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Thread: Pharos 1 to 2, vacuum hold down dogs, RDT and countersunk top plate screws

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    Pharos 1 to 2, vacuum hold down dogs, RDT and countersunk top plate screws

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hi all


    Have posted this new thread to avoid further hijacking a separate thread on Rosco vs Pharos.


    I recently purchased the Pharos 1 to 2 upgrade kit and can highly recommend this to any P1 owners. The new catch cup completely transforms the Pharos experience.


    I also recently purchased two 55mm diameter vacuum dent puller tools as an experiment in restraining the Pharos while grinding. If you have a smooth bench surface these allow for some restraint without the need to modify the bench with, for example, screw down dogs.


    At the moment I am just pushing against two of them at the back of the Pharos but will look at adding some fingers to hold the base of the Pharos. Once that is perfected I would probably add two more suction tools to add downward pressure on all sides of the Pharos.


    I am also going against OE advice about RDT treatment of the beans as this eliminates static retention of grounds around the bottom bearing carrier and the catch cup. I can't see any corrosion arising at the moment but figure that another set of burrs (anyone know of 68mm burrs in stainless?) is a small price to pay for simplicity of use. A ceramic coating process like the nerost process used by Made by Knock in the Aergrind is another solution to the possibility of corrosion.


    Another mod is to replace the top plate burr locating cap screws with countersunk head screws (but maybe not for the fainthearted). This makes use of the bean loading funnel much more effective. While this mod does not allow application of the recommended torque; by using high quality countersunk head screws and hex driver bits in a drill press to maintain firm downward pressure significant torque can be applied. A little valve grinding paste applied to the hex bit will provide additional grip to avoid slippage. I have not experienced any loss of alignment since making this mod.
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    Should clarify that the drill press is only used to apply downward pressure - not using the motor to turn the hex driver. The hex driver is turned manually. A rudimentary method would be to use large multi grip pliers, but a tidier method is to make a C spanner with a spigot into one of the chuck tool holes.

  3. #3
    Senior Member Lyrebird's Avatar
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    The reduced torque on the CS screws is because you are using Philips head: these were designed to "cam out" to limit the torque that can be applied*.

    CS screws are easily available in Allen head or Torx; use of either will solve your problem.



    *They were used in aircraft and the idea was the driver would cam out before the thread in the aluminium airframe stripped.
    Dimal likes this.

  4. #4
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    Would wish that CS Allen head or Torx screws be "easily available" here in Tasmania. However, will be getting some on-line in due course.

  5. #5
    Senior Member Lyrebird's Avatar
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    Surprisingly, the electronics companies RS and Element14 carry a good range of fasteners at fairly good prices and their delivery is excellent.

    If, for instance, those CS screws are M5 x 25 you could get them in Security Torx (with the pin) in 304 stainless from Element 14 (item number 2886698), a box of 100 will cost you $21



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