In the previous post I explained my mains power EAA set up where all the power ‘bricks’ fit neatly into a portable water-proof socket box that clips to the tripod legs.
It has been nothing but clouds here for many weeks, so I have used the time to make progress with my ambition of also having a wireless, similarly cable tidy, yet compact, battery powered EAA system for use with a large sensor/many pixel camera. As before, this alternative links up wirelessly to a laptop in my (warm) office using TeamViewer.
Key to achieving this goal was the construction of a simple ‘open box’ cradle comprising two sheets of 3mm ‘hobby’ aluminium plate (painted black) and a VESA plate with all parts being assembled using M4 bolts and spacers/washers and Zacfton cable ties. The cost of the parts was under £10.
The Intel NUC is bolted to its regular VESA plate as normal and the 12v battery is affixed to the upper aluminium plate by Zacfton cable ties that are bolted to the plate. Drilling holes in the aluminimum plates isn't difficult. These two (front) plates are then affixed to the back aluminium plate by suitably long bolts + spacers. The 19v battery powering my NUC simply slots between the plates whilst resting on the hexagonal spacers (n.b. choose spacers to create the right sized gap depending on the size of your battery). Then the entire assembly is then affixed to Evolution mount by two Zacfton cables ties bolted to the back plate (I love these cable ties, so much better than sticky Velcro). If you have a single battery set up you obviously won’t need the upper plate. But I have ended up with two batteries of different voltage (long story!) so this was a bit more challenging.
The joy of this particular assembly is that it is very compact and everything rotates with the mount, so no risk of cord warp. Zacfton cable ties (other makes are available!) are basically strong cloth straps. This assembly is easy to build, incredibly secure yet it is lightweight and doesn’t affect the balance of the scope if you need to carry it fully assembled to its location (as I do from my office/garage). I suppose this comment is relative to the owner’s strength, but compared to the Evolution with a 15lb wedge this is easy to carry.
From this simple cradle assembly run just TWO long cables that will also rotate with the mount, so no risk of cord wrap. The first is the USB cable from NUC to camera which might be front (Hyperstar) or rear mounted. The cable is just a simple loop. The second cable runs from the 12v battery to a four socket cigarette splitter. Note that the only other cable directly related to the cradle assembly is the very short one from battery to adjacent NUC. To keep with the tidy cable theme, I use a very short StarSense camera cable (an AVX part) to AUX1 and a cable splitter from AUX2 to extend my HC cable whilst accommodating my SkyPortal external WiFi accessory (my internal WiFi is awful), overall cable management is really neat because of the next step...
Here, I have affixed the four socket cigarette lighter to the OTA using a long Zacfton cable tie. As it is positioned between the StarSense camera and RACI Finder it is over the OTA centre of gravity and hence has no impact on balance. The joy here is that whether your camera is forward positioned (Hyperstar) or rear mounted the power cable (not shown) from splitter to the device can simply run along the OTA, so it is very easy to keep tidy (yes, you guessed it) with Zacfton cable ties. Similarly any cable from splitter to powered Microfocuser, auto-guider or whatever else you want to add runs along the OTA and when not in use, you just disconnect (no need to remove if you keep your scope fully assembled). Even if you must break up your scope for storage after use it is simple a case of undoing three Zacfton straps to remove the two components (e.g. battery cradle and cigarette lighter splitter).
I think this arrangement is about as cable tidy as possible given it has only two long trailing cables (and even they rotate with the mount) and of course, from here it is then totally wireless to my laptop in my warm office via TeamViewer. I hope this approach to the challenge might help others. The cradle assembly took far longer to design than to build, but isn't too challenging once you realise that clamping both bits of metal together (e.g. front and back plates) and drilling through them simultaneously is the way to line up their holes accurately for the assembly of the Hexagonal (screw through) spacers. Similarly, when calculating the (spacer) gap required for the principle battery to go between plates make sure you allow for the screw heads that attach the straps that go around the mount (their fixings need to be no wider than the mount to ensure that the assembly doesnt wobble). The sharp eyed will notice I didn't, but four extra washers resolved the spacer problem.
I have added another minor refinement that I think is worthwhile;
Rather than have the battery rubbing against the bolt heads with a risk of it getting scratched I have added a number of small circular self adhesive rubber bits to the inside of the cradle to protect it. I don't know what they are called, but they are normally put on the inside of kitchen cupboard doors and drawers to stop them banging when overly aggressively shut. This image also provides a better idea of the assembly. Note how I had to add additional washers as I didn't allow enough clearance for the bolt heads!
Edited by Noah4x4, 17 January 2018 - 10:08 AM.