VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

  #1  
Old 02-26-2021, 08:37 PM
N804RV's Avatar
N804RV N804RV is offline
 
Join Date: May 2013
Location: Mount Vernon, Wa
Posts: 710
Default RV-8 MLG alignment

Any tail draggers wanna share their secrets and pictures for main landing gear alignment?

This is a new build. Haven't drilled the holes through the lower longerons yet. I'm installing the SkyDesigns gear. So, I've already trimmed the Z bracket. But, I kinda feel like I'm playing whack-a-mole, trying to get the leading edges of the gear legs to line up with the wear plates correctly positioned.
__________________
Ken W.
Mount Vernon, WA
2020 VAF Supporter

Last edited by N804RV : 02-26-2021 at 08:40 PM.
Reply With Quote
  #2  
Old 02-26-2021, 09:36 PM
skylor's Avatar
skylor skylor is offline
 
Join Date: Aug 2009
Location: Southern California
Posts: 959
Default No pictures but...

Quote:
Originally Posted by N804RV View Post
Any tail draggers wanna share their secrets and pictures for main landing gear alignment?

This is a new build. Haven't drilled the holes through the lower longerons yet. I'm installing the SkyDesigns gear. So, I've already trimmed the Z bracket. But, I kinda feel like I'm playing whack-a-mole, trying to get the leading edges of the gear legs to line up with the wear plates correctly positioned.
I don’t have any pictures, but I did this before drilling the outboard gear holes:

After securing the inboard part of the gear legs with the large fasteners I installed the axles the used ratchet straps attached to the outboard end of the axles and run across the top side of the fuselage (now the side closest to the floor while upside down) and pulled the gear legs down (towards the floor) so that the outboard portions were pulled flat against the outboard wear plates, before I did the final alignment and hole drilling.

What I found was that when the gear legs are initially set on the fuselage and aligned, the outboard part of the mounting area doesn’t necessarily sit flat against the outboard wear plates. If you align and drill them in this condition, the legs will twist slightly in the fuselage area, shifting their alignment when the bracket fasteners are torqued. By pulling them down with the straps, you help ensure that they will remain properly aligned once drilled and the outboard brackets are bolted in place. Also be sure to follow the plans and instructions regarding bolt torque and ensuring you have at least 1/32” inch clearance between the brackets the the wear plates.

Skylor
Reply With Quote
  #3  
Old 02-27-2021, 05:55 AM
RYOUNG RYOUNG is offline
 
Join Date: Feb 2010
Location: NC
Posts: 60
Default

I also have the SkyDesigns gear. I purchased two aluminum angles from Lowes 1 1/2 x 1/8 x 8 ft and clamped each to the outside face of each gear leg to align with the fuselage centerline. Drew a centerline reference on the floor with fuselage leveled laterally inverted. Placed two lines parallel to the centerline that are the width of the outside face of the gear with clamped aluminum angles. Used plumb bobs to align aluminum angles with reference lines on floor. When both legs are lined up, clamp the two angles to each other front and back (I used a couple of 3/4 in aluminum angles long enough to reach) so they cannot move and double check that they are parallel to each other and the fuselage reference line. Snug the 7/16 inboard gear bolts of each leg so they wonít move. When everything was set up, I double checked everything again. I step drilled the longerons using a bushing I made to start with a 1/8 in drill. I put a bolt in each hole as it was final drilled to prevent any movement. The holes came out exactly where they were supposed to. I also planned all holes drilled undersized and finished with a correctly sized reammer. Take your time, I spent a couple of days aligning, checking and double checking before I was comfortable drilling the first hole. Good luck!
__________________
Robert

RV-3B Flying
Wagabond Flying
RV-8 Tail completed, QB Fuselage in progress
Reply With Quote
  #4  
Old 02-27-2021, 06:25 AM
JET14 JET14 is offline
 
Join Date: Aug 2019
Location: Ridgeway, SC
Posts: 11
Default

I made a jig out of a 2X6 and a few pieces of 2X4. Used two chalk lines lengthwise set apart the diameter of the axel and screwed the 2X4s on either side to make a saddle where the axles go, then clamped the axels in. I measured from end of the axles to the aft most bulkhead to get them even.
Reply With Quote
  #5  
Old 02-27-2021, 12:22 PM
Champ's Avatar
Champ Champ is offline
 
