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europa(at)pstewart.f2s.co
Guest

Posted: Wed Sep 06, 2006 10:52 am Post subject: prop bolts

Anyone got a top tip for torquing up the prop bolts (Airmaster CS /  

914 combo) - I can't get a socket and torque wrench on straight  

without fouling on the gearbox housing.



Regards



Paul

G-GIDY

Dave Miller

Joined: 10 Jan 2006
Posts: 51

Posted: Wed Sep 06, 2006 11:55 am Post subject: prop bolts

Paul, 

 

For my Woodcomp prop I used a "crowsfoot" open ended socket ( from an auto supply store), and adjusted the torque 

setting for the extra length of the socket. 

 

Dave C-FBZI  

 

 

    Paul Stewart <europa(at)pstewart.f2s.com> 

Sent by: owner-europa-list-server(at)matronics.com 

09/06/2006 02:52 PM 

Please respond to europa-list 

          

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

        cc:         

        Subject:        prop bolts 

 

 

--> Europa-List message posted by: Paul Stewart <europa(at)pstewart.f2s.com>

 

 Anyone got a top tip for torquing up the prop bolts (Airmaster CS /  

 914 combo) - I can't get a socket and torque wrench on straight  

 without fouling on the gearbox housing.

 

 Regards

 

 Paul

 G-GIDY

 

 

 

 

  

 

 [quote][b]

ward.t(at)xtra.co.nz
Guest

Posted: Wed Sep 06, 2006 11:59 am Post subject: prop bolts

Paul,

Make your own torque wrench as I did for the airmaster prop as I had the 

same problem.

 Bolt the correct spanner size to a piece of  'U' aluminum to take it 

exactly to 1 foot length from the bolt to the end. Drill a hole at the other 

end and with a spring weight (hardware stall) tighten up the bolt to the 

correct torque through the weight at 90 degrees. Very accurate.

Keep the tool as you will need it in the future!!

Cheers,

Tim

Tim Ward

12 Waiwetu Street,

Fendalton,

Christchurch, 8052

New Zealand



Ph +64 3 3515166

Mobile 021 0640221

ward.t(at)xtra.co.nz

---

grahamsingleton(at)btinte
Guest

Posted: Wed Sep 06, 2006 3:40 pm Post subject: prop bolts

Paul

I can lend you a crow'sfoot if you need one?

Graham



Paul Stewart wrote:



 	  Quote: 	
		   



 Anyone got a top tip for torquing up the prop bolts (Airmaster CS /  

 914 combo) - I can't get a socket and torque wrench on straight  

 without fouling on the gearbox housing.



 Regards



 Paul

 G-GIDY

europa(at)pstewart.f2s.co
Guest

Posted: Thu Sep 07, 2006 12:00 am Post subject: prop bolts

Thanks for the tips - Graham I may well take you up on the offer when  

we get back from France.



Regards



Paul

On 7 Sep 2006, at 00:41, Graham Singleton wrote:



 	  Quote: 	
		   

 <grahamsingleton(at)btinternet.com>



 Paul

 I can lend you a crow'sfoot if you need one?

 Graham



 Paul Stewart wrote:



> 

> <europa(at)pstewart.f2s.com>

>

> Anyone got a top tip for torquing up the prop bolts (Airmaster  

> CS /  914 combo) - I can't get a socket and torque wrench on  

> straight  without fouling on the gearbox housing.

>

> Regards

>

> Paul

> G-GIDY

sidsel.svein(at)oslo.onli
Guest

Posted: Thu Sep 07, 2006 8:59 am Post subject: prop bolts

Paul,



1. Set the torque limit on the torque wrench in the normal way.

1. Use a fixed spanner on the prop bolt.

2. Use a transition piece for the torque wrench that goes into the other end 

of the spanner.

3. Orientate the torque wrench so that its handle is 90 degrees (right 

angle) to the spanner.

4. Apply force on the torque wrench handle at 90 degrees to the handle, i.e. 

straight out, i.e. parallel to the fixed spanner.

