Dome build: New clamps and wheels.

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Monday am. I had ordered 18 new Rawlink 15cm/ 6" spring/glue clamps despite having badmouthed my original Rawlink clamps. Now I am delighted to report that the new Rawlink clamps are a vast improvement! They have the same shaped handles but now have nicely grippy, rubbery pads. Making them very easy to use. They also seem just as powerful but with slightly shorter jaws for better leverage when opening them.

I think the spring wire is slightly smaller diameter so it may be improved steel for greater lightness. The previously loose jaws are now properly pinned so they can't fall out like the originals. Making them excellent value compared to the pricey and much weaker Bessey clamps.

Having opened my parcel of clamps I painted the new, 2x8, wheel support ring with the Safeway, mineral/water wood treatment. I have been delighted with the very even, silvery-grey appearance of the treated timber. The bare larch floor boarding has weathered to a very similar appearance. It may not be to everybody's taste but I like the "abandoned barn" finish.

I finally ordered 8 off 160x50mm nylon wheels today in pressed steel forks to support and rotate the dome. Each, individual wheel has a capacity of 350kg.  That's 770lbs! Which would easily carry the full weight of the dome all by itself. Each wheel has ball needle roller bearings for easy movement. The hard wheels should avoid flats forming if the dome isn't turned regularly.

I liked the slightly increased height of the fork to provide a marginally taller dome. At nearly 6.5" diameter I imagined these wheels would roll more easily over inconsistencies in the track than my earlier choice of 5". My eye level, when standing on the observatory floor, would then be just above the intended base ring height.  So a horizontal view of the distant woods is still possible without needing a ladder to reach the eyepiece. 

Shopping around online provided considerable savings. The most heavily advertised Danish dealers on Google are wholesale only. However, they do not make it remotely OBVIOUS that they will not deal with private customers! I wasted considerable time on their websites picking and choosing! As it was, I found better wheels with higher load capacity for about the same money from a much more friendly dealer. They should be with me on Wednesday.

Click on any image for an enlargement.

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