Pier-time!

[vineyard]

Hello,

Hope all safe & well. So it looks like a pier is a go. No room for ROR, so it will have to be open-air.  I'll share the journey on this thread, and start with Qs.

The current mount is an HEQ5Pro, but perhaps eventually that might be upgraded to something beefier (but not by much).  The kit that would be on it would typically be a 4" frac, but perhaps in the future that may go up to 6-8".  I use a Pegasus UPB which connects onwards to the mount, the cameras, dewstraps, and backwards to the laptop.

1.  The concrete base.  I'm thinking a square of 90cm by 90cm, but how deep would it need to be?  I think I remember reading a SGL thread that as shallow as 6" (so long as that is below the frost line) can be sufficient?  Would that be cutting it too fine?

2.  Aesthetics will be important (as part of the successful negotiation ).  Right now, I'm leaning towards a Pulsar (Todmorden is a no-go unfortunately).  I suspect I will need to put a pier extension on top of that, with the mount on top of that.

3.  There'll be 12V electricity running to about 60 cm away (all-weather plug points).  Ideally I'd like to run a data cable in to the same all-weather power board, and from there into the house, so that I don't need to use wifi.  But what is the longest that a data-cable can run?  (I'm a bit confused about powered vs unpowered data cables).  And for the data cable jack that enters the house: is it like an old-fashioned  telephone point that I can then just run a USB cable to my laptop?  Or would it better to use Powerline adapters to connect the data from the pier-side to laptop-side?

4.  For all weather protection, it'll probably be an inverted old laundry bin (thin wood), with a Telegizmo 365 cover over the top of that.  Insulate the inside of the laundry bin.  Leave the bottom of the cover open enough to let it ventilate.

I'm sure I'm missing things in this cunning plan?

Cheers & stay safe,

Vin

[Neil H]

Hi mate it sounds brillant 👍

[Stargazer33]

For the data cables use Cat 6 LAN cables not USB. The kind of cables that connect computers in an office etc. 

[pete_l]

On 06/12/2020 at 19:13, vineyard said:

 There'll be 12V electricity running to about 60 cm away ... Or would it better to use Powerline adapters

I haven't ever seen a powerline adapter that works with 12 Volts. All the ones I use plug into 230V mains.

And on that point, personally I'd run a higher voltage (e.g.24V) to the power board and then step it down to 13.8V to power the mount. That way you avoid voltage drops due to the distance, which can lead to unreliable operation.

[vineyard]

Thanks both @Stargazer33 & @pete_l v helpful.  I also spoke w Pulsar about base depth, and they recommended 60cm depth, so that's what I'll go with.  Cheers all.

[vineyard]

So a short update on connectivity for the data.  Managed to test something & I think it should work.  Basically, a Powerline into mains electricity, and then a Stellarmate RPi3 connected to the Powerline with an ethernet cable.  With cameras, mount etc connected to the Pi via USB.  The other end of the Powerline is connected to the wifi router inside the house.  Tested it, and I could use my laptop to connect to the Pi, and use the EKOS on my laptop!

This link was very helpful.

So with this setup, I can either VNC into the RPi ("stellarmate.local:6080" in the browser) or use the RPi as the server ("stellar mate.local:8624" or "stellar mate.local:8624/#" in the browser).  I think the 2nd option is better b/c it allows the laptop's faster processing, SSD etc to be used rather than relying on the little Pi to do it all.

I think the EKOS on the RPi has to be switched off (in case it comes on automatically when the Pi is plugged in) but that can easily be done by VNC, and then switch to the server mode.

If this is a stable setup, then that's brilliant.  No need to run ethernet cables from the pier into the house, nor any need to rely on wifi.

Just need to get the pier sourced & installed now? 😂

[vineyard]

So an update.  The Powerline based route above seems to work & be nice & stable.  The connectivity goes when the washing machine is running (!) so I will probably put an ethernet cable down anyway.

I'm wondering whether a Pegasus UPB could be connected via USB to ethernet directly to the router (and so whether I could just 'see' it as a remote USB device directly from my laptop), or whether the RPi3 would still be needed as a remote server.  Easily experimented with.