5. The torque thus created at the "other end of the spanner" transfers along 

the length of the spanner and onto the prop bolt.



As you apply the force/torque, the prop. bolt will turn and you then simply 

follow with it, i.e. maintain your hand force parallel with the spanner.



Re. 2 above:  Alternatively, use the "open" end of the spanner on the prop 

bolt and put a suitably sized bolt (one that the torque wrench will fit 

onto) through the "star" end of the spanner, with a nut tightened hard on 

the other side.



I have attached (I hope it comes through!) a rough sketch illustrating the 

principle.



Good luck!



Svein

A225 - now in Norway



 	  Quote: 	
		  

 Anyone got a top tip for torquing up the prop bolts (Airmaster CS /  914 

 combo) - I can't get a socket and torque wrench on straight  without 

 fouling on the gearbox housing.



 Regards



 Paul

 G-GIDY

Torque.pdf

Description:

Download

Filename:

Torque.pdf

Filesize:

34.39 KB

Downloaded:

204 Time(s)

europa(at)pstewart.f2s.co
Guest

Posted: Thu Sep 07, 2006 10:20 am Post subject: prop bolts

Thanks for the ingenious solutions

Paul

On 7 Sep 2006, at 17:58, Sidsel & Svein Johnsen wrote:

 	  Quote: 	
		   Paul,

 1. Set the torque limit on the torque wrench in the normal way.

 1. Use a fixed spanner on the prop bolt.

 2. Use a transition piece for the torque wrench that goes into the  

 other end of the spanner.

 3. Orientate the torque wrench so that its handle is 90 degrees  

 (right angle) to the spanner.

 4. Apply force on the torque wrench handle at 90 degrees to the  

 handle, i.e. straight out, i.e. parallel to the fixed spanner.

 5. The torque thus created at the "other end of the spanner"  

 transfers along the length of the spanner and onto the prop bolt.

 As you apply the force/torque, the prop. bolt will turn and you  

 then simply follow with it, i.e. maintain your hand force parallel  

 with the spanner.

 Re. 2 above:  Alternatively, use the "open" end of the spanner on  

 the prop bolt and put a suitably sized bolt (one that the torque  

 wrench will fit onto) through the "star" end of the spanner, with a  

 nut tightened hard on the other side.

 I have attached (I hope it comes through!) a rough sketch  

 illustrating the principle.

 Good luck!

 Svein

 A225 - now in Norway

>

> Anyone got a top tip for torquing up the prop bolts (Airmaster  

> CS /  914 combo) - I can't get a socket and torque wrench on  

> straight  without fouling on the gearbox housing.

>

> Regards

>

> Paul

> G-GIDY

> <Torque.pdf>

rowil(at)clara.net
Guest

Posted: Fri Sep 08, 2006 5:12 am Post subject: prop bolts

At 2006-09-07 18:58 +0200 Sidsel & Svein Johnsen wrote:



 	  Quote: 	
		  I have attached (I hope it comes through!) a rough sketch 

illustrating the principle.


	


Svein - your diagram is excellent and clearly shows what you mean to 

do - but I'm having trouble understanding how this ensures correct 

torque at the prop bolt.



Initially, I thought it was fine, but when I try to analyse what is 

happening in terms of the forces that are being applied at various 

points, I don't seem to be able to extract a sensible answer.



I also imagined a different geometry - such as the torque wrench in 

line with the ring spanner - and it seems that wouldn't work unless 

the torque setting was adjusted to allow for the relative lengths of 

the torque wrench and spanner.



Can you (or anyone else) offer an explanation of why the 90-degree 

geometry works?



regards



Rowland

-- 

| Rowland Carson  PFA #16532    http://home.clara.net/rowil/aviation/

| 750 hours building Europa #435 G-ROWI  e-mail <rowil(at)clara.net>

kheindl(at)msn.com
Guest

Posted: Fri Sep 08, 2006 12:54 pm Post subject: prop bolts

I have seen a licenced aircraft engineer do same on my aircraft. It makes 

sense to me, but I guess someone could provide the mathematics. My Woodcomp 

nuts are 1/2 inch, and the torque wrench can also be set up for 1/2 inch. 

