Review of Commercial Rotators - Revision history

Zisi: Add a link related to G-5500 controller relays

2020-11-14T17:29:52Z

Add a link related to G-5500 controller relays

Vk5qi: /* Electronics */

2020-10-08T07:31:48Z

‎Electronics

Pierros: Pierros moved page Review of Commercial Rotator to Review of Commercial Rotators

2020-08-06T08:34:51Z

Pierros moved page Review of Commercial Rotator to Review of Commercial Rotators

Oz1sej: Plural 's' in title

2020-07-05T14:17:13Z

Plural 's' in title

Oz1sej: Reworded a bit to be more readable - I hope that the original meanings are preserved!

2020-07-03T21:58:56Z

Reworded a bit to be more readable - I hope that the original meanings are preserved!

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Jebba: categories

2020-01-19T22:38:30Z

Zisi: Add link for motor repair process

2019-04-22T14:35:56Z

Add link for motor repair process

Zisi: Add alternative rotator controller for yaesu G5500

2019-04-08T11:33:27Z

Add alternative rotator controller for yaesu G5500

Zisi: Add the review for commercial rotator

2019-03-01T16:31:18Z

Add the review for commercial rotator

New page

== Intro ==

The existing rotator controllers are old fashioned and use obsolete technology either in hardware or in software. Almost all the motor drivers are based in electromechanical switches like relays. This introduce in a system a limit of how usual could be used for an observation of a satellite and also in accuracy in movements of the rotator. In this review, it is presented the most popular in HAM community, rotator systems.

Existing commercial rotator systems:
There are three rotator systems, as i searched, are the most popular in HAM community for tracking satellites.
* [https://www.yaesu.com/indexVS.cfm?cmd=DisplayProducts&ProdCatID=104&encProdID=79A89CEC477AA3B819EE02831F3FD5B8 Yaesu G-5500]
* [http://www.alfaradio.ca/ SPID rotators]
** [https://www.rfhamdesign.com/products/spid-antenna--rotator/ras-az--el-rotator/index.php RAS]
** [https://www.rfhamdesign.com/products/spid-antenna--rotator/big-ras-az--el-rotor/index.php BIG-RAS]
* SPX rotators,
** [http://www.rfhamdesign.com/products/spx-antenna-rotators/spx-01-az--el/index.php SPX-01]
** [http://www.rfhamdesign.com/products/spx-antenna-rotators/spx-02-az--el/index.php SPX-02]
** [http://www.rfhamdesign.com/products/spx-antenna-rotators/spx-03-az--el/index.php SPX-03]

== Yaesu G-5500 ==

=== Electronics ===

[https://www.yaesu.com/indexVS.cfm?cmd=DisplayProducts&ProdCatID=104&encProdID=79A89CEC477AA3B819EE02831F3FD5B8 Yaesu G-5500], it is an AZ/EL rotator. From [http://www.radiomanual.info/schemi/ACC_rotator/Yaesu_G-5500_user.pdf data sheet], could understand that it has AC motors (26V@2.8A, specifications of transformer for both motors), potentiometer (isn't multiturn) for position feedback which are operated in +6V, and all control loop is implemented with analog IC's (comparators and op amps). Also the system has end-stops in both axis in both directions (min-max), that immediately cut off the current of motors. The connection with a client is implemented via a rotator interface for example an [https://gitlab.com/librespacefoundation/satnogs/g5500-ardushield ardushield] that runs [https://github.com/ppapadeas/k3ng_rotator_controller/tree/lsf-g5500 k3ng rotator firmware]. The cost of all system is ~750$ with analog controller.

[[File:Yaesug5500-electronics-1.jpeg|thumb|center|300x300px|alt=|Yaesu G5500 - Controller]]

=== Mechanical ===

The gear box of rotator it is a spur gear box. Almost all the gears are made from laser cut sheet metal and the output gear is a stack of laser cut sheet metal gears. Another interesting thing is the brake system that it's a torsional spring in motor axis that blocks the movement from output to input. When a torque applied from output to input the torsional spring "opens" and block the rotation. A mechanical fail of one bracket that mounts the pins of gears are done in [https://network.satnogs.org/stations/6/ station 6] after a lot of observations (oval hole). This problem is produced because the antennas are back mounted without counter balance.

