LEFT: RMI knobs fitted to the RMI frame of the MIP. ProSim737 allows for a number of differing style RMI gauges to be displayed - framed and frameless (click to enlarge).
The replacement knobs are highly detailed reproductions of the original B737-800 RMI knobs. I would like to have used genuine knobs; however, as they are usually attached to an RMI gauge, finding the knobs alone at a reasonable price would be a difficult if not an impossible task.
The knobs have been individually sculptured using clear ABS plastic while the front plate is made from clear acrylic. The knobs are then painted in the correct Boeing grey colour and the black and white stenciling applied directly to the front of the knob. The knobs can be easily backlit using an LED, although I have yet to do this. The sizing of the knobs can be determined from information supplied by EHC Knobs located in Farmingdale, New York.
Stand-by Instruments - RMI Gauge
There is no "stock standard" concerning how the stand-by instruments are displayed with a reproduction MIP. You may have the capacity to include real stand-by gauges (lucky you…) or reproduction solid state gauges manufactured by Flight Illusion, Sim Kits or similar.
Flight Deck Solutions (FDS) have choosen to use a single LCD monitor to cover the EICAS and stand-by gauges. Fly Engravity use solid state Flight Illusion gauges.
At the moment the knobs have not been interfaced and just sit there “looking pretty”.
In the future, I may interface the knobs by installing micro-buttons and/or a micro- rotary behind each knob. The knobs will then be connected to an interface card. However, at the minimum this requires cutting the MIP to create additional space for the location of the micro-switches – something I do not want to contemplate at the moment. If given a choice, procuring a genuine OEM RMI gauge would be my preferred option.
In the interim, the RMI Switch Assembly panel discussed in my earlier post will suffice.
The RMI knobs are now replaced with OEM knobs from a B737-800 that are fully functional.
MIP – Main Instrument Panel
RMI – Radio Magnetic Indicator. The gauge that displays VOR and ADF mode. Part of B737 NG stand-by instrument cluster
I have been very fortunate to have been given by a friend, a pair of B737-800 NG RMI knobs(THANK YOU). The knobs are as new in their plastic bags. I've attached some pictures. It is interesting to note that the difference is very minimal between the reproduction-style knobs I have been using and the OEM knobs.
The main difference is that the OEM knobs have a metal surround in the inner part of the knob in addition to a metal hex screw. Both these items add longevity to the knobs.
ABOVE LEFT: Reproduction and OEM RMI knobs - can you pick the difference... (click to enlarge)
ABOVE RIGHT: OEM B737-800 NG RMI knobs - just removed from plastic bag...