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Engine basics => Engine set up tips => Topic started by: frank mccune on February 17, 2014, 10:04:11 AM

Title: How do I keep a spinner from coming loose when starting?
Post by: frank mccune on February 17, 2014, 10:04:11 AM
     Hi:

     The spinner is a good brand name that has a aluminum backplate, an adapter nut, a plastic cone and a screw through the centre of the spinner.

      Suggestions?

                                                                                                                      Tia,

                                                                                                                      Frank
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: RC Storick on February 17, 2014, 10:47:07 AM
     Hi:

     The spinner is a good brand name that has a aluminum backplate, an adapter nut, a plastic cone and a screw through the centre of the spinner.

      Suggestions?

                                                                                                                      Tia,

                                                                                                                      Frank

Double nut or a sandpaper washer
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: Bill Little on February 17, 2014, 11:54:21 AM
As Robert said, I use a "washer" made of 60 grit emery cloth between the thrust washer and the aluminum back plate.  Check occasionally that the prop nut is tight.  And, use a box end wrench to tighten the prop nut, not a "hobby" wrench.  So far, no problems in about 20 years of doing it. Do you use an electric starter?

BIG Bear
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: frank mccune on February 17, 2014, 04:32:33 PM
        HI:

        I will try the sandpaper trick.  I had sandpaper between the prop washer and the  prop and dusted  all areas with with rosin but to no avail.

       I do not think that I can put much leverage on the "union" nut as it made of aluminum.  As a matter of fact, there is not enough room on the shaft for a steel prop nut with the union not in place. To double nut it is out of the question.  Just too few threads on the crankshaft.  Perhaps it is time for a drop of Locktite! LOL

      I do not use an electric starter as the old O.S. 35 is very easy to hand start!

      Thanks for the replies!

                                                                                                            Stay well,

                                                                                                            Frank     
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: Chris Wilson on February 17, 2014, 06:58:30 PM
Perhaps try a sleeve nut that takes the length of the thread through the prop hub and then pin the hub to the spinner back plate - I think that Al Rabe describes this well in one of his articles.

Trouble with any abrasive paper is that once it slips the friction co-efficient rapidly degrades back to being simply a gritty piece of paper.

Good luck.
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: Steve Helmick on February 18, 2014, 01:29:26 PM
What brand is that spinner?  I have only seen one that meets the description...and it's very heavy. If you need nose weight, that's ok, but thought you oughta know there are lighter options, either cheap or expensive.

I have one spinner backplate that is glued to the prop driver with JB Weld epoxy, and has been for years. Good prep of the spinner backplate and prop driver would be required. If you need to change to a different spinner, a heat gun will disassemble the two parts. Not a bad way to go, IMO. I do NOT like to have my plane spewing parts on an official flight.  :-[ Steve

 
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: Balsa Butcher on February 18, 2014, 04:55:49 PM
Use steel mounting hardware. Tru-Turn sells it separately. Can be tightened without fear of stripping the threads.  Might as well swith to a Tru-Turn spinner also, or if nose weight is a factor, a Brodak spinner because they are lighter.  8)
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: Bill Little on February 18, 2014, 05:10:58 PM
I run into the problem using Veco spinners, especially with Fox .35s! LOL!!  But I have had the problem before.  The Vecos have a Union Nut that goes through the prop and is made of aluminum.  Maybe I am just not cautious enough, but I never worry about using a box end wrench to get it tight.  In fact, I have even broken a wood prop while tightening a nut.

As to the emery cloth "coming apart", or "spewing parts during an official flight", that is just absurd.  I have never used sandpaper.

I wouldn't give a suggestion unless I am 99.9999999999999999999999% sure it works and will give no problems.

BIG Bear
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: Dallas Hanna on February 19, 2014, 05:21:45 AM
Back in the early 60s I started using the Veco extension shafts on T-Birds and initially had props spinning off.  The fix was to drill a 1/16" hole (has to be blind in drive washer on motor and extension shaft so care needed here!) and use a short length of 1/16" wire to key the two parts.  The same method for keying the spinner backplate to the extension shaft except you drill through backplate into extension. 

If no extension shaft, just drill the 1/16" hole through backplate into drive washer and use 1/16" wire to key the two parts.  The backplate is knurled so will bite into the wood prop so problem cured without tightening the prop nut with the feel of a gorilla!

I've seen people using the emery cloth but still have props spinning off at startup.  Being from an engineering background I prefer the mechanical drive of a key.   If you are worried about balance then drill another hole at 180 deg and use two keys as a complete overkill. D>K

HH
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: Bill Little on February 19, 2014, 07:02:55 AM
Back in the early 60s I started using the Veco extension shafts on T-Birds and initially had props spinning off.  The fix was to drill a 1/16" hole (has to be blind in drive washer on motor and extension shaft so care needed here!) and use a short length of 1/16" wire to key the two parts.  The same method for keying the spinner backplate to the extension shaft except you drill through backplate into extension. 

If no extension shaft, just drill the 1/16" hole through backplate into drive washer and use 1/16" wire to key the two parts.  The backplate is knurled so will bite into the wood prop so problem cured without tightening the prop nut with the feel of a gorilla!

I've seen people using the emery cloth but still have props spinning off at startup.  Being from an engineering background I prefer the mechanical drive of a key.   If you are worried about balance then drill another hole at 180 deg and use two keys as a complete overkill. D>K

HH

Hi Herbie,

If I thought I could still drill that accurately with a hand drill I would try that. ;D

BIG Bear
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: Dallas Hanna on February 19, 2014, 03:41:56 PM
Hi Herbie,

If I thought I could still drill that accurately with a hand drill I would try that. ;D

BIG Bear

As a kid Bill that's all I used!   For the extension I drilled the drive washer first, inserted the bit of wire, put the extension on and gave it a twist.  Then drill the hole in the extension on the scratch mark.   These days we are spoiled with all these cordless drills which make life much easier.

HH
Title: Re: How do I keep a spinner from coming loose when starting?
Post by: Steve Helmick on February 19, 2014, 07:17:59 PM
Bill...Regarding "spewing parts during an official flight"...I meant during the starting for an official flight, of course. Once you give the hand signal to the judges, as I see it, the flight has begun, whether the engine has been started or just "spewed parts". I saw that happen to an 11 time Walker Cup winner, OBTW. But only once...

Pete...You betcha, I set aside the aluminum adapters and get steel parts, but usually from Dave Brown's Products instead of Tru-Turn. They both go out the same door at Tower Hobby.  Besides, nose weight is often needed and easier to counter than a stripped spinner adapter at a contest.  H^^ Steve