in the file Support Plates.lxf and were designed to make the array more rigid and easier to move around.
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To be able to stack arrays vertically, or to add a cover to the arrays, a few support structures need to be added to the pumps. The file Single pump, with multiplexing supports.lxf shows a single pump with these supports added.
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Once these supports have been added, a cover can be added. We use the same combination of plates as in Support Plates.lxf. This is shown in the file Four multiplexed pumps with top cover.lxf. Instead of the cover, one may simple stack another array on top, as shown in the file Eight multiplexed pumps.lxf.
We tend to make arrays of four because:
- If longer, these tend to be unwieldy and not rigid enough
- Our controllers can control sets of four by default (see the electronics section for more information).
We have a PDF, which was generated by Lego Digital Designer's excellent automatic building guide generator. To see the guide with animations on the software itself, once you open one of the .lxf files mentioned above, you can access the guide by pressing the F7 key. There are only two things you need to be aware of.
(Aside from the)
- The linear actuators (the parts that actually move the syringe) are held firmly down by two planks. These can be seen in the below figure:
In real life, these press down hard on the linear actuator, but Lego Digital Designer doesn't allow for ovelapping pieces. Therefore the 3D model includes one extra piece which is not needed in the real pumps, seen below.
When building the pumps, do not include this piece or the linear actuators will not work properly.
- Before assembling pumps into an array, the motor connectors will need to be cut and stripped, as explained in our Electronic Controller > Installing cables on the pumps section.
To load syringes, we use rubber bands to help keep them in place. It's important to buy a bag of rubber bands ahead of time.