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Everwild 01-16-2022 07:25 PM

Torque wrench recommendations
 
Any RV-10 builder recommendations on what torque wrench(s) to purchase to get through the build and beyond?

Is there one wrench that will do, or do I need different wrenches for different ranges / jobs?

I like to buy quality tools (buy once) but not necessarily looking for the most expensive option.

What do the A&Ps (professionals) in the crowd use?

Thanks!

rockwoodrv9 01-16-2022 07:44 PM

Craftsman at Lowes
 
I knew almost nothing about torque wrenches. I had never used one until I built my plane. Previously I just tightened nuts on bolts as tight as I could. It never occurred to me a bolt could stretch. I had never built anything out of metal or aluminum and wood is much more forgiving.

I bought 2 of torque wrenches. One for inch pounds and one for foot pounds. I am OK using them and Im sure of my results for direct wrench - socket torque. If you use an extension or other adapters, you could have incorrect results. I have no idea how to figure those. I need a mentor for that.

The other thing to check is accuracy. For that you need someone who knows what they are doing and has a way to verify. There is way more to using them than just pulling until it clicks.

Good luck.

I just noticed you are not that far from me. If you are ever in the Lansing - Mason area, let me know.

BillL 01-16-2022 07:49 PM

CDI is a good brand.
I find the wrench part number then google for a price. Like Zoro

Take care and they should last a long time. I have a MAC 250 ft-lb unit purchased in 1974 and it is still in calibration per electronic test. Used on hundreds of engine rebuilds.

wirejock 01-16-2022 08:02 PM

CDI
 
Quote:

Originally Posted by BillL (Post 1582612)
CDI is a good brand.
I find the wrench part number then google for a price.

Take care and they should last a long time. I have a MAC 250 ft-lb unit purchased in 1974 and it is still in calibration per electronic test. Used on hundreds of engine rebuilds.

Same here. CDI. Someone mentioned they make torque wrenches for Snap On.

I have a 1/4" in/lb and a 3/8" ft/lb. I also have a 1/4" torque screwdriver. Handy for really low settings down to 5 in/lbs. I wish I had a CDI dial type. It would be nice to read running torque instead of using the screwdriver or multiple tests to figure it out.

My big dog is a Home Depot. Seems fine but hasn't been tested in a long time.

AV8ER 01-16-2022 08:22 PM

CDI - Dial type
 
I have the CDI dial type and love them. Note that a torque wrench has almost no accuracy in the lower scale of its range so lower scale wrenches are necessary. I got a beam type with a ratcheting head for big stuff. Really love that one too.

I wrote up some info on the wrenches I have.

https://n7zk.com/build-log/torque-wrench-solved/

Everwild 01-16-2022 10:05 PM

Quote:

Originally Posted by AV8ER (Post 1582618)
I wrote up some info on the wrenches I have.

Thank you for the helpful write up. The VS and HS have #8 and AN3 fasteners, so I'll give the CDI 0-75 in-lb dial type a try to start. The 0-300 in-lb is out of stock everywhere.

rgmwa 01-17-2022 04:42 AM

I have 1/4" and 3/8" Norbar torque wrenches. Also very good.
https://www.amazon.com.au/s?k=norbar...l_8pvvra74mr_b

Gusmax 01-17-2022 05:09 AM

This guy does a great job at breaking things down. https://www.youtube.com/watch?v=HP4u...el=ProjectFarm

Desert Rat 01-17-2022 06:21 AM

Snap on. A good torque wrench isn't something to skimp on.

rocketman1988 01-17-2022 06:50 AM

+1 for CDI
 
+1 for CDI...

...and CDI is the commercial Snap On brand without the name brand cost...

BillL 01-17-2022 08:22 AM

Quote:

Originally Posted by Desert Rat (Post 1582661)
Snap on. A good torque wrench isn't something to skimp on.

An AP friend uses a snap-on ($$$$) with inserted end tools, it is excellent for using where only an open end wrench will fit. Ratchet head, and crowfoot is really dicey but works. $50 for a single 3/4"open end insert indicates how pricey it can get.

