Pimp up Channel Master

RimaNTSS

RimaNTSS

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Some SAT-related hardware.
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N-E from Riga
Hi! For last couple of days, and sometimes nights, I am developing an idea to make new feedarms and universal LNB-holder for CM dishes. As far as I remember I've got one 1.2m CM dish without any feedarms and another one had feedarms so rusted away that I had to use angle grinder to remove them. So, idea is to make new feedrams from my favorite material ....... you know :) I have already ordered 20mm INOX pipe to fit in 3 holes in the mirror. As far as I can see in my brain, new feedarms will look very nice and shiny, so nice that I will install such a feedarms on all my CM dishes. For sure, such a feedarms will stay in original shape much longer than CM glass mirror. Needless to say that CM is continuing to be one of my favorites SAT-equipment making brands. I do not have any pictures to add yet, but, surely they will come soon. BTW, if any of you guys have some ideas, I would gladly receive them.
 
Channel Hopper

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Why not make your next dish and reflector out of Inox ?
 
RimaNTSS

RimaNTSS

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My Satellite Setup
Some SAT-related hardware.
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Reflector of CM dish is already perfect, so makes no cense to try to improve it. Furthermore, it is not so easy to replicate the mirror itself.
 
Captain Jack

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Make some for 1.8m too ☺
 
RustySpoons

RustySpoons

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2,244
My Satellite Setup
50E - 30W
CM 1.2m Polar Mount/Jack
65E- 65W
Gibertini 1m OP100 - STAB HH100 - Inverto Black Ultra 0.2 Twin
Mutant HD51
Edision Primo IP S2
Dreambox DM800HD
Venton Unibox HD2
Sony Bravia 50W829 DVB-S2 Tuner
My Location
South Wales
RimaNTSS

RimaNTSS

Super Moderator
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4,727
My Satellite Setup
Some SAT-related hardware.
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N-E from Riga
OK, back to topic. Idea is to make 3 identical pieces which will be inserted in the holes where original feedarms are fixed. Original CM feedarms are 19mm in diameter, but holes are slightly bigger, so I will use 20mm pipe and it fits perfectly. After several trials&errors (spoiled material) I came to this design IMG_20180413_185557 (Medium).jpg . It is, of course, not perfect, and could be done in easier way, but I am pretty sure it will work. After nuts are tensioned it is no way that feedarms will become loose. For feedarms I will use 10-12mm pipes, should be enough strengths.
 

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st1

st1

SMC-dish aficionado
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2,806
My Satellite Setup
Mostly SMC dishes pointing at 28.2E
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Nordsjælland, Denmark
OK, back to topic. Idea is to make 3 identical pieces which will be inserted in the holes where original feedarms are fixed. Original CM feedarms are 19mm in diameter, but holes are slightly bigger, so I will use 20mm pipe and it fits perfectly. After several trials&errors (spoiled material) I came to this design View attachment 116351 . It is, of course, not perfect, and could be done in easier way, but I am pretty sure it will work. After nuts are tensioned it is no way that feedarms will become loose. For feedarms I will use 10-12mm pipes, should be enough strengths.
Excellent result.
I think the bottom arm (which some refer to as the feed arm, and the one's you've made as the feed support arms, but I am bewildered as to which is the most appropriate) initially could be a square section tube. This would allows heavy duty feed-loads.
But having mulled this for a bit, I think the bottom feed-arm should really be a equal-legged triangle (I don't know if that's the term in English), with the shortest (base) section at the front. The front would then be an arm onto which you could fix (a dare say, screw?) multiple LNB holders....