The open end then of a common garden wrench fits onto the torque wrench, and 

the other end fits onto the nut. Torque is then applied at right angle.



Karl





 	  Quote: 	
		  From: Rowland Carson <rowil(at)clara.net>

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

To: europa-list(at)matronics.com

Subject: Re: prop bolts

Date: Fri, 8 Sep 2006 11:00:01 +0100






At 2006-09-07 18:58 +0200 Sidsel & Svein Johnsen wrote:



>I have attached (I hope it comes through!) a rough sketch illustrating the 

>principle.



Svein - your diagram is excellent and clearly shows what you mean to do - 

but I'm having trouble understanding how this ensures correct torque at the 

prop bolt.



Initially, I thought it was fine, but when I try to analyse what is 

happening in terms of the forces that are being applied at various points, 

I don't seem to be able to extract a sensible answer.



I also imagined a different geometry - such as the torque wrench in line 

with the ring spanner - and it seems that wouldn't work unless the torque 

setting was adjusted to allow for the relative lengths of the torque wrench 

and spanner.



Can you (or anyone else) offer an explanation of why the 90-degree geometry 

works?



regards



Rowland

--

| Rowland Carson  PFA #16532    http://home.clara.net/rowil/aviation/

| 750 hours building Europa #435 G-ROWI  e-mail <rowil(at)clara.net>

rowil(at)clara.net
Guest

Posted: Fri Sep 08, 2006 1:44 pm Post subject: prop bolts

At 2006-09-08 11:00 +0100 Rowland Carson wrote:



 	  Quote: 	
		  



At 2006-09-07 18:58 +0200 Sidsel & Svein Johnsen wrote:



>I have attached (I hope it comes through!) a rough sketch 

>illustrating the principle.


	


 	  Quote: 	
		  Can you (or anyone else) offer an explanation of why the 90-degree 

geometry works?


	


Apologies for replying to my own post, but the penny has finally dropped!



Consider (as they say in all the best textbooks) a virtual lever 

going diagonally from the handle end of the torque wrench to the 

centre of the prop bolt. This will be longer than the actual torque 

wrench, but the component of force effective at right angles to its 

axis will be smaller than the force exerted by the operator, in the 

exact proportion required to apply the required torque to the prop 

bolt.



All I had to do was remember that the torque-wrench & spanner 

assembly is a rigid body (at least until the torque wrench clicks) 

and sketch the components of the operator force. Sorry to be so slow 

on the uptake, and apologies, Svein, for casting doubt on your 

suggestion!



regards



Rowland

-- 

| Rowland Carson  PFA #16532    http://home.clara.net/rowil/aviation/

| 750 hours building Europa #435 G-ROWI  e-mail <rowil(at)clara.net>

sidsel.svein(at)oslo.onli
Guest

Posted: Fri Sep 08, 2006 10:34 pm Post subject: prop bolts

Rowland,



You did not cast doubt on my suggestion, you only wanted to be certain that

you fully understood what you might be doing to your aircraft!



Your looking at the set-up as one rigid unit explains it in

easier-to-understand terms than if I had started explaining how a bending

moment (the torque) applied at one end of a cantilevered beam (the spanner

placed on the prop.nut) without any transverse force (since your hand pull

is axial on the spanner) sets up the same bending moment at all points along

the length of the beam and at its fixed end, i.e. onto the prop. bolt.



Your way of looking at it prompts one word of caution, however:  It is

important to apply the hand force parallel to the spanner.  If applied at an

angle, the transverse (to the spanner) component of this force acts at the

outer end of the spanner (where the torque wrench is affixed), giving an

additional torque moment on the prop.bolt (equal to the transverse force

component multiplied by the spanner length).  This is the reason for

recommending that the torque wrench is orientated at right angle to the

spanner before you begin to apply hand force - it is natural to pull on the

torque wrench handle at right angle and thus the pull is approximately

parallel to the spanner.



