Sunday, 18 August 2013

The Merry Mixer moves on a stage

Click on any picture to enlarge!

The base and lower support are getting there

I managed to spend a few hours, over the weekend, sorting out the base and thrust bearing for the lower frame. The idea at the moment (and this could change!) is to chain drive the three smaller spiders from the static sprocketed half of the thrust race.

Large axle parts give rigidity to the main bearing
Large axle part are being used for support with hollow rods and standard diameter stainless steel rods being used as the pivot. The large diameter (LD) rod passes through an LD bush wheel and is terminated in a LD heavy bush that is bolted to the top plate of the trust bearing.

Solid base will support the entire weight
A small base supports the sprocket side of the trust bearing and is strengthened with a 2½ x 2½ inch square plate on top and a couple of angle girders underneath.  Black plastic spacer washers are used to space the thrust bearing sprocket off the base to ensure plenty of clearance for the drive chain. The intention is to add stabilising 'legs' to the base and the whole lot will stand on rubber tyres acting as feet. Power will have to either come from a motor under the base. In which case I might extend the base itself, or the drive could be positioned at the top of the central column, but that will mean getting power up through the thrust bearing which will mean some redesigning... I am still thinking about that one.

Lots of bracing - Victorian over-engineering principle!

The end of one of the drive arms
with test sprocket fitted
Drive to the spiders will be via sprocket on the end of each arm. The spiders weight will be taken by the top frame so they will be 'suspended' from it and no weight will be taken by the drive frame. Its only function is to provide a bearing for the drive sprocket. These will be attached to the underside of the end of the rod that passes through the centre of small spiders. In the picture , there is a small rod fitted so the system will be able to be tested without having to fit the spiders. It is now easier to see where it is going The final picture shows Sue holding one of the completed spiders in position over the base and drive frame. With all three spiders in place, the centre column built and the top frame in place this is going to be a sizeable model!

Finally getting a feel for it
Hopefully some more progress will be made tomorrow and a few of the decisions I have been putting off will get made!


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