Deep Sky West (Midlands)

[tomato]

52 minutes ago, Davey-T said:

If it was me I'd shorten those spindly bolts and probably add a couple more.

Dave

Looking at the photos on the net I think older?newer? Altair piers came with 4 rods not 3. I take your point it looks a tad spindly in the photos but in the flesh it is pretty darn rigid, better than when the rig was on a portable steel pier. However, that was with one 150 on there, it might be a bit different when there is two up.

[Tomatobro]

We did a lot of work to improve the damping of the pier and its not bad as is with three M16 stainless studs but it will be monitored.

So is it the journey or the destination that gives the most pleasure, for me its been both🙃

Edited October 21, 2019 by Tomatobro
correction

[Tomatobro]

I have been asked what are those red and black connectors. They are Anderson 30 amp. The internal connecting fingers can be replaced when worn.

The red/black plastic half's have dovetails so can be locked together and the when the centre screw is fitted they are locked. The fingers will take 12 swg cable at a pinch but are better with 14 swg. Fingers can be crimped or soldered.

[tomato]

Some further additions, first a Steampunk inspired drain pipe for the dehumidifier, second, a set of 4 LED lights for standard illumination inside the dome, and thirdly an intercom so the telescope  technician  can talk to the imager in the warm room. This may seem a bit OTT, but better than shouting to each other at 2 a.m. which could be considered a bit anti-social. @Tomatobro picked this up (new) for £5 on eBay.

[Laurin Dave]

All looks very neat, especially the plumbing !  and just noticed the drainage channel, very clever.. Angle grinder?

Edited November 2, 2019 by Laurin Dave

[JamesF]

26 minutes ago, tomato said:

thirdly an intercom so the telescope  technician  can talk to the imager in the warm room. This may seem a bit OTT, but better than shouting to each other at 2 a.m. which could be considered a bit anti-social.

Having already established a bit of a steampunk theme, I'm slightly disappointed that you didn't go for a "speaking tube"

James

[tomato]

56 minutes ago, JamesF said:

Having already established a bit of a steampunk theme, I'm slightly disappointed that you didn't go for a "speaking tube"

James

Unfortunately there is not enough room left in the conduit.😊

[Rusted]

Slight worry if your dehumidifier drain freezes solid.

Foam pipe lagging? A bit naff? 

Is the drainage warm or cold?

I imagine cold as it is condensate.

[PhotoGav]

And it will freeze... my dehumidifier drainage tube is not nearly as beautiful as yours, it’s just a bit of clear flexible plastic, does the job though! When it gets a frozen lump in its end, I just pour a bit of warm/hot kettle water over it, problem solved and free flowing drainage again. Wouldn’t be much use if it wasn’t in my garden though...

[tomato]

5 hours ago, Laurin Dave said:

All looks very neat, especially the plumbing !  and just noticed the drainage channel, very clever.. Angle grinder?

Yes, just a steady hand with a small angle grinder, it does eliminate some of the standing water on the plinth.

I thought the drain could freeze up in cold conditions, lagging might work, we will have to see how it goes over the next few months.

[GCG-Observatory]

On 21/10/2019 at 17:12, tomato said:

Finally getting on to the good bit...

The refurbished Altair pier (purchased second handwith the dome) is now bolted into place, @Tomatobro machined up the Mesu adapter plate and sorted the 12V power distribution. 

Initial altitude adjustment completed with an inclinometer, a guidescope and camera attached directly to the main saddle will be used to carry out accurate polar alignment.

A single Esprit  will be on the mount for now, I will get back on the imaging saddle with this one before attempting set up of the dual rig. The dome drive will be high on the to do list however, at the moment I will have to set a reminder timer to go in there and nudge it round about every 40 minutes.😊

How are you getting on with the Altair Astro pier? Considering getting one of these for my upcoming dome project.

[tomato]

So far so good. The top plate is only supported by 3 threaded bars and not 4 as I have seen on other versions, but no flexing or vibration has been detected on the (very) limited imaging done to date.

Rather than bolt the base directly to the uneven concrete floor, 8 substantial steel spacers were machined up and put under the base flange, this also brought the pier flange flush with the false floor, which looks better.

Just starting installation of the rack and pinion drive for the dome.

[GCG-Observatory]

So you decided to not go with the Pulsar drive system? Is your rack and pinion an off the shelf product or is this something you have built?

[tomato]

It’s an older Pulsar dome which is not compatible with the Pulsar drive system, and I have to say I’m not overly compatible with their £1300 asking price. Myself and @Tomatobro will supply details as it comes together, but the steel rack was sourced from China in straight sections which have been bent to suit the curvature of the dome. They are mounted on fabricated adjustable angle brackets which pick up off the bolts holding the steel hoop which the dome section runs on.