Best regards,

Svein

---

philipgeorge347(at)hotmai
Guest

Posted: Sat Sep 09, 2006 2:46 am Post subject: prop bolts

Rowland I  was at one time a Snap on tools dealer and Snap on used to 

produce a chart for use with torque adaptors for use in this situation ie. 

any adaptor offsetting the torque length as used on for example .  V12 Jag 

cylinder heads when the casting overhangs the head bolts . the angle that 

the torque wrench is pulled makes no difference (unless someone corrects me) 

any Snap on dealer should be able to supply the chart .  Philip George

 	  Quote: 	
		  From: Rowland Carson <rowil(at)clara.net>

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

To: europa-list(at)matronics.com

Subject: Re: prop bolts

Date: Fri, 8 Sep 2006 11:00:01 +0100






At 2006-09-07 18:58 +0200 Sidsel & Svein Johnsen wrote:



>I have attached (I hope it comes through!) a rough sketch illustrating the 

>principle.



Svein - your diagram is excellent and clearly shows what you mean to do - 

but I'm having trouble understanding how this ensures correct torque at the 

prop bolt.



Initially, I thought it was fine, but when I try to analyse what is 

happening in terms of the forces that are being applied at various points, 

I don't seem to be able to extract a sensible answer.



I also imagined a different geometry - such as the torque wrench in line 

with the ring spanner - and it seems that wouldn't work unless the torque 

setting was adjusted to allow for the relative lengths of the torque wrench 

and spanner.



Can you (or anyone else) offer an explanation of why the 90-degree geometry 

works?



regards



Rowland

--

| Rowland Carson  PFA #16532    http://home.clara.net/rowil/aviation/

| 750 hours building Europa #435 G-ROWI  e-mail <rowil(at)clara.net>

BEBERRY(at)aol.com
Guest

Posted: Mon Sep 11, 2006 10:16 am Post subject: prop bolts

Inexperienced as I am (1 year with a Europa) perhaps I can ask more  advice.

  

 Today I wheeled my 914 out of the hangar for the first time in a good few  weeks (having been away for some time) and immediately I noticed a slight clear  oil drip from the air box breather pipe.

  

 Engine was not started until later (ran beautifully) so I am puzzled at why  this should happen.  The engine has been dry as a bone until now but has  not been run for some two months.

  

 Comments please.

  

 Thanks 

  

 Patrick

  [quote][b]

hurstkr(at)growzone.com.a
Guest

Posted: Mon Sep 11, 2006 7:17 pm Post subject: prop bolts

 	  Quote: 	
		   Sorry to be so slow on the uptake, and apologies, Svein, for casting doubt 

 on your suggestion!


	


Rowland,



If it makes you feel any better, I'm glad you asked the question.  I have 

known for some time (since purchasing my Airmaster) about the spanner trick 

but didn't understand how (or why) it worked.



The diagram posted by Svein and your second posting combined sorted it out 

for me so I am pleased to be able to say I now understand the principle and 

conseqently will now be able to remember it.



I just wasn't game to ask for fear of getting foot in mouth disease.



So thanks again Rowland and to you too Svein.



Regards

Kingsley in Oz.

europa(at)pstewart.f2s.co
Guest

Posted: Tue Sep 12, 2006 12:02 am Post subject: prop bolts

Svein

Many thanks for your solution - torqued up the airmaster last night  

no problem at all. Even did a bench test with and without the  

spanner  just to get the 90 degree pull correct.



Regards



Paul

G-GIDY

sidsel.svein(at)oslo.onli
Guest

Posted: Tue Sep 12, 2006 7:52 am Post subject: prop bolts

Paul:  Glad to be of help.



All:  If for some reason you should find the 90 degree orientation awkward 

for some application, where the spanner and wrench in straight line would be 

better, here's the equation to use for setting the adjusted torque limit on 

the wrench if you do not have a table for your wrench:



Twa = T x Lw / (Lw + Ls)



where

Twa = adjusted torque wrench setting

T = specified torque for the bolt

Lw = length of the torque wrench (from center of connection to the spanner 

to the middle of the grip of your hand)

Ls = length of spanner (from center of bolt to center of connection to 

wrench)



Examples:  Wrench and spanner of equal length then set wrench to 1/2 of the 

specified torque.