<gallery widths="300" heights="300" perrow="2">
File:Yaesug5500-mech-1.jpeg| Yaesu G5500, Gear box
File:Yaesug5500-mech-2.jpeg| Yaesu G5500, Mechanical fail
</gallery>

=== Alternative Rotator Controllers ===

A list of available digital controllers:
* [https://www.greenheronengineering.com/proddetail.php?prod=RT-21azel RT-21 Azimuth/Elevation, Green Heron Engineering LLC], 889$
* [http://www.arrl.org/files/file/ETP/Satellite%20Tracker%20Interface%20ver%201_2.pdf DIY solution from ARRL]

== SPID rotators ==

This company it has two AZ/EL models:
* [https://www.rfhamdesign.com/products/spid-antenna--rotator/ras-az--el-rotator/index.php RAS]
* [https://www.rfhamdesign.com/products/spid-antenna--rotator/big-ras-az--el-rotor/index.php BIG-RAS]

=== Electronics ===

Both of models are using DC motors, according to data-sheets, [https://www.rfhamdesign.com/downloads/spid-bigras-specifications.pdf BIG-RAS] and [https://www.rfhamdesign.com/downloads/spid-ras-specifications.pdf RAS]. The power consumption for both rotators is , 12V@6-10A or 18V@6-11A. For position sensor, a reed switch is used, one in each axis. This sensor is mounted in the first stage of worm gear box (in total two worm gear boxes), with total 6 magnets that produce pulses with Vp-p according to Vcc of reed switch.

<gallery widths="300" heights="300" perrow="3">
File:Ras-reedswitch.jpeg| RAS, position sensor
File:Ras-magnets.jpeg| RAS, magnets of position sensor
File:Ras-pulses.jpeg| RAS, pulses of position sensor (reed switch)
</gallery>

It seems that the encoder is relative, so when the system starts it programmed the zero position. When the system lose the power, the rotator controller knows the last position, it stores the last position in a non-volatile memory.
Also the system has two hard stops in elevation axis that limits the rotation between 0-180 deg. This switches immediately cut off the current to elevation motor. In the azimuth there is no end-stop.

[[File:Ras-endstop.jpeg|thumb|center|300x300px|alt=|RAS, end-stops in elevation axis]]

The default rotator controller is [https://www.rfhamdesign.com/downloads/spid-ras-specifications.pdf Rot2Prog], the motor driver again, it consist of relays. The interface with client is done with [Hamlib](https://hamlib.github.io/) via a USB. A note here, is the cable is USB-A male to USB-A male, that is weird. Two rectifier bridges used for protection of the board from the currents of DC motors. The cost of Rot2Prog is ~250$.

[[File:Ras-rotatorcontroller.jpeg|thumb|center|300x300px|alt=|RAS, Default rotator controller]]

The [https://www.rfhamdesign.com/downloads/spid-ras-specifications.pdf datasheet of RAS] is referred to a parameter [https://en.wikipedia.org/wiki/Mean_time_between_failures MTBF] which is the mean time between failures. For rotator controller is 15000 hours @ -5 to +40°C. For a system that is connected to [https://network.satnogs.org/ SatNOGS network] means:
* in 1h, at least 2 observations of 15min each
* in 15000 hours, 30000 observations
* which means almost 2 years of operation
But how usual the relays are worked?

=== Mechanical ===
Both of the rotators are consist of two stages of worm gear box. The second stage (the output) it takes all the loads. In this system the brake mechanism is the two stage worm gear box (big gear ratio and also the lead angle of worm gear). The cost for RAS with Rot2Prog controller is ~1200$, for BIG-RAS with Rot2Prog controller is ~1600$.

