Astro photography places rigid demands on a permanent telescope pier and we want light hitting any pixel to stay on that pixel and not move around as the equipment deflects. Acceptable deflection is then a matter of pixel size and focal length. A 4.78µ pixel at 500mm is 1.97 acrsec per pixel while the same camera at 2000mm is only 0.49 arcsec per pixel. When we go planetary with 3.8µ pixels at 5600mm, we are down to 0.13 arcsec. Less deflection is always better and becomes more critical as focal length increases and as pixel size decreases. MOAP 43 Series telescope pier deflection at 43" height is 0.383 acrsec: 3x to 20x less than other piers. Shorter heights are even less. A MOAP 43 Series telescope pier at 35" height is only 0.272 arcsec.

Sizing a length of pipe is straightforward but only accounts for just a bit over half the deflection of a total telescope pier assembly. We use bending moment diagrams to identify where the bending is taking place and then use an iterative 30,000 node 3D finite element structural analysis method to converge on designs that minimize deflection of the entire pier assembly: the same software NASA used to design the James Webb Space Telescope. To achieve these low deflections, optimization of every element is critical and requires unique attention to detail.

Telescope pier components are cut by a 5-axis CNC water jet providing quality 5 (best) edges. Welding is done on automated rotary tables. Surface contaminants are removed and the assembly is abrasive blast cleaned to grade SSPC-SP6 prior to powder coating with a proprietary hybrid urethane/polyester resin. Materials are critical to achieving low deflection. Big box Chinese hardware simply won’t cut it. We use new domestic steel and fasteners meeting the following specifications:

• Pipe: ASTM A500 Grade B, 46,000 psi yield, 58,000 psi tensile
• Plate: ASTM A36, 36,000 psi yield, 58,000 psi tensile
• Stainless steel fasteners: ASTM F879 alloy group 1, condition CW, 65,000 psi yield, 125,000 psi tensile. ASTM A380/A380M finish. 4,940# clamp load.
• Hot dipped anchor bolts: ASTM A36/A36M & ASTM F1554 Grade 36, A563 grade A, ASTM A153. 36,000 psi yield, 58,000 psi tensile. 14,400# clamp load.

The gravity load on a telescope pier is light - seldom over a few hundred pounds. Holding it up takes very little. The engineering problem is deflection and when properly designed for that, the weight of equipment becomes inconsequential. The MOAP will not yield until a horizontal load greater than 19,000# is applied at the top of the mount plate and will not fail until that horizontal load reaches 27,000#. Embedded anchor bolts yield with a load of 65,000# and fail at 104,000#. Anchor bolt pull-out force is several times that. To put that in perspective, a large construction backhoe can exert 15,000# of force. With the MOAP telescope pier, it’s not about the load. It’s all about minimal deflection and dependably handling critical tasks. Capacity is not an issue with the MOAPs.

Gussets are the small triangular fins at the end of a pipe and may stiffen the connection by about 5%. With proper design of pier geometry and material sizing, gussets are entirely superfluous. Stiffeners are the fins running nearly the height of the pipe and do work but indicate an undersized pipe. For example, a commonly available 42" pier with nearly full height stiffeners has a large deflection of 12.8 arcsec with stiffeners and would have 22.4 arcsec without the stiffeners. Stiffeners do help but are no substitute for sound engineering in the first place. MOAP telescope piers need no rocket fins. The MOAP 43 Series deflection is 0.384 arcsec and less. The MOAP 65 Series deflection is 0.398 and less.

We established a standard load condition for design and comparison with fixed support of anchor bolts where they meet the concrete and a 5# horizontal force applied at the topmost part of the pier assembly in the weakest direction. Five pounds has been used previously by others as a reasonable force to simulate a bump, wind puff, and other forces acting on the pier. It's also large enough to far overshadow the torque created by the mount itself. It's a subjective but appropriate and consistent force to standardize performance measures.

Please contact us using the form at the bottom of this page or via email at [email protected] with inquiries. We collect information on the Mount Plate bolt pattern needed, height needed, and shipping address so we can calculate freight. We work with you to provide exactly what you need and email an invoice with the payment total and check out instructions (major credit card). Then, in a few days, you will be in the MOAP family of astronomers.

(CNC template, eight 5/8" ASTM A36 G90 galvanized bolts with nuts and washers, 4" thread length. Can be shipped in advance of pier)

Yes. If your mount attaches to a flat plate, the mount will bolt directly to the MOAP Mount Plate's pre-drilled holes prepped specifically for your mount or adapter. The Mount Plate can also be drilled in the field in case you change mounts later. If your mount attaches with a ring or cup, an owner furnished adapter is required and the Mount Plate is pre-drilled for that adapter. You simply attach your mount to the Mount Plate and then attach the Mount Plate to the MOAP pier Top Plate. If you use multiple mounts, each can be attached to a plate and changing mounts is as simple as removing three bolts.

Just tell us! The MOAP 43 Series covers telescope piers to 43" high. Deflection increases with height. For example, the MOAP 43 Series at a height of 43" has deflection of 0.383 arcsec while the MOAP 43 Series at a height of 37" has deflection of 0.272 arcsec. The MOAP 43 Series 43" and 37" heights are normally stocked. Other heights are 4-5 week lead times. The MOAP 65 Series covers telescope pier heights from 44" to 65" and are larger diameter. Lead times are also 4-5 weeks. Deflection is less than 0.398 arcsec. Heights above 65" are bespoke and engineered to specific customer needs.

Everything vibrates. Even the back of your eye has a resonant frequency. A telescope pier has not one but several modal frequencies. Fundamental frequency corresponding to first modal shape is called natural frequency of the system. Increasing stiffness increases the natural frequency. Increasing the mass decreases the natural frequency. An increase in the damping diminishes the peak response but broadens the response range. What does this mean to a properly designed telescope pier? Absolutely Nothing! Since the magnitude of the vibration is less than the MOAP's deflection, less than the camera can detect, it doesn’t matter if it’s vibrating at 40 Hz, 400 Hz, or 4,000 Hz.

Material selection is critical to telescope pier performance and price. Aluminum is 3x lighter than steel but mass is our friend so aluminum's lightness is working against us. Aluminum is also 3x more flexible than steel so we need a lot more of it. It’s 3x the cost of steel and it doesn’t play well with concrete. Everything about aluminum is working against us in a telescope pier so you won’t find any aluminum in the MOAP.

We also design and fabricate custom piers such as equatorial piers and other less common designs. Please contact us to discuss your unique requirements and performance specifications. We'll put our engineering talent, creativity, and ingenuity to work to make your project an outstanding performer. We send you the engineering analysis for your approval prior to fabrication.