1/18 ERJ-145XR Depron Build - RC Groups
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Mar 11, 2016, 01:08 AM
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Dirty Dee's Avatar
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1/18 ERJ-145XR Depron Build


I'm currently developing a design for a 1/18th Scale ERJ-145XR. All these depron airliner builds got me interested in trying this method. Compared to my first scratchbuild with over 700 individual parts, I'm going to be going much more simpler .

Primary construction materials will be 3mm depron for formers and ribs, 3mm Depron for sheeting, Balsa, and some birch ply for a small number of structural areas.


Specifications:
1/18th Scale
46.4" Wingspan w/ winglets (43.7" without)
65.3" Length
252.48 sq. in. wing area (no winglets)
AUW: 1415g (3.11lbs)
Wing Loading: 28.4 oz. / sq. ft.
CWL: 21.5

Electronics:
(2) Changesun 50mm 11-blade EDFs w/ 4900KV motors
(1) 2650mAH 4S 35C
(2) 30A YEP ESCs
(10) HXT900 Servos (2 Ailerons, 1 Rudder, 4 Flaps, 2 elevator, 1 Nose Steering)



Design Considerations:
-3D printed winglets
-WBPU coating only vs WBPU+newspaper?
-Electric retracts vs custom designed mechanical retracts (possibly use the turnigy servoless linear actuators)
Last edited by Dirty Dee; Jul 16, 2017 at 10:29 PM. Reason: Updated based on maidened setup
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Mar 11, 2016, 02:42 AM
Up-Out-&-Gone
demondriver's Avatar
HI Dirty! You can't go wrong with anything From Embraer!

Sign me up for this one buddy!
Latest blog entry: My RC 737 Assembly line!
Mar 11, 2016, 07:20 AM
Skylar's People
cwrr5's Avatar
I like it! Such a sleek looking little bird.
Mar 12, 2016, 01:09 PM
Registered User
Dirty Dee's Avatar
Quote:
Originally Posted by demondriver
HI Dirty! You can't go wrong with anything From Embraer!

Sign me up for this one buddy!
Glad you're on board . How are your ERJs coming along?


Quote:
Originally Posted by cwrr5
I like it! Such a sleek looking little bird.
Agreed. Also, has a pretty sweet seating arrangement so you can snag a single seat an not have to deal with people spilling over you the whole flight.




Some modeling progress. So far its calculated out to be 92 grams. Based on my initial weight calculations from the BOM, I need to keep the fuselage,wings, stabs within 300 grams to meet my goal AWU. So far it is looking to be on track.

I have a 130g allowance for paint, wiring and miscellaneous items like hinges, control horns, etc.
Last edited by Dirty Dee; Mar 12, 2016 at 01:29 PM.
Mar 12, 2016, 03:33 PM
was geht , müssen unten kommen
Keenan smith's Avatar
looking good!
Mar 13, 2016, 12:44 AM
Up-Out-&-Gone
demondriver's Avatar
Quote:
Originally Posted by Dirty Dee
Glad you're on board . How are your ERJs coming along?




Agreed. Also, has a pretty sweet seating arrangement so you can snag a single seat an not have to deal with people spilling over you the whole flight.




Some modeling progress. So far its calculated out to be 92 grams. Based on my initial weight calculations from the BOM, I need to keep the fuselage,wings, stabs within 300 grams to meet my goal AWU. So far it is looking to be on track.

I have a 130g allowance for paint, wiring and miscellaneous items like hinges, control horns, etc.
Beautiful progress Sir! You asked about my 145's. . . . I just worked on The BA 145's wings about an hour ago. . . They are progressing steadily.
Latest blog entry: My RC 737 Assembly line!
Mar 13, 2016, 01:41 AM
Airliner Builder
WAGliderGuy's Avatar
Nice CAD work, I'm looking forward to this build
Mar 13, 2016, 08:56 PM
EDF rules... :)
AirX's Avatar
Nice cad work Dee, I did a little on a Bombardier 900.
Will follow along with you here.

Cheers,
Eric B.
Mar 14, 2016, 12:57 AM
Registered User
Dirty Dee's Avatar
Thanks guys. AirX, you got any pics of your 900?

Kinda got sidetracked and worked on the main landing gear. Will need 85 degree retracts based on the geometry. Not sure yet if I want to just use a simple bent wire, or build it up with brass or aluminum tubes for either static looks, or make it have a shock absorber built in.

The wing thickness where the landing gear will be located is pretty slim, so that leaves me with 3 options:

1: Fixed gear.
2: Have blister mounts under the wing to give enough room for retracts.
3: Build my own mechanical retracts.

I'm most likely going to try #3, and then fall back on #1.
Mar 14, 2016, 09:57 PM
EDF rules... :)
AirX's Avatar
Hi Dee,

I have a couple pics from my model in Sketchup. I have been leaning it for the last few years and am getting a hang of it.
The model is a little course compared to yours but it gets me to the point where parts can be cut from foam and final shape sanded in.

Thanks for the interest in mine, I will get to it someday soon.
Cheers,
Eric B.
Mar 14, 2016, 11:53 PM
Registered User
Dirty Dee's Avatar
Very nice Eric. thanks for sharing.
Mar 17, 2016, 11:26 PM
Up-Out-&-Gone
demondriver's Avatar
Quote:
Originally Posted by Dirty Dee
Very nice Eric. thanks for sharing.
Hi Dee! Have you started Construction on your 145XR yet?
Latest blog entry: My RC 737 Assembly line!
Mar 18, 2016, 12:01 AM
Registered User
Dirty Dee's Avatar
Not yet, been tied up with overtime at work this week so I've been falling behind.

I'm basically going to build everything first on the computer to make sure it will all work out. This way I can catch any issues and fix it before it can become a headache during construction.

If I spend the time at this stage right, the building phase should go pretty quick.
Mar 19, 2016, 12:16 AM
Registered User
Dirty Dee's Avatar
A little more modeling progress. estimated at 124g for the pictured assembly.

I found out that Changesun makes a slim .15 size electric retract, so I think I'll be aiming to use those on this. It says to be careful on planes over 1kg, But I'm hoping it will work fine on this plane.
http://x-flight.com.hk/index.php?sp=...&more=&lang=en

This seems to be the slimmest retract I could find that can fit in the wing. The downside is it is 90 degree, and I need 85. It comes with an electronic failsafe against overcurrent. I'm thinking I can use that failsafe to get me the 85 degrees. Otherwise I might open up the units and see if i can relocate the endswitches.

Otherwise I might just use great planes mechanical retracts
Mar 19, 2016, 04:45 AM
Up-Out-&-Gone
demondriver's Avatar
Quote:
Originally Posted by Dirty Dee
Not yet, been tied up with overtime at work this week so I've been falling behind.

I'm basically going to build everything first on the computer to make sure it will all work out. This way I can catch any issues and fix it before it can become a headache during construction.

If I spend the time at this stage right, the building phase should go pretty quick.
Life, bills etc come first then hobbies!

Let me congratulate you on your excellent 145 CAD models Sir.
Latest blog entry: My RC 737 Assembly line!


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