Lightning CG
 

HI all, knowing the Lightning is usually tail heavy, I built a bridge in the nose to carry all the batteries. I balanced the lightning tonight and it"s 2 3/4'' in front of the center of the wing tube, a little nose heavy. Question, should I move the CG to 2'' or do the first flight at 2 3/4''.
Rcpete

RE: Lightning CG
 

Your CG should be 45-50mm in front of the center of the wing tube. Remove the wing tube & set your fuse on it at that CG point to balance. My CG has been between these two points since the maiden & seems perfect for my flying style. My batteries are far out in the nose, but I still needed to fine tune it with a little lead.

RE: Lightning CG
 

Pete, The Lightning likes to be a little nose heavy. Keep it there and evaluate after a few flights. WHMC STL

RE: Lightning CG
 

RCPETE,

Gorgeous paint job!! Post some more pics of the comlete plane.

David S

RE: Lightning CG
 

HI, thanks guys, I"ll try the first flight at 2 3/4'' and see what happens.
Rcpete

RE: Lightning CG
 

Guy's

A friend lost his Lightning today due to the failure of the "nailhead" style axel breaking{the head came off} and loosing a main wheel during a take off run. The head appearently is not machined on but appeared to be "rivited" on by some mechanical means. The area that broke was about 1/8" dia with a shoulder making up the rest of the axel diameter.
This plane had about 10 flights

Jerry

RE: Lightning CG
 

Jerry, We immediately replace all Intairco Axels down here in Austin. None of them are fit for duty.

We have learned this lesson over the last few months.

Mcmaster sells these cotter pin shafts in 1/4" and 3/16" and I buy a bag of 25 at a time, they are a perfect fit for axels. if you need the part number, let me know.


Sean

RE: Lightning CG
 

Are your guys using the new black hardened axles?
The original silver ones were a problem, but I've yet to break the new hardened ones & I fly off grass all the time. In fact, I just suffered a flame out at the worse time & my Lightning had a "high sink rate" from about 12 feet (I had to avoid a corn field). It hit right main first & literally blew out the frame slots of a Behotec C50 retract and bent the struts - but ironically the axles were still good.

I did have an issue with the original struts that have only one bolt & bushing in the slider. A bolt snapped on takeoff roll allowing the wheel to rotate causing a violent hook almost flipping the jet. The new stuts have 2 large brass bolts as sliders to prevent this problem and cut down on the toe in/out slop from wear like the original strut design.

RE: Lightning CG
 

Actually, we have retrofitted two lightnings here with Robart 635's and Eurofighter Struts.

The setup is far superior to the behotec setup in our opinion.

RE: Lightning CG
 

Sounds good. Now that I have to get new gear, I'm shopping around for what to use next. I'm trying to find a good knee-strut for the mains and some lighter wheels. The stock wheels are too heavy at about .5 lbs each.

Got any pics of your Robart set-up? PM me or post here.

Thanks...Scott

RE: Lightning CG
 

I'm saving the pictures for Waco Jet rally. We really accomplished something cool here, and I want to make a new thread of it.

I can tell you this without any reservation. YOU CAN NOT LIGHTEN THE WHEELS!

THE WEIGHT IS IN THE TIRE, NOT THE RIM!

How do I know for sure? Here's a hint:

RE: Lightning CG
 

I was thinking of different wheels that are lighter, but did think of drilling the stock wheels like you.
I look forward to your new thread...

RE: Lightning CG
 

We CNC'd them. The rim is hollow, and I got lucky on the dimensions, I was within .002 of having an aesthetic problem. When you see the other side of this RIM, you are going to want to send me your wheels and have these holes put in your wheels. I think all Lightning guys are gonna want to do this.


There is no slop at all in the Retracts/ Struts/ Brakes now.

RE: Lightning CG
 

HI Scott, where do you get the black axles from. I remember seeing a post on the up graded strut, but forget where.
Rcpete

RE: Lightning CG
 

Has anyone come up with a successful trailing link landing gesr for my lightning? I was told that the spring for the jet 1A needs to be stiffer for my heavy Lightning/ jetcat 180?

RE: Lightning CG
 

Rcpete

By the way I love your scheme

Jerry

RE: Lightning CG
 

I get all my Lightning parts thru Ray Labonte. He is a great Comp-Arf rep - always has the answers and parts to my door within a few days. His hobby shop is in Maine & his office # is 207-347-6079. If he is not available, a guy named Tim can help you with parts.

You could also order thru the Comp-Arf website, but I prefer talking to someone on the phone to see if parts are in stock, etc.

Comp-Arf has all the gear spare parts listed (still shows old strut though)
http://www.composite-arf.com.hk/ar/R...925&spare=true

RE: Lightning CG
 

Hey scott thanks for the reply. Comp arf does not offer the trailing link mains landing gear but I will try ray tommarow .Thanks Bill