antic

I need to start a: O.S., 120, twin, that does not have a spinner, just the bare, two bladed, prop. I have a conventional electric starter, with a rubber cone, but need to come up with a clever adapter. Any ingenious ideas out there? Thanx: JH

Mnw1998

Here is usually what you can do. the insert on you starter look like the picture below right? well if you take it out of your starter (usually a small flat head screw driver works best) and pop it out. when you put it back in don't put it in like you usually would put it in backwards. this will have a small opening and it fits just right.

JohnBuckner

My Feedback: (1)

First order of business would be to obtain not a spinner but a Spinner nut like the link (confirm your crankshaft size threads) and they are avaliable in metric sizes to facilitate the OS four strokes. In this way there would be no problems fitting a normal cone starter cup.

Now failing that I would make sure the propwasher (the one behind the nut) was of the tapered variety and in this way the conventional cone starter cup can be used without turning around albeit with much care. That means the starter operator uses both hands on the starter at all times and there is present an airplane holder person that not only can oppose the starter operators push backwards even if the airplane is in a so called safety stand. The starter operator will need to take great care in assurring the motor shaft is alighned perfectly with the engine crankshaft before ever keying the switch.

The worst case senario is if the prop washer is totally flat then I would turn the starter cup around and the inner hole must be large enough to assure the is plenty of room to fit over the prop nut with lots of clearance. Do not use this method if the inner hole in the cone is a tight fit over the prop nut. Agine care must be assured in lining up the motor shaft with the crank shaft long before that trigger is pressed if not the result will be a ballistic cup rubber flying through the air in almost any direction as well as a broken/damaged prop from the aluminium cup striking the prop.

One last point for that engine in particular I would if you are using a convention power panel on 12 volts I would abandon that and convert any type of starter inexpensive or otherwise over to a minimum of eighteen volts and a portable system. There are many threads here at RCU doing just that for as little as fifteen bucks. Was ten, but inflation ya know


http://www3.towerhobbies.com/cgi-bin...E162&P=RF#tech


John

jaka

Hi!
You use an aluminium spinner nut and reverse the silicon nose cone on the electric starter. Thats it!

carrellh

http://www3.towerhobbies.com/cgi-bin...?&I=LXLW07&P=0

Gray Beard

My Feedback: (-1)

Wow Carr, I have never seen that, Very cool item. I did the conversion to 18 volts as John said. John once posted the Harbor Freight number for the battery and charger he used and a bunch of us on RCU changed our starters over, back then the battery was $10.00 and $5.00 for the fast charger. Turned my old starter into a crank twister!! I can even start the DLE 30 with it now. Just flipping the rubber nose cone around works on just the prop and nut but I agree, getting the cone prop nut or even the Higgly weighted type of nut is a good way to do it.

jester_s1

But I'm curious, why do you want to fly this plane without a spinner?

Bozarth

My Feedback: (15)

jester,

Is a spinner needed rather than the stock nut and prop washer?

Kurt

jester_s1

Not unless you want to look cool. Of course, these are model planes and the looking cool portion is a significant one. Spinners do offer some aerodynamic benefit so on a speedy plane you'd definitely see a difference, but otherwise I suppose it's mostly about having a place to put your starter.

Bozarth

My Feedback: (15)

jester - agreed! They finish the lines of the model.

Kurt

airbusdrvr

I have flown both the OS 120 and 160 twin without prop spinners. Just reverse your starter silicone cone and it works great. The one draw back you will find with those larger spinner nuts that a couple of people recommended is that they often spin off instead of the motor turning. I gave up on those years ago.

jester_s1

I've never had a spinner nut spin off. I keep a pair of channel locks in my field box so whenever I install a prop I crank that sucker down until I can feel the prop flexing. I find that lots of guys don't tighten their prop nuts down hard enough. I promise, you won't hurt your engine doing so.

jaka

Hi!
Never have I !
A good tighten up is all it needs. 4-way wrench is useless for this.

flycatch

My Feedback: (26)

I like my finger do you.

thepamster

Channel Locks???? I'd hate to see your nuts. HaHa.
I would never try to start an engine without some kind of spinner nut. Too dangerous. There are so many options available these days anyway.

Gray Beard

My Feedback: (-1)

I have never had one come off either and for the cone type I just keep a piece of piano wire in my flight box to tighten them up. I have a few of the weighted Higgly nuts in my box too. There are so many options but I have often just used the stock prop nut that comes with the engine and simply reversed the silicone in my starter.

thepamster

Though starting with a reversed cone is certainly doable if you are not exactly lined up with that nut and washer you will likely be buying a new rubber cone because you just chewed it up. Perhaps it is just me though as the starter should be lined up anyway, reversed or not.
I am not sure that the OP is a newbie or not, with a 120 twin probably not, but was recommending the safest route.
I always respect your advice GB.