Where to put a second pier

[Nathan_Pembs]

Looks the business so far Gina Maybe a cupholder too?

[Demonperformer]

Like it.

Now you've got me thinking ...

[Gina]

Thank you folks

[Demonperformer]

Just been trying to get my head around this shelter.

Apologies if these are stupid questions, but visualising 3D things is not my strong suit.

Presumably the 800mm dimension runs along the axis with the counterweight bar?

Looking at the diagram, if we call the side with the hinges 'the back', would you not also need to make 'the front' hingeable/openable in some way to get it over the rig?

[Gina]

Just been trying to get my head around this shelter.

Apologies if these are stupid questions, but visualising 3D things is not my strong suit.

Presumably the 800mm dimension runs along the axis with the counterweight bar?

Looking at the diagram, if we call the side with the hinges 'the back', would you not also need to make 'the front' hingeable/openable in some way to get it over the rig?

Yes, you really want the actual 3D sketch so that you can look all round it, under it and over it and inside it.

That's tight,m the long axis is along the counterweight bar which will be horizontal in the parked position.

I'm hoping I can design this in more detail so that the front inside of the lid will clear the rig.  I shall need to check the arc the bottom fornt edge describes as the top is opened.  In fact, it does need changing - I can see that now

[Gina]

Here are some more screenshots.  I've changed the decor   And added roof detail.  Bottom left off for clarity also mount and imaging rig.  The last 2 images show the arc described by the bottom edge of the top, firstly with the current design and secondly with the hinge point moved up a bit - hinge shown in red.  Of course, I shann need to change the box to suit.

[Gina]

New design.

And the roof detail

[Gina]

Here's a photo of the widefield rig (less cameras) on the NEQ6 and pillar mount from the same end as the end view of the box above.  This is without weights, as can be seen.  It shows that the imaging rig doesn't stand out as far as the polar scope cap on the mount.

[Demonperformer]

How far down the pillar are you planning on having the base?

Just thinking out loud (and I'm sure you've considered this), and I'm not overly conversant yet of the orientation of the counterweight bar in all possible permutations, but you wouldn't want it to collide with the base if it was pointing as far downwards as it travels (if that makes sense).

[Tinker1947]

The long threaded bolt of the left, i have shorten mine so there's a little bit of thread showing, it will save the weights or the tube from running into it,  once you have the rig/rigs on there adding a extra weight may allow the weight rod to be pushed into the mount therefore shortening the distance they stick out, on my NEQ6 with 4 weights and a C11 the other end the rod is pushed right in, the teldrad position balanced it all...

[Gina]

How far down the pillar are you planning on having the base?

Just thinking out loud (and I'm sure you've considered this), and I'm not overly conversant yet of the orientation of the counterweight bar in all possible permutations, but you wouldn't want it to collide with the base if it was pointing as far downwards as it travels (if that makes sense).

I was thinking of just below the top of the tube but I shall set up an imaging rig indoors, connect up the netbook etc. and see where everything goes.  When I get the time that is

[Gina]

The long threaded bolt of the left, i have shorten mine so there's a little bit of thread showing, it will save the weights or the tube from running into it,  once you have the rig/rigs on there adding a extra weight may allow the weight rod to be pushed into the mount therefore shortening the distance they stick out, on my NEQ6 with 4 weights and a C11 the other end the rod is pushed right in, the teldrad position balanced it all...

That's a good idea - thank you   And yes, I've yet to see how much the weight bar will need to stick out.

[Gina]

I'm beginning to get interested in AP again with some better weather lately   Still far from perfect but we are getting the occasional night with some clear sky for a few hours.  Not sure what DSOs I shall be imaging but with nice weather today I felt the need to get outdoors and look at what jobs I felt like doing.

Having had a look at the repairs and improvements to the property I looked at more interesting stuff and got the pillar mount out and surveyed where I thought of putting it.  Found some hefty concrete blocks that I thought might make a reasonably solid support for widefield use.  Time will tell how well this works but nothing ventured, nothing gained

Here are some photos taken this afternoon showing the location.  It's about 6m from the obsy which I think will give enough clear sky above it - just have to see.

[Tinker1947]

If you use the location the grass bank will be a serious source of broken limbs as the grass will get slippery once some dew lands on it, maybe some shuttering and gravel to keep you on your feet...

[Gina]

I'm intending to build a gravel path to the main obsy anyway and that will pass the pillar.  I think gravel would be preferable to concrete slabs as the latter can get icy and slippery in winter - gravel drains better.

[Tinker1947]

Yes to the gravel, makes a noise when people walk on it, it don't ice up, self cleaning when it rains......anybody approaching my obby has to walk over this lot, it through the gap off to the right a bit....

[Gina]

I guess the gravel path should be given a high priority while the weather is good   We have two vehicles that would be an enormous help in transporting the gravel from the heap in the yard round to the job both of which will need some work to get going.  One is our old tractor and the other the power unit of a ride-on mower.  I'll have to see which I can get going   The ride-on mower would be easier to get out (I think) but either will need lots of stuff moved out of the way.

