bob_nj

My Feedback: (62)

With the advent of digital servos and larger scale aircraft, I've been noticing the ads for servo equalizers and JR's matchbox. On page 13 of the April issue of RCM there was an interesting comment made about the matchbox. An excerpt from the sentence goes like this; "Besides offering convenient servo matching, MatchBoxes can reduce the need for multi-channel mixing, prevent voltage drops to the receiver, and even eliminate the use of second receivers as nothing more than expensive bus bars." The last part is what caught my attention. I'm going back through some old posts about the pro's and con's of multiple receivers and give it some thought. My question is this, has anyone out there eliminated a second receiver by using a MatchBox? Would a scenario like this seem feesible where let's say all four elevator servos from a giant scale went into one matchBox thus using one receiver channel, and the other 8 servos went into thier appropriate receptacles in the receiver?
Whadya think

CAPtain232

My Feedback: (40)

That is pretty much the idea. The match box allows you to plug four servos into one receiver channel AND use a separate battery for the high current servos. This eliminates the need to use 2 RXs (as mentioned) simply for a bus bar. There have been cases where, in a dual RX setup, one RX went bad and the other one was able to bring the plane home safely, so there are more pro's to using a dual RX setup than just as a bus.

Jeff

bob_nj

My Feedback: (62)

Why do we hear about so many times that one receiver did go bad anyway? Do they just stop working and failsafe to neutral so half the plane is semi controllable? How many of us use one rx in 33%, and two in 40%? How many are willing to use one rx in a 40% plane?

CAPtain232

My Feedback: (40)

I do not think that there really are that many cases where the RX actually failed, most often they take a hit from someone elses radio, in which case it doesn't matter how many RX's you have. You hear people talk about RX failing here on these boards like RCUNIVERSE, but how many do you really hear about and figure that into how many RC planes there are. The odds are definitely on your side.

In most cases, while at the field, if everyone would pay CLOSE attention to the BOARD, these numbers would be even lower. This being said, I think even the biggest of models could use one RX. Especially now that the maychbox is here. In my oppinion, any plane that I will ever own in the 35% and under class will have only one RX. Any plane over 35% will have two. I would just feel STUPID if I lost a plane of that value due to something as simple as redundancy, or lack thereof. SMALL price to pay for a small insurance policy.

Jeff

bob_nj

My Feedback: (62)

I'm still curious about landing a plane while controlling one aileron, one elevator and one rudder servo while the other surfaces may very well be driven to the stops on one side or the other?

CAPtain232

My Feedback: (40)

I wish I could tell you how it is done or at least that I have seen it done, but I haven't and that is part of my point. It happens so rarely that it really is not neccessary to use dual RX's. I spoke with one of the guys from CARDEN at Toledo and he said it happened to him and he was able to bring the plane back even though he could only control half of the plane. ????? It does leave questions. Good luck on the hunt to find the answers!

Jeff

bob_nj

My Feedback: (62)

Leave it up to me to find the answers

R Plante

I Have only seen dual rxs come into play once .A friends 14' span b 17 had the elevator on the right side quit in the full up position. It was brought down in one piece , not gracefuly but it only suffered minor damage to the retracts. This was a brand new rx that HAD NOT been test flown in any other plane.The manufacturer of the rx replaced it but did not offer anything for repair of the retracts.


Randy

bob_nj

My Feedback: (62)

Couldn't resist

Forgues Research

My Feedback: (7)

Landing a plane with only half of the plane controllable is doable with a J-3 Cub, but with a highly unstable aerobat, good luck.

I have heard claims that its been done, but I have never seen it.
Receivers rarely fail, they are well made. Battery packs rarely fail also, switch harness fail the most. Bad maintenance is another culprit. Bad installation is another. The word "its good enough" is just not acceptable with expensive and potentially dangerous airplanes.

Dazzler

My Feedback: (6)

I have landed my GP F14 with only 1 elevator half working, it was no problem, you could hardly tell it was gone, and landed fine. Another guy at our field has the TT G200, and 1/2 the stab along with the elev half came off and he landed it, and he's a rookie. Daz...

Forgues Research

My Feedback: (7)

Daz, I have done so with half of a stab, but half of everything with hard over servos is another matter, don't you agree.

Dazzler

My Feedback: (6)

Yes Aero, I would definetly agree, that would be interesting, but at that point it would depend on plane type, and pilot skill to get it down safely. Daz...

Forgues Research

My Feedback: (7)

As I said earlier, a J-3 Cub might be possible

Dazzler

My Feedback: (6)

Yeap, a J3 Cub might make it possible. Like you said, I would rather have to do it with a J3 Cub, than a Aerobat. Daz...