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