Unitork 25

UnitorK is our high precision intubation set for reflection optics, a compact and high-performance solution.
All design parameters have been extensively studied to give optimized results, which allow the full exploitation of your optical system, no matter how sophisticated or demanding it might  be


In order to guarantee the best performance ot the optical set up, we recommend only high precision engineering.

The precision is provided basically by higth tolerances but also by an accurate design project which foresees the points which can generate flexions, twists and transmission of dangerous vibrations into the tube. NortheK has made  the tubes of its reflectors instruments following a clear, simple, economical design with a no-frill look as you  would expect a precision instrument to be.

The material used are Halo 25 aluminium and its variants, steel, carbon fiber, Ergal alloy, technopolymer with self-lubrification matrix. Each component of the UnitorK tube is made with the best material for the purpose. There are no plastic or laser-cut parts or multicoloured anodising which, although visually good, they do not give adeguate precision. UnitorK has precision, solidity, a nice look and a competitive price compared to a similar quality product. Improved performance at lower costs! UnitorK is not only a NortheK brand  but a long term committment to design, study and research in projects using the latest software engineering. Having studied all the applications for this instrument, the Maxproject Team has worked out the optimum quality that it should have for both amateur and semi professional use, in  this way the end-user can always be assured of the best performance in any conditions.

UnitorK has been entirely made using precision engineering, there are no moulded components, bolts and screws are stainless steel, other metal components are always machined to specification in order to ensure flatness, thickness and size within tight tolerances. The performance of your telescope relies on this precision. Our task is to deliver the optical beam exactly where and how you need to find it!
The carbon fiber is the essential component in the construction of the UnitorK tube. The technologically advanced know-how of NortheK allows them to supply extraordinary high performance tubes thanks to the specially developed lamination of the carbon fabric and wrapping techonology. Temperature controlled curing, hight-tech resins and anti UV gel coat make UnitorK tubes among the best for precision applications. Each UnitorK tube comes with a certificate of quality and origin of the carbon fiber. UnitorK can be purchased as it is or made to order, completed with NortheK high precision cells StabilobloK  and AxyS and professional 2″ Feather Touch 2000 focusers. It is also possible develop special alterations to satisfy any special requirement. UnitorK can come in a “naked” version – for those who prefer the classic, totally open Serrurier – or in a “closed” version with a pipe, also totally made in thin carbon. For the “close” version it is possible to include forced ventilation system near the optical surface to cool down the glass surface quickly (this fast cooling option  is useful only for those who do not have the time to acclimatize the telescope, as glasses are thin and a standard rear ventilation is already provided). UnitorK come with carbon fiber joints AS01. Upon request it is possible to supply the better performing AS02 which will be designed specifically for the optical scheme.

Support rings Halo 25 alloy
Dimensional tolerance on supports rings less than 0,1 mm.
Ball joint support Halo 25 alloy
Dimensional tolerance on ball joints supports 0,1 mm.
Ball joints chrome steel
Rear plate Halo 25 alloy
Planarity of the rear final plate less than 0,1 mm.
Nuts and bolts Stainless steel
Carbon fiber truss tubes 100% carbon, manufactured  whit wrapping technology
Type of carbon fiber tubes sandwich, manufactured  whit wrapping technology
Type of sandwich original design
Surface treatment of carbon tubes grinding and protection with anti UV finish
Endings of the carbon tubes Halo 25 alloy
Internal tube of the truss structure 100% carbon, manufactured whit  wrapping technology
Focuser connection Halo 25 alloy, flattened within 0,1 mm. tolerance/accuracy
Ovalization of UnitorK 0,1 mm. on the worked/tooled parts, 0,0 mm. induced
Forced ventilation of optical surface
UnitorK horizontal flexion too small to be measured
specifications may change without notice
Product code: UNITORK 25 Sale unit: linear meter

Note: the tube is sold by the metre, UnitorK ALREADY comes with side supports for the axial connection to the axis and the movement translation system for the AxyS support or similar. Do not hesitate to ask further details to
UnitorK is a modular design from NortheK. It has been developed as an essential component for intubation of 250 mm. reflector telescopes.
The UnitorK design is available in various options, depending on the size and the application required. It may be adapted to fully open, partly open or closede Serruriers, using the truss as structure reinforcement.
UnitorK can be adapted to a wide range of diameters (from 250 mm. to 800 mm.) and mounts (German equatorial mounts, fork arms, or single arm forks). The carbon fiber is an essential design component, but for very large structures it is also possible to use metal only.
UnitorK can be used for refractor telescopes of large diameter and focal lenght. It is simple and economic solution, designed to exploit the maximum performance from your telescope.

Carbon fiber.

