Paul,
If your controller doesn't have a DIN socket on the back, then your best bet is to look at the ERC units - the ERC-M interface will talk to azimuth and elevation simultaneously, either on one or two separate connections, and they also sell "rotor cards" which you can install inside your controller, effectively adding an interface to a controller which lacks one. The rotor cards are basically boards with a bunch of relays addressable by the main ERC-M unit.
You can find it all on www.easy-rotor-control.com and the best bit about the ERC-M is that it will talk GS232B protocol to a PC, meaning any app that can talk GS232B can address it (including all the popular satellite software). There is also a dedicated rotor control app that ERC produce which is capable of control and readout.
73,
John (XLX)
-----Original Message----- From: Paul paul@ukdx.org.uk Sent: 16 June 2018 19:48 To: John john@amber.org.uk; amsat-bb@amsat.org Subject: Re: [amsat-bb] Another KR500 thread, maybe.
Just a quick update, I took the controller capacitor out of line and now the limit switches behave as expected so that's good news. Having cleaned everything I put it back together without grease for the time being with 20 of the best condition bearings in one end and am pleased to say everything works perfectly using the old controller.
The new stainless bearings, M6 bolts for the casing and M8 bolts for the bracket have been ordered so hopefully it won't be too long before my £1 elevation rotator is brought into service. I've downloaded a few manuals now so can match up what I have motor and controller wise.
Just being lazy for the moment and to save me searching is there a PC interface available for the 5600 motor and old style Kenpro KR-400 (my azimuth rotator), one that has a stand alone programme to operate them?
Thanks again for your help with this little project John.
73 Paul G7PUV
On 16/06/2018 15:06, John wrote:
Hi Paul,
Yes, I'm 99% sure it's the elevation unit side of a late model KR5600B. I would not recommend running it with both capacitors inline, as the capacitors are effectively used as a timing device to ensure the motor spins in the correct direction. The capacitance delays the current hitting the second set of coils long enough to make the motor spin which allows it to drive the rest of the system. Sending current up both sides at once (due to your capacitor in the controller) will confuse things somewhat
The motor auto-reversing is possibly a symptom of this extra capacitor in the wrong place, though since I had weird wiring in my rotor unit which I needed to pull out, I can't verify that from experience. Pull the capacitor wires from your controller and see if you get the same behaviour or not!
The disc brake is between the gear on the motor shaft, and the motor housing, and is usually a cork disc. It adds enough friction to 'brake' the motor, but when you energise the coils, the motor shaft physically lifts away from the brake disc. You'll see, if you give the shaft a gentle pull, that it almost lifts away from the motor unit - this is the brake release mechanism.
The main thing to remember is that you're working with AC motors here, which run at around 26-28V.
As an aside, if you don't have the manual for it, it's worth finding one - I probably have a digital copy somewhere I can send you if needed. The manual has a full and complete wiring diagram for both sides of the system in them.
73,
John (XLX)
-----Original Message----- From: Paul paul@ukdx.org.uk Sent: 16 June 2018 09:41 To: John john@amber.org.uk; amsat-bb@amsat.org Subject: Re: [amsat-bb] Another KR500 thread, maybe.
Hi John,
Thanks for your lengthy reply, I really appreciate it. Just to clarify one thing you think this is a late model Kenpro due to it having the switches and cap inside the casing attached above the positioning pot?
I tested the motor last night using the KR400 controller, wiring seems standard on pins 4,5 and 6 so I gave it a couple of briefs bursts to see if it turned, it didn't! Well not initially then all appeared OK, on closer inspection I discovered that the motor itself has some form of brake or stop inside. While it's free to be turned manually in the same direction it was last powered it will not turn in the opposite direction until power is applied to move it that way. At first I thought it was jammed or broken but it appears to be normal operation as the rotation is quite free with no nasty feeling rough spots.
The limit switches surprised me as well. I come from a satellite background where I'm used to a limit switch killing power to an actuator, if I press one of these it switches the motor into the opposite direction, is that right?
Now I know the motor is free to move I've purchased new bearings and will source some suitable grease, primer and paint. The case has become quite pitted inside where the water was laying but it's now all clean after wire brushing and rubbing down. Externally it's in very good condition even where I hit each point with the gas gun to get the bolts out. It goes without saying they'll all be replaced with stainless socket head bolts.
73 Paul G7PUV
On 15/06/2018 09:13, John wrote:
Paul,
It's a Model B KR500 I would say. The very last version of the KR5600 (the KR5600B set) had limit switches and capacitors inside the motors.
As for how to proceed, you have two options. Firstly pull the limit switch mechanism out and rely on the controller's start capacitor, or secondly pull the start capacitor from the controller and use the rotor limit switches and capacitor. As far as I can tell from the in-depth dismantling I've done of a couple of these, either should work, but having both would effectively render the limit switches redundant, and probably play some kind of havoc further down the line.
What I'd recommend personally is that you start by checking the wiring config on the back of the screw block - this will have an effect on what you do later. There was some weird wiring in one of the rotor units I bought, and it ended up with pins being shorted together inside the connector block and made everything weird. I made the decision with that one to return it to 'A' spec as I couldn't be sure what else had been done. If yours is similar that's the approach I would take.
If, however, the inside wiring on the motor unit is sensible and sane, and matches spec, then I'd probably go for keeping the limit switches installed, as otherwise your only limiting is a mechanical stop, and if you hit that and don't realise, but keep sending current up the cable, you'll inevitably burn out your motor windings after a while. Not such a fun job to fix (dismantling the motor housing is at least an hour's work on its own), although easy enough to do with patience.
Feel free to ping me off list if you want to chat about it further!
73, and a firm left handshake, John (2E0XLX)
-----Original Message----- From: AMSAT-BB amsat-bb-bounces@amsat.org On Behalf Of Paul Sent: 14 June 2018 18:18 To: amsat-bb@amsat.org Subject: [amsat-bb] Another KR500 thread, maybe.
Hi all I recently won a Kenpro KR500 rotor on Ebay for the princely sum of a quid. The alleged history was it was purchased, had antennas attached but was never wired or used and this I can believe because the connector block looks untouched. It was however left on its side in the garden so looks pristine but has suffered water ingress. I started to strip it down today and of course the eight M6 Phillips heads put up quite a fight but I attacked it with fire and it is now apart.
Having opened it up I'm now slightly confused as to what model rotor I actually have. It has the eight screw terminal block, the casing is stamped Kenpro but internally it has the limit switches and a capacitor.
The controller I intend using is an old Kenpro KR400 model and I assume has the 70uF cap across the switches. Do I leave this in place to use it with my rotor or should I remove it, or remove the cap in the rotor?
Paul G7PUV Sussex Coast. JO00 _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
-- Paul Sussex Coast. JO00
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