Discussion torquing 4 bolt props

[kerwin50]

Just how necessary is it to torque 4 bolt props.
I have had guys tell me thier arm works just fine as long as they are snug
I have also heard that they need to be torqued at 40 to 45 inch lbs and checked often.
The engines in question are the DLE 30 and the PTE.

[Tony Hallo]

I don't use a torque wrench however that doesn't make it right, the wrench can be had for reasonable cost today so why not just set the standard, maybe others will follow. Checking often is good advice.

[Capt. Roll]

I torque mine to 45 in lbs; bought one of the Harbor Freight wrenches, around $14. I checked the wrench and it does meet their published margin of error; within 4% accuracy of the set torque value.

I still check the bolts for tightness after every three to four flights.

[pe reivers]

I use a T-key with torque reading collar. The marking on the collar is 5 Nm (~44 inlbs)
Wooden props should be checked every day you go fly. If the prop crushes, the clamping disks are too small, or the wood is too soft.

[Bill Vargas]

	Quote: Originally Posted by kerwin50
	Just how necessary is it to torque 4 bolt props. I have had guys tell me thier arm works just fine as long as they are snug I have also heard that they need to be torqued at 40 to 45 inch lbs and checked often. The engines in question are the DLE 30 and the PTE.

YES its important.

As our planes get bigger, the more one has to apply Basic Torque Proccedures for attaching hardware. So in a nutshell,,, to tight and you will damage the bolt/nut threads and or crush the item(prop) that it goes thru. To lose and it will come off.

Here's some more info,,,
http://www.flyinggiants.com/forums/s...ad.php?t=73331

[jamesrxx951]

every ones arms are at different calibrations. i can loosly install a bolt and my wife will have a hard time getting it loose. different strenths and different measuring points. i use a torque wrench my self. i have both a $300 i used for work and a $14 harbor freight one i use for my hobby. they both are pretty close to each other in calibration.