Graupner Tricopter toy (Hornet 250)

[billyd]

Looks like I started a flame war. I apologize for buying this. Didn’t mean to upset anyone. I’ll return it immediately.

<end sarcasm>

[Terje]

Hey! _I_ started it by mentioning the Graupner Tricopter – but I wasn’t being american-clear about being ironic. My bad 😉

Diversity is good. Please do test it and post your findings. There might be stuff to learn! 😀

It just pains me that a company like Graupner can and will continue to sell overpriced stuff, even when they were so close to bankruptcy because of their greedy business practices 🙁 Have a look at the Flitetest waterproof foam they sell. They just doubled the price in Europe – because they can. Now some guy sells it in Sweden, and has to sell it at a higher price than Graupner in order not to underbid the greedy giant that flitetest has sold their soul to. Dammit.

[billyd]

I get it, and I realize the kit is ridiculous. But that’s why I like it. As far as the price goes, I don’t care about $50. In the realm of FPV rc aircraft, $50 doesn’t even qualify as pocket change.

[billyd]

Just getting around to building this. Using David’s electronics for the baby. Just have to modify the tail (slightly) to fit the slightly larger servo. The hornet will live! (eventually)

[billyd]

Here it is. Uses the baby electronics set from rcexplorer, along with the F3FC racing board and pdb, and the graupner hornet 250 kit (about $50). The kit didn’t come with leds for the eyes so I have them on order.

It ended up about 100 grams heavier than the baby, but it flies great and still a TON of power. Also it is larger than the baby, actually closer in size to the mini. So perhaps you might consider going with the mini electronics but I tell you even with the baby the hornet flies great and fast.

The head has a nice integral mount for a standard board camera, I had a 1000 line one on the shelf with a 2.5mm lens. I am using dragonfly mini tx 5.8 for video. I also have a 25w adjustable voltage regulator and an LC filter for 12v power to the camera and tx.

Using the XR4-SB receiver.

In order to use David’s 210DMH servo with feedback wire I had to re-engineer and 3D print the tail arm, servo holder and tail motor mount. I can’t post the STL’s because even compressed they are about 4mb. But if anyone wants the STL’s just ask and I can put them on thingiverse.

I have to say this is way nicer than I expected. Yes it probably won’t survive a crash too well, but it flies great and looks excellent in the air. I will say that the tail mechanics are superior to the rcexplorer tail. It uses bearings on the tilt mechanism, and is super smooth. I wouldn’t mind David co-opting this design for future tri’s. Also I like the way the servo is held in place, no tie-wraps. The servo is clamped in place and will not move at all.

Attachments:

1. 

   hornet250-1a.jpg
   

2. 

   hornet250-2a.jpg
   

3. 

   hornet250-3a.jpg
   

4. 

   hornet250-4a.jpg
   

[billyd]

Here is an image of my solid models that I created to fit the 210DMH servo with feedback.

Attachments:

1. 

   graupner_hornet_tail_arm_210dmh.jpg
   

[billyd]

Crashed today when I guess I had a failsafe, from 20 feet high. No damage to the frame! Very tough, and I am shocked. Two broken props and a bent tail servo main shaft (it was one of the older aluminum ones). New stainless steel one on order.

This hornet flies great! Loving it. Started out as a joke but it really moves. Went up to 4sx1500 75c lipo to add a little bit of flight time and now it seems to have more power. Probably just because it’s brand new and that 1300 lipo I was using is a few years old now.

I think the power to the rx was cut causing the crash. Replacing that connector.

[izorkus]

Hi

I know this is old topic, but i’m intrested in STL files of Hornet tail arm. I crash today so badly :).. Original Graupner servo is plastic junk. I hope ‘bilyd’ is still here.

[billyd]

You can download the files at the bottom of this post: https://www.rcgroups.com/forums/showpost.php?p=38845780&postcount=12

[izorkus]

Thx man :).

My mk2 is hot already…

It’s your hornet still alive? Which flight controler and firmware you use?

[billyd]

Yes it still flies. Although it’s been gathering dust as I’ve got a lot of projects.

If you read the rcgroups post I linked above it details the setup in detail.

Good luck with the build!

[Author]

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