Counter balance a SG2100 for Large dish??

[jerryt]

Thinking about a new project.

I don't see any reason why my trusty SG2100 positioner could not turn a much larger dish, provided I counter balance it so that the motor never sees the added weight.

Currently at my motor's limit with a 1 meter dish and multiple LNBs. This motor has an external power supply of 20 VDC, but when the dish is skewed near the ends of my arc, the motor slows down from the added weight when returning the dish to the true south satellite.

Thinking counter balancing the weight of the dish would not be too hard to do. Some engineering and trial and error (Mostly error with my projects)

If people would be interested in this project, I will added it to my long term project list.

Thanks for any and all feedback !!

 

[voomvoom]

I'm interested, sounds like an interesting project? Have Fun!

 

[qwert1515]

What kind and size of dish are you planning on using?

 

[jerryt]

What kind and size of dish are you planning on using?

I would start by counter balancing the existing 1 meter dish, and if that works out good I might try a 1.2 meter dish and a C band LNB.

(put up a second T90 so my motorized dish is not being used)

 

[PopcornNMore]

I have been using a SG-2100 motor drive on my Channel Master 1.2m dish for 3 - 4 years with no counter balance and no issues.

This dish receives every satellite from 30 degrees to 138 degrees West.

 

[corey006]

I have been using a SG-2100 motor drive on my Channel Master 1.2m dish for 3 - 4 years with no counter balance and no issues.

This dish receives every satellite from 30 degrees to 138 degrees West.

I like to hear this....:up

I am picking up a Andrews Channel Master 1.2 meter dish this week...and I also have an SG2100.

 

[Sadoun]

I have tried that a few years ago on an SG2100 and an HH120 with a 1.2m dish. It worked fine. The counter balance I used was a sledge hammer with the hammer side away from the dish. I tied the long handle to the dish's mounting bracket. The sledge hammer formed a 90 degrees with the dish surface.

If you go that route, I would also recommend that you use the bigger 50mm shaft on your SG2100 if you don't have one yet.

 

[Anole]

JerryT -

I've been thinking about your counterweight idea since you posted.
Couldn't come up with anything useful, 'till Sadoun mentioned his sledgehammer!

While you could have a large weight close to the pivot point, I think the better road would be to have a small weight far back behind the motor.
The results would be the same, but the lighter weight would add less overall side-load to the motor bearings.
Now , this would seem to preclude having the motor anywhere except at the top of the mounting pole.
If you want to figure out how to make a counterweight go around the mounting pole, well . . . my hat's off to ya. -

I have been using a SG-2100 motor drive on my Channel Master 1.2m dish for 3 - 4 years with no counter balance and no issues.

Yea, but everybody who does a Primestar on 2100 makes slightly different bracket designs.
Maybe yours is just superior to many others (Now, I'll have to go research your pictures) -
I think how high up on the motor shaft you put the dish, matters.
I think how close to the motor shaft you put your dish, matters.

Looking forward to seeing some good pictures or drawings.
This forum is always a great place for brainstorming -

 

[PopcornNMore]

I think how high up on the motor shaft you put the dish, matters.
I think how close to the motor shaft you put your dish, matters.

You are exactly correct! My first design caused the dish to get stuck if on Galaxy10R or below. My second design works like a charm.

I assembed part of a Winegard 76cm dish mount onto a 3/4" plywood painted with several layers of outdoor latex paint. I believe the hole spacing on a 1.2m CM dish are 12" on center. I have older pictures posted with several threads on this forum if interested. As soon as it gets warmer (it's only 3 degrees today) I will take new pictures and post them on this thread.

 

[GrumpyGuy]

While a counterweight will reduce the static load seen by the positioner, dynamic loading forces will still be in play.

The the counterweight will not help reduce the torque produced by wind loads - the larger the surface area of the dish, the greater the wind load.

The counterweight will add to the moment of force felt by the positioner when it must start, stop, or hold the dish steady against an outside force (such as wind load.)

I'm not saying that a counterweight is a bad idea, only pointing out that the dead weight of the dish is not the only factor that determines just how much dish a positioner can handle without suffering excessive wear and tear.

 

[Sadoun]

I'm not saying that a counterweight is a bad idea, only pointing out that the dead weight of the dish is not the only factor that determines just how much dish a positioner can handle without suffering excessive wear and tear.

I agree with you. The counterweight is a good short term solution. I would upgrade the motor to a bigger motor for long term solution.

 

[jerryt]

What channels could I get with a 1.2 m offset C band dish?