Apertura Roll Easy Kit for Dobsonian Telescopes: Installation Guide

Maintains Stable Platform

These mobility and lift upgrades are securely tied into your existing base with the sturdy caster mounting bars. The bars, proudly fabricated and finished right in New York, USA, are easy to install but still ensure your Dobsonian remains just as firmly planted as it originally was.

Prior to installing any parts, you should prepare a well-lit work area with room to place the telescope’s ground board. The ground board is the bottom portion of the telescope base. This ground board needs to be removed from the telescope base so that holes can be drilled in it, without drilling into other parts of the telescope base.

Remove the telescope from the base. Then, remove the locking knob and hardware from the center of the base. Next, pick the base up off of the ground board, being careful to keep track of the hardware. Once the base has been removed from the ground board, turn the base over onto its side so that the bottom of it is clearly visible and place it on your work area.

Use the included screwdriver to remove the three rubber feet from your telescope ground board. Take each of the mounting bars (#2) and position them so that the first hole lines up with the factory hole used in attaching the rubber feet to the telescope, originally. You’ll want to place the laser-marked logo facing down at this step so that once the bars are installed and the base flipped over they will be visible.

Use one screw (#3) and one washer (#4) per bar, attaching them to the ground board. Snug them into place but do not fully tighten the screws yet. Adjust the position so that the space between the ends of the bars is even. Then tighten the screws fully before moving on to the next step.

Position the base in such a way that you can safely drill holes into the base without over-drilling into your bench or work area. Some people might use scrap pieces of wood to place them under the board that is being drilled. Others might overhang the base off of their workbench. You might even consider using saw horses or similar support for this portion. Please be sure that you are knowledgeable or comfortable with the use of power tools and follow all manufacturer safety recommendations. Wear appropriate safety gear for the task at hand.

Use the current position of the bars to mark your drill hole locations. The bars can be used in place as they are, like a drill guide. Drill one hole with the ⅛” drill bit included in the kit, and then grab a (#3) screw and (#4) washer. Install these just the same as you did the initial set of bar mounting hardware - inserting the screw with a washer attached through the bar and into the hole you just drilled, and tightening down until snug.

Caster Installation

Now that the mounting bars have been installed, the casters can be attached to them. Four of 5/16-18 stainless steel caster mounting screws (#6) and four washers (#5) are used to hold each caster to the bar. This is a simple matter of starting each machine screw by hand and then using the included 3/16” hex key to drive to tighten the screws. The bar is aluminum so be mindful of overtightening the screw; tightening this down until it is flush and slightly snug will correctly set the tension on the caster. The machine screws are oversized, and therefore extreme tension is not necessary to secure the part.