<gallery widths="300" heights="300" perrow="2">
| RAS, position sensor
File:Ras-magnets.jpeg| RAS, First stage of worm gear
File:Ras-wormgear.jpg| RAS, Second (output) stage of worm gear
</gallery>

=== Alternative Rotator Controllers ===

A list of available digital controllers:
* [https://www.greenheronengineering.com/proddetail.php?prod=RT-21azel RT-21 Azimuth/Elevation, Green Heron Engineering LLC], 889$. This feature is nice, "Allows different Azimuth and Elevation rotators from any manufacturer provided they both use either AC or DC motors. (Example: We can configure the Azimuth to use an OR-2800 and the Elevation to use a DC motor linear actuator. OR, the Azimuth to use a T2X, and the Elevation to use a Yaesu G-550)"
* [http://www.rfhamdesign.com/downloads/spid-ras_hr-specifications.pdf MD-01/02 HR], it is high resolution edition of rotator controller, with resolution of 0.1875 deg. Instead of using reed switches in first stage of worm gear box, it uses a hall effect sensor. Again the motor driver is electro mechanical switches as shown in picture in the [http://www.rfhamdesign.com/downloads/spid-ras_hr-specifications.pdf page 3 of data-sheet]. This controller, also, support soft-start functionality (PWM control) only when the power supply is higher than 20V, [https://community.libre.space/t/review-of-commercial-rotator-controllers/3428/7 according to this post].

The cost of this controller (only) is calculated:
* RAS/HR, RAS rotator and MD-02/HR controller is ~[1435E](http://www.rfhamdesign.com/products/spid-hr-antenna-rotators/ras-hr-az--el-rotor/index.php)
* only the RAS rotator costs ~900E (an estimation)
so the cost of MD-02/HR is ~500E.

<gallery widths="300" heights="300" perrow="2">
| RAS, position sensor
File:Az-El controller front G.gif| RT-21 Azimuth/Elevation, Green Heron Engineering LLC
File:Rotator-controller-md.png| Rotator Controller, MD-01/02 HR
</gallery>

== SPX rotators ==

=== Electronics & Mechanical ===

A series of AZ/EL rotators:
* [http://www.rfhamdesign.com/products/spx-antenna-rotators/spx-01-az--el/index.php SPX-01]
* [http://www.rfhamdesign.com/products/spx-antenna-rotators/spx-02-az--el/index.php SPX-02]
* [http://www.rfhamdesign.com/products/spx-antenna-rotators/spx-03-az--el/index.php SPX-03]

All of these rotators it seems that are based in the same, first stage, worm gear box with the RAS. The second stage it is like [https://ae01.alicdn.com/kf/HTB1uzY4PVXXXXX4XXXXq6xXFXXXE/NMRV050-Speed-Ratio-50-1-Worm-Gearbox-14mm-19mm-Input-Shaft-90-Degree-Worm-Gear-Speed.jpg_640x640.jpg that] and changed according to the maximum output load (and maximum break torque). From all the data-sheets seems that motor needs power 12-18V@3-20A or 20-24V@3-20A (max current depends on load or rotator controller, e.g. PWM control). All of these rotator use the same controllers with RAS/BIG-RAS. The motors are DC (it seems that are the same with RAS/BIG-RAS). For position sensor, a reed switch for standard version and a hall effect sensor for high resolution version. From the number of cables and from the type of controller it seems that there no an interface of end-stops connected to rotator controller. [https://community.libre.space/t/review-of-commercial-rotator-controllers/3428/7 This post] confirms that the SPX-01 and SPX-02 have no end stop switches on either azimuth or elevation. Also the limits are set in the controller, based on the users cabling setup.
In this system the brake system is the double worm gear. In the specification, the rotation range is AZ/EL:360/180deg is the same with the RAS. The available rotator controllers are the same with the SPID rotators.

<gallery widths="300" heights="300" perrow="2">
File:Spx-wormgear.jpeg| SPX, second stage of worm gear
File:Spx-station232.jpg| SPX-02 rotator, [https://network.satnogs.org/stations/232/ station 232]
</gallery>

← Older revision		Revision as of 17:29, 14 November 2020
Line 23:		Line 23:

	*[https://kb5wia.blogspot.com/2012/03/yaesu-g5500-rotator-motor-repair.html Motor Repair]		*[https://kb5wia.blogspot.com/2012/03/yaesu-g5500-rotator-motor-repair.html Motor Repair]
		+	*[https://community.libre.space/t/g-5500-controller-relays/6303/4 G-5500 controller relays]

