Monday, 7 May 2018

Imp... my UK Rocket Altitude record!



 So.. Had a fab weekend. I travelled down to the mighty BigEARS rocketry event (another post on that later) and whilst I was there I finally got to launch my imp scratch built rocket and set a new UK rocketry altitude record in the A impulse class! The previous record was from 2013 and set at 143 metres and I am very happy to report and show that imp achieved 214 metres!

So above is imp just prior to launch, I managed to nearly half the mass of this rocket  compared to the previous record holders airframe. Imp weighed just under 18grams and this was achieved through some saving of weight due to the altimeter but also through my 3d printed transition and nosecone. I printed both these objects as a single filament line wall 0.4mm wide with no infill, I then sanded the outer surfaces smooth further reducing the wall thickness... the nosecone weighed less than half a gram!

As you can see I went for a standard rail deployment with a short standoff rail lug and there are certainly gains to be made if I did another attempt using piston ejection launch methods. I sanded down the estes tubing to reduce weight and also did a small bit of an attempt to aerofoil the thin balsa fins.. I now have some thin 0.8mm g10 fibreglass sheet in stock and would probably go with that as a fin material if I had another attempt!


I fiddled about on the pad for far to long getting it to sit right and at the height on the rod I wanted. Then returned to the control box and got the countdown from the very experienced range safety officer (RSO) Rod Stevenson. It leapt of the pad and shot away... it wasn't actually the most straight or vertical flight so, again, some gains to be had there. It deployed its small silver mylar streamer well and came down ok. Took quite a while to find the tiny airframe but me and my brilliant teammate Seren Hinchliffe searched and recovered it with payload section and airframe intact. We walked back to the RSO area, nervously opened the payload section and retrieved the altimeter... which was happily blinking so I knew it had logged ok! (Incidentally I followed the Perfectflite guidance diligently on the vent hole advice which resulted in 4 holes at 90 degrees at 0.8mm each around the altimeter bay).

I gathered a legendary bunch of witnesses, Rod Stevenson, (EARS  RSO), Charles Simpson (UKRA Chair) and Andy Mell (UKRA council) and a few others and we counted the blinks on the altimeter indicator led numerous times making sure we all agreed and had seen it (and I video'd the LED!). It reported 703 feet which converted to a shade over 214 metres... :) Job done! Massive thanks to the above and particularly Charles for nudging me along that morning to fly and also massive thanks to my team mate.. Seren who took photo's, carried stuff and helped massively in the search part of the flight!


A happy, hot and been camping in a field scruffy record attempt team. x

3 comments:

The Rocket N00b said...

Whew! That thing is tiny!

Was that the Firefly altimeter you used?

Congrats on the record!

jo hinchliffe said...
This comment has been removed by the author.
jo hinchliffe said...


Yes! Perfectflite Firefly and thanks for the congrats! Love your recent post about paint and weight!