VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Model Specific > RV-12
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 05-24-2018, 08:36 PM
psalys psalys is offline
 
Join Date: May 2017
Location: Eugene
Posts: 17
Default Don't make this mistake installing the wheel fairings!

Page 36A-06. When installing the left outboard main gear fairing bracket (U-00002 and U-00004) with the long AN3-40A bolts, I broke off both bolts in the holes in the axle. Sounds pretty dumb but here's how it happened.

As I screwed the bolts in they became tight with about 1/8" left to go. I was puzzled so I turned the small 1/4" socket wrench carefully and then, snap, the bolt broke off. I thought I had a bad bolt so I carefully tightened the other bolt and it snapped off as well.

I tried to drill out the bolt shanks but was unsuccessful. I believe the problem is that the holes in the end of the axle were not tapped deep enough for the bolt. I bought a 10-32 tap and tapped the other axle until the tap reached the bottom and the AN3 bolts worked perfectly.

I spoke with Van's a couple time and they will send me replacement bolts but for the axle, they referred me to Matco. Matco asked me to send the axle back and I don't know if they will charge be for a replacement ($71 + shipping on their website).

So this is an easy mistake to make that could cost you $100 and a couple weeks to fix so the moral of the story is: if your bolt gets tight before it should, STOP! Go buy the correct tap and tap it deeper. That solution would have cost me $5.77 and an hour of time.

Just because it's a machined part doesn't mean it's right.
__________________
Working on finishing kit
Fuselage complete
Wings complete
Emp and Tail Cone complete
Dues paid
Reply With Quote
  #2  
Old 05-25-2018, 04:41 AM
BigJohn BigJohn is offline
 
Join Date: Nov 2008
Location: Gloversville, NY
Posts: 1,501
Default

I have had two of those bolts break off. Once when I hit a ridge of ice pushing into my hangar, the other time one was just broken when I took the wheel pants off. Both times I was able to extract the broken bolts using a drill press, left hand drill, and an easy-out. Has to be done carefully but it can be done. And, an excuse to buy a few more tools!
__________________
John Peck, CFII, A&P, EAA Tech Counselor, Flight Advisor.
RV-12 N37JP 120176 Flying since 2012.
VAF paid through 10/2018. Best bargain in town.
Reply With Quote
  #3  
Old 05-25-2018, 10:02 AM
benfra benfra is offline
 
Join Date: May 2007
Location: ft MYERS, FL Based @KPGD
Posts: 6
Thumbs up Wheel pant bolts

Did same thing, dosent appear to be enough threading in axel. Next time I was careful and used a good amount of blue thread lock. Good Luck
Reply With Quote
  #4  
Old 05-25-2018, 07:58 PM
RFSchaller RFSchaller is offline
 
Join Date: Oct 2010
Location: Phoenix, AZ
Posts: 2,228
Default

I have had fairings on my plane since it was licensed in 2012, and they look great, but itís a pain to check pressure or add air, so I plan on removing them at next oil change when I usually go through the rigamaroll of topping off tire pressure.
Reply With Quote
  #5  
Old 05-28-2018, 06:43 PM
EXflyer EXflyer is offline
 
Join Date: Jan 2016
Location: Chiloquin OR
Posts: 66
Default Bolt Lenght

Quote:
Originally Posted by benfra View Post
Did same thing, dosent appear to be enough threading in axel. Next time I was careful and used a good amount of blue thread lock. Good Luck
Its very easy to bottom a bolt out, but to over tighten it and have it break is another thing. There are torque limits for a reason, just because its not all the way down, item its supposed to hold and has a space under the head does not mean keep wrenching. It means, find out why the bolt is not going to tighten against the item. Real easy take a wire and use it to find out what the problem is. Use it to measure from the surface of the item to the bottom of the hole. Happens quite often that the bolt is too long or hole needs to be threaded more or drilled deeper. More than just a little force was exerted to break it off.
Reply With Quote
  #6  
Old 05-29-2018, 07:25 AM
Snowflake's Avatar
Snowflake Snowflake is offline
 
Join Date: Oct 2009
Location: Victoria, BC, Canada
Posts: 3,119
Default

Quote:
Originally Posted by EXflyer View Post
Real easy take a wire and use it to find out what the problem is. Use it to measure from the surface of the item to the bottom of the hole. Happens quite often that the bolt is too long or hole needs to be threaded more or drilled deeper.
A wire can easily check for hole depth, but it can't easily confirm thread depth.
__________________
Rob Prior
1996 RV-6 "Tweety" C-FRBP (formerly N196RV)
Reply With Quote
  #7  
Old 05-29-2018, 08:12 AM
EXflyer EXflyer is offline
 
Join Date: Jan 2016
Location: Chiloquin OR
Posts: 66
Default

Quote:
Originally Posted by Snowflake View Post
A wire can easily check for hole depth, but it can't easily confirm thread depth.
Didn't say it could but by running bolt in by hand will tell how far threads go. Then check with a tap will confirm it as to take out a small piece of material can be done with little force. That will tell if there is any hole left to tap other wise one could do damage by forcing a tape against the bottom of the hole. Been there done it many times that way during my years as a heavy duty mechanic.

And will add another thing that many don't do, blow the hole out with air as some times they are not cleaned after drilling and tapping, just an FYI for those who have never done this.

Last edited by EXflyer : 05-29-2018 at 08:15 AM.
Reply With Quote
  #8  
Old 05-29-2018, 10:25 AM
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 7,575
Default

There has been communications with Matco in an attempt to gain an understanding of what the problem might be.

It seems that occasionally an axle doesn't have fully cleaned up threads at the bottom of the hole.

Light clean-up of the threads can be done using a 10-32 tap if the threads of an AN3 bolt wont easily thread in full depth. Just be sure not to bottom out the tap and break it off in the hole.

As already mentioned, never exceed the max. torque value for a fastener.
An AN3 bolt begins to yield in torsion at something in the neighborhood of 60 inch pounds (only a bit more than 3X the normal torque value).
__________________
Any opinions expressed in this message are my own and not necessarily those of my employer.

Scott McDaniels
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 11:59 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.