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Hi Chris,A wonderful last shot to conclude the process. Absolutely brilliant work.John
So Chris, firstly.. this is a 'lifting' pulley as it lifts the bucket arm, as distinct from the 'luffing' pulley [orientated in the horizontal plane] for raising or lowering [luffing] the jib beam?, is my assumption correct?.... it does make a difference in understanding Is this pulley [wheel] free to rotate in the outer sheave plates, or does the chain simply slide through the channel recess as machined in the centre of the pulley?Where I am coming from, is with the actual pulley sheave block would have been subject to wear, dust and a high level of friction between the chain links & the wheel and hence create a series of flats on the major diameter of the wheel?....if this happened, the friction between the chain & the wheel would tend to rotate the wheelAlso somewhere down the track, you will need to manufacture the luffing pulley.....will it be of a similar design with the luffing jib chain sliding around the when channel recess?Or a final question , is the luffing of the jib by wire or chain?Derek
Wow. Seems like yesterday you were turtlle-ing.Wonderful progress and pictures.
There is a good chain pulley in this video. Brian Block is building a large shop in an old barn and incorporates a bridge crane. The crane had been manually chain-driven, then electrified, then Brian decided to convert it back to chain operation. This video is part of the process.[youtube1]https://www.youtube.com/watch?v=uvhDZleeR-Y[/youtube1]If you have also followed Brian (bcbloc02 on YouTube), you will know that he did not replace the lifting cable and a heavy load fell while lifting (Worst Shop Day). Several of the other YouTube machining community have mentioned this. All in all, his shop build and posts show a one-man-band building a shop for heavy machining using large machines.--ShopShoe
Great progress with the sheave block. Another masterclass in fabrication As you say, the pulleys are just guides to change the direction of the pull so would always have been smooth. However, in the spirit of 'nit-picking', I wonder if the original block would have been open at the bottom to allow dirt, gravel, rocks, etc. to fall through rather than build up and jam the pulley? It appears to be so in the photo of full size one.Clearly not likely to be a big problem on the model . . . so I'll get my coat Mike.