	[[File:Yaesug5500-electronics-1.jpeg\|thumb\|center\|300x300px\|alt=\|Yaesu G5500 - Controller]]		[[File:Yaesug5500-electronics-1.jpeg\|thumb\|center\|300x300px\|alt=\|Yaesu G5500 - Controller]]

@@ Line 65: / Line 65: @@
 [[File:Ras-endstop.jpeg|thumb|center|300x300px|alt=|RAS, end-stops in elevation axis]]
-The default rotator controller is [https://www.rfhamdesign.com/downloads/spid-ras-specifications.pdf Rot2Prog], the motor driver consists of relays. The interface with the client is done with [Hamlib](https://hamlib.github.io/) via a USB. A note here: The cable is USB-A male to USB-A male, which is weird. Two rectifier bridges are used for protection of the board from the currents of the DC motors. The cost of Rot2Prog  is ~250$.
+The default rotator controller is [https://www.rfhamdesign.com/downloads/spid-ras-specifications.pdf Rot2Prog], the motor driver consists of relays. The interface with the client is done with [Hamlib](https://hamlib.github.io/) via a USB. A note here: The cable is USB-A male to USB-A male, which is non-standard. The USB-Serial chip inside the Rot2Prog is normally powered via the USB port, and there are known issues with inrush current on Raspberry Pi units, resulting in the USB-Serial not operating. This can be resolved by modifying the Rot2Prog to power the FTDI chip from the onboard 5V regulator (which powers the main micro-controller) instead of the USB port.
 [[File:Ras-rotatorcontroller.jpeg|thumb|center|300x300px|alt=|RAS, Default rotator controller]]
@@ Line 75: / Line 77: @@
 *which means almost 2 years of operation
-But how are the relays worked?
+Station #232 has observed one relay failure (open circuit, thankfully) approximately every year of operation. The relays are [https://octopart.com/rm85-2011-35-1012-relpol-30513939 readily available] via most major electronics parts outlets, and are fairly easy to replace with a desoldering station. A suitable [https://octopart.com/gd50-altech-24259941?r=sp relay socket] is also available to make relay changes easier.
 ===Mechanical===
@@ Line 117: / Line 119: @@
 *[http://www.rfhamdesign.com/products/spx-antenna-rotators/spx-03-az--el/index.php SPX-03]
-All of these rotators seem to be based on the same first stage worm gear box as the RAS. The second stage looks like [https://ae01.alicdn.com/kf/HTB1uzY4PVXXXXX4XXXXq6xXFXXXE/NMRV050-Speed-Ratio-50-1-Worm-Gearbox-14mm-19mm-Input-Shaft-90-Degree-Worm-Gear-Speed.jpg_640x640.jpg this] and changed according to the maximum output load (and maximum break torque). From all the datasheets, it seems that the motor needs 12-18V@3-20A or 20-24V@3-20A (max current depends on load or rotator controller, e.g. PWM control). All of these rotators use the same controllers as RAS/BIG-RAS. The motors are DC (it seems that they are the same as RAS/BIG-RAS). For position sensor, a reed switch for the standard version and a hall effect sensor for high resolution version are used. From the number of cables and from the type of controller it seems that there are no end-stops connected to the rotator controller. [https://community.libre.space/t/review-of-commercial-rotator-controllers/3428/7 This post] confirms that the SPX-01 and SPX-02 have no end stop switches on either azimuth or elevation. Also the limits are set in the controller, based on the user's cabling setup.
+All of these rotators seem to be based on the same first stage worm gear box as the RAS. The second stage looks like [https://ae01.alicdn.com/kf/HTB1uzY4PVXXXXX4XXXXq6xXFXXXE/NMRV050-Speed-Ratio-50-1-Worm-Gearbox-14mm-19mm-Input-Shaft-90-Degree-Worm-Gear-Speed.jpg_640x640.jpg this] and changed according to the maximum output load (and maximum break torque). From all the data-sheets, it seems that the motor needs 12-18V@3-20A or 20-24V@3-20A (max current depends on load or rotator controller, e.g. PWM control). All of these rotators use the same controllers as RAS/BIG-RAS. The motors are DC (it seems that they are the same as RAS/BIG-RAS). For position sensor, a reed switch for the standard version and a hall effect sensor for high resolution version are used.
 In this system, the brake system is the double worm gear. In the specification, the rotation range is AZ/EL:360/180deg - the same as the RAS. The available rotator controllers are the same as the SPID rotators.
 <gallery widths="300" heights="300" perrow="2">

