Reed Sensor

[tvropro]

I'm curious, does that Saginaw have any hardware limit switches? I can't see any in the picture. Most of the actuators I've owned (most are of the Houston Tracker variety, although some rebranded) have had a long screw that as the motor turns, a threaded thing moves down the screw and will eventually contact a cutoff switch to avoid damage to the actuator in the event that it goes too far. I don't see any limit switches in the picture, so I'm just curious how or if it's done with the Saginaw?

It's a ball screw not an acme. It has a slip clutch that engages at the end of the arms travel. My Sag is vintage 20 years old and is the old style. I don't know if the new ones have any other limit devices. In all the years I had it running the receiver limits never failed me.

Still it's built like a tank and moves my 12 foot like it's butter. (designed for 14.5 foot fiberglass) I noticed that it's faster than the Moteck was and dead nuts on Ball screws are for the big boy dishes.

 

[B.J.]

It's a ball screw not an acme. It has a slip clutch that engages at the end of the arms travel. My Sag is vintage 20 years old and is the old style. I don't know if the new ones have any other limit devices. In all the years I had it running the receiver limits never failed me.

...

OK, re ball screw design. Just looked that up. I never knew what the difference was before. Thanks.
But regardless of ball screw or acme, the "screw" I was talking about was about a 3 or 4 inch screw inside the motor box next to the magnet wheel. I wasn't talking about the big drive screw.
And even if you have the slip clutch thing, it's still nice to be able to adjust the limits to control how far the dish itself will go, even if you're not approaching the actual limits of the actuator. Like I didn't like my actuator to drive my dish too far past due south, because there became a point where the actuator would jam against the side of the dish.

 

[tvropro]

All the gears are in another section of the motor drive assembly. They can't be seen in the picture I have here. The unit goes together in 3 pieces. All my gears were checked and are fine and been re lubed. I know some actuators you can see all the gears etc with the back cover off.

 

[tvropro]

Motech Reed Picture

Here is the picture of the Motech 3624 reed switch.

 

[Sadoun]

A source for replacement reed switches is here: Gopher Electronics: Home - Switches - Reed Switch - HSIHSR-004DT 5/15

 

[classicsat]

I used a burglar alarm NO type reed switch on my Saginaw arm. I don't recall if it has limit switches, but I my last IRD (Uniden Ultra), had software limits.

 

[tvropro]

UPDATE

Still waiting for a reply from Sadoun on a replacement part being sent to me. I left 2 messages on there voicemail about this early this week One directly on Sadouns VM. If you read this Sadoun please update me on the status.

On the flip side of the coin it's 6 degrees outside now and my old rebuilt Saginaw is counting perfect every time.

I would like to wrap this up with the Moteck though since this is really dragging out as far as getting warranty replacement parts.

So glad I swapped the Saginaw back. I'd be going crazy by now with the way the Moteck kept loosing 40 counts between birds

 

[Sadoun]

TVPRO,

Got your message. The holidays and end of the year is causing some delays on my part

Next week we will be back to normal.

 

[tvropro]

TVPRO,

Got your message. The holidays and end of the year is causing some delays on my part

Next week we will be back to normal.

Thanks for the update. Hope to touch base with you sometime this upcoming week.

 

[Lak7]

Any update?

 

[tvropro]

Any update?

I got a PM from Sadoun. He said he sent a replacement reed switch out a couple days ago. I waiting to get it now.

My rebuilt Saginaw has been treating me really well. Even with the super cold we had in the past few weeks. No problems at zero outside. I was messing around with G1 the other day to see if I lost any counts on the Sag. If I went E or W the signal went down. The original spot set when I swapped it was still the best .

Not to totally knock the Motech, but it is a $129.00 arm. And really cannot compete with the Saginaw, which now cost $400+ dollars. (Mine was around $200 in 89)

I did notice something with the Motech even last winter after install in Jan 09. It would need slight adjustment every couple weeks. When it warmed up outside that stopped. So maybe this defect was starting to rear it's ugly head last winter already. This has not been the case on the Saginaw.

