Bavarian RC – Messerschmitt 410 Hornisse (Hornet) - design and build

[Bavarian_RC]

As promised a little update on the Me-410.

During the build of the V1 fuselage and also during the first flights it was getting more and more clear that I had to do a major re-design of the fuselage.

The main objectives were:

• Reduce weight
• Position the battery further back (I needed a lot of balance weight in the tail of V1)
• Replace the slide-on nose cover by a canopy hatch
• Improve the design of the canopy
• Make some small improvements on the wing attachment
• Improve the horizontal stabilizer

Quite a long list and I think I even forgot to list some of the further modifications I made.

So here we go: Fuselage V2!

The inner structure of the rear part is quite similar to V1, just added some lightening holes in the middle sheet and made the spine a little longer to support the horizontal stabilizer. The forming of the rear skin is quite tricky due to the tight radius on the bottom. Maybe I will try to split it next time into a forward and rear part.



The horizontal stabilizer now has a BBQ skewer on the leading edge and the paper wraps around to give it a clean look.



The forward fuselage structure with the pieces for the wing attachment and the formers:



Installing the skins on the fuselage front part. The nose was the most difficult part and I think I made in total 5 or 6 versions until everything was fitting and I had found a repeatable process for getting this good fit.

In the next post I will show you the progress I made on the canopy hatch. But that’ll have to wait for another day…

 

[Bavarian_RC]

These are some pictures of the second version of the canopy hatch. I will do some more modifications based on the experiences I made in order to ease the build process and make it repeatable (e.g. a longitudinal former with slots to easily position the formers at the correct spot.

The attachment of the hatch caused some headaches as I didn’t just want to use magnets. My main concern was that the airpressure during flight could go inbetween the hatch and the fuselage and lift it up. So finally I came up with a simple 3D printed hook that slides into a slot of another 3D printed part that is installed on the fuselage. When sliding the hatch all the way back the hook grabs the horizontal plate at the rear of the slot and locks the hatch in place. To complete the attachment I added a magnet at the rear end of the hatch.

 

[Bavarian_RC]

Last weekend I had the re-maiden with the new fuselage. It flew very nice from the beginning - even in the windy conditions we had. With the new fuselage design I was able to position the battery a lot further back which really helped with the CG. On V1 I had to put 46 grams in the tail to get it to balance. On V2 I only needed 6 grams. If I would paint it I think I wouldn’t even need any weight in the tail as the paint usually makes a plane more tail heavy. The canopy hatch was also holding tight to its position.

Finally I have decided that it is time to work on the beta plans in order to make them available to you soon. So give me a few more days to clean up the plans and write a short build instruction.

Once done I will post it here in the thread, so stay tuned!

 

[Bavarian_RC]

I have just uploaded the first release of the Beta plans V1.0 (see first post).

You will find there:
- Plans Beta V1.0 (All-In-One) at full size
- Plans Beta V1.0 tiled A4
- Plans Beta V1.0 tiled letter
- Build instructions Beta V1.0
- ZIP file with all STL files Beta V1.0

As the plans are still in Beta status you might find the one or the other mistake or inconsistency. Just let me know and I will update the files accordingly.

Have fun building

 

[tomlogan1]

Let me wrap up my progress of last week. I finally started building the wing. As you can see it’s a classic fold-over wing. In the outer section I added 2 BBQ skewers on each side to reinforce this area. This is something I use on every wing I build.

View attachment 183883 View attachment 183884

The double spar is reinforced by two 4mm plywood spars that have some lightening holes to save a few grams. The other 2 plates are reinforcing the area of the wing attachment. You’ve already seen this at my test wing.

View attachment 183885 View attachment 183886 View attachment 183887

By gluing the fwd and aft plywood spar to the foam board spars the wing gets the desired 4 degree dihedral on both sides.

View attachment 183888 View attachment 183889 View attachment 183890 View attachment 183891

The fwd and aft reinforcement plate for the wing attachment are in place. You might have noticed that I have added flaps to this design. There were 2 reasons for this. First I always wanted to test flaps and second, I want to reduce the landing speed as much as possible to avoid breaking props. With the nacelles so close to the ground there is a real risk of breaking them.

View attachment 183892 View attachment 183893

That's all for this week. More updates latest next weekend...

Very inspirational. Excellent work. Thanks for sharing.

 

[Bavarian_RC]

Very inspirational. Excellent work. Thanks for sharing.

Thanks a lot! Just started a new project: Building the ERC TimSav. The first plane to be cut with it will be the final version of the Me-410. That one will also get painted. Not sure if I will make a build video or just a time lapse build... let‘s see.

 

[cochise99]

Thanks @BATTLEAXE that means a lot to me!

Your hard work and attention to detail in your description and photos are welcomed.

 

[cochise99]

The nose cover is now held in place by two magnets.

View attachment 187698 View attachment 187699

To complete the scale look of the Messerschmitt I designed 3D printed spinners. They consist of a base plate with 2 square nuts and a cone that is screwed onto the baseplate with two M3 screws.

View attachment 187701 View attachment 187702 View attachment 187703

The spinners make a real difference. Came out great!
All of the electronics are also installed, the throws of all control surfaces setup and the CG dialed in. Due to the specific design of the Me-410 with the motors so far in front I had to add 46 grams of weight to the tail to properly balance the plane on the CG. So much dead weight is definitely too much. For the next version I will have to redesign some parts to save more weight in the nose. The best opportunity will be to relocate the battery over the wing (once I have re-designed the fuselage to make it accessible from the top with a removable canopy instead of the slide-on nose cover).
The AUW is 1016 grams, the wing loading is 58.7 grams per dm2 (19.24 oz/ft2 … if I well converted it). I will definitely be happy to have flaps!

So all is ready for the maiden, just need to wait for better weather.

View attachment 187708
View attachment 187710
View attachment 187711

BRAVO!!

 

[Bavarian_RC]

I haven't been around the forum for a while. Just noticed that I never posted any pictures of the painted Messerschmitt 410.
So here we go: