Go Back  RCU Forums > RC Airplanes > RC Jets
Reload this Page >

1/4.5 T-38C Talon scratch build

Notices
RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

1/4.5 T-38C Talon scratch build

Old 12-25-2019, 05:05 PM
  #51  
Viper1GJ
My Feedback: (20)
 
Viper1GJ's Avatar
 
Join Date: Oct 2003
Location: Saint George , SC
Posts: 1,345
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by paulhat View Post
My curiosity has got the better of me
Whats the story here? Did you damage the aircraft while flying it ?
Also is that a foam core wing ? Paul.
Hi Paul,

Don't want to hijack Thomas's thread here but short story is...yes. The outer 3' of the wing tips are honeycomb aluminum sandwiched between top and bottom skins. Skins could delaminate and fail causing the tip to break off. Tip fails were a known problem along with other wing issues in the late 70s and the jets were limited to 5G. In this case we had a tip fail at 5G and it departed the jet doing damage to the fuse side as it folded up and rolled over inboard. This caused the jet to pitch up and exceed 8G which broke the other tip off because of same the failure. This all happened in about 1 second. After the big boom and lurch, and after getting my heart started again, I was shocked to see both wing tips gone. Structural damage checks showed we were good to 180kts which was a normal no flap landing speed, so landing was mostly uneventful except for the "pucker factor."

I have about 1200 hrs in T-38s and always wanted to model one. If I ever do, it will have the 46366 tail number and white scheme because of this flight!
Gary
Old 12-25-2019, 06:14 PM
  #52  
Dapreacherman48
Junior Member
 
Join Date: Dec 2019
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Default

my dad ran NDI non-destructive investigation on t-38 wings in the 70’s. Our house was in the landing pattern an t-38s flew over my house every few minutes... prettiest plane.

vance afb and USAF is retiring t-38s and replacing the with the t-7a redhawks.. thats a pretty plane too...
j
Old 12-26-2019, 07:42 AM
  #53  
kevinthoele
My Feedback: (1)
 
Join Date: Feb 2002
Location: Spring, TX
Posts: 1,369
Likes: 0
Received 0 Likes on 0 Posts
Default

Love this project. Looking forward to the molding of parts!!!!!!!
Old 12-26-2019, 09:59 AM
  #54  
grbaker
My Feedback: (29)
 
grbaker's Avatar
 
Join Date: Dec 2001
Location: La Porte TX
Posts: 3,465
Likes: 0
Received 0 Likes on 0 Posts
Default

I have about 1200 hrs in T-38s and always wanted to model one. If I ever do, it will have the 46366 tail number and white scheme because of this flight!
The clipped wing version?LOL

That's a heck of a story. Thanks!!
Old 12-26-2019, 06:27 PM
  #55  
Viper1GJ
My Feedback: (20)
 
Viper1GJ's Avatar
 
Join Date: Oct 2003
Location: Saint George , SC
Posts: 1,345
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by grbaker View Post
The clipped wing version?LOL
That's a heck of a story. Thanks!!
I think the RC would fly better with both wingtips! Don't need any more pucker factor landing the RC version. I get enough of that each landing now!

By the way I grew up in your neighborhood in Baytown, TX. The wingtip even occurred south of Wichita Falls, TX where I was based at Sheppard AFB. A local rancher returned the both wingtips back to the base about a month later. The Air Force awarded me a ball point pen for saving the jet. As they say... the reward for a job well done is no punishment!
Gary
Old 12-27-2019, 04:50 AM
  #56  
tp777fo
My Feedback: (28)
 
tp777fo's Avatar
 
Join Date: Feb 2002
Location: Greer, SC
Posts: 3,097
Likes: 0
Received 1 Like on 1 Post
Default

I'll bet my last dollar that the pen didnt work either.
Old 12-27-2019, 08:56 AM
  #57  
Viper1GJ
My Feedback: (20)
 
Viper1GJ's Avatar
 
Join Date: Oct 2003
Location: Saint George , SC
Posts: 1,345
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by tp777fo View Post
I'll bet my last dollar that the pen didnt work either.
Tom, you’d win the bet. Pen didn’t work worth a you know what.
G
Old 01-16-2020, 11:20 AM
  #58  
invertmast
Thread Starter
My Feedback: (22)
 
invertmast's Avatar
 
Join Date: Dec 2003
Location: North Port, Fl
Posts: 7,808
Likes: 0
Received 2 Likes on 2 Posts
Default

Not much of an update as ive been busy with work and family stuff since christmas and it doesnt look like it’ll slow down any.

i have been able to do a little bit of surface detailing on the wing with the laser though.