This does mean the motor will be mounted off the moving dome so will need an independent power supply with sufficient capacity to last a full imaging session (about 30 mins in the UK?😊)

[JamesF]

3 minutes ago, tomato said:

the steel rack was sourced from China in straight sections

I might have a use for that sort of thing myself.  Come the time I may be badgering you for more details :D

James

[Nigella Bryant]

20 minutes ago, JamesF said:

I might have a use for that sort of thing myself.  Come the time I may be badgering you for more details

James

Me too as I've an older pulsar dome that I'm working on after a house and dome move, lol. Be really interested in the supplier and all bits that's needed. Brilliant build and thanks for sharing. 

[Nigella Bryant]

On 16/10/2019 at 17:48, tomato said:

Time for an update. As posted previously, Mrs Tomato didn’t like the white dome so it is now resplendent in British Racing Green. The weather has played havoc with the finish on the dome, how do outside painters make a living in the UK with the current weather? I only had this one job, could get on with it virtually any day of the week, and it still took nearly two weeks, dodging in between the rainy days. Anyway, it’s painted, and Mrs Tomato likes the colour, so it will stay like this until next summer, the ancient photons don’t care about the finish on the dome.

Mains power from the warm room is all in, but this will only be used for maintenance, all the imaging gear will be 12V supplied from the warm room.

And finally, we have now layed the interlocking rubber floor purchased from the Aldi centre aisle back in May What a nice psychological satisfying job that is, much better than painting.

I'll be painting mine green too, what paint did you use? 

[tomato]

Here are the details of the paint supplier, it was the fibreglass grey undercoat and British Racing Green topcoat. Make sure you apply the topcoat in a dry spell, rain or condensation will ruin the gloss finish.

https:/supplyshed.biz

Hopefully @Tomatobro has some details on where he sourced the rack rails from, but it was a while ago.

Edited November 26, 2019 by tomato

[Nigella Bryant]

11 minutes ago, tomato said:

Here are the details of the paint supplier, it was the fibreglass grey undercoat and British Racing Green topcoat. Make sure you apply the topcoat in a dry spell, rain or condensation will ruin the gloss finish.

https://www.supplyshed.biz

Hopefully @Tomatobro has some details on where he sourced the rack rails from, but it was a while ago.

Many thanks 

[Rusted]

You had more luck with the paint than I did!

My sage green top coat is already flaking off the white undercoat and looks a sight!

Only complete rural isolation allows me to hide the shame. 

[steppenwolf]

On 02/11/2019 at 22:44, tomato said:

I thought the drain could freeze up in cold conditions, lagging might work, we will have to see how it goes over the next few months.

Stick a dew heater on it!! 🤣

[tomato]

Further progress made over the festive season, the circular rack made up of 6 lengths joined together, has been installed using adjustable brackets so that it can be made reasonably level and circular so that the drive motor does not have to be spring loaded. The rack sections were purchased from Poland as a one off on eBay, but I have had a quick look on the net, a lot of powered gate fabricators can supply something very similar, around £22 for a metre length.

The motor and drive gear is almost complete, a rotary encoder has been fitted, to enable precise positioning of the dome aperture, this will be needed when two 150mm refractors are in there. Today we connected a temporary power supply and drove the dome around under it’s own power.👍

Today, I took the scope off the mount, to size up the saddle and plates for the dual rig...😊

[tomato]

Here is a well overdue update:

Dome rack and pinion drive installed and operational.

As the control system is a bespoke unit, it was decided to go with an empirical engineered approach to the automation of the dome. 
To that end, 3 low power lasers have been set up at the aperture limits with corresponding detectors to detect the point at which the dual scopes are approaching the edge of the aperture. This is not wholly straightforward of course due to the relationship between the azimuth rotation of the dome and the tracking of the equatorial mount. Extended dual shields (cardboard mock ups in the photo) are needed to ensure reliable operation, and a switchable third laser is required for certain orientations of the scope. A 10 sec delay has been built into the control program to allow for transient events interrupting the beam (eg moths, bats, me).

There are a few more embellishments to come but it was working in auto tonight, as shown by the notepad (running Windows 95!) monitor.

Still working on the shutter open/close drive which has proved to be quite a challenge, but that’s another story. 
 

Dome drive motor

Drive Control Panel and Power Monitor

 

Extended dewshield and laser impinging on the side of the scope

 

Laser detectors mounted at base of aperture

 

Lasers mounted at the top of the aperture

 

Control Monitor

Edited February 5, 2020 by tomato

[Rusted]

Whoah! Reverse Engineered Alien Technology alert!  👃🏻

 

 

 

 

 

I am unworthy! 🐵🦴

[Tomatobro]

And no 1202 alarms........