RC India

RC Models => Self-designed, DIY and College Projects => Topic started by: rockmania.89 on January 12, 2018, 08:49:02 AM



Title: Learjet 70 - Build
Post by: rockmania.89 on January 12, 2018, 08:49:02 AM
Hello Folks,

Another build log here. I got obsessed with this jet a couple weeks ago and wanted to build this. There were no plans that I could find for this plane, therefore a lot of measuring had to be done form the scale drawings I could get my hands on.

Here are some images.


Title: Re: Learjet 70 - Build
Post by: rockmania.89 on January 12, 2018, 08:51:21 AM
More images...


Title: Re: Learjet 70 - Build
Post by: gaurang.1972 on January 12, 2018, 10:51:59 AM
very good progress keep going on :thumbsup: :thumbsup: :thumbsup:


Title: Re: Learjet 70 - Build
Post by: swapnilnimbalkar on January 12, 2018, 11:39:10 AM
you are awesome.


Title: Re: Learjet 70 - Build
Post by: prabal276 on January 12, 2018, 12:12:35 PM
Awesome!


Title: Re: Learjet 70 - Build
Post by: rockmania.89 on January 12, 2018, 04:59:22 PM
Some more...


Title: Re: Learjet 70 - Build
Post by: prabal276 on January 12, 2018, 05:13:05 PM
Span?
Which EDF's?



Title: Re: Learjet 70 - Build
Post by: rockmania.89 on January 12, 2018, 09:19:24 PM
The following are the specs.

Airframe
============
Span: 1.3 m
Length: 1.5m

Power System
============
2 X 70mm EDF
2 x 60A ESC
4S 4000mAh LiPo


Title: Re: Learjet 70 - Build
Post by: wingmanbunty on January 13, 2018, 10:35:05 AM
nice


Title: Re: Learjet 70 - Build
Post by: rockmania.89 on January 15, 2018, 04:38:17 AM
When I first began the build, I had an idea of the effort that would be needed to make the skin of the aircraft. For the Learjet, most of the detail is in the nose, the wing bay and the tail cone, the rest is just a cylinder. I thought of couple ways to do this starting with the idea to simply make a big chunk of foam and sand to shape. The other approach that I thought of was to make the contours using the geometry of cones. However, this approach was way more complicated than what I anticipated as the shapes involved are fairly complex. In another approach, I tried to make the model of the aircraft in Rhinoceros. The idea was to model the contours and then unwrap them to the 2D plane and print the projections as templates. However, the construction of a model in the CAD program is not straightforward when one aspires to achieve a degree of detail. I searched the internet in an attempt to find any existing models of the aircraft. I found one that costed Euro 16. Would have gone for that one, however, in the meanwhile I did find a paper model of the plane. Now this wasn't the Learjet 70, rather its predecessor, the Learjet 23. Although the aircrafts are different, they are fairly similar in the nose and the tail geometry. I spared no thought and bought this pdf for Euro 4. I figured out the scales and had to scale this up by 284% to match my model. I am fairly satisfied with the result. There is still some sanding to be done to get the final finish. Here is the first look.



Title: Re: Learjet 70 - Build
Post by: sbajare on January 15, 2018, 12:22:35 PM
HI,

I remember seeing this model built by a some modeler and published in some RCM magazine. THe construction was foam using hot wire and sheeted balsa or may be glass fiber skin. Powered by 2 x cox 049 each using 2 propellers at 90deg to make it a 4 blade prop for max thrust.

Best of luck for your maiden


Title: Re: Learjet 70 - Build
Post by: sbajare on January 15, 2018, 12:25:52 PM
hi,

here it is don't now if it is same

https://pulling-gz.blogspot.in/2015/01/rcm-learjet-35a-part-1-article-and-plan.html?view=flipcard


Title: Re: Learjet 70 - Build
Post by: rockmania.89 on January 15, 2018, 07:22:05 PM
Yes I looked this model up, it differs a bit from the 70 variant. In fact I started off with a thought of building the 35 variant until I saw the 70. This is what I referred to: Scroll to the bottom of this page. https://businessaircraft.bombardier.com/en/aircraft/learjet-70#!#bba-pdp-section-5