Old 01-16-2020, 12:36 PM
  #59  
yeahbaby
My Feedback: (21)
 
yeahbaby's Avatar
 
Join Date: Dec 2001
Location: FT Worth, TX
Posts: 6,266
Likes: 0
Received 2 Likes on 2 Posts
Default

Impressive work lil fella
Old 01-17-2020, 05:54 AM
  #60  
pccdtk
 
Join Date: Feb 2009
Location: Bucharest, ROMANIA
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Default

Very detailed and smooth work . Congrats !!!
Old 01-17-2020, 06:57 AM
  #61  
kevinthoele
My Feedback: (1)
 
Join Date: Feb 2002
Location: Spring, TX
Posts: 1,369
Likes: 0
Received 0 Likes on 0 Posts
Default

I love the progress. Cant wait to see it all done
Old 01-17-2020, 11:13 AM
  #62  
invertmast
Thread Starter
My Feedback: (22)
 
invertmast's Avatar
 
Join Date: Dec 2003
Location: North Port, Fl
Posts: 7,808
Likes: 0
Received 2 Likes on 2 Posts
Default

Thanks guys. Its getting there slowly.. still alot of sanding left to do, but im pretty confident these will be the nicest plugs and molds i have done. It has been decided to throw some extra $$$$ into more production oriented materials so the molds will last longer and produce nice parts. Mostly so if approached by a third party on purchasing the tooling and design data, that buyer will have better tooling to get started with.
Old 01-22-2020, 08:27 PM
  #63  
JSF-TC
My Feedback: (2)
 
JSF-TC's Avatar
 
Join Date: May 2002
Location: Fort Worth, TX
Posts: 988
Likes: 0
Received 1 Like on 1 Post
Default

Thomas,

That wing is looking great - glad the laser engraving process is working out. I should have patented the process, but cut you into the profits as you suggested it in he first place!!!

Makes me wish I'd got a bigger laser so that I could put bigger panels into it.


Paul
Old 01-23-2020, 08:20 AM
  #64  
invertmast
Thread Starter
My Feedback: (22)
 
invertmast's Avatar
 
Join Date: Dec 2003
Location: North Port, Fl
Posts: 7,808
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by JSF-TC View Post
Thomas,

That wing is looking great - glad the laser engraving process is working out. I should have patented the process, but cut you into the profits as you suggested it in he first place!!!

Makes me wish I'd got a bigger laser so that I could put bigger panels into it.


Paul

LoL. Im glad you took the charge to see if it would work! Knowing it would work made the decision of getting a laser easier and is one reason i decided to get the biggest one i could afford and fit. The table is massive!
Old 01-23-2020, 08:22 AM
  #65  
invertmast
Thread Starter
My Feedback: (22)
 
invertmast's Avatar
 
Join Date: Dec 2003
Location: North Port, Fl
Posts: 7,808
Likes: 0
Received 2 Likes on 2 Posts
Default

I got the bottom of the wing done. At this point, i just have to engrave the other wing, do some “wavey sanding” and the wings and tail components will be ready to mold.




Old 01-23-2020, 06:44 PM
  #66  
mr_matt
My Feedback: (10)
 
mr_matt's Avatar
 
Join Date: Dec 2001
Location: Oak Park, CA,
Posts: 10,368
Likes: 0
Received 0 Likes on 0 Posts
Default

Looks great, are you using leading edge flaps?
Old 01-23-2020, 08:49 PM
  #67  
invertmast
Thread Starter
My Feedback: (22)
 
invertmast's Avatar
 
Join Date: Dec 2003
Location: North Port, Fl
Posts: 7,808
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by mr_matt View Post
Looks great, are you using leading edge flaps?
T38 doesnt have leading edge flaps
Old 01-24-2020, 05:45 AM
  #68  
kevinthoele
My Feedback: (1)
 
Join Date: Feb 2002
Location: Spring, TX
Posts: 1,369
Likes: 0
Received 0 Likes on 0 Posts
Default

Wing looks awesome. Great job!!!!
Old 01-25-2020, 01:38 PM
  #69  
invertmast
Thread Starter
My Feedback: (22)
 
invertmast's Avatar
 
Join Date: Dec 2003
Location: North Port, Fl
Posts: 7,808
Likes: 0
Received 2 Likes on 2 Posts
Default

Ive been in Nyc for the past week and still have a week to go, so ive been doing cad work.

To make my life easier and produce some nicer parting planes, i have been designed and drawing them in CAD. There is a combination of 3D printed and laser cut ones. In the following photos, the green pieces will be 3D printed. The striations will just be tapes over to reduce the labor involved and provide a nice smooth surface. The pink pieces will be laser cut from the smooth white tempered hardboard:






I have also been working on the remainder of the parting planes for the airframe. All of the tail section and wings are completed and ready to be cut (if they arent cut already). The Flaps are a unique challenge due to the Quarter round of the Leading edges. You cant just cut these in half or else you end up with a negative draft and that makes getting the parts out difficult at best or even impossible. Not wanting to do a 3 piece mold for the flap, i elected to go with what is in the following photo. It uses some 1” foam insulation as a “cradleL and then 2 pieces of laser cut hardboard for the parting planes. The slot you see at one end is for the aluminum Hex shaft that doubles as the inboard flap hinge and the control arm attachment.




