turnnburn

My Feedback: (49)

I am helping setup a jet that was purchased on the used RCU market. I have never used the JR matchboxes and this aircraft has a number of them installed. I downloaded a set of instructions and I am able to program the center with no problems. I need to program some end point adjustments and I must be doing something wrong as I have been unable to get anything to change.

For instance I need to adjust the flap servo end points as they are not traveling equally. I need to lengthen one end point and shorten the other. I have the flaps on a three position switch (JR 12x tx) and I have set some travel limits for mid switch position (take off flap) and switch all the way down (landing flap), this has been accomplished in the flap system menu item.

Can some one tell me how to accomplish the end point adjustments with this setup ?

Thanks

rhklenke

My Feedback: (24)

When you adjust the center, the channel you are adjusting must be in the center. I believe that when it is in the center (or close enough), the LED will be on. When you adjust the endpoints, the channel must be at that endpoint. At this point, the LED should be off.

Don't forget to turn the selector switch to the 0 position before you turn the radio off (and back on) or you'll loose your adjustments...

Bob

turnnburn

My Feedback: (49)

Yes, I have been doing all of that just like the instructions say. im wondering if because I have the travel restricted via the tx maybe Im not getting to the end point that the matchbox needs to see. I will pay more attention to the LED next time.

rhklenke

My Feedback: (24)

Yes, that is your problem. The matchbox uses the input channel to determine which endpoint or the midpoint to adjust. If the input doesn't go beyond the "trip point", the you'll never be able to adjust the corresponding end point. Conversely, if you have too much sub trim on the input channel, you'll have difficulty adjusting the midpoint.

Bob

bcovish

My Feedback: (8)

Brian, what plane is it that it has to have "a number " of match boxes with a 12x radio

kimhey

Matchbox? I had a crash some months ago, caused by a confirmed matchbox failure. Naturally, all my 3 matchboxes are now removed from my jets....

turnnburn

My Feedback: (49)

Well Bob it is nothing exotic or unique. A local fellow who flys moderate and high performance EDF stuff bought a Sky Master F-15 with the idea of getting his turbine waiver. The 12 x TX is mine, the airplane came with a 9ch rx. The airplane came with 5 match boxes on: ail/elev/rudder nws /flaps and speed brakes. If it was my airplane I wouldnt have any match boxes, I would either use a "y" or more likely assign each servo to a diff channel. If I do either of those we wont be able to do buddy box trainer system. So, I'm left with trying to make them all work. I may end up doing away with the one on flaps and the one on speed brakes. I tried to "y' the ailerons, horizontal stabs and rudder but then I both ailerons going the same direction or both stabs going opposite directions and ditto for the rudders and nws. Thats my story and I'm sticking to it untill I think up a better one !!

turnnburn

My Feedback: (49)

I am curious about more details of how a match box caused your crash and how you determined that it did. How close or how far away from the receiver was the crash causing unit mounted from your receiver. I see where the instructions say to mount as close to the receiver as possible. The airplane I m working on came with 3 matchbox's in very close proximity to the receiver and two that are mounted about 12-15 inches away from the rx.. I am a little concerned about these being so far away from the rx.. I will probably be running A 123 6.6 volt unregulated airborne battery. I dont know if that will help the situation, make it worse, or no difference.

siclick33

I wouldn't have thought you would need very many channels for a F-15.

I might be tempted to leave a matchbox on rudders/steering (and maybe flaps) but I would put the elevators and ailerons all on their own channels; this would obviously solve the problem of reversed controls when using Y-Leads. That should still leave you with enough channels for the other functions.

turnnburn

My Feedback: (49)

Minor typo. it is an F-18 not an F-15, not that that really matters for this disscusion. You missed the point. If I do as you say I can not use my buddy box trainer system. JR buddy box only allows the student to operate channels 1 thru 4. If I didnt want to be able to put him on the buddy box I would do away with most if not all match boxes. Plus, a 9ch rx wont get the job done without the match boxes.

Randy M.

My Feedback: (38)

i'm assuming you are correct on the buddy box thing. however, my 10x would allow buddy boxing with mixed channels to primary functions. as does my dx18. but, I don't have the 12x.

kimhey

I used the matchbox on elevator(s), and had +/- 100 flights with my jet. The matchbox died on the second flight of the day, first flight was 100% normal. I always yank the sticks as I taxi out, something I have done since I began this hobby some 30 years ago, and elevators was alive and kicking. When I start the take off run, the jet (Mig-15) takes off by itself when the speed is right, and this take off was just like that. I tried to pitch down slightly, to build up more speed, but the Mig just wouldn't respond. I killed the turbine, and went for a extended center line "emergency" landing. I managed to keep the wings level (never stop flying the airplane), so except for the l/g being ripped out, the Mig was "intact".
Back at the depot, we started investigating why the elevator (both) was dead. Everything else worked 100%. When we disconnected the matchbox, both elevators came back to life. My matchbox was mounted approx 4 inches from the rx.

rhklenke

My Feedback: (24)

When I was back using a 9 channel radio and Matchboxes, I tried not to use them on primary channels - especially elevator and aileron. That being said, I have used them on dozens of aircraft, both personal and "professional" with literally hundreds, if not thousands, of flights, and I have never experienced a failure of a Matchbox. That is not to say that they never fail, but in my experience with them, which is quite extensive, their failure rate is no larger than other critical electronics items like receivers, etc.

I would not be overly concerned with using Matchboxes - although as stated, I do try to keep them off of the elevator and aileron channels...