Somthing like this:

ST1_suggestion.png
 
RimaNTSS

RimaNTSS

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4,727
My Satellite Setup
Some SAT-related hardware.
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N-E from Riga
It is funny when not native English speakers (one of them, me, could be the weakest link) start to discuss proper terms :D
My original thoughts were about making 3 identical (lower one shorter) feedarms and LNB-holder for just one LNB (I do not like multifeeds). But, I think it is possible to make all 3 feedarms longer (red) and connect them further from the dish. Then fix horizontal bar (green) between 2 upper feedarms and make multifeed on that bar. ST1_suggestion.png
 
Channel Hopper

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There is really no reason why you couldn’t have the feed assembly mounting points directly bolted to the motor and pole, and have the reflector as a counterbalance device.
 
RimaNTSS

RimaNTSS

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My Satellite Setup
Some SAT-related hardware.
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Agree with you CH, it is possible, however not so easy to do. Besides, I wish to design simple system which can be easily replicated by anybody.
 
RustySpoons

RustySpoons

Sleepy Hollow
Messages
2,244
My Satellite Setup
50E - 30W
CM 1.2m Polar Mount/Jack
65E- 65W
Gibertini 1m OP100 - STAB HH100 - Inverto Black Ultra 0.2 Twin
Mutant HD51
Edision Primo IP S2
Dreambox DM800HD
Venton Unibox HD2
Sony Bravia 50W829 DVB-S2 Tuner
My Location
South Wales
OK, back to topic. Idea is to make 3 identical pieces which will be inserted in the holes where original feedarms are fixed. Original CM feedarms are 19mm in diameter, but holes are slightly bigger, so I will use 20mm pipe and it fits perfectly. After several trials&errors (spoiled material) I came to this design View attachment 116351 . It is, of course, not perfect, and could be done in easier way, but I am pretty sure it will work. After nuts are tensioned it is no way that feedarms will become loose. For feedarms I will use 10-12mm pipes, should be enough strengths.
Engineering mature content :wub:
 
RimaNTSS

RimaNTSS

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4,727
My Satellite Setup
Some SAT-related hardware.
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N-E from Riga
Have made several identical (as much as possible) bits. IMG_20180414_205535.jpg But still can not decide how to deal with other end of the feedarms where LNB-holder (holders in case of multifeed) will be located.
 
st1

st1

SMC-dish aficionado
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2,806
My Satellite Setup
Mostly SMC dishes pointing at 28.2E
My Location
Nordsjælland, Denmark
Have made severa identical (as much as possible) bits. View attachment 116443 But still can not decide how to deal with other end of the feedarms where LNB-holder (holders in case of multifeed) will be located.
Ok, now that you have set the ball in motion, here's another 5 cents of speculation:

Thinking about the concept, I believe it would be good to scope the project.

I would section a feed-arm concept into three different types:
  1. Single LNB, with room for adjustment to find the perfect spot for the LNB.
  2. Mlutiple LNB, using LNBs offset left and right to receive multiple sats on a fixed installation ("semi-multi-focus").
  3. Single LNB, with Cassegrain sub-reflector.
As you are working with refelctor attached feed-arms, we will disregard all the Rx/Tx configured feed-arm holder which have additional (steel) support for the feedarms (in order to avoid warping the dish when hanging several Kg of electronics at the other end of the feed arm).

The first type are for fixed installations, and only need to support the weight of a standard LNB, but in such a way that the positioning of the LNB can be changed up/down, in/out, and possibly even left/right. You have yourself made designs in the past with square feed-arms that would fall in this category. One possible focus point could be to make it very easy to angle and move the LNB when tuning the dish (think no-tools).
This type also work for motorised single LNB installations.

The second type is is for your fixed installations, but supporting reception from multiple sats at the same time. For this set-up, I would still propose to use the triangular feed-arm configuration, as this fits your bottom arm bracket concept better than a square tube that requires attachment to the rim of the dish. L-shaped steel bars would work very well, minimising the amount of customised material required. You can graft some attachment bar to the far ends supporting your very nice LNB holder for the T90s (or even the SMW OA-1600).

The third type requires and LNB arm that is lower than a "normal" arm, and supports the sub-reflector of some other dish manufacturer (Fibo, Visiosat), has plenty of room for an LNB hanging "down". For this arrangement, I would again promote the triangular feed-arm configuration, which could leave space enought for e.g. an Inverto Black Ultra fitted just before the sub-reflector between the two feed-arms.

