Propellor Bolt Torques

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John Austin
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Joined: Sat May 29, 2010 2:10 pm

Propellor Bolt Torques

Post by John Austin » Fri Jun 08, 2012 8:01 am

Hello

I have a Tipsy Nipper with a 1835cc VW engine and Chris Lodge Propeller. The prop has taken some damage so I'm going to take it off and send it away for refurbishment. Does anybody know what the bolt torque settings should be, what the bolt tightening sequence is and where I might but a set of new bolts?

Thanks.
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Noel Howard
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Re: Propellor Bolt Torques

Post by Noel Howard » Sun Jun 10, 2012 4:06 pm

Based on an article that appeared in Popular Flying years ago, I set propeller bolt torque on my 1835 VW to 12 lb ft. I tighten the bolts up in stages diagonally. When they are right, I place an object (eg wood or cardboard box) about 1/16" in front of one propeller tip, I then turn the propeller through 180 deg. so the other tip is close to the object. Both tips should track accurately to within 1/16". If not then make small adjustments to the bolt torques so as to get the propeller to track correctly. Finally wire lock the bolts in pairs so as to prevent them from unscrewing.

It is good practice to take a wooden propeller off twice per year (late spring and autumn) and re-tighten the bolts, as above, to allow for seasonal changes in the wood. I would advise you to discuss these procdures with your LAA inspector.

You can get new bolts with drilled heads for wire locking from LAS or Sky-Craft Ltd.

Regards,
Noel.
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ColinC
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Location: Derbyshire

Re: Propellor Bolt Torques

Post by ColinC » Mon Jun 11, 2012 9:55 pm

This document from Sensenich makes useful reading:

http://www.sensenich.com/files/document ... 581692.pdf

regards,

Colin
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Colin Cheese

Rob Swain
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Re: Propellor Bolt Torques

Post by Rob Swain » Tue Sep 04, 2012 12:09 pm

Noel Howard wrote:You can get new bolts with drilled heads for wire locking from LAS or Sky-Craft Ltd.
Bit late with this reply but hopefully not too late...

Some VW prop hubs have metric threads for the prop bolts. Not sure if LAS or Skycraft supply these.
Rob Swain
If the good Lord had intended man to fly, He would have given him more money.

Harry Hopkins
Posts: 124
Joined: Fri Mar 13, 2009 9:58 am

Re: Propellor Bolt Torques

Post by Harry Hopkins » Wed Sep 05, 2012 7:45 pm

This is the advice given by Dick VanGrunsven of Van's Aircraft:

"We have found that bolts on new wood props loosen and should be re-torqued after just 5-10 minutes ground running; then after the first flight (of no more that an hour) they need to be checked and re-torqued. Then again after 10 hours or so. At this point the prop should have "settled in" and the check-torque schedule of 3 months, 50 hours or seasonal humidity drop‚ (which ever comes first) should be adhered to."

Hope that helps.

Harry
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