NavList:

   

Reply

I figured that out, as long as the two pointers maintain their
relative positions their absolute positions do not matter. I noticed
when I examined a the Bygrave in London that the pointer to to the
cotan scale was bent down to be close to the scale to eliminate
parallax.


I am not happy with the one and a half PVC pipe since it is thick and
heavy and the outside diameter is 1.9" placing the cosine scale .2"
above the cotan scale.
My next step is to order a couple of pieces of aluminum tube use for
antennas. 1.625" O.D. and 1.750" O.D with a thickness of .058". I will
see how these fit together with my 1.500" drain pipe, 1.520" over the
existing cotan scale. I am thinking of bushing up the inner tube with
some wraps of plastic sheeting, if necessary, to minimize the
difference between the cotan scale and the cosine scale. I want to
keep the 1.5" drain pipe because the locking mechanism works so well.
I will be out of the country for the next seven weeks so I  will not
be able to get to it until mid November.

gl

On Oct 1, 11:49�am, Brad Morris  wrote:
> There has been some discussion over how the MHR-1 tubes are constructed.
> Based upon inspection of the MHR-1 in my possession, it appears to be cast aluminium parts.
> They are probably post machined to obtain the appropriate dimensions and finishes.
>
> One thought for Gary. �If the parallax in pointer to surface is an issue, 
bend the pointer. �Yes, I realize that is pretty dang obvious, but
> it will eliminate the parallax . �There will be no requirement on how 
accurately the bend is performed, since the two pointers establish
> the relative placement of the two scales. �Even if the pointers are twisted, 
the relative placement of the scales will still be maintained, albeit
> at a different position than some other Bygrave that does not have that twist in the pointers.
>
> "Confidentiality and Privilege Notice
> The information transmitted by this electronic mail (and any attachments) is 
being sent by or on behalf of Tactronics; it is intended for the exclusive 
use of the addressee named above and may constitute information that is 
privileged or confidential or otherwise legally exempt from disclosure. If 
you are not the addressee or an employee or agent responsible for delivering 
this message to same, you are not authorized to retain, read, copy or 
disseminate this electronic mail (or any attachments) or any part thereof. If 
you have received this electronic mail (and any attachments) in error, please 
call us immediately and send written confirmation that same has been deleted 
from your system. Thank you."
--~--~---------~--~----~------------~-------~--~----~
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To , email NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---

   

Reply