CS Prop Installation

[RV_7A]

Nope not true. An extension is an extension no matter how you look at it. Typical torque wrenchs that use sockets attached measure the torque at that specific point (center of the socket). If you add to the length of that point you would need to subtract from the actual torque setting to get the desired torque needed at the bolt.

[Steve Sampson]

Jeff, with respect, Marc has it right. Think about moments!

[frankh]

Originally Posted by MCA

An A&P friend told me that putting the torque wrench 90 degrees from the extension means that the torque reading is accurate and you don't need to do any calculations. If the torque wrench is parallel to the extension then you need to do some math.

Anyone heard anything similar?

Your still applying torque to the end of the open end wrench...Doesn't matter what angle you apply it...Dan Checkoway has a handy dandy torque extension calculator if you don't want to do the math.

Frank

[RV_7A]

Originally Posted by Steve Sampson

Jeff, with respect, Marc has it right. Think about moments!

I stand corrected...

-Jeff

[rv969wf]

Originally Posted by RVPilotDotCom

Can anyone tell me what special tools ( crow foot wrench size... whatever ) I will need to install my CS Hartzell prop? This is my first and those bolts are very hard to get to, I can't even imagine what it will take to get them to the proper torque.

Thanks,

- Jim

Hi Jim, you can borrow mine if you need it. I machined it myself and it is heated treated and 1/2" thick, the calculations for torqueing are on the wrench. Let me know if you need to borrow it .

[Joey]

Originally Posted by MCA

An A&P friend told me that putting the torque wrench 90 degrees from the extension means that the torque reading is accurate and you don't need to do any calculations. If the torque wrench is parallel to the extension then you need to do some math.

Anyone heard anything similar?

Your A&P friend is correct.

I don't want to sound rude, but there is some very dangerous advice being given in here. Advice that could lead to people improperly torquing their propellers.

Originally Posted by frankh

Doesn't matter what angle you apply it

Absolutely incorrect. The angle does matter. If you require proof, this link does the math to demonstrate.

PLEASE be more careful with this stuff! I hope Dan sees this and adds a caution to his calculator that the values given are only accurate if the extension is kept inline with the tool.

[AlexPeterson]

Joey's comments are absolutely correct. The angle matters, and this is not ambiguous to those who has studied physics and engineering, no offense intended to those who haven't. The link he refers to might not seem clear to those who haven't studied that sort of thing, but it is correct. While it is often fashionable to bash engineers with comments like "what do they know, I'm the one trying to get this thing to work", there are certain things that should be respected. Bolt torque settings are not simply to keep the bolt from loosening.

Please trust us on this one -

BTW, here is another good option for a torque wrench in the mid price range (about $200 with a crow's foot):

http://www.mcmaster.com/ and then go to page 2673. Item 5347A24 plus the appropriate size crow's foot on the same page works very nicely.

[RV_7A]

This is good info Joey. I appreciate you guys bringing this to our attention. Its nice to learn something everyday. I stand corrected.

-Jeff

[Jekyll]

Originally Posted by MCA

An A&P friend told me that putting the torque wrench 90 degrees from the extension means that the torque reading is accurate and you don't need to do any calculations. If the torque wrench is parallel to the extension then you need to do some math.

Anyone heard anything similar?

Yup, its in the FAA circular.

Jekyll

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[MCA]

Thanks everyone for the great info!