TOPIC: Flying capacitor powered models

These are my models using the Power Up capacitor units, a Cutlass, DH Swallow and my own design Swallowtail all made from Depron and have been out flying (or trying to fly) them a few times lately for short periods in nearby small fields. Although these are not Rapier powered they are scalish models of jets or they could look like jets so I hope they are not out of place here. Unfortunately the actual capacitors in these cheap units designed to power a paper dart are variable and sometimes only have a short life. However when they work and the model is light enough they do work very well, for instance this morning I had several 40 second flights and one 55 seconds thermal assisted flight with the Swallowtail which weighs all of 13g. The Cutlass weighs in at 16g and will fly for around 25 seconds but today the capacitor decided to gradually fail and despite new batteries the flights got shorter and short. The DH Swallow weighs 18g and while in the past it has done long low flights this time it would not even do a powered glide so I have put in an order for some replacement units, as the fault seems to lie with the capacitor perhaps I also try to find a replacement somehow for those. They are fun and easy to fly as there is no messing with igniting fuses or winding rubber, below is another model using a different power unit (from an X Fighter model?) for Bill Dean's Spook seen here with the larger Rapier version, this was a very good flyer both for indoors or outdoors until I gave it away, pity, I’ll have to make another.

I can attest that these sorts of models can fly very well. They are a good relaxation from making the more demanding rocket-propelled models and fun (and cheap) to make. They are also a good introduction into these sorts of models.

Way back in 2016, and looking for a suitable 'jet' subject (large area with delta wings) I put together a model I was also considering for Rapier power, as there was already an all sheet profile plan out there:





I left off the jet pods off but otherwise stuck to the old ('Model Aircraft'?) plan.



The capacitor could be hidden in the canopy:



and the motor hidden as a 'pusher':



The fuselage is foam with light thin balsa sheet sides ; the wings are thin insulating foam covered with tissue (both sides) with a balsa leading and trailing edges and the fin is 1/16" Depron. The elevons and rudder are hinged as a trimming aid.

It flies very nicely indeed, cruising around at head height in wide circles, though it needs a large hall or a very calm evening.



I might try Howard's Cutlass (I have the templates) as a relaxation from preparing and posting off Jetex.org kits (this 'lockdown' has been good for business) .

What is the weight of your Arbalete Roger. I found that lighter is better as the power runs down very quickly, the best flights I had were with the Swallowtail, that weighs 13g.
I mounted the capacitor unit underneath the fuselage on the Cutlass and DH Swallow but had to modify the charger a bit to access the charging point from the bottom rather than the front.

Hi Howard,
it weighs a tad under 20 grams. You will note there is plenty of wing area, so wing loading is not an issue. Perhaps I made it a bit big, though its size is predicated by the length of the thin rod that takes the wires from the capacitor to the motor .

It flies OK, but never gets much above 10 ft.

I have other units in the workshop - perhaps now is the time to build another capacitor powered model. We will see.

Thanks Roger, at 17.5" wingspan and 18g my DH Swallow flew much the same but only about 5 ft off the ground for some considerable distance outdoors. I should do a smaller one as it would be easy to mount the capacitor further forward and lose some of the 0.5g nose weight. If I shrank it by 4/5ths it would work out about 13.5" wingspan and maybe I could do it silver, and if I could get the weight down and the drag would be down perhaps it would be sparkling, perhaps. All good, I like to dream, err plan ahead!! Hmmmm, must get on with the Sabre though...........

Roger comments: get back to the Sabre, Howard ....

I've decided to repair the two duff capacitor power units I found in the last flying session by installing new 2.7V 3.3F 8 x 20mm capacitors from Radio Spares. Slightly slimmer and 0.5g lighter the units now work as they should, hope they will last. This morning I have been reinstalling them and repairing the Cutlass and DH Swallow. The underside of the Cutlass shows the charging port for the modified charger unit, maybe I will be able to fly three of them in the calmer weather tomorrow.