There is potentially a fourth type, which caters for a motorised LNB changer - but this needs to incorporate changer mechanism in feed-arm assembly. And it will probably also require the feed-arm to be attached and support by something more sturdier than the bottom feed-arm attachment point on the dish surface. And thus mean danger of warping the dish. I will therefore leave this out of this category.

There is of course the fifth type, which is S-band-gizmo supporting feed-arms, but these are very rare and S-band has a nice Prodelin for this purpose. :cool:

...

The beautiful thing would of course be if all three types of feed-arm configurations could be made with a modular approach, so that the components for all three types were more or less the same, with the same feed-arms, the same LNB holders, etc.etc. You could make a generic "pimp-up" kit, which could be used for any of the configurations... Now there's a design challenge!
 
RimaNTSS

RimaNTSS

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My Satellite Setup
Some SAT-related hardware.
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Right now I am more leaning towards light version, which is single LNB (maybe easy adoptable for small multifeed).
Cassegrain sub-reflector
Did you mean Gregorian? :confused
 
st1

st1

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My Satellite Setup
Mostly SMC dishes pointing at 28.2E
My Location
Nordsjælland, Denmark
Right now I am more leaning towards light version, which is single LNB (maybe easy adoptable for small multifeed).
Did you mean Gregorian? :confused
Ach! Too many late night edits. :-doh
Yes, I do mean Gregorian. (Very few convex sub-reflectors of the right size are available. :))
 
RimaNTSS

RimaNTSS

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My Satellite Setup
Some SAT-related hardware.
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Spent quite some time creating this. But, TBH, not really happy with the result. Of course, it is possible to tune this system and when all nuts tighten everything will stay tuned. But main problem that there are too many joints and installation would be not so easy. I think I will redo it to have 3 feedarms connected together and then will add rail for the LNB-holders between 2 sidearms.
All 3 feedarms I made adjustable in length 90-90-60cm and they can be extended to ~115-115-85cm.
 

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Captain Jack

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I like it! Tidy!
 
st1

st1

SMC-dish aficionado
Messages
2,806
My Satellite Setup
Mostly SMC dishes pointing at 28.2E
My Location
Nordsjælland, Denmark
Spent quite some time creating this. But, TBH, not really happy with the result. Of course, it is possible to tune this system and when all nuts tighten everything will stay tuned. But main problem that there are too many joints and installation would be not so easy. I think I will redo it to have 3 feedarms connected together and then will add rail for the LNB-holders between 2 sidearms.
All 3 feedarms I made adjustable in length 90-90-60cm and they can be extended to ~115-115-85cm.
Exactly! The base shold not be a single arm, but a triangle with dual arms! Removes all the wobbliness (well, some of it).

The original CM design for multifeed was very similar to what you have done (byt IMHO yours look way better!)
Very flimsy, if I recall the comments from other members (@Captain Jack?). Much better with a sturdy horizontal base plane for the LNB holders.

If you do the three feedarms, you will have to make them uncomfortably long to supoprt a wide multi-focus angle.
Much better to do a triangular base...

But ignoring all that - I have to admit it is an admirable job, you have done there.
I am sure there are people across the UK who would sell their mother-in-laws for this design!
Love those details where things attach! Keep up the good work...
 
RimaNTSS

RimaNTSS

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My Satellite Setup
Some SAT-related hardware.
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I think I will go this way. Now it is much more sturdy, it is even possible to lift whole antenna holding only one feedarm and nothing wobbles. IMG_20180416_213326 (Large).jpg
I only need to find the way how to connect (in easy way) cross-bar for multifeed. IMG_20180416_214020 (Large).jpg
 
S

Sat1969

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CM 90cm
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London
RimaNTSS,

May I suggest that you make the flat end plate wider with holes ready to mount a or multi Lnb holder.
 
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