danielhv

danielhv

Well Known Member
Forgive the lack of part #'s, im not at home right now... but I'm attaching the elevator hinge brackets etc. The bearing assembly (VA-146?) calls for nuts, bolts, and washers... Do I need to torque these or just tighten them up and call it good? And when I look at the torque wrenches on sears.com, I see some with rediculous price tags... I know I need one in inch/pounds, but which one? (If I even need one at this point.)
 
You need the torque wrenches

danielhv said:
Forgive the lack of part #'s, im not at home right now... but I'm attaching the elevator hinge brackets etc. The bearing assembly (VA-146?) calls for nuts, bolts, and washers... Do I need to torque these or just tighten them up and call it good? And when I look at the torque wrenches on sears.com, I see some with rediculous price tags... I know I need one in inch/pounds, but which one? (If I even need one at this point.)
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Yes, you absolutely need a torque wrench, in fact you need at least two because of the wide range of torques involved. The recommended torque for most of the hardware is around 24 inch pounds. That isn't much. Many people can tell of simply twisting the heads off bolts by going by the old feel method. The higher torque fasteners, like are used in things like wing attachment, I would also consider critical. I can't tell you what wrenches to get but you don't want the torque value involved to be too near the edges of the range.
 
Yes, you will need a torque wrench. But first you will need (more) drills and reamers so you get correct size holes.
 
Torque Wrench

I can only say you betcha! I have inch-oz , inch pounds , and foot pounds. Click and beam type.
 
danielhv said:
huh? :confused:
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I guess he means that you won't need them for a while. You get pretty far with tail kit before you need torque wrench and if you don't finish your tail (i.e. connect stabilizers with rudder/elevator) but go a head with a wing you won't need it for a even longer time. Then finally get one and get back to your tail and then wing...
 
danielhv said:
And when I look at the torque wrenches on sears.com, I see some with rediculous price tags... I know I need one in inch/pounds, but which one? (If I even need one at this point.)
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Here is the one that I have... and while it starts at 25 in-lbs it has worked fine for me. But then again, I am not flying yet.

If you do buy one of the sears models, make sure you understand how it works (RTFM). I have been asked to help two other builders with theirs because they thought they were broken and kept snapping off bolt heads. One builder even returned his twice for a new one before calling me. The proper torque indiciation is subtle, and they were expecting more of a loud snap or click-click-click sound.

You don't have to torque the bolts now. My practice is to install inspection lacquer only after a bolt has been torqued. No inspection lacquer and that means I need to check the torque later. Besides, there have been many times I've torqued something only to find I had to remove it later.
 
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RV7Factory said:
Here is the one that I have... and while it starts at 25 in-lbs it has worked fine for me.

If you do buy one of the sears models. Make sure you understand how it works. I have been asked to help two other builders with theirs because they thought they were broken and kept snapping off bolt heads. One builder even returned his twice for a new one before calling me. The proper torque indiciation is subtle, and they were expecting more of a loud snap or click-click-click sound.
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24 in/lb equals TWO foot/lbs. Basically, the weight of your hand resting on the end of a 1 foot long wrench or ratchet handle.
 
danielhv said:
huh? :confused:
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If you haven't already discovered this, you'll find that drill bits often make triangular holes (search VAF for an explanation), especially as the holes get larger (like for AN3 / AN4 bolts). These triangular holes can lead to a tiny bit of slop in the hole, or you may find that the bolt simply won't fit even though you used the correct size bit. I think what SvingenB was getting at is that you will find a set of reamers will give nice round holes, which are important for proper bolt fit. I know, I know, more tools to buy. :eek::)
 
RV7Factory said:
If you haven't already discovered this, you'll find that drill bits often make triangular holes (search VAF for an explanation), especially as the holes get larger (like for AN3 / AN4 bolts). These triangular holes can lead to a tiny bit of slop in the hole, or you may find that the bolt simply won't fit even though you used the correct size bit. I think what SvingenB was getting at is that you will find a set of reamers will give nice round holes, which are important for proper bolt fit. I know, I know, more tools to buy. :eek::)
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Good advice, I'd recommend grabbing a reamer set from enco or grizzly, you'll get all common fractions up to say 1/2, then you can buy any special stuff you need like, .249 or what have you.

As far as torque wrenches, I'd highly suggest getting beam type wrenches or even better; dial wrenches. The clicker wrenches are good, but MOST people forget to back the adjustment off before storing it, which can screw with the calibration of the tool, no worries with a beam wrench. I doubt vans has done alot of bolt fatigue calcs on the airframe, but for ANYTHING on the prop or engine, you want to be sure to use the recommended torques, and good torque wrench will help this. I suggest buying some good quality used dial torque wrenches (bluepoint, snap-on, matco, beta, mac if not calibrated, or any decent calibrated industrial brand (EBAY is your friend here). If you go to sears you're gonna get a wrench that will function, but I don't trust them. We've got some Lowes/Sears/Depot clicker wrenches at work and the varibility in actual torque is pretty scary.
 
Reamers for bolts are essential. I got advice here on this board for which reamers to purchase (3 reamers and 3 drills, because the drills must be one number smaller i diameter).

Usually (in machine design) bolts only take tension, and there is no need to have accurately sized holes. There are lots of exceptions and special cases, but a bolt are in 95% of the cases made for tension. In aviation however, bolts also take shear load just as often as they take tension, and this requires accurately sized holes for proper shear distribution.
 
