What is the T-REX?
Based on the basic "T-MOUNT" alt-azimuth, made by Yuhan in Maizuru City, Japan, the T-REX is the result of a collaboration between Kokusai Kohki and Yuhan that brings together the many good points of the rugged T-MOUNT with the addition of new features based on user preferences gleaned from over 22 years of activity in the astronomy equipment market. T-REX updates the strong base of a T-MOUNT with the added features of full DSC compatibility, and easy attachment of all manner of OTAs. As for the name, it is based not on the dinosaur, but as an abbreviation that encompasses the meaning of a T shaped mount that is Really EXciting and Really EXcellent!
Moving on from the old T-MOUNT, the T-REX brings the user a much higher level of functionality as a smart, as well as a strong, precise and well made mount that easily supports various telescopes. With the addition of your own (or an optional) digital setting circle readout module that plugs directly into the encoder jacks provided with your T-REX, precise dialing in of thousands of objects from its database is at your fingertips. Slow motion controls on each axis allow the user to pan the telescope`s field of view with precison and control, and without shaking the telescope. For longer sweeps of the sky, a quick release of the clamp handles on each axis lets you move your telescope freely by hand to any point in the sky, as all the while the DSC is keeping track of where your telescope is pointing.
Good news for owners of large telescopes!
The T-REX mount is great news to users of larger aperature telescopes looking to enjoy them on a strong but intuitive, easy to use and uncomplicated alt-azimuth mounting. In addition to complete DSC compatibilty, the T-REX supports your larger telescope without the necessity of a bulky, heavy counterweight (though, based on customer requests, we do intend to offer counterweights and weight shafts as an option to meet the specific needs of users in the future). Additionally, very smooth dual axis 360 degree slow motion gears controlled by long and easy to grip aluminum handles, built in and well protected internal encoders, a Vixen dovetail plate compatible saddle plate, a high profile "pier" body design that helps raise your telescope`s focuser to a comfortable viewing height. The T-REX alt azimuth mount is all Made in Japan and designed for a long working life of graceful, maintenance free dependability. The Made in Japan designation also means that your T-REX is of precision manufacture, with great attention to detail paid throughout. Enhanced DSC object acquisition accuracy is an added benefit of precision manufacturing. Coupled with accurate placement of DSC initialization marks at 0 degrees and 90 degrees on the altitude axis, this means spending more time finding and observing objects, not searching for them. Your versatile T-REX is the perfect visual observing platform for your refractors, reflectors, SCTs and most any small to larger aperture telescope. And telescopes attachment to the T-REX, and next balance adjustment, is easy and fast, via the mount`s now nearly universal Vixen dovetail plate compatible saddle plate.
Just how large is large? The T-REX is a strong mount designed for a large payload but just how large is large? While it is possible to overwhelm the T-REX with a huge tube assembly that would ride unsteadily, we like to think that users really are looking for a maximum payload capacity that is also fun to use. With this in mind, we rate the T-REX as being fully able to competently carry up to a Celestron C-11 SCT, a 6" F8 achromat refractor, or a 20cm F5 to F6 reflector, with ease. The T-REX is now out in the field carrying heavier scopes like 6 inch F8 ED apochromats, a number of C-11s, and even a 10 inch reflector. As a rule of thumb reference, we feel the T-REX can competently support up to about a16Kg (35lb) payload. The T-REX saddle plate As standard equipment, the T-REX uses a Vixen dovetail plate compatible saddle plate on the altitude axis for telescope attachment. Two large handled lock bolts specially made for the T-REX securely and attractively lock down on the dovetail plate attached to the telescope`s tube (see price list below for low cost long and short length dovetail plates). At the discretion of the user, this saddle plate can be attached to the T-REX`s altitude axis in either of two different directions, depending on how the user wishes to point their telescope in actual operation. The T-REX saddle plate attachment holes are Takahashi standard M8 (8mm) holes spaced on 35mm centers, making the T-REX compatible as-is with saddle plate of other makers, such at the Losmandy G-11 SPT saddle plate. Special purpose saddle plates can also be made to order for T-REX users wishing a different method of telescope attachment.
Lock bolts secure the dovetail plate Two special hand made saddle plate lock bolts that secure the telescope`s dovetail plate to the T-REX saddle are standard accessories of the T-REX. The large surface area of the heads of these bolts provide plenty of grip to tightly secure your precious telescope to the mount without tools.
