The spinner is not absolutely necessary. The spinner contributes to
aerodynamics. you will lose some efficiency and fly slower, but the best
way to find out is to just try it. 99% chance it will fly just fine.
To reply by email: vhoward1122 at gmail dot com
I have flown glow fuel planes without spinners, also. I even use electric
starters with the rubber insert flipped around the other way. The prop nut
centers the starter insert on the engine shaft. I .could not tell any
difference in the performance of the plane.
Depending on the weight of the spinner it could effect the balance to
leave it off. Not much, but the plane may be more pitch sensitive
(need less up and down control to manuver). I would just give it a
+ Look Good
+ Slight increase of aerodynamics in large models
- Hamper cooling of motor
- Cause imbalance
- Add weight
- Add rotational mass (wears bearings during violent 3D
On my SkyArtec Cessna 182 I use a prop saver and no UC. (bellylandings
It looks ugly, but the prop lives forever and motor axis never bends.
True - "Looks" can be very important. I used to own a 60 size Hotts
that would be visually unbearable without spinner. (some may argue
that it was unbearable *with* spinner as well :-)
Spinners are some harder to balance - I had a few that would change
form while turning fast and cause imbalance whereas statically it
would be OK, or spinners that are 0.1mm out of centre alignment after
tightening the nut etc. etc.
I guess spinners are feminine: some look good, but hard to handle
If in any way defendable aesthetically - I avoid spinners. (and my
planes are ugly anyway - which cause the ground to repel them)
It typically won't affect anything on a small park flyer - it can be a
problem on larger planes. If the spinner is one of those rubber push-
ons from GWS, it will probably have little or no affect. Having said
Airflow changes are minimal unless it's a large diameter spinner. It
can block some airflow into a cowl, reducing cooling but it can also
allow a higher airspeed because of improved aerodynamics.
It can have an affect on the CG location, I have planes that needed
the CG moved forward so I added a heavy spinner. It's out in front as
far as you can get so a small amount of weight can make a big diff in
the CG location.
If you are unfortunate enough to hit a child, then you will do less harm if
you have a spinner fitted rather than just a prop-nut.
Also check your insurance - you might find that you are not covered in such
an event if you don't have a spinner.
You might be okay with a domed prop nut.
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On Mon, 13 Jul 2009 22:11:55 +0100, "Nigel Heather
Depends on the spinner - I have seen some fierce metallic pointy ones.
Rather would be hit by the nut.
I am fully insured. My insurence company does not have a clue what a
spinner is, and expect I use my brain (or whatever passes for that in
my case) to avoid harm. (I am not living in the USA remember..)
Not sure what constitutes a "park flyer"; if it is a smallish foamy, a
prop saver would be way safer - as nothing pointy is actually
portruding past the propeller.
In larger models, a plastic "blunt" shaped plastic spinner with
crumple zone may add safety indeed. Though a 60 size 3 KG model with
+1HP spinning in front will never be safe to get in the head.
A 600gr foamy however..
I suspect Nigel was thinking of the GWS-style park flyer gearbox, which
has a very long 3mm shaft that extends about an inch beyond the prop.
With sharpening this would make a nice spear point; as it is it'd hurt a
lot more than the GWS-style spinner if it hit.
More normal propeller attachment arrangements are probably no better or
worse than a spinner.
My Artec Cessna had the same long shaft. With the same dangers /
So I swapped it out for a prop saver - now the axis is very short, and
any bending action is taken up by the saver rubber band.
Does not look all that well, but is bullit proof.
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