INSTRUCTION MANUAL Versione February 2014

Transcription

1 EQUATORIAL MOUNT (Made in Italy) INSTRUCTION MANUAL Versione February 2014 All the pictures and contents included here are propriety of AVALON INSTRUMENTS. They cannot be reproduced, published, copied or transmitted in any way, including the internet, without the written permission of AVALON INSTRUMENTS.

2 SAFETY STANDARDS AND WARNINGS Read carefully the manual before installing and using the mount. Use the power cable supplied with the mount or a 12V- 3A stabilized power supply as suggested in the manual. Connect the power cable correctly and securely to the power socket. Do not bend, pull or press the cable as this may damage it. For any assistance or repair, please contact only the manufacturer. Be sure to remove the power supply at the end of its use or before any cleaning or maintenance. This mount must be used exclusively by adults, do not allow use to children or to people with reduced mental capacity. Avoid to operate the mount except as strictly indicated in the manual. Modifying or altering in any way the characteristics of the mount, will void the manufacturer s limited warranty. Never modify the tension of the belts (by dedicated screw), these is set in the factory and any unauthorized change will void the manufacturer s limited warranty. After using it, avoid to store the mount in areas exposed to sunlight or in wet places. 2

3 Summary Technical Specifications... 4 Forewords... 5 Packing Content... 5 Mount Description LineAR initial Setup Tripode Positioning Installing the Mount on the Tripod Bar and Counterweight Customize the latitude adjustment system Installing the Optical Tube Telescope balancing RA Balancing Dec Balancing Mount Polar Alignment Adjusting the mount in latitude Adjusting the Mount in Azimuth Polar alignment Polar alignment with a Skywatcher Polarscope Polar Alignment with a Losmandy polar scope External programs for Polar Finding APPENDIX A Astrophotography Tips

4 Technical Specifications Type of mount Head weight Maximum load Motion System German Equatorial 12,5 kg (27.5 lb) without counterweight and bar 20 kg (44 lb) for photographic use, 25 kg for visual Four-step reducer via pulley-tooth belt system on ball bearing, with no play on both the axes Periodical Error Mean +/- 5-7" Construction Material Transmission System RA Axis DEC Axis Polar Scope Control System Counterweight Bar Counterweight Dovetail Plate Warranty Anodized aluminium, worked out from single blocks with high precision CNC machines Pulleys made with special glass fiber polymer and high precision tooth belts Heavy duty steel, diam. 35mm; 2 conical roller bearings, diam. 62mm + 1 roller bearing diam. 72mm + 2 roller bearing diam. 45mm On bearings clatch system Heavy duty steel, diam. 35mm; 2 conical roller bearings, diam. 62mm + 1 roller bearing diam. 72mm + 1 roller bearing diam. 45mm On bearings clutch system Skywatcher (optionally Losmandy) Avalon StarGO goto system Quick release, 30mm diam. (1,181 "), stainless steel bar One, 6 kg (13,2 lb) stainless steel Losmandy, 3" (75mm), dovetail, single knob with 2 tightening points 2 years from the purchase date, extended to 5 years for the transmission system 4

5 Forewords This manual describes the Avalon LINEAR mount, the procedures for mounting and tuning the mount on the tripod, for the installation of a telescope. Additional Information on the LineAR mount and on the StarGO control system, containing also the procedures for the use with third-party software and in particular with the ASCOM driver and Software Bisque TheSkyX, are reported in additional documents as part of the mount supply. A careful reading of this manual will enable the use of your mount safely and with the maximum satisfaction. The images and the descriptions of this document refer to the first version of the mount and therefore small differences could be present in comparison to your own mount. The mount design and its configuration could be subject to modifications, without prior notification, based upon designer s improvements and the requests, if applicable, by the mount users. Packing Content Open the box take all the content out. Extract all the components from the small cardboard box and from the mount bag side pocket putting them on a clean, flat surface. Box Content Accessories Component List Mount Head with integrated StarGO control system. StarGO Keypad and dovetail plate for the telescope installation. Tripod plate and screws for fixing the mount to the tripod. Control Keypad Keypad connecting cable (HDMI) Counterweight rod 6 kg stainless steel counterweight Polar scope Power cable Warranty Certificate & Testing Certficate Declaration of Conformity Allen screew tool set M8 screw for extreme latitudes regulation Pendrive USB with manuals and software 5

