Jetco Thermic 72 from PVHC - Page 2 - RC Groups
Thread Tools
Jun 28, 2012, 12:34 PM
Registered User

Hollow Boom

I just finished the boom. I already splitted the original one into 2 halfs with a balsa cutter. I bought 2mm plywood and copied 2 times the shape of the boom onto the 2 mm plywood. After I cutted 2 pcs, I cutted 2 slots out of the 2 pcs, so that I have 1 1.5mm space, just enough to lead the control rods through. I won't use outer tubes as I don't need them in this way. The control rods will just go through the hollow boom without outer tubes. In this way, I only need to remove wood from the boom as less as possible to keep strength.

The 2 control rods will be situated next to each other through the boom. I just used balsa glue, this will provide me some time to adjust and position the parts exactly without the risk of filling the hole with glue that will block the control rods later to get them through. CA would be good too, but will not give you the time to settle everything correctly while epoxy has the risk to fill the hole with glue that you can't remove lateron.
The result now is a very stiff boom. Stiffer than the solid boom was before. It has now a width of 8mm against the width of 7mm as before. That will reduce a bit due to sanding.
Sign up now
to remove ads between posts
Jul 03, 2012, 01:00 PM
Registered User

Built-up Pod

It has been a few days ago since my previous post. That is not because I haven't done anything, I just wanted to wait and see if I was able to change the solid pod into a built-up one, and I think I succeeded.
I have added a 4 degrees angle of attack to the main wing. I have used 1.5mm plywood to make the formers. I also made a kind of removable cover that will give access to the RC equipment later.
Next job will be covering the pod with 1mm balsa stringers and add the nose that will contain the ballast to get the CG right.

Notice the push rods going through the formers. I made a small mistake, can anyone see what mistake I made? Can be easily fixed.

The result is very strong and stiff.
Last edited by micheldeman; Jul 03, 2012 at 03:20 PM.
Jul 10, 2012, 07:12 AM
Registered User
The pod has been covered with balsa strips. Glued with CA works fine and fast, no need to wait until the glue has settled every strip that is to be glued.
There are about 60 strips used to cover the pod. From the inside, I have put CA glue in order to improve the strength of the covering, which appeared to be a bit weak. I have used soft balsa, better used some stronger balsa for covering.
Jul 10, 2012, 07:14 AM
Registered User
Actually what you see above is a modified version of the pod of the Jetco thermic 72". A build-up pod giving the main wing an angle of attack of 4 degrees.
Jul 21, 2012, 04:06 AM
Registered User


I have adapted the rear lower part of the boom/rudder, so that the control rod for the elevator can pass trough it. The slot will house the horn for the elevator too.

I have adapted the elevator for RC use. I have splitted the elevator flaps in two parts, connected through a fiber rod on which the horn will be mounted. The horn will be inside the rear lower part of the boom/rudder.
Last edited by micheldeman; Jul 21, 2012 at 04:16 AM.
Jul 22, 2012, 09:15 AM
Blueplaidcanard flyer
I like the tail treatment should look real fine through the covering.
Aug 20, 2012, 06:56 AM
Registered User
I assembled the main wing parts together. I didn't chose to keep them seperated for 2 reasons. 1: it was easier just to assemble them rather than keeping them in 2 parts. 2: it's much stronger and reliable to assemble them together.

I have added a centre rib that wll become part of the canopy construction. I am going to apply the same kind of construction as for the pod, opposed to using solid pieces of wood as suggested by the design.

I am in the process of filling the top of the pod with pieces of balsa wood in order to get enough support for the wing rest. Finally, I will cover the wing rest with 1mm balsa wood.
Sep 10, 2012, 02:33 PM
Registered User
I have finished the wingrest and covered with 1mm balsa.
I also have glued the tail on the boom.
Here are some pictures of the progress.
I only need to make a support for the stabilizer and cover and fix the nose filled with weight to the pod.
Then I need to install the RC equipment and lead the control rods through the boom. As you may remember, I made up the boom out of several parts so that it is hollow inside.
Then to cover the model. I am going to use probably just tissue. It is the lightest option and gives the most strength to the wings, it's only very fragile to dammage when punctured by sharp objects like dried grass straws.
Last edited by micheldeman; Sep 10, 2012 at 02:42 PM.
Sep 10, 2012, 02:50 PM
If the winds blowin, I'm goin!
CashRC's Avatar
Very, very nice. I grew up with Jetco kits in the late 60s and early 70s, so they have a special place in my heart.
Again, top-notch work.
Oct 02, 2012, 11:31 AM
Registered User
Okay guys,

here it is, covered in tissue with coloured trims,

not bad if I may say so,


Oct 02, 2012, 02:02 PM
I like real wooden aeroplanes!
Sundancer's Avatar
Very classy!
Oct 02, 2012, 11:38 PM
The dog ate my clearance
brokenspar's Avatar
Nicely done!
Aug 22, 2013, 03:28 PM
Registered User
After being stored nearly one year after completion, my jetco thermic 72 went out into the sky.
It's flying fine and is very stable, I have had a many thermals already and it's even capable of doing some manoeuvres including loopings. The rudder is very efficient as well as the elevator.
I have been out flying twice now and the floater is really giving fun and satisfaction of the effort put in it during the build. Also the looks are great, especially the double dihedral and bird shape of the main wing is awsome.

See below for 2 videos:

2ch rc converted 50's Jetco Thermic 72 free flight floater / glider (3 min 18 sec)

Jetco Thermic 72 going into thermal (2 min 13 sec)

have fun,

Aug 22, 2013, 07:27 PM
Registered User
Great job, and a great conclusion...congratulations! I especially liked the planked pod and the soaring flight videos.


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Found Jetco G-4 THERMIC 72 Towline Glider Model Kit or others. Beardiedrg Aircraft - Sailplanes (FS/W) 3 Jun 10, 2012 03:52 PM
Sold JETCO Thermic 50-X $100 shipped conus wing881 Aircraft - Fuel - Airplanes (FS/W) 0 Mar 20, 2012 01:35 AM
Sold JETCO Thermic 50-X $100 shipped conus wing881 Aircraft - Sailplanes (FS/W) 3 Dec 26, 2011 07:53 PM
Sold Jetco Thermic 72 Pod & Boom by TMRC Buran Aircraft - Sailplanes (FS/W) 1 Oct 27, 2010 05:53 PM
Discussion jetco thermic 72? balsabozo Slope 6 May 11, 2006 01:06 AM