Rob Roy advice needed

[Anthony TauntonParticipant @anthonytaunton43819]

What is the received wisdom on the making of the reverse eccentric rod on Rob Roy, namely the 1/4" offset required? Carve from solid? silver soldered fabrication? I have also seen adjustable versions involving a threaded rod. Is adjustment necessary to achieve perfect valve timing?

Thanks in advance

Tony

[Anthony TauntonParticipant @anthonytaunton43819]

Reverse eccentric rod offset.

[BazParticipant @baz89810]

Having access to a CNC mill I carved them out of the solid, first op was the straight and offset view then a simple fixture to tip them sideways to profile them, held by 5BA bolt in the eye and a small clamp at the eccentric end.

[Phil H1Participant @philh196021]

Anthony,

I was going to machine mine from solid but I thought I would give the laser cut versions a try. They arrived and consist of 4 flat profiles with 2 additional rounded ends for each rod (a rounded end is silver soldered either side of the flat profile of each rod). A photo will probably help I suspect.

I plan to silver solder all the additional ends to the flat profiles, bend the reverse rods as carefully as possible then set all 4 onto the same fixture to machine the expansion link slot with a slitting saw.

Phil H

[Anthony TauntonParticipant @anthonytaunton43819]

I originally built mine in February 1986 (long project; lots of things got in the way, a familiar story!) Anyway now I'm retired, and have a chassis that runs on air, I intend to re-do the eccentrics, as I was never too happy with them. I think I heated them and then bent them to shape back in the day when I had hair, but bending them correctly and getting the offset alignment exact etc is a bit unpredictable I found. I would be interested to hear from anyone who used this method and what problems they had, if any.

Tony T

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