Thermic 50, 50-X and 70

The classic Frank Zaic/Jasco designed Thermic 50, 50=X and 70 are all here. These vintage kits have been updated and adapted by Tom Martin to build in about half the time with self-jigging and pre-shaped parts. Each laser cut kit comes with the original plans and all the parts you need to build each model - you supply the covering. All three of these kits can be built by a beginner but will be challenging. Those of you who have done balsa build-ups in the past will find these builds to be most satisfying. We also have build logs for each model that you can find below:

Thermic 50: Scroll down on this page.

Thermic 50-X: Scott Voigt did a detailed log here: Thermic 50X - Scott's build log.

Thermic 70: Adrián Muiño from Argentina is doing an electric Thermic 70 here: Electric Thermic 70 - Adrián's build log.

THERMIC 50

The Thermic 50 has the the classic lines of a majestic floater. The Thermic 50 is a great winter build project which can be easily completed in a few weeks of dedicate effort or take your time over the long winter. I guarantee as you build the Thermic 50 your face will light up as you walk into your shop and see this beauty come to life!
 

Thermic 50 build log can be found by scrolling down this page. 
 

The kit comes with complete plans.

Span: 49"
Length: n/a
Aspect: n/a
Area: n/a
All up weight: n/a
Wing loading: n/a
Airfoil: n/a
Scale:
Servos Req'd: Optional rudder, elevator.
   
FUNCTIONS: Free flight or RC

PARTIAL KIT CONTENTS: Kit comes complete with laser cut parts and plans.

All of our vintage gliders can be purcahsed at our company store www.gliderworkshop.com.  

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THERMIC 50-X

Young Scott Voigt is launching his Thermic 50X. The Thermic 50X is a close cousin to the Thermic 50 with the major difference being the fuselage. The 50X has a pod and boom construction which gives it a quite racy profile. 

 

Thermic 50-X: Scott Voigt did a detailed log here: Thermic 50X - Scott's build log.

The 50X comes with complete plans...

Span: 49"
Length: n/a
Aspect: n/a
Area: n/a
All up weight: n/a
Wing loading: n/a
Airfoil: n/a
Scale:
Servos Req'd: Optional rudder, elevator.
   
FUNCTIONS: Free flight or RC

PARTIAL KIT CONTENTS: Kit comes complete with laser cut parts and plans.

All of our vintage gliders can be purcahsed at our company store www.gliderworkshop.com.  

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THERMIC 70

Below you see Adrián Muiño about to toss off his electrified Thermic 70. The Thermic 70 is the big brother to the Thermic 50. The 70 inch wingspan produces a magnificent profile in flight. If you ever thought about powering a Thermic Adrián's build log is an excellent resource. 

 

Adrián Muiño Thermic 70 build log is here: Electric Thermic 70 - Adrián's build log.

 

The Thermic 70 comes with complete plans.

Thermic 70: Adrián Muiño from Argentina is doing an electric Thermic 70 here: Electric Thermic 70 - Adrián's build log.

Span: 70"
Length: 34 3/4"
Aspect: n/a
Area: n/a
All up weight: 12 oz
Wing loading: n/a
Airfoil: n/a
Scale:
Servos Req'd: Optional rudder, elevator.
   
FUNCTIONS: Free flight or RC

PARTIAL KIT CONTENTS: Kit comes complete with laser cut parts and plans.

All of our vintage gliders can be purcahsed at our company store www.gliderworkshop.com.

Please email us at [email protected] or call 816.331.8807 or 415.234.6757 if you have any questions or need assistance with ordering, we appreciate your business!

THERMIC 50 Build Log

I want to keep this build as close to the original plan as possible - which means I won't be using any carbon or kevlar and I won't be substituting fir for balsa for the spars. I will adapt the design to add RC control - rudder and elevator - again trying to make this addition as "not-intrusive" as possible. Your humble builder is intermediate at best with my skill set so expect a few mistakes along the way that Tom can correct and we can make sure you don't do when you do your build. I'm thinking I'll fly the Thermic 50 on some of our gentler slopes here in Northern California on days with a slight breeze.You can hand tow this also and I think it will take a very gently bungie launch.