6 1.3 Mount Description The Linear Fast Reverse is an innovative mount that accomplishes the movements of right ascension and declination by means of pulleys and tooth belts in the place of the classic worms and gears. This choice has allowed to obtain several advantages: a really steady motion without play (no backlash) and sudden peaks, factors of paramount relevance for long guided exposures and during high magnification visual observations. These features are of particular relevance especially for the declination axis motor that can now quickly reverse the motion without breaks to recover the plays: from here the mount name Fast Reverse. The toothed belts used in the M-uno have the structure made of special material with steel strands to avoid any deformation, elongation and stress. It is important to underline that in the pulleytoothed belt system, no direct contact occurs between the pulley and the motion is transmitted by the belt engaging from 50% to 90% of the girth surface. Consequently any error, eventually present, is averaged among the cogs, moreover soft, pledged over the pulley, greatly reducing the tracking error. On the contrary, in the classical worm gear systems the motion transmission is performed in a single contact point between the worm and the gear thread and therefore any error in one of the contact surfaces is taken into account as a tracking error. Since there are no gears, there is no need of periodical lubrication of the internal components and therefore the maintenance is extremely reduced and limited to the external cleaning. The picture shows all the main items of the mount. Their use is described in detail in Section 2. The front panel of the StarGO control system is placed in the opposite side of the mount and cannot be seen in the picture. The tripode shown in the picture is not part of the supply. For the maximum stability it is advised to use the Avalon Instruments T-pod offered as an option. 6

7 1. LineAR initial Setup The LineAR can work at latitudes range from about 10 to about 70. For compactness purposes, the mount is supplied regulated at about 40 and therefore the first operation to perform is its regulation of the latitude to the value related to the site in which the mount will be used. The same operations will be carried out in the case the mount is transferred in a site which is outside the range already set. The operations that will be described require the firm installation of the LineAR on the tripode and therefore the first sections of this chapter will describe the steps needed to tripode mounting and LineAR installation. 1.1 Tripode Positioning Whatever type of tripod is used it must be mounted with the right orientation. This mean that the brass contrast block which is installed over the tripod mounting plate, is oriented to the North with sufficient approximation. A mechanical or digital compass can be used to perform this task. 1.2 Installing the Mount on the Tripod Unscrew the azimuth knobs of just a few turns. Put the mount on the base plate, so that the plug coming out from the plate will fit in the proper housing in the bottom of the mount. Screw the azimuth knobs until they will touch the mentioned plug. 7

8 The mount must be properly fixed to the base plate with the two M8 screws provided with the mount. They must be screwed on both the sides of the mount. 1.3 Bar and Counterweight Remember to perform the following operation before the installation of the telescope on the mount. Installing the telescope without counterweigh, even with the AR and Dec latches well tight, there is the risk of a unadvised rotation of the telescope around the axis leading to hit the tripod legs with its consequential damage. The counterweight shaft has a special groove to allow a quick setup and a safe usage even if the fixing screw of the shaft is accidentally loosened. Unscrew the knob on the bottom part of the declination axis, place the shaft in the hole and push until the shaft is fully inserted; at this point tight the knob to properly fix the shaft. Depending on the telescope you want to use, one or more counterweights will be needed. Unscrew the security screw from the bottom of the counterweight shaft, take the counterweight and unscrew its own small knob of 2 or 3 full turns; Insert the counterweight in the bar, placing it at the center. Screw the counterweigh knob to fix it firmly and then screw the security screw on the end of the shaft. 8

9 1.4 Customize the latitude adjustment system As mentioned, the LineAR is designed to work at latitudes between 10 and 70. To obtain such a wide range of latitudes, the mount is provided with a gusset with three positions. Position 1 enables height adjustment from 10 to 31, position 2 between 32 and 55 and the position 3 between 56 and 70. On delivery the gusset plug is set for the latitudes of Europe and North-Central United States. Should it be necessary to change the latitude beyond these limits - for example, to use the mount in Northern Europe or in the Tropics, you must perform the repositioning of the metallic gusset placed under the mount. This adjustment requires a 5 mm Allen wrench and the M8 hex head screw supplied as standard. The operations required to adjust the range of useful latitudes are as follows: 1) Unscrew the 2 screws under the base 2) Unscrew the 4 screws of the side bracket 3) Remove the bracket 4) Unscrew the brass piece 9

