Keil Kraft Gypsy Build Series - Pt 5: Fitting a Dethermaliser - 1949 Design by Bill Dean

[@christopherhutchinson8043]

Remember making one for my first free flight glider , and the fuses to go with it , string soaked in salt peter

[@StiloFpv]

Good going Mark🤠👍🇿🇦🛩️

[@MarkRobinson555]

Thank you very much, pleased you enjoyed it 😀

[@farayidarlingtonchaparadza20]

Another great build in the works. Loving it!

[@MarkRobinson555]

Glad you enjoy it!

[@freeflightscale]

I like how you added a flare to the end of the aluminium tube. I will certainly be using that idea! I also like how you’ve done the DT on the tail as well. It looks very neat and tidy. 👍🏻 I use talcum powder mixed in with slow acting CA to fill areas and add strength. Does the same thing as your method with the epoxy and balsa dust, but you can hit the CA with kicker to make it go off much faster.

[@MarkRobinson555]

Glad it was helpful, thank you very much for the comment, really pleased you enjoyed the video 😀

[@NormanLedoyen]

Nice way to swage that Mark. Looks perfect for small wire like you are using. Very impressive.

[@MarkRobinson555]

Thanks Norm, pleased you found it interesting 😀

[@MarkCroucherRC4fun]

The control of the rudder will be interesting with the DT in place.

[@JamesBaker-n5x]

With pull - pull cable it will work fine.😊

[@MarkRobinson555]

Yes, that is what I have used. I have seen people use flexible snakes in such situations, but I didn't feel it looked good and it could cause jamming issues I think 😀

[@alfredvink]

Looks stunning, I might have a go at it myself. Never build anything with a dethermalizer or rubber powered before.

[@MarkRobinson555]

Go for it! Its a lovely iconic model and is a nice build. Pleased you liked the look of it, thanks for the comment 😀

[@terryblackman6217]

I'm so looking forward to see how you get over the problem of controlling the rudder at 45 degrees.

[@MarkRobinson555]

@@terryblackman6217 Hi Terry. There will be no rudder control once the dethermaliser is activated, as it will not be needed and if you could control it it wouldn't be effective. At this point the model should be descending vertically- hopefully! 😜

[@Arclike]

​@@MarkRobinson555 Im thinking maybe pull-pull cable system?

[@MarkRobinson555]

Yes absolutely, best way to go, thats how I have done it and it works well 😀

[@CliffHarveyRCPlanes]

An interesting modification Mark, I'm guessing the rudder will have pull-pull strings that will go slack when you operate the DT?

[@MarkRobinson555]

@@CliffHarveyRCPlanes Hi Cliff, yes absolutely Pull, Pull will work well. I have seen people use a flexible snake, which worked ok, but really didn't look good 😀

[@EleanorPeterson]

The Gypsy's a lovely model, although that name is apparently "offensive" these days.🙄 Perhaps there'll be calls for it to be renamed the 'Traveller'. [🤭] You're right about dethermalisers not always being effective. I remember losing a 3' span free-flight glider when I was about 10. (I'm based in West Yorkshire.) Attached the towline, got my dad to light the dethermaliser fuse, launched it into a summer sky on a baking hot day at around noon. There was no wind; we were flying on the edge of a freshly harvested cornfield (corn as in wheat, not maize/sweetcorn). Farmers were still allowed to burn stubble back then; nowadays it has to be ploughed back in. The ground was warm and there was a smell of smoke everywhere. It was a cracking flight. Even the local buzzard came to see what was going on. Up, up, up, circling lazily... Counting the seconds till - POP! The dethermaliser released. But the model kept rising. It wasn't flying - it was just being dragged upwards, tumbling through the air like a balloon. I watched in tears as it went, heading for the base of a monstrous grey cloud. My dad was sympathetic, but I was as much exhilarated as I was upset. I'd never seen anything like it before; it was a fantastic moment. We watched it through binoculars until it was gone. There was a lot of rain in the afternoon, rain and pea-sized hail, so I like to think that my little tissue-covered morsel was eaten by a storm cloud which chewed it to bits with icy teeth, then spat out its balsa bones over some other field several miles away.

[@MarkRobinson555]

Thank you for the comment and memory, so sorry you lost your plane, it must have been well built! Very bitter sweet! Pleased you are enjoying the videos 😀

[@RichardTapp1]

Maybe put two 1/8" square strips on the top of the fuselage, adjacent to the front of the fin, so that the fin is captive in the slot they form, avoiding the risk of the bottom of the fin jamming on the edges of the slot in the top of the fuselage ...

[@MarkRobinson555]

Hi Richard, thanks for the suggestion, it's greatly appreciated. You will see the front underside of the fin has been extended down, so that it is always positively engaged in the slot, having the same effect as you suggest. Thanks again 😀

[@Ouch.]

Surely if you're going to add another servo why not fit a rudder and elevator?

[@MarkRobinson555]

There is no reason the tailplane couldn't be altered and an additional servo added, but it all adds weight and I didn't feel it was necessary. I have to have the rudder due to the restrictions where I fly

[@stephenwoodmansey3333]

Why not just fit elevators rather than dethermaliser ?

[@MarkRobinson555]

I have had vintage models, with reletively small elevators stuck in thermals so was thinking this would be more effective. Also, just fancied doing somthing a bit different, not somthing I have done on the channel before. Good point, thanks for the comment