For the actual mini-obsy I'm looking closely at the design and materials involved.  Rather than softwood uprights I'm thinking of making use of the galvanised iron pipes I bought for the earlier tripod.  Of course, there are only three of these rather than four so I either have to redesign with three uprights of see if I can get another length of pipe.  I think galvanised iron with Hammerite paint on will be much lower maintenance than softwood timber.

[Gina]

The galvanized steel pipe is still available but it isn't cheap as the carriage almost doubles the price.  Link here.

[Astrokev]

Well on track to beating the main obs build thread for number of posts :-)

Tripod on sunken flags; Tarp to cover it; Location - any where in the garden (difference in view will be so marginal as to make little difference).

Project complete.

[Gina]

Yep   Did consider making a mini dome - that should keep me out of mischief for a while

I currently have the NEQ6 on the pillar covered with a heavy duty dustbin bag tied with bailing twine round the pillar.  For operational use though I shall need a 13.8v PSU for the mount and 12v for camera, remote focussing etc. plus netbook or laptop.  I could easily bring the netbook indoors after a session but it would be useful to keep the PSUs etc. in situ.  I'm planning to run mains power from the warm room along the fence in water pipe.  Control will be via WiFi from undoors.

It's a big nuisance that the SW mounts won't run off 12v as I have several ex-PC supplies hanging about.

[Lonestar70]

Hi Gina,

The NEQ6 should run ok on 12volts from a PSU... what gets most folk into trouble is when they run on batteries and the battery voltage drops to less than the SW minimum of 11v.

I have run my HEQ5 using a variable output voltage mains - DC supply and deliberately reduced the output voltage in stages... everything was fine until I got to 11v DC... then all sorts of strange things happened.

Pushed it back up to 12v and it was fine again.

That was just an experiment to see what the mounts tolerance was... I now use a fixed 13.8volt DC mains supply the same as you.

So you should be OK with an ex PC power supply.

Keep Happy... you could certainly do with some luck for a change.

Best Regards.

Sandy.

[Gina]

Hi Sandy

I tested the NEQ6 mount and it needed a minimum of 12.5v.  Had a thought though - there might be an adjustment for O/P voltage inside.

[Gina]

I've had the lid off one 235W PC PSU and had a very good look over the circuit board and can't see any adjustment   Pity   I still have others to look at though.

[Gina]

One idea for a power supply would be one of my jump starters (if I can find a charger otherwise I'll have to make one up).  OTOH a sealed lead acid battery such as they contain and home made charger would be much smaller and neater.  I have several variable output switch mode 12/24v regulator modules (from China) so could make up an efficient power supply and distribution unit.

Next question is how big would the biggest imaging rig want to be.  I'm just debating with myself whether I might want to use the Esprit 80ED on it while I'm using the MN190 in the main obsy.  I think it's unlikely really.  In any case I guess I could take that off after a session.  I'm thinking more in terms of widefield imaging for this second setup so that I don't need as great stability from the mount/pillar. 

Use of Esprit with my ultimate modded DSLR with built in FW and OAG is a possibility I have considered but although the DSLR will give a pretty wide FOV with the Esprit, the pixel size is still quite small so it would need a good stable mounting.  No, I think I would try that out on the EQ8 on the ultra solid concrete pier   So DSLR with lens seems the setup I will be using and unless I get round to debayering more DSLRs, it will be a single barrel imaging system.

So it would seem to come down to the ultimate modded DSLR with lens, the biggest I have being 300mm FL but more often I'd use a wider aperture shorter FL lens.  So the cover would only need to cater for that and the power unit.  Maybe just a large plastic bucket   Then add something to hold the netbook.  A fold down shelf or bracket - or just a portable table, but I think a box to house the netbook while imaging, to keep the dew off, would be a good idea.

I think my ideas on this are beginning to come together

[Gina]

With the new widefield triple imaging rig build now in full swing, I'm thinking again about the no. 2 pier and mini obsy (or removable box).  I have decided that the no.2 pier will be exclusively for this widefield rig and telescopes will be deployed in my main observatory.

With the longest FL lenses of 200mm and 3 460EX cameras plus guide scope with lens and electronics, I estimate the weight will be around 4.5 - 5KG.  Overall I think the longest dimension with the mount parked should be just under 30" or 750mm.

I think I could do with sorting out the covering/box/whatever pretty soon, while we have this nice weather.  I think the SW pillar mount sitting on three concrete blocks is pretty stable and should suffice for widefield using the NEQ6 mount.  What I'm not sure about is the box to contain the kit and protect it from the weather.  We are in a very exposed position.  It would be nice to have a box base fastened to the pillar just under the NEQ6 but I think rather better anchoring to mother earth will be required.

I'm thinking in view of the above that posts driven a good way into the ground is probably the best solution.  I have three galvanised steel tubes that I might use but OTOH it would be easier with four posts and a rectangular structure.  I used the only hardwood posts I had for the main obsy.  This is going to need a lot more thinking about   If I had a huge 3D printer I could print a nice dome - but I haven't.  Even the large experimental one will be limited to around 350mm.  In any case, I want it THIS year