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Also beware that not all main gear  rigging tools are equal- the newer ones on the market aren’t the same as the original tool- the square socket for the torque wrench has been rotated 45 degrees. The torque wrench needs to be attached so that it is in line with the tool…not at 90 degrees, not at 45 degrees, per the Mooney manual drawing.

If you get a newer tool with the square hole rotated 45 degrees, go buy a  1/2” to 3/8” adapter with a 45 degree offset to correct this (not easy to find)- otherwise, you’ll be setting the pre-loads wrong.

Surely this will invite discussion. I had the opportunity to use both tools side-by-side and if the torque wrench is not in line with the tool, the torque readings change considerably= wrong pre-loads.

 

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1 hour ago, PilotCoyote said:

Also beware that not all main gear  rigging tools are equal- the newer ones on the market aren’t the same as the original tool- the square socket for the torque wrench has been rotated 45 degrees. The torque wrench needs to be attached so that it is in line with the tool…not at 90 degrees, not at 45 degrees, per the Mooney manual drawing.

If you get a newer tool with the square hole rotated 45 degrees, go buy a  1/2” to 3/8” adapter with a 45 degree offset to correct this (not easy to find)- otherwise, you’ll be setting the pre-loads wrong.

Surely this will invite discussion. I had the opportunity to use both tools side-by-side and if the torque wrench is not in line with the tool, the torque readings change considerably= wrong pre-loads.

 

I have new tools available and am working provide the adapter for each of my tools until the next run and I rotate the square socket.

Thanks,
David

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57 minutes ago, PilotCoyote said:

The torque wrench needs to be attached so that it is in line with the tool…not at 90 degrees, not at 45 degrees, per the Mooney manual drawing.

Interesting.  My MLG tool has the 45 degree offset.  Using that, am I setting the torque on the high end?  My first annual, my main gear torque settings were on the low side, out of spec.  Is that the reason why?  The figure below shows the torque wrench orientation what I would describe as perpendicular (90 degrees)… not inline.  Am I confused?  Is it morning?

image.thumb.png.ee22a1c0949a90af30b20ab1dfbc19d8.png

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22 minutes ago, 47U said:

Interesting.  My MLG tool has the 45 degree offset.  Using that, am I setting the torque on the high end?  My first annual, my main gear torque settings were on the low side, out of spec.  Is that the reason why?  The figure below shows the torque wrench orientation what I would describe as perpendicular (90 degrees)… not inline.  Am I confused?  Is it morning?

image.thumb.png.ee22a1c0949a90af30b20ab1dfbc19d8.png

Ah, I knew this would cause some confusion….including my own!

This is from a more current manual. Which should we use, I wonder?

 

0CB05E33-5745-4CF5-9613-9BA334040F9B.png

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23 minutes ago, PilotCoyote said:

This is from a more current manual. Which should we use, I wonder?

Mooney lists Manual 104 applicable to my year (‘63C).  

But, I’m still waiting for someone to explain why orientation of the torque wrench matters.  Maybe the concept is beyond my capability to reason.  Checking the torque values has a certain amount of ‘technique’ involved already.

image.thumb.png.fc25d38afd1070ca963c8d91e20af89f.png

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37 minutes ago, 47U said:

Mooney lists Manual 104 applicable to my year (‘63C).  

But, I’m still waiting for someone to explain why orientation of the torque wrench matters.  Maybe the concept is beyond my capability to reason.  Checking the torque values has a certain amount of ‘technique’ involved already.

 

If the point of torque being applied was at the hole where the socket attaches, then it would not matter. But the point of torque is at the left end of the tool to break open the gear - which is several inches to left. That adds a lever arm to the torque reading - recall the formula for recalculating the torque like this?  But when the torque wrench is applied at a 90 degree angle to the lever arm that nullifies the lever arm effect. Since they're saying the hole is at a 45 degree angle, we should be in the middle between full effect of the lever arm and no effect. But the 250-280 inch pounds is based on torque applied with the full lever.

 

For the Torque wrench lever arm formula fig 7-2 in AC43.13-1B here https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43.13-1B_w-chg1.pdf 

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1 hour ago, 47U said:

Mooney lists Manual 104 applicable to my year (‘63C).  

But, I’m still waiting for someone to explain why orientation of the torque wrench matters.  Maybe the concept is beyond my capability to reason.  Checking the torque values has a certain amount of ‘technique’ involved already.

image.thumb.png.fc25d38afd1070ca963c8d91e20af89f.png

As mentioned, it's similar to using a crow's foot.   Because you're measuring break-away torque at a point other than where the torque wrench is moving, the lever arm changes if you move the orientation.

That said, a ratcheting torque wrench rather than a torsion-bar style solves the problem. 

