Sturdy Telescope Mountings

After many years of experimenting with and designing mountings, we have concluded the product we produce affords the best compromise of function, cost, durability and vibration dampening. We could produce fork styles, Alt-Alt, English and various cone bearing designs. Each has its limitations, either through poor dampening suppression or begin cost prohibative from an investment standpoint. In the final analysis, mass, support mechanism and its proportion are the test of function. In all cases the mountings we produce are over-designed to support instrument weight and the ability to dampen vibrations. Most of our customers come to us after they have experienced marginal performance from their mounting and drives from companies that mass product questionable systems. Optic-Craft provides overall system functional upgrade.

Home | Clock Drives | Photo Gallery | Features | Models | Ordering Information | Pillow-Block Bearings | Contact Us

Features and Specifications

• Solid shafts
• Large diameter flange couplings
• Extended bearing support centers
• All models have lubricating fittings on each bushing bearing or pillow block bearing
• All steel construction
• Material substitution - Aluminium available for mount heads (not the bearings) to reduce weight by approximately 42% for models 3 and up with extra charge
• Wedge bracing exterior from the center of gravity
• Rigidity, light-weight, portability
• Models 3 and above use pillow-block bearings for exceptional radial and thrust load capability
• Ease of polar alignment
• Complete guarantee on all models including parts and labor
• Delivery time on all orders normally within five to eight weeks

Models

• Ease of assembly
• Self aligning pillow blocks seek there own center line.
• Once center line is achieved parallelism of both axes is maintained by the flatness tolerance of the sub plate they are attached too.
• On all mountings the RA axis is perpendicular to the DEC axis within a few seconds or arc.
• Concentricity of the bearing to shaft and pillow block bearing to it's housing combined concentricity is plus or minus .0015".
• All pillow block bearings have an ABEC classification of 5 or better.
• Models 6 and above use block bearings with roller tapered rod bearings for thrust and roller ball for radial loads resulting in equal load handling for both radial and thrust.

Here are two examples:

Model 3

1" shaft assembly (2) bearings

Radial load rating 2340 pounds
Thrust load rating 1176 pounds
Target load weight 60 pounds

Model 7

3" shaft assembly (2) bearings
Radial load rating 8420 pounds

Thrust load rating 4193 pounds

Target load weight 280 pounds

Example overload for both mounts is 500 pounds.

As one can see, for an assembly turning one revolution per sidereal day, the safety factors for a telescope weight of 500 pounds for a 1" pillow block bearing is 430% overrated for radial and over 200% for thrust. For a 500 pound telescope using 3" pillow block bearings the saftey factor is 1600% for radial and 800% for thrust. This is dead weight carrying capacity. One does have to consider mass of the telescope mounting to distribute dampening and stability. So a 500 pound telescope will dampen much sooner on a set of 3" pillow block bearings running on a 3" shaft, then that of a 1" pillow block set. Keep in mind that the 1" pillow block bearing set with a 1" shaft will mechanically support a 500 pound telescope, but with very poor dampening capability; This is the reason we suggest 60 pounds as a practical limit for the Model 3 in telescope applications and similar limits for the larger mounts. The motto here is more mass means more dampening which for telescopes is a good thing.

Ordering Information

1. Delivery - 5 to 8 weeks from receipt of order.
2. Warranty - 5 years parts & labor.
3. Shipping - C.O.D. United Parcel Service shipping charges only U.S.A. & Canada. C.O.D. Air Mail only foreign orders.