| These nine no-tool knobs make it easy to collimate both the primary and secondary (diagonal) mirrors of your Meade 12" LightBridge Dobsonian reflector for optimum image quality. You don’t need any tools, so you never have to worry about dropping the flat blade and Philips head screwdrivers that you need to collimate the factory screws and losing them in the grass in the dark (or, worse yet, dropping the diagonal mirror screwdriver on your primary mirror). Purchasing this set, containing both primary and secondary mirror knobs, eliminates the need to carry two different screwdriver types out into the field. It also saves you nearly 10% over the cost of buying the two sets of knobs separately. Installation of the knobs is a snap with the included instructions, and you can undo the modification at any time. All the screws used in this Bob’s Knobs set are made of stainless steel. The knobs on the primary mirror collimating screws are five-point smooth fluted black plastic, 30 mm (1.25") in diameter. The knobs on the primary mirror locking screws are knurled black plastic, 25mm (1") in diameter. The difference in size and shape assures that you won’t confuse the function of the knobs in the dark. The telescope optical tube assembly will clear the rocker box with the collimation knobs installed. The knobs on the secondary mirror screws are knurled black plastic, 13mm (1/2") in diameter. These knobs are small enough not to impinge on the scope’s light path, yet large enough to grasp and turn easily, even when wearing gloves in cold weather. The factory dust cover will fit normally with the collimation knobs installed. One of the primary mirror knobs may interfere with the cooling fan connector. The cooling fan plug will fit properly between the knob flutes (as shown in the feature photo), so leave this one knob stationary and collimate the primary mirror using the remaining knobs. If desired, you can leave the factory collimation screw that is next to the fan connector in place, rather than replacing it with the Bob’s Knob. Bob’s Knobs recommends that you remove one primary mirror collimation screw at a time and replace it with a knob, then repeat the exchange one at a time with the remaining five screws. Check the thread size of each factory screw as you remove it and compare it to the replacement knob, as the collimation and locking screws use two different thread sizes. Repeat the procedure with the secondary mirror, removing one collimation screw at a time and replacing it with a knob, then repeating the exchange one at a time with the remaining two screws.
|
Printer friendly version
Email page link to a friend
Do you have a question about this product?