Yes, you need a beam or dial type torque wrench calibrated in inch pounds and able to read in a very low range.

See AC 43.13, page 7-6, para 7-40c. It basically says, to torque properly, you first have to measure the drag of the nut, e.g., when you use one of those nuts with the plastic inserts, you might get 10 lbs or more before the nut bottoms out. And it varies, from nut to nut,. so you can't just use some arbitrary number. So, with a beam type wrench, you measure what the drag is, then add that to the spec and torque to the sum of the 2 numbers. You can't measure the drag with a clicker wrench.

Bicycle tool suppliers sell a torque wrench that reads low numbers. Find them on Ebay, search for Park TW-1; they generally run about $35 and measure 0-60 inch pounds.

What, you don't have a copy of AC 43.13? It's the FAA bible on acceptable practices. Get one from Van's, who has them for a decent price. Has all the info you need and then some.
 
Get some Torque Seal as well

As soon as you torque a bolt, put some torque seal on it so you know later on it has been torqued. No torque seal and you can bet it isn't torqued.

I know one Tech Advisor who refused to sign off on an engine installation because nothing had any torque seal on it. How was he to know if things were tight enough?
 
I got a Proto 0-600 in-lb dial type torque wrench on eBay for $100, brand new with a calibration certificate. It works great.
 
I hate to swim upstream

But I totally dissagree...I nver used a torque wrench any where..Oh the wingspar attach bolts I did, but the rest of the hardware...Nope!

Fasteners will not fail in service if they have been "over torqued"...But they certainly will if they have been under torqued in tensile applications.

It just so happens pretty much all the bolts are in shear so the ridiculously low torque values quoted on the hardware won't make any difference...But so called over torquing won't hurt either.

Disclaimer...By over torquing I am not talking about tightening the fastener into the plastic range of the fastener...If you feel it give as you tighten it, its a bit much but experience told me pretty quickly where this point was.

I have built two airplanes this way with a combined total of 1000 hours, not one fastener failure.

Frank
 
General rule of thumb.... If you don't know if you need a torque wrench, you need a torque wrench.

Frank -

I hear you on the comments of not using a torque wrench. But the skill set of the readers/builders out there varies widely. As related to my rule of thumb above, those not qualified to be using their calibrated elbow may be doing just that.
 
Fair comment

My point was though with a little finesse..:).. there is a WIDe range of acceptable error on the torque applied.

Frank
 
I am with Frank on this one.

frankh said:
My point was though with a little finesse..:).. there is a WIDe range of acceptable error on the torque applied.

Frank
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We use Self Locking Tension nuts in mostly Shear Applications. I did not use a torque wrench until I was very near the end of the build for critical engine components, wing spar bolts, etc....
The potential for using a torque wrench incorrectly, especially on the small AN3 hardware, fuel fittings, etc... outway's good mechanical inclination as far as I am concerned. Good mechanical inclination being the unkown here. If you dont know, get someone with experience to help you, whether you torque everything, or nothing.
Humble opinion.
 
Low Pass said:
General rule of thumb.... If you don't know if you need a torque wrench, you need a torque wrench.

Frank -

I hear you on the comments of not using a torque wrench. But the skill set of the readers/builders out there varies widely. As related to my rule of thumb above, those not qualified to be using their calibrated elbow may be doing just that.
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Exactly right, in my opinion. It's the same response to the question "is it OK for me to do low level aerobatics"? If you have to ask...

The dynamic range of A&P skill in this community is such that if plotted on a graph, it would require a logarithmic scale. ;)

In fact, that's one of the reasons for this community. :)
 
I love the common sense approach!

"General rule of thumb.... If you don't know if you need a torque wrench, you need a torque wrench."

-Ron
 
I'm a big fan of torque wrenches for all my toys, some you can guesstimate, but airplanes are a must have!

On a side note: Ever watch OCC? (Orange County Choppers)

Have you EVER seen a torque wrench on that show? I really don't think they own any! :D
 
Oh boy, I see another war topic!

:D
So we need to add "Torque Wars" to Primer, Tailwheel, Oil Cooler, Slider, and the host of other fun topics with lots of opinions. Just part of the fun.
 
I can't believe I'm even gonna chime in on this but.....I use a torque wrench, was trained to use a torque wrench, paid **** for not using a torque wrench by QA/QC and any other USAF quality types...(of which I later became):p I reckon there must be a reason for using one besides the Maintenance OIC waving a LOR in front of me for not doing it:eek:). What I HAVE discovered is my elbow seems to have developed it's own form of calibration. Since I seem to have memorized all the "common" AN-3, -4 etc torques...I snug up the nut, grab the torque wrench and the nut moves less than a half of a hex flat and "click"...BUT, I still pull out the right tool for the right job and make sure it's right. My 2 cents... Remember Builders and maintainers....the infamous "best practices" speech everyone must have heard at least once in their lives.
 
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Truce?

No need for a war, we just need a torque wrench waiver:
Those that wish to commit aviation wrenching sans torque wrench need a sign off from a certified "golden hands" mechanic.
:D :D :D
 
A "must have" for some things

The nuts and bolts that hold these planes together are torqued to surprisingly low values. In fact, I wouldn't really describe it as tight, but more like snug. Once you get a feel for this, a torque wrench is overkill. However, engines (and props) are a different story. You probably won't need one for a while, but eventually it is something that your toolbox should include.
 
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