2" shaft mounting Pt.50: Boxing in the forked base.

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The height of the base fork blades is still annoying me slightly . The fork only has to be high enough to allow the 11.5" wormwheel to fit under it without contacting the base plate.  I'd like to lower the height of the fork base for cosmetic reasons alone. No doubt a shorter base height would also help to increase its stiffness.

It is now much too cold to be working with epoxy out of doors. So at least the pressure is off to finalize the fork length for the moment. I shan't be able to bond the doubled blades until I can arrange local heating in my normally unheated workshop. I don't want to risk the wrath of my long suffering wife by working with epoxy indoors. There has recently been a huge health problem for those working on epoxy laminations in the Danish windmill industry.

The image shows how the forked base will appear once it is boxed in [at the front and back.] Boxing is important to avoid the fork blades moving independently of each other around the pivot on the RA housing. When I lower the mounting, on the chain hoist, the mounting wants to lean drunkenly to left or right. Each fork blade wants to 'fold' around the polar altitude pivot. Eventually the polar altitude will be finely controlled by a stainless steel turnbuckle fitted between the base and the polar axis, bearing housing.

It took some time to saw out and file a neat circle in the 10mm, 3/8" alu. The hole will provide access to the azimuth nut for using a ratchet. I allowed a little extra freedom at the top of the stiffening plate between the fork blades. This was to ensure the altitude pivot clamping was still secure.

I also beveled off the top and bottom of the front plate so that it sits flush against the base plate and polar axis housing. The height of this stiffening plate will be determined by the PA altitude angle. As will the angle of the fork base where it rests on the base plate. Mine is set up for 55N.

A base plate between the forks proved to be more important for maintaining squareness of the fork blades than a rear sloping one. Though the polar axis housing at the top provides plenty of squareness there is no harm in further reinforcement at the base.

Soaping the 36 grade, angle grinder disks does seem to help the disks to continue cutting. Soap works on the files too provided they are cleaned with the file card [flat steel brush] in between efforts to remove metal. The mounting is finally beginning to look as if it actually means business. The next step is to drill the fork blades for cross studs and furniture nuts. Just as I used them on the bearing housings. Then the azimuth pivot arrangements need further scrutiny.

Click on any image for an enlargement.  

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