Powered Counterweight - Four Different DesignsCarry only one heavy part, no weights, just power
When I started with the idea to combine the battery with the counterweight, I thought, it will be a one-shot project. Well, it gradually became more a learning and a research project. Now, there are four different models made, whereas I do not count the first one here. Today, I see it more as a “public prototype” for discussions…
The initial shot and why it was not enough
The story of creation of this version and some rational for the idea in general can be found here.
I used the first version several times with the Sky-Watcher AZ GTI mount controlled by ASIAIR Pro and used with Canon 800Da, ZWO EAF ZWO ASI120mm mini as the guiding camera. This setup was not consuming a lot of power and able to run around 5-6h without anti-dew heaters. A cooled monochrome astro-camera changes this. The energy provided 18 18650 LiPo cells with 3300mAh was TBD. This will be not sufficient for mono-setup which usually consumes 2-3.5A.Mark I – Right Cell Technology
Even though round cells are are generally known to have larger energy density, putting multiple larger cells in a compact construction and with simple components is not simple. Due to this, I’ve decided to try prismatic cells. The most common capacities of variants in compact sizes are 14Ah, 25Ah. Moreover prismatic cells are available in the LiFePO4 technology which has a few advantages. The battery on the picture above uses four 14Ah LiFePO4 cells.
Mark II – The airlines will let it pass, most probably
By a chance, I found an interesting module which combines a BMS (Battery Management System), charger circuit, a display with all buttons, a 12V DC output. Plus, I found 18650 cell holders which can be stacked and mounted together in a good way. This was a new choice to still get a battery based on 18650 cells which would make it compatible with the rules for transportation of LiPo cells on the planes.
The battery on the picture above provides TBD Ah with 12 18650 cells with 3300 Ah each. In this design, it is actually more than the one based on four 14Ah cells can provide.
Mark III – For ZWO AM5 – a mount which actually does not need a counterweight
I invested in the new ZWO AM5 mount which does not require a counterweight by default, but still does not eliminate the need for a source of power 🙂 With this mount, like with other mounts based on harmonic drive, the a powered counterweight makes even more sense. Since it brings some help in balancing in a compact size. It can also be placed on the mount so that the outgoing power cable is not involved in the rotation and so can’t cause any mess.
The battery on the picture above provides TBD Ah with four 24Ah prismatic cells. This amount of energy would be sufficient to drive dew heaters in addition to a cooled astro-camera.
Mark IV – The power horse for classical counterweight bars
Mark V – Filling the empty space
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