I can't really comment if I would recommend the Motech to anyone now. I may have a lemon or possibly they all have issues when very cold outside. I know that the reed sensor/magnet setup is a kinda poor design. It is nothing like the Saginaw which you can tell that longevity was taken into consideration in it's design. Maybe if one redesigned the Motech reeds assembly it could work very well. The motor and acme screw worked well even on my 12 foot so it's weak area would be in the reed assembly.

One last comment on a ball screw (Saginaw) vs the Acme (Motech). The ball screw handles my 12 foot like it's a toy. It's fast and very smooth (no strain). The Acme while it moved it alright. I could tell it was working harder to get the job done. One of the reasons I bought the Saginaw in 89 was I wanted the best and it proved that. Money was no object back then. These days every penny count's with the economy, less income etc.

 

[Lak7]

I believe I have the same Motech Arm, with similar issues.
Thanks for the update.

 

[tvropro]

I believe I have the same Motech Arm, with similar issues.
Thanks for the update.

Might be a global thing, since now we know of 3 with this problem. I think what may be happening is the reed switch is either getting corroded and not making good contact and or sticking when cold. I think whats needed is a redesign of the magnet wheel (bigger wheel with individual magnets) and a better quality reed switch. The bigger magnet wheel with individual magnets would create a more defined pulse width.

See Pictures

 

[tvropro]

UPDATE

I received a replacement sensor in the mail today from Sadoun. Thank You Sadoun.

I will have to mess with the Motech when I get a chance to see what happens. I may look into modifying it as above .

 

[Sadoun]

I received a replacement sensor in the mail today from Sadoun. Thank You Sadoun.

Good, I hope it will work well for you. I sent you a Powertech brand sensor.

 

[tvropro]

Good, I hope it will work well for you. I sent you a Powertech brand sensor.

Thank's again.

A bit of food for thought in it's current design. The magnet wheel on the Motech is very small and had 6 magnetic area's. The Saginaw's design uses discrete magnets, 4 on the approx 2" OD plastic wheel. Could it be that the Motech having 6 close spaced magnets on a wheel approx the size of a nickel cause 2 or 3 pulses be read as one because of slow action of the reed switch in very cold temperatures? The Saginaw design allows a complete cycle of the switch with the larger wheel and less counts per inch. The Sag also has a smaller area that the reed sensor looks at vs the Motech. Any take on this theory Sadoun?

 

[Sadoun]

I will check with the factory about this? I can see how the Saginaw has discrete magnets on the wheel. Which allows a complete cycle of the switch with the larger wheel and less counts per inch

The counts 33.33% less than the Moteck or the PowerTech.

Let me know how the PowerTech Reed sensor work for you. As I mentioned before, we no longer carry the Moteck linear actuator in the model you have. Converting to PowerTech gave us better overall product quality and design.

 

[tvropro]

I will be putting the sensor in the arm, when I get some time I will hook it up to an analog receiver and run some test's on the bench. If it seems fine I will put it on the side for a spare. I may even scope the output and look at the pulse waveform.
I may play with modifying the setup using the Powertech reed switch.

I will not be changing the Saginaw out on my dish since it's working great. But it's good to know I have a spare in case of an emergency. But it may take another 19.5 years for the Saginaw to stop working again.

Thank's again.

 

[Lak7]

I found a spare "Super Jack" branded sensor in the Part Dept, so with a few minutes of daylight left, I decided to replace it.
So far, so good. Can bounce from 55.5 to 125 and back, and land with peaked Quality readings.

 

[tvropro]

I put the Powertech sensor in the Moteck arm but been so busy lately I haven't had a chance to do any in house testing. The Saginaw has been "dead on balls accurate" (it's an industry term, from My Cousin Vinny)