CDI is snap on w/o the lifetime service.

rongawer 01-17-2022 08:27 AM

Harbor Freight Quinn
 
No, seriously...

I have a CDI 1/4" digital torque wrench and a Snap-on 1/2" digital, but thought to upgrade my 3/8 Snap-On to a digital as well and bought a Quinn 64915 3/8" digital to experiment with.

Having an excellent mechanical research facility available at work, I tested my torque wrenches using weight standards in the lab, I found the HFT 3/8" with 2.1% error at 50 pounds (51.05 lbs) and 1.72% at 100# (101.72 lbs) in the CW direction. And then about 2.8% in the CCW direction for both weights. I tested each weight 5 times and averaged the error for each direction. For comparison, my mechanical Snap-On was closer to 3% in both directions - still within the certificate +/-3% tolerance. Note that most torque wrenches have a tolerance of around 3%, although I've seen some provided as high as 5%.

I do very much like my CDI torque wrench, and in reality, except for the engine case, cylinders, spark plugs and wing attach bolts - a 1/4" drive is all you really need to assemble an RV (er...pretty much any GA aircraft). So if you're going to spend a lot of money, spend it on the 1/4" torque wrench.

However, for considerably less money, I recommend buying the HFT Quinn line of torque wrenches,

TIP: the highest inaccuracy of a torque wrench is typically within the first 1/3 of range - target using the middle third to 100%.

Everwild 01-17-2022 08:42 AM

So much good information here!

Am I correct in thinking that a dial or split beam type wrench is necessary in order to measure the "friction drag" and then add it to the standard torque value?

I suppose you could find the friction drag with a click type through trial and error?

Strasnuts 01-17-2022 09:08 AM

+1 snap-on
 
Self calibrating digital snap-on. Never looked back at the cost after using so many times.

rongawer 01-17-2022 09:10 AM

ASME
 
The Van's KAI Section 5 has a very good description of torquing and discusses friction drag, which is technically "prevailing torque". I recommend reading that section rather than restate it all here.

Prevailing torque is almost always within 5% of the total torque, but more on smaller fasteners, less on larger ones (depends on the fastener retention mechanism, i.e. elongate thread, nylon locking, lock washer, etc...) and whether dry or lubricated threads, or if it's a previously used fastener. I wouldn't stress over it, just measure it.

In reality, most fasteners have +/- 5% torque tolerance available - some much more. It lines up well with the 3-5% torque tolerance of torque wrenches. It's almost like a bunch of engineers got together and planned it that way ;)

More food for thought - how many people actually get their torque wrenches calibrated every 12 months (or a certain number of cycles if more often)? It's actually the ASME standard and required for most certified work. But I'd guess not many folks do, especially for personally owned torque wrenches. I'm pleasantly surprised when folks even USE a torque wrench. I've observed many people, certified mechanics at that, use the "that's about right" torque setting with their "calibrated" hands.

So, the fact that you know the required torque setting, are actually using a torque wrench (properly I hope) and measure the prevailing torque first, then add it to the final torque - well, you're ahead of a lot of folks. Now, if you're doing so with a wrench with a known, valid, calibration, you get bonus points.

rongawer 01-17-2022 09:18 AM

Quote:

Originally Posted by Strasnuts (Post 1582698)
Self calibrating digital snap-on. Never looked back at the cost after using so many times.

Love your stuff man....sorry to be the kill-joy, but if the self-calibrating method you referring to is the calibration that occurs when turned on, it is misleading and really means self re-zeroing. It doesn't actually calibrate the accuracy of the mechanism, but it does ensure you automatically reset the mechanism, unlike a mechanical wrench which should be stored at or near 0. Snap-On has an excellent calibration service center if you choose to have this done. Or you can perform the calibration steps yourself using a standard weight and the wrenches' internal cal program described in the manual. You can make your own standard weight using water at a known temperature if you are that motivated as well.

BTW, all of the digitial torque wrenches I've checked, which include Snap-on, CDI, Mac, Irwin and, yes, even Quinn, have a self-calibrating feature when you turn it on.

