15.11.2021 Inline skate wheels as shutter slides.

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Monday 15th 44F, overcast again.

I have been trying to design roller blade slides for the shutters. A sandwich of wooden strips is an easy way to build the rail. Provided the center strip is wider than the wheels they should be self centering. Without the risk of escaping if the resulting slot is deep enough.

I am loathe to have rails sticking out sideways from the dome. Which rather limits my options. So I am trying to imagine a full extension slide using roller blade wheels. If I had two sets of wheels, one arranged above the other, then one set could support the shutter when it is outboard of the dome. 

This would require the wheels be closely contained in a moving channel. Once the shutter reaches half way the inner shutter rib would drag the moving rail out for the second half. 

Or not. A 2m long track just reaches the edges of the base ring. So there is no real extension to worry about. In fact the rollers would remain safely on the base ring itself if they were brought inboard slightly. A simple vertical scraper on the outside, of the outer shouter rib, could push snow and ice off the track.

The image shows a very rough mock-up from inside the dome. The 2m long aluminium straight edge is only there to suggest a rail. I have just propped up the inline skate wheels against the lower boards. They could be separated slightly more if the slit ribs were slotted to clear them. Just to provide a slight extra margin of stability. 

If the upper slides were replaced with inline skate wheels these would have to be enclosed in a channel. If that were the case then [I imagine] the lower wheels would have no need to be steered by a channel. Though one could be easily be provided if it was necessary. Who knows whether free running wheels would need to be steered to remain parallel with the top slides?

The second image is an other mock-up and shows how the base ring height suits the shutter wheels. An off-cut of 2x4 has been temporarily arranged to act as the track for the photograph. Had I known that I would need a track I could have extended the base ring plywood outwards at that point.

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