The pier has been bought - 2nd hand via UKABS - photo attached.  V solid - used to carry a Meade LX200 (I think) w wedge etc for the previous owner.  So should be fine for my purposes (& allow for some growth).  Still has to be put into the concrete base but that's for later in June hopefully.  Not sure yet whether to have the pier "lip" (see photo) pointing to the N or the to S - any thoughts from more experienced folks pls?

The clear skies are all on the Zenith, E, SE, S & W.  N is straight into a wall of houses, so most of the time the scope will not be pointing in that direction.  Will probably use a pier extension on top of the pier plate anyway to just get a bit more elevation & angles.  But I reckon w the pier adapter & HEQ5Pro, even without the extension the counterweight arm would not hit the lip (if the lip is to the N).  With the pier extension its moot I guess.

Another Q pls for more experienced folks.  I currently put a Telegizmo dobsonian cover over the mount.  Eventually I will probably use a bag or a tub of cat litter as a desiccant under the hood?  Or would it be better to use a cat-mat heater (as I think I read Olly recommend somewhere once).  These last days during the daytime the temperature under the cover has gotten to about 27C - is that too hot (I guess it would encourage humidity if no dessicant)?

Looking forward to having it up & running - it makes such a difference not having to schlep things.  Once its polar aligned it'll be aligned  I can't leave the scope out 24/7 so will have to re-balance each time.  I did think whether that would throw off the alignment if I didn't put the scope back in precisely the same home position to the fraction of a degree, but then realised I was being silly and the rotational axis of the mount doesn't change!

Long post so will stop now!

Cheers.

[jacko61]

My thoughts on the Pier 'lip' would be to have it on the North side otherwise it will obstruct your polar finder (if you have one).  On the other hand, it might obstruct your balance weights if it's on the north.  Can it be cut off?  I have the altair astro pier that has a circular cut out to allow use of the polar finder 'tho I'm now using an ioptron ipolar.  

Depending how tall you are you may need a pier extension otherwise it can be pretty uncomfortable bending over to see things at the zenith - again this might not apply as the previous posts suggest you're going to be sitting in the comfort of your living room.

Graeme  

[ollypenrice]

We have four square topped piers in one of the robotic sheds and they can snag cables. The fix is easy: attach strips of metal pointing downwards and, if you like, reaching in to the column. These simply stop the cables hooking under the corners of the top. For anyone designing a new pier, though, I would advise against square tops in the first place, or certainly ones which overhang the column.

Olly

[vineyard]

@jacko61 its far too solid for me to be able to cut off - I don't think it'll ever leave this garden! 😂 But yes I'm 99.99% going to use a pier extension to get clearance with fences so that means the lip overhang should be much less of an issue (& yes should hopefully make polar alignment easier).

@ollypenrice that's a v neat fix, thank you.  Hopefully I'll be able to avoid the snagging risk b/c of the pier extension & by having most of the wires connected to an on-scope UPB (or a Pi attached to the pier extension cylinder above the rectangular top) so that only 1 power cable & 1 ethernet cable need to be routed any lower 🤞🏾 - let's see.

The concrete is in & curing (or whatever the right term is).  Just need to get the pier adapter sorted soon, & then hopefully pier gets bolted in sometime in next fortnight, & then get to discovering what quirks the setup brings (there's always quirks?).

Cheers both & stay safe.

[vineyard]

The pier is in!  Next step would be to eventually get an ethernet point close by, but for the time being powerline over an extension lead will have to suffice.  It feels pretty solid.  Just need some clear skies to PA & then - hopefully - it will be ready for quick setup imaging!

In case you're wondering what that black patch bungie'd at the bottom of the pier extension is, its a reptile heat mat (a trick I read @ollypenricerecommend on a post somewhere) to deter dewing under the hood when its covered.  I want to try connecting it to something like this solar-powered rainproof powerbank to see if a trickle charge would allow it to keep the heater running for a decent chunk of time.

Because the pier was bought 2nd hand, the fiddliest bit was attaching the pier adapter to the base (there were some bolts weren't quite straight & must've been rusted in so getting them out was very time-consuming).

Cheers all.