Modify the $12 Daisy Red Dot BB-Gun Sight for Astronomical Use

You can buy the same red-dot "zero power" reflex sights for 4 times the price or you can go to Wal-Mart and modify one in no time for a few bucks. Most Wal Mart and Kmarts sell these BB-Gun sights in their sporting goods departments, they retail for about $12-$14. You will also need to stop by your local Radio Shack and pickup a 10K PCB mount potentiometer (RS# 271-282 as pictured on the side of the sight above). The lens on the sight has a darkened coating for daytime use, while it is not imperative that this be removed (since you can use the sight with both eyes open and see the same image while not actually looking through the lens) I prefered to remove the coating on mine. The lens is held in with a plastic ring that is glued in. While it looks impossible to remove it actually comes out quite easily since it is flexible. First feel the lens so you know how it is shaped and which side should face out. Now take an Exacto knife and insert it between the lens retaining ring and the outside barrel. Once started it will easily go all the way around the perimeter. Now get something round that you can insert in the other side (cover it with something soft) and push the lens out of the barrel. Now look carefully at the lens to see which side is coated. You can determine this easily by placing a pointed object up to it. If the point and its reflection meet then that is the coated side. The coating may be removed in several ways. I used a dremel moto tool with a polishing pad and red rouge to buff it off. Toothpaste is another mild abrasive that may remove it. Don't buff too much or you may actually change the figure of the lens, just enough to remove the coating. I have also heard reports of people using Muriatic acid to remove the coating (and not even removing the lens, just putting a few drops on it and rinsing). Either way once the coating is removed and the lens reinserted it is time to modify the electrical portion. The LED is way too bright for night time use, a potentiomer added to it will function as a dimmer. Remove the vertical and horizontal adjustment screws and the sight will open into 2 pieces. Drill tiny holes in the side where they won't interfere when it is reassembled (look at the picture for where I put mine). Take one of the wires off the switch (or cut it) and bypass it through the potentiometer. The potentiometer has 3 electrical contacts, one on each side of the resistance medium and 1 on the sliding contact. You want to use the center one (the sliding contact) and either of the other 2 depending on which way you want it to dim or brighten (as the sliding contact moves towards the connector you choose the LED gets brighter). Mount the "pot" and wire it up, reassemble the 2 pieces and center the adjustment screws. For mounting you can either remove the included "dovetail" pieces and just stick it on with 2 sided tape or you can use the dovetails to mount it to something (in the picture above it is mounted using the dovetail brackets to secure it to a self adhesive "Utility Wire Clip" (RS# 278-1647A). Once you mount it, zero it in and adjust the brightness you will wonder how you ever got along without one. With the money you save you can make 2, one for your main OTA and one for your guide scope! If all this is too much work for you just order our economical ScopeTronix LightSight!