Monday, 20 February 2017

Revolution!

Welford Observatory was built in 2007 and since then I've been struggling with the rotation of the roof.

The idea was that the roof would sit on two wooden discs, kindly manufactured for me by a friend. It was thought that the disc would wear smooth over time making rotating the roof easier. 



Cutting out the discs - 2007

You can see more on the original construction here

I used torch felt to seal the roof and although it was a good choice for durability, it proved to be extremely heavy, making the roof very hard to rotate.

So as I'm getting older and I could see my back or some muscle was going to give out under the strain something had to be done.

The answer was obviously to put it on wheels. The problem I had with doing that was the accuracy required in getting all the wheels tracking perfectly, how to keep the roof in place while on wheels and the weight that would be on them, they'd have to be heavy duty - yet small enough that the roof didn't sit too high above the walls.

We've had a lot of building work done by Neil Cheshire of Grove, Oxfordshire to include two large wooden garden decks and new fencing (contact him at cheshbury at yahoo.com for any building work quotes - highly recommended) . 

Neil's work is always exceptionally well finished so I figured he'd be just the guy to look at the roof issue and hopefully come up with a solution.

Thankfully he did! And it's worked out perfectly.

Neil suggested we put 8 wheels (one on each wall of the observatory) by mounting them not on top of the lower ring...but through it. To do this we had to somehow lift the roof out of the way to drill through the lower ring. As I was explaining to Neil how heavy the roof was and how I thought me might try a number of methods to lift it out of the way.....he casually got underneath it, lifted the whole thing up and asked me to put the wooden block in! LOL! These things are always so much easier when you're working with someone that can lift a house! 


Roof lifted out of the way for drilling to begin


It doesn't look that heavy but it weighs a ton! ish...lol

The next thing that prevented me from attempting this myself was the accuracy required in placing the wheels in a perfect circle around the observatory - if one wheel was tracking out of alignment it wouldn't rotate easily. Again, Neil had a plan and carefully marked out the location for each hole and began drilling.





Absolutely perfect fit

The wheels Neil used are very high quality with bearings and hardened rubber face. With eight of the them taking the weight of the roof it gives a really smooth rotation as opposed to nylon wheels that would've eventually dug into and mangled the ply.

Once the wheels were done I had to lengthen the guide wheels (I got them off a skateboard years ago and they've been working really well) to cover the distance created by the new wheels. Luckily I hung on to the extra bolt I had left over when I put the guide wheels on originally - normally I throw stuff like that away!lol



New longer guide wheels in place

Once all the guide wheels were in place we spun the roof to test it.

I could not believe how easy it rolled!

I only had to push it with two fingers and it started moving. LOL! 

After 10 years of having to brace myself against the wall, start pushing and then track with the roof as it slid along in order to keep the power aligned to the movement of the roof - this was nothing short of a revolution! :-) ....so cool.

Neil had to go to another job so after he left I spent the next 10 minutes spinning the roof around :-)

When I was done I turned my attention to the finals.

As you can see there was a new gap created by the wheels - I decided to cover that - but couldn't think of what to use so I went to the DIY store and rummaged around looking for some flexible, thin wood I might use - and then I saw this!



That's right, carpet strips! Perfect :-) 

All I had to do was drill some holes along the upper edge to fix them on the upper disc of the roof. The bottom edge of the strip barely contacts the lower roof disc so there's no binding.

And it looks kinda snazzy too har har! 




I have plans to cover the gap inside as well but more on that later....

A big thanks to Neil Cheshire for his ideas and work today - thanks to him I might have many more years of my hobby as I won't be breaking my back any time soon ...pushing the roof :-)

WOBSASTRO 2017