Gina

Arrived in th post this morning - a couple of M8 x 200mm coach bolts to hold a bracket for my observatory roof automation. Well, one for that use the other for stock (2 was minimum order).

Been out and put the guttering back up with outlet at south end. Think that will be all I do today for fear of overdoing it. Forgot to take a spirit level out with me - maybe do that tomorrow or another day.

Very nice

Here is a screenshot of the CAD design for the bracket to attach the chain to the east end of the roof (open end). The circular groove takes the chain which will emerge from the LHS of the groove, down and across to the right giving clearance for the large pulley when the roof is open. A bolt in the vertical hole will hold the chain from pulling out. A 200mm M8 coach bolt through the roof frame and the hole in this bracket will secure it to the framework, with a nut and penny washer to hold both bracket and chain in the groove. The RHS of the bracket is secured to another member of the roof framework to add strength and prevent the bracket turning. This is probably over-engineering but that is me!

I use those too.

I have one coffee a day around mid-morning. Otherwise it's tea all the way. Except for water with my porridge and orange squash with evening meal.

Been out to observatory. Opened east drop down window, rolled roof back a bit and the forward hitting the end with some force which shook half the water out of the gutter. Opened the roof fully, undid the downpipe end and unclipped the guttering far enough back to be able to get it free and lowered guttering and downpipe to empty the guttering. After that was able to free most of the guttering, unscrew some brackets and get the rest down. Closed up the roof and came back indoors. At least the rainwater runoff will now be spread out. Now having a coffee break.

I wanted to post about that somewhere - this is where it landed 😄

FLOods 🤣

With the rain stopped I donned my Wellies and went out to the observatory intent on taking some photos of where certain roof parts might go but I was thwarted by a flat camera battery! It was a worthwhile trip though as I discovered a problem with the ROR guttering. Luckily, I noticed some drips from the guttering at the stop end having opened the drop down window. So I reached up and felt in the guttering - water at the supposed high end - gutter full. Felt at the downpipe end - no water. Felt along the guttering and the water didn't reach much further than half-way!! This is in spite of the downpipe end being seemingly lower on the roof end beam. So something has changed since I built the observatory. I can't believe the woodwork could have shrunk or expanded by that much so the foundations on the south side must have subsided. Guess the floor is no longer level. I'll take a spirit level out tomorrow and check - not going out again tonight (still need to take it easy). This is the roof and guttering after the roof repairs and before the downpipe was added. This would seem to show that guttering slopes considerably to the right (north). Compared with the roof, it does. Compared with the wide world, it doesn't - the left-hand end is actually a couple of inches lower. The only way to deal with the problem will be to turn the guttering round and have the downpipe on the right (south). It will need a fine day to do this but the sooner the better as raianwater is running out of the guttering at the south end and onto the observatory structure.

Seems unlikely that there will be any progress on astro imaging for a few weeks but who knows...

I've composed a Blog on my observatory roof automation so will be posting further progress there. This thread will return to imaging. Observatory Roll-Off-Roof Automation

Blog here Observatory Roll-Off-Roof Automation

The NW corner is done and the same as above but I haven't got a photo yet. The east corners will have gate hanging hinges use as peg and loop - at right angles to normal orientation. This shows the idea.

My original objective was to make the roof remote controlled and storm-safe when closed remotely but it may not be necessary to go that far as it adds a lot of work. However, I might go a lot of the way towards this and provide anti-lift locking pins at each corner. The drive motor may be strong enough to prevent the roof being blown open. Apart from the roll-off-roof itself there's the opening east end window to consider. I have various ideas for this. However, the main reason for motorised roof closing is from detection of unexpected rain for which I have a rain sensor. With the prevailing wind direction being SW most rain comes from that direction and just closing the roof would be a bit step forward.

These pictures show the previous running track which has since been replaced by heavy duty galvanised iron sliding gate track from FH Brundell.

The large pulley was attached to the partition wall frame of the observatory with a long bolt and covered by a 3D printed cover to keep the wet off as part of it would be outside the protection of the observatory wall.

As the diagrams show, apart from the motor unit, chain and brackets to attach the chain ends to the roof, two sprockets or pulleys are needed - a small one and a large one. I had some black ABS circular blanks some 150mm diameter x 22mm thick and decided to machine one of these in my lathe to make the large pulley. The smaller one I 3D printed.

The roof will be pulled open and closed using bicycle chain and a garage door opener. Since it is essential to be able to close the roof manually if the motor drive should fail, I needed a way to disengage the drive from the roof. The easiest solution to this was a motor unit with a clutch whereby the chain could be free to be pulled through with little resistance. These were seemingly unavailable in the UK or extremely expensive but the late Per Frejval offered to get me one and send to me from Sweden. (Oh how we miss dear Per!!) Being able to feed the chain through the motor unit without having to run the motor would also be a great help in setting up. This quote form earlier shows the rear of the motor unit where the chain runs (top groove). The clutch mechanism can be seen - a simple dog clutch, which when disengaged leaves the sprocket free to rotate. Testing showed that it was easy to pull the chain through or indeed to push it through initially.

I'll start with some photos of the observatory taken a few years ago. From the north looking roughly south and then from the south at various angles.

This Blog will describe adding motor drive to my roll-off-roof and the electronics to control it.

Wet today so nothing doing outdoors but design is always possible if I feel like it.