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Over-torqued GSC Prop
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Dwayne

Joined: 15 Apr 2006
Posts: 13

Posted: Fri Dec 22, 2006 11:17 am Post subject: Over-torqued GSC Prop

 Has anyone had any sucess in shimming an apparently over torqued GSC three blade on 912... ie; no gap, blades will start going out of pitch in 30-40 hours. Someone has likely been sucessful in shimming this prop. I know this may sound dangerous but it could be done safely too....

flier(at)sbcglobal.net
Guest

Posted: Fri Dec 22, 2006 3:00 pm Post subject: Over-torqued GSC Prop

I just ordered new blades from GSC as I've had my prop now for 10 years.



The first question they asked when I inquired about the prop was whether

there was a gap in between the hub halves.  If there's not a gap, there's no

question that the blades should be replaced.



IMHO, don't screw around trying to shim.  If the hub isn't holding the

blades, replace the blades.  Slinging a blade could end up killing you when

the engine comes off.  A set of 3 new blades is $450.  Very cheap insurance.



Regards,



Ted



--

roncarolnikko(at)hotmail.
Guest

Posted: Fri Dec 22, 2006 5:18 pm Post subject: Over-torqued GSC Prop

Might be better off milling, filling, or sanding off some of the aluminum at 

the parting edge.  Ron NB Ore

 	  Quote: 	
		  From: "Dwayne" <dwaynemccourt(at)yahoo.com>

Reply-To: kitfox-list(at)matronics.com

To: kitfox-list(at)matronics.com

Subject: Over-torqued GSC Prop

Date: Fri, 22 Dec 2006 11:17:15 -0800

  Has anyone had any sucess in shimming an apparently over torqued GSC 

three blade on 912... ie; no gap, blades will start going out of pitch in 

30-40 hours. Someone has likely been sucessful in shimming this prop. I 

know this may sound dangerous but it could be done safely too....

Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=83056#83056

_________________________________________________________________

 	  Quote: 	
		  From photos to predictions, The MSN Entertainment Guide to Golden Globes has 

it all. http://tv.msn.com/tv/globes2007/

crazyivan

Joined: 25 Aug 2006
Posts: 62
Location: Pensacola

Posted: Fri Dec 22, 2006 6:24 pm Post subject: Re: Over-torqued GSC Prop

If the aluminum clam shells are touching then that means that the wooden blades have been crushed at their roots...very bad!  Sanding, milling, shimming, or filing the aluminum will only make the prop more dangerous!  Do not try to jerry-rig a fix.  Remove it, send it to GSC, and have them evaluate it.



Throwing a prop and crashing because you did your own make-shift maintenance is not only bad for your health and insurance premiums, but it is another argument people can make against experimental aircraft.

_________________
Dave
Piper PA-22/20

davedawe(at)msn.com
Guest

Posted: Sat Dec 23, 2006 6:39 am Post subject: Over-torqued GSC Prop

Merry Christmas to all!





  > Subject: Over-torqued GSC Prop

[quote] From: dwaynemccourt(at)yahoo.com

 Date: Fri, 22 Dec 2006 11:17:15 -0800

 To: kitfox-list(at)matronics.com

 

 --> Kitfox-List message posted by: "Dwayne" <dwaynemccourt(at)yahoo.com>

 

 Has anyone had any sucess in shimming an apparently over torqued GSC three blade on 912... ie; no gap, blades will start going out of pitch in 30-40 hours. Someone has likely been sucessful in shimming this prop. I know this may sound dangerous but it could be done safely too....

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=83056#83056

 

 

 

 > =================

 

 

&g'http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d' target='_new'>Windows Live Mail.   	  Quote: 	
		  [b]

Dwayne

Joined: 15 Apr 2006
Posts: 13

Posted: Sun Dec 31, 2006 2:42 pm Post subject: Re: Over-torqued GSC Prop

Thanks to everyone for their input. Its finally good to at least get some response here. I have sought information in the past on seemingly vague Kitfox questions, ie; torque specs, etc that should have been in the build manuals but never got a response here. 