Step 1 - I'll start with the wings. My order of build will be center panels, then tip panels. Make sure you read the plans carefully. Frank Jaic has excellent pointers written all over the plan plus his suggested order of build is spot on. My first step was to lay out the parts and trial fit everything.

 

 

Step 2 - Building the center panels. When you've layed out all the parts for the center panel make sure you get the ply dihedral braces placed in the rights spots and the correct orientation. If you place the braces over the plans you'll see where they go.

 

 

 

 

Step 3 - The tip panels. The tip panels build just like the center panels.

 

 

 

Step 4- Joining the tip panes to the cneter panel

 

Basic wing structure complete.

Step 5 - Framing the fuselage

 

 

 

 

 

 

Step 6: Horizontal stabilizer and elevator

 

Step 7: Removable canopy

 

 

Step 8: RC equipment bay

 

Step 9: Test fit all parts

 

 

Click the link for another online build log: building the Thermic 50X and 72.

Comments

[Tom Martin]

Nicely done Mike!

[Tom Martin]

It looks like the fuselage went together very straight. How did you accomplish such a uniform build?
I check all of the parts drawn on these old plans as I draft each and compare them back to the respective station points in both side and top views to make sure that the fuelage in this case remains fair and smooth in both the main side longerons and the upper or lower stringers. How did I do?

[Bolt 55]

Hi Tom,

The fuselage went together quite nicely. At this smaller scale I prefer not to use "mechanical" jigs but instead to build "in-hand" continually fussing with it to make sure everything is straight and uniform. You can do this with a 60" model - you can't with 1/4 scale and up. So this is how I did it.

1. Cut the vertical side braces in pairs so you have EXACTLY the same length brace for each side.

2. Build the sides flat on the plans. I liked your suggestion of building the second side on top of the first after first laying a piece of wax paper between the two.

3. With the sides complete clamp the tail end together - but make sure you have a little freedom of movement so you can scrunch things around.

4. Next take formers 6 and 7 and fit them into place. I marked in pencil on the side of the fuse panels the locations of the formers. Use a thin rubber band to clamp the nose section and hold the formers in place.

5. Now fit former 1a at the tip of the fuselage letting your rubber band provide the clamping tension. You now have the basic geometry of the fuselage in hand so you can scrunch the parts around until you have perfect alignment.

6. When everything is perfectly aligned use CA to glue one former in place 6 and 6a is a good place to start. Eyeball your work again make sure everything is still uniform then move on to 7 and 7a. Then do the tip former 1a.

7. At this point you should still have your mechanical clamp on the tail. Do one last visual walk around to make sure everything is straight and then CA the tail together - but first make sure you've tapered the inside of the tail sides so you end up with a 1/8" cross section per the plans.

8. From here on out it goes together like a jigsaw puzzle. Great job Tom on the adaptation and Alex on the cutting.

[Bolt 55]

Hi Tom,

I'm trying to strip 3/32" square balsa. Grrrrrrrr...

I'm torn about offering the long stock cut to length for the stringers, longerons, braces, etc.

I could make it work with 1/8"square but I want to keep it as close to original as possible.

Any suggestions on stripping/cutting 3/32" sq?

[Tom Martin]

Mike, I've done it with the Master Airscrew stripper but have probably experienced the same thing you are - the knife tends to follow the harder grain at times making the fence wander and resulting in a wavy cut.

I would suggest leaving the blade partially up for the first cut and then lowering it to make the final cut.

I've also contmplated making my own jig, laser cut of course, with an extended fence or fixing the entire jig to the benchtop and passing the balsa through the cutter rather than passing the jig along the balsa.

I hope this helps.

[Yohan]

What a great looking glider.I will clear my work bench and order on soon.Thank you Yohan

[Bruce Carroll]

I have ordered a Thermic50 kit from you and was wondering if there are ant tips about electrifying it and adding the alavator to the stab.
Thanks,
Bruce.

[Mike Smock]

Hey Bruce... Go to the build log section - there is a build log for an electric 70...