                  Wrench twice the length of the spanner then set wrench to 

2/3 of the specified torque.



Again:  Direction of your pull vs. wrench is not an issue (need not be 90 

degr.), but the spanner and the wrench must be aligned.  Somewhat sensitive 

to where your grip is on the handle, but if you mark with tape or felt pen 

and measure to the middle you should be all right for the applications in 

question.



Best regards,

Svein



---

DuaneFamly(at)aol.com
Guest

Posted: Tue Sep 12, 2006 8:08 am Post subject: prop bolts

Svein and Others,

  

 I'm not sure I agree with this method. I don't think the torque wrench  knows how long a handle is exerting the force. I think that it will still  "click" at the setting you set it at. If the proper setting is 50 inch lbs (EU's  have to do the conversion) and you set it the torque wrench for 25 inch lbs,  then the wrench is going to click when you have 25 inch lbs exerted on it. And  your bolt is only torqued to 25 inch lbs, not 50. Making the handle longer only  allows you to have to exert 1/2 the pressure to get that 50 inch lbs to the  torque wrench.

  

 Am I missing something here?   

 Mike Duane  A207A

Redding, California

XS Conventional Gear

Jabiru 3300  

Sensenich R64Z N

Ground Adjustable  Prop



  [quote][b]

sidsel.svein(at)oslo.onli
Guest

Posted: Tue Sep 12, 2006 9:45 am Post subject: prop bolts

Mike, 

  

 Yes, with respect - assuming you refer to the "spanner and wrench in  straight line" method:  

  

 Conider the case when you set the torque for 25 in lbs: 

  

 - Assume that the wrench is 10 in long (distance from grip to attachment to  spanner)

 - A fraction of force before the wrench clicks, the pull then is a fraction  less than 2.5 lbs (10 in x 2.5 lbs = 25 in lbs)

 - Assume that the spanner also is 10 in long.

 - Just before the wrench clicks, the force of 2.4999999 lbs has a lever of  10 in (wrench) + 10 in (spanner) = 20 in on the bolt, i.e. a torque of 20 in x  2.5 = 50 in lbs.

 - Look at it this way:  Just before the wrench clicks, the set-up does  not know that it is about to break.  There is therefore only one stiff  piece between your pull of 2.5 lbs and the bolt, and that piece is 20 in  long.  Using a torque wrench as an extension to the spanner limits  your maximum pull, you might say, in this case to 2.5 lbs so that the torque on  the bolt cannot exceed 50 in lbs - the click breaks any stronger pull.

  

 Best regards,

 Svein

  

 [quote]   ---

Dave Miller

Joined: 10 Jan 2006
Posts: 51

Posted: Tue Sep 12, 2006 10:12 am Post subject: prop bolts

Still makes more sense to me to buy a set of crowsfoot socket wrenches. 

They only add about an inch to the length of the torque wrench, so a huge mathematical error is unlikely. 

Mine came from offshore, but excellent quality and only about $15 Canadian 

 

Dave [quote][b]

DuaneFamly(at)aol.com
Guest

Posted: Tue Sep 12, 2006 11:16 am Post subject: prop bolts

Svein,

  

 Please have no fear at offending me as I feel this is a very good example of a learning discussion and I appreciate your input.

  

 Now back to the discussion, I understand your point and equations in this discussion. My only concern is changing the setting of the torque wrench. I feel that no matter what length spanner is added to the end of the torque wrench, the only thing that changes is the amount of force your hand needs to exert in order to achieve the torque wrench setting and get the click. If a bolt needs to be torqued at 50 inch lbs, then the torque wrench needs to be set at 50 inch lbs.

  

 Unless you are saying that the spanner extension is on the bolt and then the torque wrench is attached to the end of the spanner? My idea is that the torque wrench is on the bolt. Is this the difference in our points of view?

  

  

 Mike Duane

Redding, California

XS Conventional Gear

Jabiru 3300

  [quote][b]

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