IMO, even though I have owned 4 Kitfox- 2--M4-912 Speedsters, M3 and M2 -582 for 600 hrs.  Kitfox kits and parts are, or at least were,  just crazy overpriced. .......... However well built two -strokes for $15K and 912s for $25K are good deals...... Just glad that I haven't paid the big bucks for a kit, put all the hours in building then see that when then need comes to sell- --------you've thrown away half of your money and all of your time.........BTW crazyivan, what does "experimental" mean?

crazyivan

Joined: 25 Aug 2006
Posts: 62
Location: Pensacola

Posted: Sun Dec 31, 2006 9:20 pm Post subject: Re: Over-torqued GSC Prop

Dwayne...sarcasm?  



Experimental means you can do whatever the heck you want to to your airplane...as long as it remains airworthy.  Flying with a damaged prop or with a damaged prop and speculatively modified hub would not be airworthy according to my (sometimes less than) humble amature, experimental opinion.

_________________
Dave
Piper PA-22/20

369PL

Joined: 08 Sep 2006
Posts: 20

Posted: Wed Jan 10, 2007 6:22 pm Post subject: Re: Over-torqued GSC Prop

Is there a minimum space?  Maybe it could be checked with feeler blades. Does anyone know what the spec is? or is enough  to say there is a space?

crazyivan

Joined: 25 Aug 2006
Posts: 62
Location: Pensacola

Posted: Wed Jan 10, 2007 6:48 pm Post subject: Re: Over-torqued GSC Prop

Thier service bulletin just calls for a "visible gap." http://www.ultralightprops.com/bulletins/051799_sb.pdf

_________________
Dave
Piper PA-22/20

Malcolmbru(at)aol.com
Guest

Posted: Wed Jan 10, 2007 7:14 pm Post subject: Over-torqued GSC Prop

call gsc they told me about over torking and shims for tracking.  they  are nice to talk to .   mal

  [quote][b]

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Thu Jan 11, 2007 5:51 am Post subject: Over-torqued GSC Prop

Check out this page... Most of your questions will be answered here



http://www.ultralightprops.com/technical.htm#What%20is%20the%20recommended%2

0torque%20on%20all%20the%20bolts?



If the link doesn't work it's probably because the "?" question mark is

supposed to be part of the URL.  You may have to cur and paste it into your

location bar.



Noel



[quote] --

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

dave

Joined: 22 Sep 2006
Posts: 1382

Posted: Thu Jan 11, 2007 6:58 am Post subject: Over-torqued GSC Prop

GSC prop.



If there is No space then the blade root ends have been crushed, squished or 

comprimised.



I would strongly suggest that you not shim it but call Rick Peters at GSC 

and replace those blades.



Did some one say GSC said to shim them ?



If interested I will post you pics of broken GSC blades at the ROOT .



I have first hand experience on blade departures and you do not want to be 

there when it happens.

Dave

---

_________________
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Fox5flyer
Guest

Posted: Thu Jan 11, 2007 7:39 am Post subject: Over-torqued GSC Prop

Was the blade that departed a GSC?

Deke



---

dave

Joined: 22 Sep 2006
Posts: 1382

Posted: Thu Jan 11, 2007 8:06 am Post subject: Over-torqued GSC Prop

Yes --  A wooden  GSC I saw last year .

Was near me but not me.    I welded him up a  new engine mount and replaced 

the Engine and gear box.

Luckily he took off as normal but something seemed not right so he landed 

and was taxing up to hangar when it departed.   He told me his 503 was about 

4000 rpm max as he taxied up  and BOOM  blade flew off . Engine did the 

boogie -ripped the engine mount apart and broke the lower cowl which I 

repaired as well for him .

Deke ,  you justd got me busy fora minute     i hade you a quick page on 

the GSC Wooden Blade that Departed

http://www.cfisher.com/gsc/



Dave



---

FLIER(at)sbcglobal.net
Guest

Posted: Thu Jan 11, 2007 8:53 am Post subject: Over-torqued GSC Prop

Ouch!  Now if that won't make you think I don't know 

what will.  



I have new blades on the way for my GSC.  It's 10yrs 

old which is about 7 yrs beyond GSC recommendations.  

I got my monies worth.  It still *appears* in 

excellent shape and I do have space in between the 

hub halves but $450 for new blades is a lot cheaper 

than a 912, 912 mount, or my life (some say anyway)!