10 5) Screw the brass piece in position 1 for latitudes from 15 to 40 or in position 3 for latitudes from 45 to 70 6) Remount the side bracket and tight all screws For latitudes from 45 to 70 insert the hex head M8 screw in the polar scope side as in the picture For latitudes from 45 to 70 insert the hex head M8 screw in the polar scope side as in the picture 1.5 Installing the Optical Tube The LineAR id provided of a Losmandy type (75 mm) dovetail plate to install the telescope. Therefore the telescope must be provided of a male dovetail bar of the same type. Before installing the tube, make sure you already installed both the shaft and the counterweight and that the shaft is vertical and pointing to the ground (Counter Weight Down - CWD position). Unlatch the DEC axis and rotate it until the dovetail plate is in horizontal position. Block both the axis latches. 10

11 Open the dovetail clamp by rotating its own knob. Take the OTA, inserting its dovetail plate on the proper platform of the mount, putting the side closer to the ground first. Then, while still keeping the OTA with one hand, screw with care the clamp until the OTA is firmly locked on the mount. 11

12 2. Telescope balancing To guarantee a precise mount tracking it is necessary to correctly balance the telescope in both the rotation axes. To perform this operation is needed to move manually and freely the telescope in RA and DEC. The LineAR mount is provided of latches in both axes, we already mentioned for the previous operations. To freely move the telescope, the latches need to be rotated in the counter clockwise direction, releasing the axes. Note: Before performing the balancing of the telescope be sure to have the full control of it before releasing the latches. An over unbalanced mount can move very quickly causing damages to the optical tube or to the mount itself. 2.1 RA Balancing 1. Make sure the telescope is firmly set on the mounting platform. 2. Loosen the latch of the RA shaft and place the telescope on one of the sides of the frame. The counterweight bar will extend horizontally on the opposite side of the mount. 3. Let go the telescope SLOWLY to see which way the telescope tends to "fall." 4. Loosen the lock screw of the counterweight, so that it can slide along the bar. 5. Move the counterweight towards the position in which it balances the telescope (i.e. the position in which the telescope remains stationary when the RA latch is loose). 6. Tighten the counterweight screw to lock it in the new position. 2.2 Dec Balancing Even if the telescope should not move in Declination during an ideal tracking, it telescope must be balanced in this axis to prevent any sudden motions when the DEC latch is loose and particularly to ensure the absence of vibrations and a quick response during the photo autoguiding. To balance the telescope in DEC: 1. Loosen the RA axis latch and position the telescope horizontally on one of the sides of the mount (as described in item 2 of the previous section) 2. Tighten RA latch to keep the telescope in position. 3. Loosen the DEC axis latch and rotate the telescope to make the tube parallel to the ground. 4. Release the tube - GRADUALLY - to 12

13 see which way the tube tends to rotate with respect to the Declination axis. 5. Slightly loosen the mount dovetail clamp knob and slide the telescope either forwards or backwards until it will not remain in equilibrium when the DEC latch is loose. DO NOT let go the telescope tube while the dovetail clamp knob of the mounting platform is loose! 6. Tighten the dovetail clamp knob to lock the telescope in place. NOTE: It should be emphasized that the LineAR mount, on contrary of the mounts based on worms and gears that slightly must be biased in the direction of motion to obtain a more regular tracking, must be balanced in an accurate way to guarantee, in every position, the absence of hysteresis effects and oscillations around the meridian. This difference is due to the toothed belts transmission system and proves to be a significant advantage because, once balanced, it is not necessary to change the position of the weights, a valuable feature for long exposure photography even at the meridian pass, as well as very useful also for remote telescopes. 13