Using the T-REX The T-REX in use is simplicity itself, with a design that is virtually free of any need for maintenance or adjustment. The T-REX mount attaches to, and releases from, the tripod, with just one hand tightenable lock bolt. Any telescope with a Vixen compatible dovetail plate easily mates to the T-REX`s saddle plate, locking in place by tightening two hand bolts. Take a quick moment to balance your telescope in the altitude axis, then begin observing! Slightly tightening the clamp handles of either (or both) axis will compensate for small balance variations, and allow the slow motion gears to clutch, and the slow motion controls to work. As needed, a hard twist of the clamp will firmly lock that axis down tight. Plug your (optional) digital setting circle readout module into the altitude and azimuth encoder jacks on the side of the T-REX body, initialize it on start up taking advantage of the initialization markers (see below) , and your DSC is then good to go. 4096 step encoders are direct coupled for a 1:1 gear ratio (T-REX`s encoder parameters are (azimuth) AZ -04096 and (altitude) AL+04096. This simple data input is all that is needed for your readout module to accurately find objects)
The tension applied to each axis of the T-REX as it rotates is controlled by a clamp handle on each axis. As conditions require, leave it completely unclamped for fast manual slewing, or cinch the clamp down tightly to firmly lock that axis in a set position. With each axis 1/8 to 1/4 clamped, the slow motion controls can then engage to apply precise and smooth panning during medium and high magnification observing sessions. Gear tension is factory adjusted to provide handles that rotate smoothly under most all conditions, but can also be adjusted to provide slightly more or less tension by the user after delivery.
Designing the T-REX One of the most important considerations in the design of the T-REX, in addition to overall rigidity, was maintaining strict perpendicular precision between the altitude and azimuth axis. The T-REX design offsets the altitude axis from the azimuth axis, with the telescope cantilevering over the side of the mount (and tripod) during use. This allows for a comfortable viewing position at the focuser but also demands great rigidity of all supporting systems to keep the azimuth axis perpendicular and without sag. And all without the use of counterweights anywhere in the system. The T-REX design supports this somewhat extreme requirement with gusto, and without backlash or horizontal sag, a factor critical to maintaining DSC pointing accuracy, especially when using a larger, longer focal length telescope. Though we have yet to actually ascertain a limit of the size of telescope that T-REX can handle, there will surely be requests for very heavy tubes (or very long tubes of great moment) that exceed the anti-sag capabilities of the standard T-REX design. For these power users, in the future, we plan to offer a conterbalance system on a special order basis that can help. And for long optical tubes that might hit tripod legs when pointing toward the zenith, in future we also plan on offering tripod pier extenders, or even complete pier tripods, that raise the height of the T-REX to accomodate them.
Slow motion flexible extension cable For longer telescopes, trying to reach slow motion handles positioned far from the focuser can be awkward. For this reason, we offer a 55cm medium length flexible extension cable for the T-REX mount that let you access slow motion control without having to stretch. Extension cables are easily and quickly installed and removed, replacing the slow motion handles in use. Release a single set screw on the slow motion handle to remove it, slip the extension cable adapter over the newly revealed shaft, retighten a single set screw and you`re done. The Super Navigator and T-REX The T-REX was designed from the beginning for complete compatibility with our digital setting circle reasdout module called the Super Navigator. T-REX encoders are also compatible with the Super Navigator DSC readout modules and its cousins from JMI, Lumicon and Televue. The T-REX also supports the Sky Commander and the Argo Navis readouts, using the same CAON encoder cable provided with your T-REX. The optional trex-sh holder tray holds the Super Navigator readout, and its compatibles, at a comfortable height. the tray also swivels up and down for easier reading of the display depending on your telescope. A holder tray specific to the Sky Commander, trex-sc, is also available for Sky Copmmander users. A holder tray for the Argo Navis, while ot currently available, would be a do-able near term project. As mentioned above, perpendicularity of both axis to each other has a large effect on DSC pointing accuracy and the T-REX is built for strict adherence to this requirement.
Alos, as a point of interest, the T-REX encoder jacks are positioned to rotate along with the DSC readout unit, so that the user never has to worry about encoder cable tangles, or cables wrapping themselves around the T-REX pier as the telescope is rotated round and round over an observing session.
Engraved position markers for fast DSC initalization For fast and accurate initialization of your digital setting circle readout module, position markers that indicate the 0 degree and 90 degree initialization positions (but not the numbers) are engraved onto the T-REX altitude axis. While this may seem a simple and inconsequential feature, having an accurately preset point of reference for initialization helps insure you will always quickly achieve the greatest pointing accuracy with your digital setting circle. And factory set precision means not having to use a carpenters level or other tools to accurately determine for oneself where this valuable point of reference is located. With the use of these position markers, with the T-REX we have time and again performed an accurate 3 point initialization (AZ, or AV, plus two initializtion stars), chosen an object from the Super Navigator database and then pointed at and found that first object in less time than it takes to describe, easily under 30 seconds from power up.