Join Date: Apr 2012
Location: Kingsville, Ontario, Canada
Posts: 318
Default

Click image for larger version

Name:	Gear Alignmnet Front Side 1.JPG
Views:	65
Size:	680.4 KB
ID:	8845Click image for larger version

Name:	Gear Alignment Rear.JPG
Views:	49
Size:	668.1 KB
ID:	8846Click image for larger version

Name:	Wheel Alignment 2.jpg
Views:	88
Size:	200.6 KB
ID:	8847

Aligned gear with plumb bobs down to 6" channels (these were hinged and were my heavy duty trailing edge brake). It's been a while but I must have squared the "brake" to the fuselage centreline, probably triangulated to the tail as well.

Final aligned the wheels with 6ft 2x2 tubes bolted to the wheel rims. The wheels were on mating plates with grease between them. Did this with the tail up in wheel landing configuration. Added shims on the axle to get alignment just right. I'm happy with the handling in the end.

I've got a lot more pictures if you need something specific but these tell my overall method.
__________________
Dennis Enns
Bellanca Champ 7ACA since 1986, restored 1990.
RV-8 IO375, Hartzell CS, dual PMags, OW Award Oshkosh 2017
2021 Donation In
Reply With Quote
  #6  
Old 02-27-2021, 04:44 PM
fl-mike's Avatar
fl-mike fl-mike is offline
 
Join Date: Jul 2005
Posts: 1,491
Default

I used two six foot harbor freight box levels clamped to the gear legs for the toe-in/out check. Nice and straight. $20 a piece and are useful for other stuff.
__________________
Mike W
Venice, FL
RV-6A. Mattituck TMX O-360, FP, GRT Sport EFIS, L3 Lynx NGT-9000
N164WM
N184WM reserved (RV-8)....finishing kit in progress. Titan IOX-370
Reply With Quote
  #7  
Old 02-27-2021, 07:17 PM
Don Patrick's Avatar
Don Patrick Don Patrick is offline
 
Join Date: Feb 2010
Location: GTA, Ontario
Posts: 852
Default This is what I did.

I stole this from Matt Dralle. My gear are aligned perfectly.

Don

http://www.mykitlog.com/users/displa...=180248&row=38
Reply With Quote
  #8  
Old 02-28-2021, 05:52 AM
spatsch spatsch is offline
 
Join Date: Nov 2014
Location: Plano, TX
Posts: 254
Default

Make sure the holes you drill go through the longron with sufficient edge distance. You can always shimmy the axils you canít get lost strength back from lack of proper edge distance.

Oliver
__________________
Oliver Spatscheck
RV-8
N-2EQ
http://www.spatscheck.com/oliver
Reply With Quote
  #9  
Old 03-02-2021, 09:37 PM
N804RV's Avatar
N804RV N804RV is offline
 
Join Date: May 2013
Location: Mount Vernon, Wa
Posts: 710
Default

Well, its a done deal! With the inboard AN7 bolt in place, and the outboard wear plates drilled onto the lower longerons, the main landing gear are pretty much locked in place.

I did use the 2 four foot levels (purchased from Harbor Freight) clamped to the outboard faces of the bottom of each MLG, where the axles mount. I adjusted the legs fore and aft until the distance between each end of the levels was the same, and the distance from the outboard plumb bobs to the one on the tail post was the same. Then, I re checked to insure I had the outboard edge of the outboard wear plates 3/16" from the vertex of the lower longerons. And, I just kept going back and forth till I could consistently get the same dimensions without making any adjustments.

The funny thing was that it was so exact. The lateral distance between the ends of the levels clamped to the lower leg outboard faces was exactly 67" forward and aft. And, the distance from each outboard plumb bob to the aft plumb bob (on the center line of the aft bulkhead) was exactly 114 and 1/8th inches on each side. Exactly!

I had to trim the aft Z-bracket outboard corners quite a bit, making the outboard most rivet hole unusable. But, I'll have to remove that much of the belly skin anyway. So, I'll just add another rivet just inboard.

The kicker is, I dropped 2 more plumb bobs on the inboard leading edges of each gear leg (ala, Van's instructions). And, all 4 plumb bobs attached to the leading edges of the gear legs line up, exactly!
__________________
Ken W.
Mount Vernon, WA
2020 VAF Supporter
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 04:31 PM.


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.