14 3. Mount Polar Alignment The Linear is an equatorial mount and therefore it is necessary to make its polar axis parallel with the Earth rotation axis. In this chapter the operations to trim the latitude and the azimuth and to perform the mount alignment to the celest pole using the standard polar scope (or the optional alternative) will be described. 3.1 Adjusting the mount in latitude The first operation to perform (after the tripod has been "levelled" using the appropriate spherical bubble level installed on the base plate) consists on inclining the polar axis at the latitude of the observation site (for example Milan and Venice are at 45, Rome at 42, Palermo at 38 ) using the two Altitude knobs (acting in pushpull arrangement) and the indication of the scale latitude, engraved on the left side of the mount. The mount adjustment range in latitude goes from about 10 to 70. The altitude adjustment is accomplished with both hands: when you screw the back knob, unscrew the same number of laps (or part thereof) the front knob (or vice versa). raising the polar axis of the mount. T o increase the latitude (lift) of the polar axis, turn the rear latitude adjustment knob clockwise. T o decrease the latitude (lower) of the polar axis, turn the rear latitude adjustment knob counter clockwise. Note: In general it is better to make fine adjustments in latitude by moving the mount in contrast with gravity, i.e. 3.2 Adjusting the Mount in Azimuth Even the adjustment in azimuth of the mount involves the use of two screws that act against the brass contrast block. The adjustment is accomplished with both hands: When you screw a knob, unscrew the same number of turns (or part thereof) the other knob (or vice versa). In particular the fine adjustment in azimuth comprises these steps: 14

15 1. Rotate the azimuth adjustment knobs located on both sides of the mount base. 2. By tightening the right adjustment knob (and loosening the one on the left) you rotate the mount to the right. 3. By tightening the left adjustment knob (and loosening the one on the right) you rotate the mount to the left. Remember that the mount adjustment should only be performed during the process of polar alignment. Once polar aligned, THE MOUNT MUST NOT BE ANY MORE MOVED. The pointing of the telescope is carried out by moving the telescope in Right Ascension and Declination, as described later in this manual. 3.3 Polar alignment The mount precise polar alignment should be performed using the polar scope. The Avalon LineAR mount is normally shipped with a Skywatcher Polarscope already installed. However it is possible for the user to choose a Losmandy polar telescope as an option. This appendix describes the operations needed to perform a good polar alignment of the mount using both the mentioned polar scopes. To use the polar scope is necessary to rotate the DEC axis of the frame until it clears the hole in the DEC axis through which the polar scope can "see" the sky Polar alignment with a Skywatcher Polarscope Looking though this scope, with the reticle well lighted internally, it is possible to se a reticle layout similar to that on the right. As is known the Polaris is several tens of seconds from the Celestial Pole and therefore it appears to orbit around the pole at a given distance, making a full orbit, every 24 hours. The bigger circle in the reticle represents the Polaris orbit and the small one, with the name of the star, represents the position of the Polaris. The problem here is to turn the reticle around the small cross in the center, to put the small circle in the position where the Polaris 15

16 is seen from a given observation site, at a specified date and time. In the past this position was obtained using several types of graduated circular scales. The Avalon mounts are not provided of these scales. Presently the most suitable method to get the exact Polaris position is the use of one of the several computer programs or mobile devices applications, both for Apple ios or Android as, for example, Scope Help for ios or Polar Finder for Android. These programs, that provide the Polaris position both visually and in the hour form, are briefly described in section Once the Polaris position has been determined and the telescope has been mounted with the contrast blocks oriented to the North (see section 2.1) the following operation are needed: 1. Untight the DEC latch and rotate the axis until the hole in the axis is in the front of the polar scope, allowing it to see the sky and the Polaris in the field of view. Tight the DEC latch in this position. 2. Untight the RA latch and consequently the polar scope until the small circle in the reticle is in the position indicated by the used application. Tight the RA latch in this position. It is possible to have a small help verifying that the position of the figures of the Big Dipper and Cassiopeia roughly correspond to the real position in the sky. 3. Untight slightly the two screws that fix the mount to the tripod to allow the mount base to rotate respect to the tripod mounting plate. 4. Acting on the two azimuth regulation knobs bring the Polaris under or over the small circle. Acting on the two altitude regulation knobs bring the Polaris inside the small circle. 5. Repeat this operation until the Polaris is centered in the circle. 6. Tight the Azimuth and Altitude knobs against the contrast blocks. 7. Firmly tight the screw that lock the mount movement respect to the tripod Polar Alignment with a Losmandy polar scope The Losmandy polar scope allows an more precise alignment because it is based upon the coincidence of three star (Polaris, δumi e OV Cep ) position with the correspondent locations in the scope reticle which has the following aspect: The dotted axes shall be neglected because they belong to the Southern Hemisphere. The alignment operations with this kind of polar scope are the following: 1. Untight the DEC latch and rotate the axis until the hole in the axis is in the front of the polar scope, allowing it to see the sky. Tight the DEC latch in this position. 16