UnitorK has been built using carbon fiber. For industrial reasons, in small diameters (200-400 mm.) carbon fiber has been used only for the main components controlling the thermal expansion of the telescope. This is because the use of carbon fiber doesn’t aim to  reduce the total weight (for this kind of products it will only reach the 12-15% less than a same quality metal instruments) but to improve the mechanical stability of your O.T.A..
UnitorK has the advantage of maintaining the light cone throughtout the observation session and when it is used in pair with the mirror cells StabilobloK and AxyS it allow a highly productive and enjoyable experience.
The carbon fiber is excellent for this kind of application, especially when it is manufactured having in mind the final product and the needs of the end-user. The NortheK lamination sandwiches are manufactured whit unidirectional fabrics, using high module fiber as well. For some special cases, it is possible to use high module carbon fiber only. Obviously, we use high-tech materials when they make the difference, otherwise we try to control the final price to the customer as long as ths doesn’t affect the telescope performance.

Metal parts.

Every metal part is CNC machined starting from milled cast blanks. This technology  assures outstanding results and precision tolerances.
Whenever it doesn’t compromise the product performance, we always use aluminum alloys for  standard diameters in order to reduce cost and weight. Obviously, in case of large customized instruments, it is also possible to use Mn and Cr  alloy steels which have outstanding thermal and mechanincal properties. The cost of these high performing materials being very high, in terms of price and cost of manufacturing, they are used exclusively for high budget projects and instruments to be installed in a fixed observatory.
The use of these steels when when joined to some aluminum alloys and carbon fiber guarantee a  high-performance, top quality instrument.
Mounting and testing procedures within tight tolerances for every single instrument allow actual tolerances to be very close to the nominal ones.

Nuts and bolts.

The standard nuts and bolts are stainless steel or Ergal alloy.
In case of special project we can supply nuts and bolts using steel and tolerances to your own requirements. The aim  is to achieve maximum precision and performance during use. In these cases we normally use high-precision threads (UNI H7).

UnitorK comes complete, assembled and centred for self-constructor amateurs.
UnitorK includes alloy rings (as well as  the terminal one for the support of the secondary), holes and threads to add StabilobloK and AxyS. These holes also allow the attachment of your own cells or stands for the secondary.
UnitorK obviously  includes a carbon framework, but it doesn’t incorporate the complete inner tube which should be purchased separately. The maximum lenght available is 1,20 mt.; for longer measurements it is possible to use modified structures designed on request.

The instrument is recommended to those who have a good manual skills and a basic mechanical back

StabilobloK 25

StabilobloK 25  is a highly advanced project for the primary mirror cells designed for reflectors telescopes.
Thanks to the extreme semplification, the accurate construction and the high quality of the materials used, StabilobloK from NortheK is one of the best thin glasses support system on the market.

StabilobloK  25 mounted with 2″ Feather Touch focuser

Our instruments are manufactured using low-expansion thin mirrors to minimize thermal effects during observation. We provide high-tech design for the support cell, in order to avoid distortion on the primary mirror that would compromise its correction, to allow a finely controlled setup, to obtain perfect collimation under all conditions and to hold collimation as long as possible, particularly for instruments taken under darker skies.The demands of a high-performance optical set can place a high challenge to the instrument design but also to the user who wants to make the most out of it, in terms of observation, astrophotography, photometry or whatever application the instrument allows.

System of the StabilobloK 25 cell.

The StabilobloK system is a mechanical solution that is well designed, simple, lightweight, and precision engineered. The optical ad mechanical performances were equally considered to deliver the best results.
The StabilobloK primary mirror cells from NortheK are produced with high precision engineering with no compromise even for the small diameters (250 mm.) where the solutions are more cost effective. The use of modern technologies has allowed the Maxproject Team to achieve a superior quality and performance product at an affordable price.
Like many other components or the NortheK OTAs, the StabilobloK primary mirror cells are made from cast blanks which are then precisionly machined for purpose. This method of production assures optimal dimensional control to achieve the best results.
Our sensitive adjustement control system makes the most of the precision optics it is coupled to,  and it will take away  all your worries about mechanical induced problems, such as astigmatism. Our system allows optimal aligment of otical beam, with easy regulations, and keeps the aligment steady, eve for the astronomers that have to regularly travel to dark skies. Of course our cell is designed with “anti mirror shift” “anti mirror flop” systems, thanks to an axial and radial control system with 6 or 12 regulation points. The choice of 18 floating points as a support instead of a budget solution such as the central pipe, says it al about design criteria.

