Rapier L-2 type Motors in the USA
The lack of Rapiers has been a great source of frustration to US modellers, but it has been a great spur to the development of 'Micro EDF', but not everybody has been happy with the status quo, and Chris Sorenson of Maker Research Labs is determined to do something about this, partly because he believes the excitement of rocket planes will be a great way to get youngsters enthused about science and technology. I have been liaising with Chris for over a year and he and his colleagues have developed a Rapier L-2 analogue that looks most promising. I received examples of their prototype X-1 and X-2 motors for testing earlier this year. As Chris has gone public with his endeavours:
now is a good time to publish my results. I also tested one of the 2017 L-2 LT motors for comparison.
The thrust time profile of the L-2 LT ‑ a very useful 125 mN for 18 seconds ‑ is in-line with the many fine flights we have seen with these motors and shows just why they are so popular. The X-1 motors, of very similar size and weight to L-2s, fired up without problems, and their performance of roughly 140 mN for 12 sec is promising. A little more duration would be nice, and experiments with the jet orifice diameter and a combustion inhibitor could pay dividends.
Below are the 'empty' brown X motors with a used Rapier L-2 motors for comparison
Added 6 May 2017:
Have a look at Chris's latest video:
The thrust of the latest motors appears 'spot on' ... we just need a little more duration!
Rapier Motors 2017
I really should update info on the availability of Rapiers more often as there still seems to be the 'fake news' out there that you can't get them!
Well, we still have stocks of L-2 and L-1 motors of good performance. The current L-2LT motors are particularly nice:
This, in old money, is about 1/2oz for nearly 20 seconds - which is equivelent thrust to a Jetex 50 for a gratifying 6-7 sec longer. They work splendidly in my Veron Quickies and Keil Kraft shadow profile models, f'rinstance the Shooting Star:
Note the Rapier in a Jetex mounting clip -this allows comparisons of the L-2LT and original Jetex 50 to be made easily. Interesting!
Hurry whilst stocks last! Dr Z hopes to be in the UK in July with fresh supplies - contact me for updates.
Jetex and Rapier related ‘blogs’
Welcome to the first of what I hope will be regular 'Jetex and Rapier related 'blogs'. As this is my first foray into the 'blogosphere' it will take me time to find my niche, so please bear with me.
These will of course be full of interesting observations about the modern 'small model jet plane flying' scene which will motivate a loyal cadre of enthusiasts to keep up with the latest news about motor availability, upcoming meetings and how to take part in what I hope will be a growing part of the free flight aeromodelling scene. Note the 'free flight' bit. I have nothing to say about those marvellous and sophisticated RC jets that we see showing off at meetings. However, free flight EDF is pertinent to our hobby and is one way of keeping our models flying. We shall see!
What with the winter weather – my own flying field is more suited to hydroplanes than aeroplanes at the moment – I have been designing some new models for the new flying season. These are simple 'semi-profile' models like the Cougar above suitable for the latest batch of Rapier L-1 and L-2 motors.
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