Pixie Mk1 Pterror-Gnat

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davejones
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Joined: 16 May 2022, 10:06
Location: Hervey Bay Australia

Pixie Mk1 Pterror-Gnat

Post by davejones »

Flushed with the succes of my Kraft 7c rest-conversion here:
viewtopic.php?f=27&t=1525&sid=182b97a20 ... 10cf001fad
I've had a go at making a Pixie Mk1 replica to steer my Pterror-Gnat model. Pterror-Gnat is a vintage style, rudder only model that was designed by a club-mate to be powered by one of the Les Saxby 0.13cc Gnat replica engines that I built. It has a wingspan of 21.5" (550mm) and weighs 2.54oz (72g) ready to fly. If you're interested, there's a write-up of my engines in the Jan 2022 edition of AeroModeller magazine.

Video of the Pterror-Gnat and engine showing a trimming flight using a fully proportional radio.


For the Pixie, I used Mike_K's 'Yet another single channel encoder' sketch and excellent instructions found here:
viewtopic.php?f=24&t=609
RF is provided by a Lemonrx DIY transmitter module.
I 3d printed the case on a resin printer using drawings by Mike Kitchen but cannot remember where I found them.
I modified the drawings in OpenSCAD to suit myself. Modifications included making the top/bottom and walls thinner to easier fit the boards and battery, removing the mounts and holes for RF module, adding a battery compartment and changing the on/off switch centres to 15mm. I've added the modified OpenSCAD files to the 3D Files forum here:
viewtopic.php?f=72&t=1561

Pics of the Pixie and Pterror-Gnat below. I have had about a dozen flights using the Pixie and now have it (my brain mostly) pretty much sorted out.
PixieMk1PterrorGnat.jpg
PixieMk1Open.jpg
Dave Jones
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Mike_K
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Joined: 16 Feb 2018, 06:35
Location: Hertfordshire

Re: Pixie Mk1 Case - Modified

Post by Mike_K »

Hi Dave

That is the most realistic "re-creation" I think I've seen, the resin print looks superb, in fact, indistinguishable from an original Pixe. Do you have a resin printer or did you use a commercial service? I had to keep the original walls a thickness I could print, but it does look like it gives you a few millimetres extra room and every little extra helps.

The LemonRx DIY modules are very compact, for most installations I find I have to replace the ipex/sma lead for a longer lead, but in such a small case it looks plenty long enough.

What are you converting/recreating next, an OS Pixie MK2?

Cheers

Mike
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davejones
Posts: 22
Joined: 16 May 2022, 10:06
Location: Hervey Bay Australia

Re: Pixie Mk1 Case - Modified

Post by davejones »

Hi Mike.
Thanks for the kind words and also thanks for making the original files available. I know how much work goes into drawing this kind of stuff.

I have a Photon Mono SE printer. A recent purchase that I'm still finding my way with. It took three attempts at printing the Pixie case before I worked out settings and supports etc that gave a decent result. The case walls are very slightly warped but not really noticable. I think the whole thing looks a bit better now that it has a bit of weathering (fuel stains).

Pixie Mk2 did cross my mind but maybe a couple of projects away as I have an MRC transmitter waiting for a resto/conversion and also a vintage fixed pitch rc heli that needs a major rebuild.

Cheers
Last edited by davejones on 28 Sep 2023, 10:49, edited 1 time in total.
Dave Jones
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Mike_K
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Joined: 16 Feb 2018, 06:35
Location: Hertfordshire

Re: Pixie Mk1 Pterror-Gnat

Post by Mike_K »

I hope you don't mind, I've moved my reply about the OS Pixie to the Single Channel section as it's where I had intended to answer
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