"Tools, like the aircraft they keep in the air, also need proper and routine maintenance. Tools get dropped, misused, even wear out, and our calibration laboratory offers the equipment and expertise to get your tool's torque spot-on when it's accuracy gets a little off.

swordtail 01-17-2022 06:53 PM

https://www.harborfreight.com/hand-t...ter-63917.html

rv9builder 01-17-2022 08:20 PM

I have a 1/4”-drive beam style torque wrench similar to this one that works pretty well for determining prevailing torque and for torquing AN-3 bolts.

https://www.amazon.com/Neiko-03727A-..._t1_B07BFGN53Y

I also have a CDI 10–50 inch-pound, 1/4-inch drive that I bought for AN-3 bolts. In tests, the beam wrench and CDI have had very similar readings.

https://www.protorquetools.com/cdi-1...ch-dual-scale/

rongawer 01-18-2022 10:51 AM

if you are already using a digital torque wrench, you can set most of them to a peak setting. And then check prevailing torque with the highest torque saved for reference on the torque wrench digital display.

My CDI wrench keeps the value displayed for something like 15 seconds. I then update the final torque setting on the wrench and continue torquing.

Strasnuts 01-18-2022 10:54 AM

Quote:

Originally Posted by rongawer (Post 1582701)
Love your stuff man....sorry to be the kill-joy, but if the self-calibrating method you referring to is the calibration that occurs when turned on, it is misleading and really means self re-zeroing. It doesn't actually calibrate the accuracy of the mechanism, but it does ensure you automatically reset the mechanism, unlike a mechanical wrench which should be stored at or near 0. Snap-On has an excellent calibration service center if you choose to have this done. Or you can perform the calibration steps yourself using a standard weight and the wrenches' internal cal program described in the manual. You can make your own standard weight using water at a known temperature if you are that motivated as well.

BTW, all of the digitial torque wrenches I've checked, which include Snap-on, CDI, Mac, Irwin and, yes, even Quinn, have a self-calibrating feature when you turn it on.

"Tools, like the aircraft they keep in the air, also need proper and routine maintenance. Tools get dropped, misused, even wear out, and our calibration laboratory offers the equipment and expertise to get your tool's torque spot-on when it's accuracy gets a little off.

Good point, thanks for the clarification. That was misleading.

CT Brietigam 01-18-2022 11:45 AM

torque wrenches
 
I found that buying a new foot-pound Kobalt torque wrench at Lowe's each spring is the cheapest and quickest way to comply with AC43.13-1B. The wrench comes with a certificate of calibration and saves me the time and hassle of shipping it off for re calibration. As a reminder:AC 43.13-1B, 7-40. TORQUES

The importance of correct torque application cannot be overemphasized. Undertorque can result in unnecessary wear of nuts and bolts, as well as the parts they secure. Overtorque can cause failure of a bolt or nut from overstressing the threaded areas. Uneven or additional loads that are applied to the assembly may result in wear or premature failure. The following are a few simple, but important procedures, that should be followed to ensure that correct torque is applied. …

Calibrate the torque wrench at least once a year, or immediately after it has been abused or dropped, to ensure continued accuracy.

Although the regulation only requires “accepted industry practices” be used, the advisory circular explains that the FAA interprets that to mean that all torque wrenches, force gauges, and other tools should be calibrated annually.

Chuck
RV-6XXL

Everwild 01-21-2022 09:57 AM

CDI 752LDINSS
 
1 Attachment(s)
Let the torqueing begin!

1001001 01-27-2022 10:10 AM

FAT Wrench
 
For smaller fasteners, I have found my Wheeler Engineering FAT Wrench to be of great use. Alternate source here...
In places where a small screwdriver will fit and a classic torque wrench won't, it's indispensible, and I find myself using it quite a bit all over the airframe. It comes with a certificate of calibration from the factory and can be calibrated as needed.

rongawer 05-03-2022 07:40 AM

Hey Moderator...
 
This one should be in Tools.

Done!


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