16.11.2021 Skate wheel shutter slides.

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Tuesday16th 41F, leaden overcast again.

Yesterday, while I was trying to raise the shutters one of the upper drawer slides began to lose its fixing screws. They were quite literally tearing out of the plywood shutter board. It is obvious that I need a much more robust, replacement roller system. 

The image shows that the vertical and horizontal spacing of the shutter slides. This large spacing has no effect on the loads on each slide. Each must bear half  the total weight of each shutter.

My first priority is obtaining a sturdy, preferably aluminium channel at least 2m long. Which must have an internal width of at least 25mm internally to match the skate wheels. 30x30m channel profile would be best if available in sufficient thickness. Two lengths would be even better. I can use doubled angle profiles bolted together, if I am desperate, but channel would be stiffer and neater.

The nearest scrap yard is open today. I may try my luck there. The DIY stores usually only hold very thin, decorative profiles. Timber can be used but won't have the "fit and forget" qualities of aluminium. Nor will timber offer the narrow sections of aluminium. The scrap yard had no aluminium of interest.

I don't believe it! There is another scrap yard in a quiet country lane which is rarely open. He has a stack of clean, aluminium U-profile in very long lengths! Absolutely perfect for my needs. 

Now I have to keep going back in the hope of catching him. Well, I took a chance and drove around there again after lunch. And there he was, pottering about. Talk about sheer luck! I bought 6m of 35x35x3mm channel and some clean alu. 30mm & 35mm Ø tube for the 10" f/8 Newtonian for a very reasonable price. Then sawed it into 2m manageable lengths, on the side of the road, to go in the car.

The wall height of the channel, U-profile, rubs slightly on the 8mm axle diameter. Though, despite this, the wheels happily rocket down the channel on an incline. I may have to sand the walls down slightly with a coarse disk in the angle grinder. 

Or fit something in the channel bed. To lift the wheels enough for axle clearance. Plastic strip would do and might reduce the risk of ice forming in the channel bed in winter. It is possible that I can find some typically thin, plastic channel which just fits nicely.

I tried a length of channel on top of the dome but it was too dark for photography. By a happy coincidence the ends of the rail could be reinforced from the dome segment seam just below.

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