FSQ106ED Mounting Notes

The FSQ-106ED provides a number of challenges when attempting to mount the telescope to an equatorial mount.  First, the back of the scope is heavy when compared to the front.  This makes balancing in the declination axis potentially difficult.  Second, the entire focuser rotates.  This can cause clearance problems with the focusing knobs and any automated focusing aids such as Robo-Focus™.  This page shows the steps I took in my quest to obtain declination balance and have clearance to rotate the focuser with Robo-Focus™ attached to the focuser. 

Side view of a RoboFocus attached to a FSQ106ED.

The picture at left shows my starting point.  I use the Losmandy dovetail system on my telescopes and mount.  This system allows me to interchange telescopes with minimal effort and allows me to fine tune declination balance by moving the plate to which the telescope is mounted forward or backward in the mount's saddle plate.  In the picture at the right, SocalAstro rings are mounted to the dovetail plate and the telescope fits snugly in the rings.  The telescope is mounted to the rear of the plate such that the focuser with Robo-Focus™ installed has plenty of clearance for focuser rotation.  The problem with this mounting scheme is that declination balance is very poor.  To obtain balance with my CCD camera, I had to add 15 lbs to the front of the mount's saddle plate.  While my mount can easily handle the weight, I prefer to not have that much dead weight in the system.

Side view of FSQ106ED in a typical mounting scheme.

The first step was to move the telescope and mounting rings forward on the plate as shown in the picture at the left.  This moved the balance point forward and allowed declination balance without the 15 lb weight.

Back view of a RoboFocus attached to a FSQ106ED showing rotational problem.

The problem with this mounting scheme is that the focuser cannot rotate 360 degrees.  Rotation is limited by the Robo-Focus™ motor on one side of the focuser and by the 10:1 focus knob on the other side.

Ring spacers.

To allow free rotation, the telescope needed to be elevated a bit higher from the mounting plate.  Taking a cue from the SocalAstro rings, I fabricated two spacers from 6061 aluminum rectangle stock.  I cut the length of the spacers to width of the bottom of the rings.  I drilled three holes in the stock which lined up with the holes in the rings.  I counter bored the middle hole to allow a cap screw to fasten the spacers to the rings.  Cap screws would go through the outside holes to fasten the ring/spacer assemblies to the mounting plate.

Side view of FSQ106ED using ring spacers.

After I drilled and counter bored four holes in the mounting plate to accept the new ring mounting scheme, I fastened the ring/spacer assembly to the mounting plate.

Back view of FSQ106ED using ring spacers.

Now I can rotate the focuser 360 degrees and have declination balance.