AJAK Polar Mount and Reed Switch

[cossie16]

Hello, having a bit of free time on my hands I decided to play with my bud, it's been unused for quite a wile. Because I wired it incorrectly I blew the reed switch. I also made the mistake of not marking the wheel with the magnets and the piece with the reed switch on the H2H polar mount.
The receiver is a Chaparral MC-115 (not sold in the US, I believe) with an added IOT-1 module for elevation using a 12inch superjack. I'm not using that at the moment, I just want to get the dish moving east west!
When I go through the menu to set the limits, I get the following error, "limits not set" as per the following.

Does anyone have any idea as to what I'm doing wrong? I may also have fried the ne reed swith when soldering it in place, sigh!

There was talk on here about changing the sensor to an optical one, anyone one done that and how easy would it be for a klutz to do.

Thanks for any suggestions. Mark.

 

[arlo]

I'm watching this post. Will reply after a bit and see who else jumps in.
I have converted the reed switch to a hall effect and now am currently conjuring up an optical sensor and slotted encoder wheel project.
As for your limits. And I'm not familiar with an AJAK. So pardon that.

Start at the lowest mechanical limit of your dish (West in my case) and give 'er a little room by extending the actuator a little bit. Then set the West limit microswitch to keep it from absolutely running the dish down to where the actuator stalls if the dish retracts and binds the mount.
Then run the dish out a touch more (extend the actuator) East and set the West limit in the receiver menu.
Then East limit would be the same. If your dish has a tendency to 'flop' after it goes past top center (highest point in the arc). Run it out to just before that point and set the East limit microswitch.
Then retract it a little bit towards west and set the East limit in the receiver.
And. I don't know if you have a limits reset in your menu.
If 5000/5000 are the soft limits and the actuator won't move.
Considering the reed switch is good and working and the receiver is counting pulses.....
You may need to reset the limits to get rid of an error.

Like for me. I like to start with low counts on the West limit and increment as it goes East (the actuator extends).
So I get the actuator mechanically retracted and extend it a few inches.
Then uncouple the motor and run the counts down to zero.
Increment it to something like 100 and bolt the motor back up to the actuator arm.
Then set the soft limit in my actuator control (ASC-1) to that after making sure the hard limit (microswitch) will trip if the actuator retracts any further than that.

Oh. You mentioned "klutz".
Does that mean 0 expertise? Does your receiver have a selection for a hall or optical switch in the menu along with reed (make/break) switch?
And if I look in your toolbox would I see Channel Locks in one drawer, a flat head in another, a hammer in the third, and condoms in the fourth?
Because you know. Sometimes if you can't fix it..... Yeah. I think you catch my drift.

 

[thedishking]

If the reed switch has failed, it should not be that hard to come up with something to replace it.

A recessed door security contact might work with some tinkering?

 

[VictoriaFTA]

I recommend this as a replacement reed switch:

59025-040 Littelfuse Inc. | Sensors, Transducers | DigiKey

Order today, ships today. 59025-040 – Magnetic Reed Switch Magnet SPST-NC Wire Leads Probe from Littelfuse Inc.. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

I had to replace the reed switch in my AJAK H180 when it failed and this one works great for me.

 

[anto@]

View: https://youtu.be/DlFwgm5C-M0

 

[cossie16]

Hello, thanks for answers so far, the 5000 in the menu can't be changed, you should be able to enter new numbers, but I just get the error message.
I have a few more reed switches so I will rig something to see if it has blown. This is the reed switch that I replaced, the original was covered in silicone to keep water out. As I said earlier, I may have blown this one with too hot a soldering iron, so with a new one I'll use something else. The dish will move when I connect it to a 12v jump starter, so I know that part is good.

Cheers, Mark.

 

[Magic Static]

For the AJAK sensor I use the LittelFuse "FLEX-14-15-20AT"
Unlike most glass reeds the leads are flexible and won't break the glass when bent. You have to be close to the original to support the 10 counts with one revolution of the five magnet wheel like the original.

https://www.mouser.com/ProductDetail/Littelfuse/FLEX-14-20-25?qs=QQJxVsr8EGax9rO2VXN88A%3D%3D&mgh=1&gclid=EAIaIQobChMIw__hrb208wIVLSCtBh2QZwspEAQYASABEgL-5PD_BwE

 

[Magic Static]

As far as the limit set issue, I'm not familiar with that receiver but the 5000 number should represent the counts received from the sensor. Since the sensor is bad the counts don't change and the dish won't move so you can't set the limits yet.

