NEW! Ultimate C/S Prop Wrench Anti Splat Aero

[PCHunt]

Originally Posted by BillL

............Think about it . . . if you applied a pure torque to that wrench and it was not attached, what would happen - it would spin, right? So the reaction at the nut can NOT be zero and the real answer is it is equal to that applied.

Yes, the adapter would spin if it was not attached to anything. Watch out, don't let your fingers get in the way!!

But when attached to the nut, it would apply ONLY a 90-degree side-load on the nut, and ZERO turning force. No torque would be applied to the nut.

In order to twist the nut with torque, the square-drive end of the adapter has to move sideways through an arc, which the electric motor with a slip-clutch can not provide.

EDIT: This was posted before I saw Steve Smith's post. I am NOT an aero engineer!!! YMMV. Do your own testing. My .02, etc.

[380mxc]

Wrench Order

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...When I came in today I received a purchase order from one of the largest propeller manufacturers in the world for 250 of our tools. They requested that we stamp into the tool the multiplier < TRQ X .8 > So their customers will use it correctly and avoid any confusion.
...The purchasing agent that I spoke to said they are having quite the laughing session throughout their facility over this. He informed me that they actually have one of the on line calculators posted for people to use. He said in their instructions is that popular diagram that keeps popping up, they never dreamed anyone would be so misinformed as to not understand that the L dimension is always 12" with all ft lb tools. I'm Happy Today! Allan
__________________
Allan Nimmo
AntiSplatAero.com
Innovative Aircraft Products
Info@AntiSplatAero.com
Southern California (KREI)
RV-9A / Extra-300

Great! Which Prop manufacturer?

[erich weaver]

Allan said:"The purchasing agent that I spoke to said they are having quite the laughing session throughout their facility over this. He informed me that they actually have one of the on line calculators posted for people to use. He said in their instructions is that popular diagram that keeps popping up, they never dreamed anyone would be so misinformed as to not understand that the L dimension is always 12" with all ft lb tools."


I have quite the opposite impression when I look at all the manuals, the AC and online calculators. Laugh all you want, but I don't know how anyone could possibly think anything other than to use the actual length of their particular torque wench. The meaning of L is explicitly shown in the diagrams. I haven't seen ANY documentation for the use of torque wrenches that says that L is always 12 with ft lb torque wrenches. Either Allan and his friendly purchasing agent are very wrong, or all the existing documentation is badly misleading. I await efforts by others to present video demonstrations.

Erich

[mcencula]

Allan,

While I have great appreciation for the products you are bringing to the RV community and have already purchased the Nose Job and have your prop wrench on order, I humbly submit that I believe you are incorrect in your statement that a .8 multiplier can be applied regardless of the handle length of the torque wrench.

I have taken some time to demonstrate the mathematics in this analysis of the forces and moments involved. I welcome critical review of this analysis and hope it results in improved safety for all...a sentiment you expressed concern for towards the end of your video.

As an aside, I recently viewed your video and while I would agree that this is a first-year engineering student math, it's not 5th grade math.

All the best,

[L.Adamson]

Originally Posted by mcencula

Allan,

While I have great appreciation for the products you are bringing to the RV community and have already purchased the Nose Job and have your prop wrench on order, I humbly submit that I believe you are incorrect in your statement that a .8 multiplier can be applied regardless of the handle length of the torque wrench.

I have taken some time to demonstrate the mathematics in this analysis of the forces and moments involved. I welcome critical review of this analysis and hope it results in improved safety for all...a sentiment you expressed concern for towards the end of your video.

As an aside, I recently viewed your video and while I would agree that this is a first-year engineering student math, it's not 5th grade math.

All the best,

Your analysis shows 60 in-lbs at the bolt head, with a 56 in-lb setting on the 48" wrench. I've been enlarging the video to 800% on my 27" monitor. There is glare on the Snap-On torque gauge, and the numbers become blurry. Therefor, I put some paper against the monitor, and traced the angles of the needle from the straight on shots. It's hard to tell exactly from freezing the frame, but the needle is at least hitting 68+ on the scale. It's definitely much more than 60.

So...............is the SnapOn gauge incorrect? Are the torque wrenches incorrect? Is your mathematics incorrect? Is the time honored mathematics incorrect...

[mcencula]

Originally Posted by L.Adamson

Your analysis shows 60 in-lbs at the bolt head, with a 56 in-lb setting on the 48" wrench. I've been enlarging the video to 800% on my 27" monitor. There is glare on the Snap-On torque gauge, and the numbers become blurry. Therefor, I put some paper against the monitor, and traced the angles of the needle from the straight on shots. It's hard to tell exactly from freezing the frame, but the needle is at least hitting 68+ on the scale. It's definitely much more than 60.

So...............is the SnapOn gauge incorrect? Are the torque wrenches incorrect? Is your mathematics incorrect? Is the time honored mathematics incorrect...

I watched the video a number of times and it looks to me like the needle hits about 64, but all of the tests done in the video are done by hand, so it's hard to say how much if any of that is overshoot after the torque wrench clicks.

After reading your question about which math is right, I looked up what AC43.13-1B has to say about this. I had intentionally not looked it up until after doing the math myself from scratch. Turns out they have the exact same formula (using different variable names) as I do.

Their formula:
T*L/(L+E)=Y

Where:
T is actual torque on the bolt
Y is apparent (indicated) torque (i.e. what you set the torque wrench to)
L is effective length lever
E is effective length extension

Rearranging their formula to show the same ratio as my analysis gives:
T/Y = (L+E)/L ==> T/Y = 1+E/L

Which is identical to what I came up with. Hrm...maybe all those of years of schoolin' paid off after all?

[PerfTech]

Very Important!

http://www.vansairforce.com/communit...209#post633209

[fehdxl]

Originally Posted by JakeLewis22

Does anyone second my request below?

Seconded.

-Jim

[JakeLewis22]

Originally Posted by fehdxl

Seconded.

-Jim

Thanks Jim but right after I posted my request on this string (a copy of post #78 on the FS: ASA Ultimate Prop Wrenches 3/4" & 5/8" forum string) I read Allan's post above and deleted it. It's no longer necessary.

Allan, your credibility just went up 10 fold. It sucks when you're wrong but it takes a big man to admit it.

[vlittle]

Allan must be crazy... like a fox!

The objective of guerilla marketing is to get noticed so you can sell more product. I can unequivocally state that Allan is the biggest guerilla on VAF!

Well done!