motor woes

[Jim S.]

I recently got tired of hearing about feeds on satellites that I wasn't aimed at, so I decided I'd motorize my 30" dish, which only had room for LNBs for 91W, 97W, and 101W. I saw that Sadoun had the Powertech DG-280 on sale on ebay, and it sounded like a decent motor, so I bought one. I got it yesterday and I was going to install it today. I immediately ran into a problem, in that the mount on my dish for some reason was only designed to accept a pole from below rather than above! Here it is, it was the cheapest 30" dish I could find when I bought it last year. I should've spent just a few more dollars and got a known name instead of going to an ebay dealer...

http://www.skytechusa.com/images/skytech/SK75-PWT4sm.jpg

It might not be obvious from the small picture, but the top of the bracket that holds the reflector has a flat piece of metal from one side to the other, so there's no way to get the motor tube in there from the top. (It's sort of like the bracket on a Dish 300.) I considered mounting the dish upside-down, but it turns out that my pole is too close to the ground for that.

But my bad luck gets worse... I tried setting the elevation scale on the dish to where it belongs for a motorized mount in hopes of getting enough clearance anyway, but of course it didn't work. But when I tried to change it back to at least put my dish back on the birds it was originally on, the damn elevation bolts both stripped! Cheap Chinese garbage! I'm running out of time today to find a way to fix it. I might tackle it tomorrow, but I have other things I really would rather be doing. Hell, I had other things I could've been doing today if I would've realized beforehand that the motor wasn't going to work, but I've never actually looked at the mount since setting the dish up the first time, I just assumed that all motors would work with all dishes.

I really want to set up a motor, so I'm tempted to just buy a new dish. I could try to cut out the offending part of the dish bracket I have now, but I still have the issue of the elevation bolts being screwed up, plus the general all-around cheapness of the mount, which flexes when I try to tighten anything. It's just a poor design, but I was trying to save a little money when I bought it.

If I would buy a WS9036 or a GeosatPro 90cm dish, am I correct in assuming that either of these have a more normal style of mount and would work with my motor?

 

[ynnedibanez]

i would try to cut a U shaped spot out of the top of the dish bracket, and flip the pole bracket upside down so the bolt at the top doesn't get in the way.

 

[Jim S.]

I don't think the bolt at the top is an issue, there are holes in my motor tube for just such a thing, plus I think flipping it would throw off the elevation scale. I don't think the elevation bolts are in line with the bolt at the top as it appears in the picture.

That still leaves me with dysfunctional elevation bolts though. I haven't figured out a way to deal with those yet.

 

[ynnedibanez]

yeah, the elevation number scale would be useless afterward, but you could still adjust it out.
but if the motor tube has holes in the right spot, i guess that solves that problem much easier
can't you just replace the stripped bolts?

 

[JerryVT]

The GeoSatPro 90 works

I have that dish mounted on that motor. Works great, and has a bolt that goes through the dish AND the motor which really locks it in. It also comes with extra hardware so if you strip another bolt, you can still use it. I stripped the elevation bolt on mine. Whoops.

I bought both from Sadoun

 

[McGuyver]

You can try mounting the dish upside down and see if the elevation is still in range. otherwise you'll have to trim some metal, you can also try eliminating the post clamp and fab short extensions (side plates) to clear the top bridge of the bracket and bolt directly to the motor post but you'll need to be accurate in any calculations when drilling holes. Where there's a will there's a way, just McGuyver it don't butcher it!

 

[Jim S.]

This is not my week!

I borrowed a reciprocating saw from a neighbor and cut out the offending piece of metal on the top of the bracket.

Guess what? It still doesn't work. When the elevation scale on the dish is set to the proper declination value for my latitude and this motor, the dish hits the top of the motor housing!

I think I'm going to be buying a new dish, rather than wasting anymore time trying to modify this one. I just wish that this one had come with a warning that you can't use it with a motor, I might've not wasted my money on it.

 

[Sadoun]

Jim,

The dish that you have will not fit on any motor for that matter, unfortunately. The bracket on it is designed for fixed stationary installations.

Did you get the DG280 or the DG280B?
The DG280 has the 55mm (2.1") shaft
The DG280B has the 42mm (1 5/8") shaft

Both motors are the same except for the shaft difference. The shafts are interchangeable. So if you got a DG280B you can always convert it to DG280 by changing the shaft. A 2 minute job to switch shafts.

The bigger 55mm shaft is recommended for dishes up to 100cm with U-Bolt mounting bracket.

The smaller shaft is recommended for all standard dishes up to 100cm with 1 5/8" mounting bracket.

 

[Jim S.]

I got the DG280B.

I also ordered a GeoSatPro 90cm dish last night. I don't know what I'm going to do with the old dish yet. Maybe someday if I have a receiver that works with a motor and a switch at the same time, I'll find something to point it to

How tall is the mounting pole on the GeoSatPro? I have my current dish mounted at ground level temporarily by bolting it to a pallet, and I'm wondering whether I'm going to have to change poles to get the new dish clear of the ground since it's bigger and the bracket is attached in the center instead of at the bottom.

 

[McGuyver]

the mounting post is about 28" tall

 

[nailpounder]

This is not my week!

I borrowed a reciprocating saw from a neighbor and cut out the offending piece of metal on the top of the bracket.

Guess what? It still doesn't work. When the elevation scale on the dish is set to the proper declination value for my latitude and this motor, the dish hits the top of the motor housing!

I think I'm going to be buying a new dish, rather than wasting anymore time trying to modify this one. I just wish that this one had come with a warning that you can't use it with a motor, I might've not wasted my money on it.

I know the declination instructions for my SG2100 motor were confusing and not worth the paper they were printed on. I finally figured it out. You set the latitude on the motor, initially align dish parallel with the motor shaft, then tweak dish elevation to get proper declination. Simple rule: Your true south elevation minus declination angle equals elevation setting on the dish.

I don't know if the DG280 settings are similiar to the SG2100, but it sounds to me like you're aiming your dish too high if it's hitting the top of the motor.

 

[Jim S.]

The manual for the DG280 says that the setting on the dish should be 35 (the bend in the motor tube) minus the declination angle. That gives me 28.6, and I had to add 3 degrees because I know that the scale on the dish is off that far, so that's only 31.6 degrees, but the dish hit the top of the motor before I got within about 5 degrees of that. If I had used your fomula, the dish would've been even higher.

I looked up the SG2100 manual and it says the same thing my manual does, except that the bend in the motor tube is 30 degrees instead of 35.

 

[Davage]

Jim S, I had a similar issue with an old Alphastar dish about 3 years ago. See link below. I managed to extend the dish away from the mount by using some mending plates that I bought at my local hardware store.

http://www.satelliteguys.us/free-air-fta-discussion/82474-success-alphastar-31-dish-stab-hh90.html

Look at the pictures on post # 6 on the above link.

 

[nailpounder]

The manual for the DG280 says that the setting on the dish should be 35 (the bend in the motor tube) minus the declination angle. That gives me 28.6, and I had to add 3 degrees because I know that the scale on the dish is off that far, so that's only 31.6 degrees, but the dish hit the top of the motor before I got within about 5 degrees of that. If I had used your fomula, the dish would've been even higher.

I looked up the SG2100 manual and it says the same thing my manual does, except that the bend in the motor tube is 30 degrees instead of 35.

It worked for me using a Fortec Star 90cm dish. Maybe the manual's way works for others. It didn't work for me. My formula could be a fluke that just happened to work in my case. Sorry it didn't help you.