← Older revision		Revision as of 14:17, 5 July 2020
Line 1:		Line 1:
		+	{{DISPLAYTITLE:Review of Commercial Rotators}}
		+
	==Introduction==		==Introduction==

← Older revision		Revision as of 14:35, 22 April 2019
Line 20:		Line 20:
	[https://www.yaesu.com/indexVS.cfm?cmd=DisplayProducts&ProdCatID=104&encProdID=79A89CEC477AA3B819EE02831F3FD5B8 Yaesu G-5500], it is an AZ/EL rotator. From [http://www.radiomanual.info/schemi/ACC_rotator/Yaesu_G-5500_user.pdf data sheet], could understand that it has AC motors (26V@2.8A, specifications of transformer for both motors), potentiometer (isn't multiturn) for position feedback which are operated in +6V, and all control loop is implemented with analog IC's (comparators and op amps). Also the system has end-stops in both axis in both directions (min-max), that immediately cut off the current of motors. The connection with a client is implemented via a rotator interface for example an [https://gitlab.com/librespacefoundation/satnogs/g5500-ardushield ardushield] that runs [https://github.com/ppapadeas/k3ng_rotator_controller/tree/lsf-g5500 k3ng rotator firmware]. The cost of all system is ~750$ with analog controller.		[https://www.yaesu.com/indexVS.cfm?cmd=DisplayProducts&ProdCatID=104&encProdID=79A89CEC477AA3B819EE02831F3FD5B8 Yaesu G-5500], it is an AZ/EL rotator. From [http://www.radiomanual.info/schemi/ACC_rotator/Yaesu_G-5500_user.pdf data sheet], could understand that it has AC motors (26V@2.8A, specifications of transformer for both motors), potentiometer (isn't multiturn) for position feedback which are operated in +6V, and all control loop is implemented with analog IC's (comparators and op amps). Also the system has end-stops in both axis in both directions (min-max), that immediately cut off the current of motors. The connection with a client is implemented via a rotator interface for example an [https://gitlab.com/librespacefoundation/satnogs/g5500-ardushield ardushield] that runs [https://github.com/ppapadeas/k3ng_rotator_controller/tree/lsf-g5500 k3ng rotator firmware]. The cost of all system is ~750$ with analog controller.

		+	Useful links:
		+	* [https://kb5wia.blogspot.com/2012/03/yaesu-g5500-rotator-motor-repair.html Motor Repair]
	[[File:Yaesug5500-electronics-1.jpeg\|thumb\|center\|300x300px\|alt=\|Yaesu G5500 - Controller]]		[[File:Yaesug5500-electronics-1.jpeg\|thumb\|center\|300x300px\|alt=\|Yaesu G5500 - Controller]]

← Older revision	Revision as of 08:34, 6 August 2020
(No difference)

@@ Line 1: / Line 1: @@
-== Intro ==
+== Introduction ==
 The existing rotator controllers are old fashioned and use obsolete technology either in hardware or in software. Almost all the motor drivers are based in electromechanical switches like relays. This introduce in a system a limit of how usual could be used for an observation of a satellite and also in accuracy in movements of the rotator. In this review, it is presented the most popular in HAM community, rotator systems.
@@ Line 114: / Line 114: @@
 File:Spx-station232.jpg|  SPX-02 rotator, [https://network.satnogs.org/stations/232/ station 232]
 </gallery>

@@ Line 35: / Line 35: @@
 A list of available digital controllers:
 * [https://www.greenheronengineering.com/proddetail.php?prod=RT-21azel RT-21 Azimuth/Elevation, Green Heron Engineering LLC], 889$
 * [http://www.arrl.org/files/file/ETP/Satellite%20Tracker%20Interface%20ver%201_2.pdf DIY solution from ARRL]