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Rigging the landing gear with these tools is why so many Mooneys have jacked up landing gear. 
 

The only place they are necessary is on the Johnson bar nose gear. On all the rest, if you set the spring compression so that the springs just don’t completely compress during the swing and the compressions of all springs are as close to equal as possible, it will pass the torque test. I consider the torque tools a quick check of the gear health, not a device to use for rigging.

With the nose rods, you can have one that is so over compressed it is buckling the rod when you swing it, and the other is so loose that you might as well take it out, and it will still pass the torque test.

Edited by N201MKTurbo
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3 hours ago, N201MKTurbo said:

With the nose rods, you can have one that is so over compressed it is buckling the rod when you swing it, and the other is so loose that you might as well take it out, and it will still pass the torque test.

I had one like that.  The eccentric bushings were not installed in the same orientation.  That changed the effective length of the rods and the longer one was carrying all the load. 

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6 hours ago, Sabremech said:

I have new tools available and am working provide the adapter for each of my tools until the next run and I rotate the square socket.

I'm having trouble getting a picture of this in my mind.  My torque wrench is also a ratchet, and it seems like I could select almost any angle by just jumping to the next tooth on the ratchet?  I'm not seeing this in my head.

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30 minutes ago, Fly Boomer said:

I'm having trouble getting a picture of this in my mind.  My torque wrench is also a ratchet, and it seems like I could select almost any angle by just jumping to the next tooth on the ratchet?  I'm not seeing this in my head.

You probably need an actual picture of the tool, the adapters, the other things involved…

Something has left the conversation…. But, I’m not sure quite what it is…

When it comes to torque wrenches, extensions, and sockets… the added details are well trained… but often barely mentioned, just referenced, in conversation…

Best regards,

-a-

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4 hours ago, N201MKTurbo said:

Rigging the landing gear with these tools is why so many Mooneys have jacked up landing gear. 

I agree!

If you want to have some fun, get 100 A&P's to check the pre-load on a particular Mooney and you'll get 110 different readings!

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5 hours ago, kortopates said:

If the point of torque being applied was at the hole where the socket attaches, then it would not matter. But the point of torque is at the left end of the tool to break open the gear - which is several inches to left. That adds a lever arm to the torque reading - recall the formula for recalculating the torque like this?

Like Boomer, I still have questions.  Torque wrench extensions change to length between the handle of the torque wrench and the socket.  An extension installed at 90 degrees to the handle doesn’t change the distance, so no adjustment is necessary.  Whether the torque wrench is in the gear tool inline with, at 45, or 90, the distance from the handle to the socket (where the torque is input to the landing gear tool) is unchanged.

The mx manual shows a picture of the torque wrench orientation in-use, which differs depending on the version of manual you’re using.  The narrative(s) for setting gear preload do not address torque wrench orientation.  If torque wrench orientation were critical, wouldn’t the mx manual be specific so the mechanic gets it correct?  

Is it relevant that the mx manual specifies using ‘a 10” nominal length torque wrench’?  The illustrations show a dial-type torque wrench.  I’d think it’d be problematic using anything else.  Lastly, is the difference in torque readings with different torque wrench orientations (that PC refers to in his post) be due to the generally awkward nature of the activity, exacerbated by changing the orientation of the torque wrench?  I have to take several readings before deciding what torque setting I’m going to call it.  

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45 minutes ago, Fly Boomer said:

I'm having trouble getting a picture of this in my mind.  My torque wrench is also a ratchet, and it seems like I could select almost any angle by just jumping to the next tooth on the ratchet?  I'm not seeing this in my head.

If it’s a click type ratcheting torque wrench, getting that exact happy spot is more difficult than a dial type with a second hand that stops when you do. I find I can focus on the movement then read what’s been recorded on the dial by the second needle. Mines not a ratcheting type so I need to have it positioned the way shown in the maintenance manual. 
Probably just a preference, but this is mine.

Thanks,

David

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7 hours ago, Sabremech said:

I have new tools available and am working provide the adapter for each of my tools until the next run and I rotate the square socket.

Thanks,
David

@Sabremech


David, I have a set of yours, do I need the adapter?

Don

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3 hours ago, hammdo said:

@Sabremech


David, I have a set of yours, do I need the adapter?

Don

Hi Don,

you might. If the square drive is turned and not in line with the tool mounting surface, I would. Let me look at what I may have. The right adapters are hard to find.

Thanks,

David

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  • 8 months later...
On 4/24/2022 at 9:44 AM, Sabremech said:

I have new tools available and am working provide the adapter for each of my tools until the next run and I rotate the square socket.

Thanks,
David

New year - do you still have some in stock and what is the asking price? Coincidentally, my annual will be at KBUU - is pickup an option?

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