I have now sorted through the batch of 300 or so L-2 motors that the estimable Terry Kidd collected from Dr Zigmund earlier this year. They were labelled "19 sec, "20 sec", "22 sec" and "L-2 LT 26 sec". I would guess, that, as in the past, these labels are Dr Z's best (theoretical?) estimations, so it is always worth putting a couple on the test rig and see what happens.
This I have now done with these, with the following results:
Note that the '+ -' refers to the standard deviation of the actual thrust data; the range of thrusts over the burn duration was greater than these figures might suggest. As usual there was an initial high 'pulse' of thrust before it settled down (and one would launch the model!).
The first thing to say is that all these motors are usable: the L-2 LT, which would be just perfect for a light profile model and the '19 sec' motor will be very happy in a built up scale job. We have quite a lot of these so they will be my 'default' choice on the flying field and to share. As can be seen, that the more thrust, the less duration, so these results kinda make sense. All motors lit well.
This is encouraging, so I'm now ready to box up batches of motors pass on these to happy flyers. All boxes will be labelled with the motor spec and my confidence that what you see on the box is what is inside!
Prices will be £15 for a box of 10, £25 for a box of 20. I estimate p & p will be about £3.50 within the UK.
So, as they say, "Hurry Hurry while stocks last".
When these stocks are finished, we are now in the happy position of being able to fly with the TSP motors (see the separate thread on these new motors).