Primary’s superior dish with 18 floating points

The location of the 18 floating points has been studied to avoid any deformation of the optical surface. With normal software it is easy to calculate the value of such deformations. The vertex of each triangle is designed to work with 50 gr. pressure, we test each vertex one by one with an electronic tester during manufacture to make sure they are operational at 35 gr. pressure. This system guarantees a very high sensivity  of the pivoting system. Every floating joint (BWK system) is also tested under stressful conditions for several hours in order to increase its performance without changing the optimum mechanical values. There are no others mass produced for the amateur market with  the same mechanical accuracy at similar costs.

The optical alignment is carried out at the optical bench in our factory, to ensure the customer receive a system that is ready for the fine adjustements at the star test. Every StabilobloK cell has three aluminum and stainless steel transaxial systems with an inner microreducer. The precision of these systems is 0,02 mm. in the rotation direction, so that  even the pivot of the visual plane can be finely adjusted to a very small angular degree. The action pivots are made in precisionally ground stainless steel and move inside inserted technopolymer moulded self-lubrificating bushes. This is an ideal mechanical solution to enable operation in adverse conditions, and it allows smoother and fine adjustments of the optical plan without introducing any distortion. If required by the optical scheme, we can supply baffles, whose dimensions are calculated with specialist software, and diaphragms adapted to the light cone. The baffles can be made either in metal alloy or carbon fibre.

Every single cell is tested and tried out in assembly room. You can buy it separately from the telescope and in this case we will provide any modifications necessary to optimally couple, it to its partner mirror. We developed a unified cell designed that can be modified according to the final application, this is a cost effective solution permitting maximum industrial and logistic flexibility.

Rear of the primary’s dish mounting with screws

With the same attention to detail in both development and manufacture, we can customize cells up to 800 mm. and beyond, using the best alloys for the design to guarantee the best performance of the optical train.

Micrometer with 0,02 mm. accuracy for the collimation of the primary mirror

Contact us, and we will be happy to give you further information.


Characteristics Technical specifications
NortheK StabilobloK ST 25
Alloy Halo 25
Metallic composition ISO AlMg4,5n0,7
Chemical composition Si,Mn,Fe,Cu,Ti,Mg,Cr,Zn
Density (gr/cm3) 2,66
Coefficient of thermal expansion (10-6k) 24,2
Degree of roughness N6
Thickness mm. +-/0,05
Parallelism mm. < 0,1
Planarity mm. < 0,2
Shape stability Optimal
Protective anodization Optimal
Surface protection Black anodization
Nuts and bolts Stainless steel, Ergal
Mirror support system 18 floating point supported by ball joints made of steel and bronze composite
Lateral support system 6 points
Optical plan adjustment Adjustment system in chrome rectified steel 3 points of fine adjustment (0,02 mm.) per 120°
Vibrating damping system On self-lubricating techno-polymer moulded joints
Forced ventilation 3 axial extraction fans
Customized for different tube Upon request
Weight without optic kg. 2,5


specifications may change without notice

Product code: ST 25 – Sale unit: piece

Can StabilobloK evolve? The design of this component has been conceived to allow further updates and improvements.

We would like to remind you that every IMPORTANT technological improvement brings a very high cost increase.

The StabilobloK project can be upgraded not only from an aesthtetical point of view, it is also possible to improve the performance of both, its structure and accessories.

For instruments with fixed position and diameters between 500 and 800 mm. it is possible to  use more appropriate metallic alloys or specially made steels. The plans adjustement is made with an electronically controlled system the construction tolerances can be dropped down to 0.01 mm. and the thermal expansion can be better controlled with an accurate material selection.

The system for the thermostation of the glass is also more sophisticated, as it incorporates thermometric sensors, automatically controlled systems and refrigerating fluxes.

The lateral supporting systems are self-compensating, while the lower supporting points have an adjustable compensator (alternatively we can offer a more advanced solution with an electromechanical system PC controlled). In the AxyS A2 version the adjustment of the primary’s plan can be made with linear system; in this way iy is possible to re-set the back focus as many times as you want and save all the different positions in the memory. You could modify the field of full light and the necessary extraction in accordance with the characteristics of the shooting sensor and the optical train applied along the back focus. Thermometric sensors and surface refrigerating systems provide all the information to the PC wich will optimize all the configurations.

The position of the secondary mirror, that is to say its distance from the primary, is electronically controlled and can be adjusted from the PC.

The primary and secondary baffles are machined  with special instruments from a solid bar in  order to locate the necessary diaphragms with the highest precision.

For this kind of cells we can also provide special customized focus and 4″ and 5″ diameter, they are made in steel, Ergal and Titanium, motorized and PC controlled.

We do not have a catalogue for those producs as we manufacture them on customer’s request and modify them in function of the use the instrumen is conceived for.

Do not hesitate to contact: