SEN 2528 - When and how do you time the engine ?

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Category: Archive 2019

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Table of Contents-SEN 2528

When and how do you time the engine ?

F1C timing comments X 4
Cal Cup F1E
Cox radial backplates

USA F1C Engine Run Timing proposal

From: gilbert morris  

Ed Carroll's engine timing proposal is, in my opinion, right-on with one
important exception: engine run down time which is a huge variable --
amounting from zero to one sec. delay. Some  engines have a brake and some
don't and flood off's can be strong or weak. I suggest adopting a Hall
Effect sensor (effectively a magnet mounted on the engine shaft which
triggers a reed switch each revolution) wired to two posts external to the
model. The demonstration Ed refers to, would be for the timekeeper to
hook-up to the two exposed posts with a black box, the flyer run his engine
from start (simulated launch) to stop. The black box would include a stop
watch and circuit filter that would allow the stopwatch to run down to  say
100 rpm ( to eliminate possibility of shaft from sometimes stopping in the
magnetic field). The flyer would set his engine timer to cut-off as
required to take into account rundown. This way there would be no invasive
inspection and ordinarily one engine run would suffice.

SEN editor on C timing

Ed

here are my comments

have not flown F1C since 1963 (or there abouts) 
Know something about electronic timers
Contest director for very large FAI World Cup event.

You do not 

1. say that the engine run must be demonstrated every round or not. 

Could say the the engine run must be demonstrated every round before the model is flown. 

2. Say if the model is changed the engine run must also be demonstrated for the replacement model. 

3. In the case of a flyoff you should probably demonstrate the engine run  before the flyoff window opens .

4. You do not say how the engine run is demonstrated.  It could be construed that  showing the time keeper the timer settings is demonstrating the engine run.

Could say . the engine is demonstrated by by running the engine on the ground  in front of the timekeepers and being timed by the time keepers to be less than or equal to 4 seconds.

Showing the timer settings would require that timers be certified and tested with engines running, it also requires that the time keepers understand how to program one of the many electronic timers that are available.  Not practical as the actual engine could be affected by the fuel system plumbing and the timers can be complex and hard for some timekeepers to understand.

Roger Morrell

Re: USA F1C Engine Run Timing 

From: Daryl Perkins

To meet the requirement as of 2020 I have installed complete electronics in my F1C models.  I am for the rule change proposal as it is written. 
 
Daryl Perkins USA, active F1C power flyer.

F1C Engine Timing

From: Bernard Guest

Regarding Ed Carrol’s F1C rules proposal: I am not a F1C flyer but I have participated as an “inexperienced timer” and I can tell you honestly I don’t see how anyone can time the engine by sound when other models are being run up or launched in the near vicinity. I certainly could not do it reliably and so I went off the spurt of fuel I could see coming out when the engine flood-off was activated. In this day and age, apes such as ourselves should not be involved in the timing of models. We are not reliable for reasons that have been discussed at length here and elsewhere and given the cost and effort required to fly FAI the uncertainty introduced by human timers seems to me to defeat the whole purpose. 
I think Ed’s proposal is a good one.

Bernard

Cal Cup f1E

It looks like we may have not have published the flyer for the CalCup F1E – so here it is

In the press - Cox backplates etc

Norn Furutani saw this on R/C Groups . It may be of interest to some

https://www.rcgroups.com/forums/member.php?u=746&fbclid=IwAR01UiIilbhsWBM9PnSJ1CzjBddZKB4avEkj-LjNQrwER8ClQgLysEmT7OY