NG3/NG4 and actuator hook up

So now that NG6 and NG401A castings were bonded to the nose strut, it was time to bond NG3/NG4. This is the assembly that the actuator gets connected with the strut.


First thing I did was dry fit NG3 onto the strut... and I noticed it was tight... so I measured the inside (1.16")


And measured the strut (1.22")...


So I had to sand 60-thou off... plus a little bit more to allow room for the 2-ply BID that goes between the strut and NG3 (for a nice strong bond).


After a lot of sanding... NG3 finally fit more loosely...



The plans say to bond NG3 such that the distance from the actuator hole to the center of NG6 is 6.71" (plus or minus .05"). But since I'm installing an electric actuator, I figured instead of trying to measure out the distance, I would simply test fit it and adjust it to where it needed to be. So I clamped NG4 onto the strut and passed a bolt through it to connect it with the actuator.


After extending and retracting the actuator a few times... and adjusting the position of NG4... I finally settled on a location and marked the ends.


I then uninstalled the strut (for the 589681328674321 time!)... and prepped the surface for bonding..


I then pre-pregged 2 plies of BID...


Coated the section of the strut with plain epoxy...


And laid the 2-ply BID over the strut.


I then painted wet flox to the insides of NG3 and installed it into place - making sure it aligned with the marks I had made onto the strut previously.


I then removed excess flox and folded the 2-ply BID over such that I could make a flat bed for NG4 to come...


I painted NG4 with flox...


And installed it in place - making sure everything aligned. I then clamped everything in place and let cure overnight.



The next day, I removed the clamps and cleaned everything up.


It was now time to drill the blind holes through NG3... man, I hate these! NG4 came pre-drilled, but NG3 didn't... so I marked (as close as possible) where I thought the center of the NG4 holes were and placed a piece of wood between NG4.


I started out by drilling a pilot hole.


This let me see how close to center I came. I then used a slightly larger drill bit and biased it towards the direction it needed to go to get to center.


Drilling the other side was easy since I simply punch-marked it through the other end...


With NG3/NG4 bonded to the strut, it was now time to reinstall everything - including installing the actuator with NG3/NG4. I used a AN4-15A bolt with washers on the outside and a typical MS21042-4 nut (although I will probably end up swapping it out with a AN4-15 and a castle nut so that I can use a pin to lock it in place).






I then played around with the limit switches to fine tune the extended and retracted position of the nose gear.


Check it out in action! ::press play in the video below::


4 comments:

Steffenator said...

Awesome,
That action is painfully slow though, (fully understanding that it came that way from the factory.) Given the light weight of the bird, and it's lack of super sonic travel, I doubt the mechanism needs that much torque. Is there anyway to change the gearing in the box? Or maybe the worm and nut for something a little faster?

Ary said...

It's purposely slow. The actuator is also used to extend/retract the gear when the pilot/pax are still in the airplane to bring it in and out of the "grazing" position.

Anonymous said...

I would like to install an acuator like yours. Which acuator are you using, what is the load limit, how long is the stroke and the length of the unit when retracted.

Thanks for your assistance.

Ary said...

I purchased my system through Jack Wilhelmson - www.eznoselift.com.

You can find all the specs there.