|These are really good chronys, well worth the money.|
Having spent just over £100 on a new chronoscope, I have spent many happy hours discovering the power output of all my air rifles. Unfortunately it was always dependant on good weather.
So it's into the shed for my testing, where I can't get a reading without a lighting system. Those things can cost up to £50 if you buy the matching set to go with the chrony unit you have purchased, however it only costs a fraction of that to make your own. You have to use the old style non energy saving light bulbs which you can plug into the mains and connect to the underside of the light diffusers, or cheaper still, use the type of battery powered LED lights - the ones that don't stutter, as you won't get a reading otherwise.
|Cheap and chearful lighting system.|
I went for the latter, choosing a common type made by Rolson that have a magnet on the back and a hook for camping purposes. They cost anything between 3 and 6 pounds each; I got two for 6 quid from B&Q.
|Magnet and Hook on the back.|
The magnet was not strong enough to hold the light to a piece of metal resting on top of the diffusers from underneath, and the light is not strong enough for it to work if resting on top.
|Plenty of LEDs for the job in hand.|
So I cut a strip of thin steel with some tin snips and rounded off any sharp edges, then folded it in half to make a clip.
|It's best to fold the metal around a pen or something, clips onto the diffuser easier that way.|
The metal clip held on to the diffuser without any movement; it needs to sit in the center of each diffuser for the lights to get the best readings on the chrony.
|The clips are not going anywhere.|
The lights stick to the metal on the underside of the diffuser and it takes a firm tug to remove them, so there's no chance of them falling off if the unit gets knocked.
|twist the light around until the on/off switch is in the best position for your taste.|
These lights take three AAA batteries and that will last quite a few hours with constant use; i've used these lights camping before and left them on all night with a decent set of batteries in them and they still worked the following morning.
|Believe me it works a treat.|
There are other styles of lights and torches you can use but it's important that they are the type that give a constant light and not stutter like the flourescent tube lights do. Any hardware shop or camping shop should sell them or they can easily be found online.
The whole thing took 15 minutes to make and only cost 6 quid as I already owned a set of tin snips, but you could even pick up a set of tin snips for a fiver if you don't have any and that's still a massive saving on buying a professional unit.
Best wishes, Wing Commander Sir Nigel Tetlington-Smythe.