I'm seriously thinking I'm gonna add some retention 

cables to my engine...



Regards,



Ted



--- Original Message ---

From: "dave" <dave(at)cfisher.com>

To: <kitfox-list(at)matronics.com>

Subject: Re: Re: Over-torqued GSC Prop



 	  Quote: 	
		  

<dave(at)cfisher.com>
	


 	  Quote: 	
		  

Yes --  A wooden  GSC I saw last year .

Was near me but not me.    I welded him up a  new 

engine mount and replaced 
	


 	  Quote: 	
		  the Engine and gear box.

Luckily he took off as normal but something seemed 

not right so he landed 
	


 	  Quote: 	
		  and was taxing up to hangar when it departed.   He 

told me his 503 was about 
	


 	  Quote: 	
		  4000 rpm max as he taxied up  and BOOM  blade flew 

off . Engine did the 
	


 	  Quote: 	
		  boogie -ripped the engine mount apart and broke the 

lower cowl which I 
	


 	  Quote: 	
		  repaired as well for him .

Deke ,  you justd got me busy fora minute     i 

hade you a quick page on 
	


[quote]the GSC Wooden Blade that Departed

http://www.cfisher.com/gsc/



Dave



---

Fox5flyer
Guest

Posted: Thu Jan 11, 2007 9:20 am Post subject: Over-torqued GSC Prop

Thanks Dave.  That's the first failed GSC that I'm aware of, but I don't

travel much outside this list.  Was the factory made aware of the failure?

Are you sure it was caused by over torqueing?  I'm sure the factory would

like to have a look at it.

Deke



---

lcfitt(at)sbcglobal.net
Guest

Posted: Thu Jan 11, 2007 10:54 am Post subject: Over-torqued GSC Prop

I don't have a GSC prop, but his discussion raises a couple of questions.



1) does the GSC blade have a knob at the base to be retained in a similarly 

shaped cavity in the hub?



2) If so, and I suppose it does, how can over tourquing result in blade 

failure.  At first glance, I suspect it would result in an inability to 

retain pitch and maybe tracking.  And if seriously abused maybe wobble.



I suspect  properly torqued prop might vary in tightness due to humidity and 

temperatures.  With the failed blade mentioned, I doubt it happened solely 

because of torquing issues.



Lowell



---

barry(at)pgtc.com
Guest

Posted: Thu Jan 11, 2007 12:46 pm Post subject: Over-torqued GSC Prop

Ted and all, you should also order the newer hub that has one of the prop 

bolts going through each blade.  I saw some small splits in two of the 

blades after about 200 to 300 hours and got all new everything.  Now up to 

about 500 hours and no problems.



Barry West

---

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Thu Jan 11, 2007 12:57 pm Post subject: Over-torqued GSC Prop

Lowell:



The GSC prop has either an aluminium root or an aluminium collar on the

root.  They also have a slot cut in them for a retaining bolt that actually

passes right through the blade.  They have been known to crack/depart but as

far as I know only after the GSC recommended TBO.  That is 5 yr or 500Hr.

Which ever occurs first.  I'm sure many are in service a lot longer than

that.



I first flew my plane on a 15 yr. old three blade GSC prop that only had the

high side of 100 hr. on it.  I contacted GSC and the rep on the phone

recommended that I not fly the blades..  He offered me a pretty good

discount on a new set of blades which were in stock.  



I went with the Ivo because I wanted the in flight adjustable.  The GSC

adjustable which I think is a superior unit unfortunately won't fit on my

"B" box.



Noel



[quote] --

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

barry(at)pgtc.com
Guest

Posted: Thu Jan 11, 2007 1:20 pm Post subject: Over-torqued GSC Prop

Lowell and all, I believe the older props actually had the hub squeezing the 

base of the wood blades.

for the newer ones and the one I now have the base end of the blades sit in 

an aluminum cylinder with grooves machined in them and a hole, actually a 

slot, through them.  One of the hub bolts goes through the slot in the 

aluminum and through the wood.  Torqueing the bolts squeezes the aluminum 

base.  It would not be impossible for a blade to break anyway but careful 

inspection during preflight looking for any small splits or other problems 

should go a long way toward preventing unexpected failure.



Barry West



---

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