I have also been working on the files so the Airex core material can be laser cut and the perforations added.








The Landing gear Cad work is also starting to come together. The main gear is 90% done with just a few tweaks needed to get it to the correct length. The nose gear is also slowly coming along as well.







The Project folder containing Just the CAD data for this project is currently sitting at 8 GIGS. Its slowly beginning to catchup to the F14 folder which is just over 20Gigs. LoL
Old 01-25-2020, 03:27 PM
  #70  
JSF-TC
My Feedback: (2)
 
JSF-TC's Avatar
 
Join Date: May 2002
Location: Fort Worth, TX
Posts: 988
Likes: 0
Received 1 Like on 1 Post
Default

Thomas,

The CAD work looks great.

It's humbling to see some of the crazy self-taught ideas that I thought up and tried on my Buccaneer project being adopted by folks that are way more experienced in this area of model building than I. I was just making sh*t up as I went along, but for the most part it seems to work. The laser surface detailing and the laser cut and perforated Airex foam skins too.

Interesting to see some of the improvements that you are trying, such as laminated hardboard vs. my foam poster board parting planes. I have modified my approach slightly by covering the foam poster board with the self-adhesive vinyl-cutter material before I laser cut the parting planes in order to get an easy release. The surface coat doesn't stick to the vinyl surface.

Keep up the good work.


Paul
Old 01-25-2020, 03:51 PM
  #71  
invertmast
Thread Starter
My Feedback: (22)
 
invertmast's Avatar
 
Join Date: Dec 2003
Location: North Port, Fl
Posts: 7,808
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by JSF-TC View Post
Thomas,

The CAD work looks great.

It's humbling to see some of the crazy self-taught ideas that I thought up and tried on my Buccaneer project being adopted by folks that are way more experienced in this area of model building than I. I was just making sh*t up as I went along, but for the most part it seems to work. The laser surface detailing and the laser cut and perforated Airex foam skins too.

Interesting to see some of the improvements that you are trying, such as laminated hardboard vs. my foam poster board parting planes. I have modified my approach slightly by covering the foam poster board with the self-adhesive vinyl-cutter material before I laser cut the parting planes in order to get an easy release. The surface coat doesn't stick to the vinyl surface.

Keep up the good work.


Paul

Paul,
Sometimes we cant see the forest from the tree’s. Your idea’s with the laser cut airex and its perforations is a great idea. I had been using a monokote “wood-pecker” to do the perforations. It was effective, but not very consistent.

I have been using the white tempered hardboards for a good while for parting planes. Its cheap and easy to cut, even by hand with just a jig saw and releases very well. I had been using MDF shelf board, but that was entirely to thick and heavy... and Expensive!


i need to figure out how to pull off your gear door inner surface molds, that idea is super cool and one i would like to do!
Old 01-26-2020, 05:46 AM
  #72  
JSF-TC
My Feedback: (2)
 
JSF-TC's Avatar
 
Join Date: May 2002
Location: Fort Worth, TX
Posts: 988
Likes: 0
Received 1 Like on 1 Post
Default

Thomas,

For the door inner surfaces, just think in reverse from the way you build the outer door skins - no difference, once you get your mind around the concept.

3D print the plug and parting planes as one single piece


Paul
Old 03-24-2020, 04:41 PM
  #73  
invertmast
Thread Starter
My Feedback: (22)
 
invertmast's Avatar
 
Join Date: Dec 2003
Location: North Port, Fl
Posts: 7,808
Likes: 0
Received 2 Likes on 2 Posts
Default

Finally got around to doing some T38 stuff.

I got the horizontal stab parting planes laser cut, then waxed the H. Stabs and rudder, got them put into position in the parting planes, filled the gaps, waxed everything 3 more times and then sprayed the Pva.







Old 03-25-2020, 05:46 AM
  #74  
kevinthoele
My Feedback: (1)
 
Join Date: Feb 2002
Location: Spring, TX
Posts: 1,369
Likes: 0
Received 0 Likes on 0 Posts
Default

Work is beautiful!!
Old 03-25-2020, 06:00 AM
  #75  
Spencer K
My Feedback: (14)
 
Join Date: Aug 2003
Location: Phoenix, AZ
Posts: 179
Likes: 0
Received 0 Likes on 0 Posts
Default

This project is epic Thomas, keep up the great work!

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.