About marking the magnet wheel and locating the sensor, no worries. You can line up the sensor in any position it will fit. It won't bother it.

 

[arlo]

.....helps if you orient the switch reeds correctly in the magnetic field too.

 

[cossie16]

Changed reed switch without any luck, I'll ask a friend if he can convert it to a Hall Effect.

 

[primestar31]

Changed reed switch without any luck, I'll ask a friend if he can convert it to a Hall Effect.

Have you checked the wiring from reed switch to receiver? Maybe a broken wire...

Haul a long extension cord out to the dish. Take the receiver & tv set out there. Temp replace the wires going into the house, with shorter wires going to the receiver right at the dish and see what happens.

Or, just use a multi-meter to check continuity of the wires from Ajak to receiver in the house.

 

[arlo]

.....helps if you orient the switch reeds correctly in the magnetic field too.

Not to be coarse. But if you're going to attempt to do your own repairs you at least will need a multimeter.
Just an el-cheapo hardware store one will work.

Finding out if the reed switch is even tripping will be very difficult without one.
Checking for sensor wire continuity back to the receiver terminals will be tough to do.
Of if there is a high resistance path from the actuator sensor wires back to the receiver.
And since there is usually a few volts from the receiver on the sensor wires to the switch, again a multimeter is needed.
I don't think you stated if the motor was actually trying to turn when you command it to.
Or if there is motor voltage present to make it work.
Again, a meter is needed.

 

[cossie16]

OK, I checked the reed switch using a 12v light and jump starter, using a magnet it closed the switch and the light turned on, so I know that is working. I ran an external cable to dish, at first no good, but then by playing with the menu, I was able to change the east and west limits, so obviously I was doing something wrong, the instruction manual is not very clear to me. I had all this running years ago complete with corotors and the like, so I knew I could do it, sigh, I think too much good red wine is starting to have an effect!

I used a piece of plastic waffle board as a temp measure, and a superjack reed switch, so now to make a permanent change.

Thanks for all the input, I have learnt a lot about reed switches! If you need reed switches for Superjacks, there is a company in Perth, Western Australia called Sciteq that has them in stock and are easy to deal with, thanks again.

 

[arlo]

Did you happen to snap a photo of under the cover you made?
I'm interested in seeing it.

 

[cossie16]

Did you happen to snap a photo of under the cover you made?
I'm interested in seeing it.

I will do a bit later today, I used hot glue to hold the switch in place, next time I’d use silicone.

 

[arlo]

I will do a bit later today, I used hot glue to hold the switch in place, next time I’d use silicone.

Cool. Asking because I cannot find any mechanical drawings on your actuator.
I've converted my supercrap actuator from reed switch to hall switch and it's working awesome.
Just sourced an Omron slotted optical sensor and a 20 slot optical encoder wheel from eBay.
Since the conversion, position repeatability (especially when signal hunting) has gotten about 1000% better.
The snap action of a Schmitt triggered sensor versus the sloppy magnet trigger of a reed switch looks great on the 'scope.

 

[cossie16]

Not sure exactly what you want, but happy to help. I will make a permanent change by replacing the original fibre board.

The black rectangular thing is a reed switch for a linear Superjack. I used this as I broke several of the glass ones, they are too fiddly for me. I didn't need to put the two holes, at first I was going to run the wires through these. So, as per above this is the outside before I tidied it up.

I'm sure there is a pdf of the h2h mount on this forum, it's very sinilar to this: https://satelliteguys.us/xen/attachments/ajakaimer-pdf.27858

.

 

[Comptech]

Hehe, reed switches are available at your local auto parts stores. I prefer the 07 Ford ranger front wheel speed sensors, the can be mounted variable ways.

 

[Comptech]

And if you are working on a actuator arm, Gm truck use a small one that can be mounted easily. Just make sure you solder and heat shrink the connections,

 

[arlo]

A perfect candidate for a count doubler mod. And better for a hall mod. Grab a stack of proper sized neodymium magnets from Amazon and 5 minute epoxy away after you Sharpie the N-S polarities.