17 2. Untight the RA latch and consequently the polar scope until the axis in the reticle with the slot for the Polaris (well indicated in the reticle) is roughly oriented in the position indicated by the used application. 3. Act alternatively on the Azimuth and Altitude regulation knobs and on the reticle rotation until the three stars are exactly located in the respective slots. In the three axes. Take into consideration that the position in the slots varies depending on the year. The four slots for two of the axes are related to the observation years reported in the border of the reticle. 4. When the three star are correctly positioned in the slots tight the Altitude and Azimuth knobs against the respective contrast blocks and, 5. At the end, firmly tight the screw that lock the mount movement respect to the tripod. Note: In case of difficulty to correct orientate the costellation in the right position it is possible to have the help of the PC, smartphone or tablet applications to perform the initial orientation of the Polaris axis External programs for Polar Finding Polar Align Ver. 4.0 is a ios app running on Apple s iphones and ipads. This program uses the internal GPS to evaluate the geographical coordinates of the observation site to calculate the exact position of the Polaris Star around the celestial North Pole. It provides also some additional information that can be useful for a correct telescope setup. The Polaris position is represented by a yellow small circle on a larger circular reticulum. To effectively use this app it is needed to evaluate the angle under which is the Polaris and rotate the Polarscope reticle of the same angle to bring the Polaris circle in the correct position. It should be noted that the reticle reproduce exactly the type of optical inversion caused by the Polarscope optics. For the Android environment, for both smartphone and tablet of different brands, it is available, among others, the Polar Finder app that, on the contrary of the ios app, reproduce with a good fidelity the reticula of the Polarscope (provided with the M-zero and of the Losmandy available as an option. This app is characterised by a particularly complete setup form to define the Northern or Southern Hemisphere, the type of reticle to use among the more commons, including those available for the M-zero. The three following figures represent the setup, Polarscope and Losmandy reticle screenshots. 17

18 This app also takes the observation site geographical coordinates from the internal GPS if available, otherwise it is needed to manually insert them, for the Android devices not provided of GPS. The additional information provided by the app are similare to those provided by the ios app but the reticula are more easily usable being them similar tho those available for the M-zero. 18

19 APPENDIX A Astrophotography Tips This is a fast step by step guide which requires about minutes of operation and is dedicated to the imagers which already have some skill with telescope imaging. It allows to take astronomical images easily with your telescope setup, particularly if you use a colour ccd camera (also a DRLs camera). For those who have no skill at all in astronomical telescope imaging we suggest to purchase some dedicated books and also subscribe to the several forum available on the web. Mount and Tripode Assembly 1. Setup the tripod and using a compass make sure it is well placed on the ground. 2. Set the mount head on the tripod and block it using the two supplied knobs. 3. Level the tripod with the help of the spirit level enclosed on the mount base. 4. Insert the counterweight shaft and after the RA counterweights. 5. Set with safety the OTA and the guide scope (if available) on the mount. 6. Insert the imaging and guiding ccd into the telescope. 7. Connect all cables (ccd cable, usb cable & power cable without powering on). 8. Balance carefully both RA and Declination axis. System Startup 1. Setup a table with the laptop. 2. Connect the cables to your laptop and power it up. 3. Power up the StarGo System. 4. Perform the polar alignment as previously described. 5. Execute the alignment on a star next to the target object. Pointing and images parameter setting 1. Set the correct focus of both the imaging and guiding systems. 2. Point the object you to want to image using the telescope keypad or PC software. 3. Center the object inside the ccd camera field according to the frame you want to acquire. 4. Make sure that at least one star of adequate brightness appears into the guiding ccd field. 19

20 5. IMPORTANT! set the "AUTOGUIDING SPEED" to the minimum value (suggested 0,125x). 6. Execute the guiding ccd system calibration using the camera control. 7. Activate the guiding system and optimize the parameters while observing the trend of the graph. 8. Make a 2 or 5 minutes exposure with the imaging camera at the highest sensitivity to evaluate the correct exposure needed to image the subject. 9. Set the final values for sensitivity, exposure, binning, file name, number of exposures. 10. Start the exposure. 20