Bob

turnnburn

My Feedback: (49)

The reason you personally try to keep them off of aileron and elevator is because it introduces one additional possible failure point on a primary flight control ??

kimhey

Each to his (her) own, and I will not judge others for how they think or prioritize. Personally, I either trust a component, or I don't. For me to speculate on which control surface a matchbox is less of a hazard if it fails, is a "no go". I do agree that the whole "getting the model up in the air" is a risk analysis of several "things" that can go wrong, and one can not eliminate all factors.... To do that, go build a static model. I have heard of modellers using servos they don't trust anymore for nose wheel steering and other stuff (doors, speed brakes and such), but why bother putting a known faulty component in your model? If that nose wheel servo locks during a high speed roll out, goes off the runway and hits someone....well, enough said.
As I started this post, I will not judge people that do so, I just don't understand.

Sorry for this side track of mine Turnnburn, lets get back to "programming the matchbox"



Kim

turnnburn

My Feedback: (49)

Unless I am missing the boat some how (which I very well may doing ) the 12x will not transfer control to any slaved functions. I just got my F-86 out, I have wheel brakes fixed with down elevator on the master. When I transfer to the s alve the brake no longer works. If I get a chance to I will do he the same test on my old 10x. I really dont expect it to work either. Maybe I m doing somtig frr

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rhklenke

My Feedback: (24)

Potentially, yes, but as I said, I have put them in many, many aircraft with thousands of total flights and never had a problem. There is also the issue that the servos on those surfaces tend to use the most power and putting them through a Matchbox means another set of connectors and associated voltage drops, but again, that's not a major issue.

Using old servos (I don't) even if you don't trust them is totally different than using a new, known component for its intended use. To compare that, or using a "known faulty component," to using a Matchbox or in a jet is ludicrous. The giant scale guys have been using Matchboxes for multiple servos on ailerons, elevators, and rudders *forever* in harsher environments than our jets and they have a good reputation. I would not hesitate to use them - if you can get them adjusted correctly.

Bob

Shaun Evans

Hi

I've used Matchboxes on primary controls for years prior to getting the Dx18. I've never, ever had a failure except on the bench after frying my whole system with a bad battery.

wfield0455

My Feedback: (7)

Yup, I think you are missing the boat I had a 12 channel receiver in my Boomerang XL, all controls on separate channels, controlled by a JR12X, and buddy boxed with a Spektrum DX8. It worked perfectly. The instructor did need to control the flaps and gear but the student had full control of everything else. I have since switched the transmitter to a Spektrum DX18 and tweaked the setup slightly so a student could also control the gear and flaps as well. When the trainer interface is activated, the instructors transmitter should be simply seeing the stick input (4 primary controls) from the student transmitter but the master should still control the mated channels, mixes, etc. There was no need to duplicate the mixes, etc in the student transmitter, I used a basic, default, airplane setup in the DX8.

kimhey

Just to clearify.... Personally I do not use matchboxes anymore, due to my bad experience. If you have only good experience it is a different matter. It boils down to that "comfort zone" thing If I steeped on some toes, I do apologize, it was not my intention.

kind regards,
Kim

spacefanmick

My Feedback: (1)

Would the matchbox work with Futaba? I'm building a Skywolf and only have 8 channels. I'm Y ing my ailerons,2 channels for elev,2 for flaps of course,rudder,throttle and batt. But I'd like to add a kill switch and Mabey a second battery pack. Any ideas?

melvin

My Feedback: (3)

Hi Spacefanmick
Pretty sure a matchbox will work with a Futaba system. As far as the Skywolf jet is this a jet large enough to contain a smartfly power expander? I would use the power expander before using a lot of match boxes. The expander will regulate voltage, has the ability to match servos and allows the use of heavy duty wire comming off the batterys and switches because it has deans connector built into it and also allows for the use of 2 batterys powering it up. This would free up at least one channel in your reciever also.
Good Luck
Mel

spacefanmick

My Feedback: (1)

Hey Mel,thanks for the responce. The Skywolf Im building is 35cc prop plane made by pilot. They do a lot of 3D stuff,but I don't fly 3D. And this plane is more like the 3DHobbyshop Bigfoot. My problem is I only have a 8 channel RECIEVER. And I'm kinda on a budget,already spent a ton on this plane,lol. But I'm running this way
1-aileron on a Y
2-elevator
3-Elevator
4-Rudder
5-Throttle
6-Flap
7-Flap
8-Battery
not neccasarely those numbers on those channels but you get the idea. But I'd like to not have to YZ the aileron,and I'd like a optical kill/or ESC. And a redundant battery would be nice. So that why I was looking for an answer,if you have any ideas let me know. I may just have to wait a little and get the 14 channel receiver the matchboxes are $50 I think. And the new receiver is $150. So Im going to go with it as described above. Until work picked up,and I can afford the other items. Been flying 49+ years,but this is m first big gasser,and man it's like its eating money,lol
thanks for the responce
mickey

melvin

My Feedback: (3)

Hello spacefanmick
I don't know what transmitter you are planning on using? If you are using a 8 channel radio than purchasing a reciever with more channels won't gain you anything. Rather than using a Y on your ailerons you might want to use 2 channels on the ailerons and use a matchbox on the flaps instead. I would use the aileron channel for the righy wing,aux 2 for the left wing and aux 1 which is the flap channel for the flaps. Are you using a JR or Specktrum transmitter? To do it this way you would have to go into your wing type and select NORMAL and then make AUX 2 the secondary channel for the left wing. Aux 1 would be the flap channel because that is the default set up

melvin

My Feedback: (3)

Hello spacefanmick
I don't know what transmitter you are planning on using? If you are using a 8 channel radio than purchasing a reciever with more channels won't gain you anything. Rather than using a Y on your ailerons you might want to use 2 channels on the ailerons and use a matchbox on the flaps instead. I would use the aileron channel for the right wing,aux 2 for the left wing and aux 1 which is the flap channel for the flaps. Are you using a JR or Specktrum transmitter? To do it this way you would have to go into your wing type and select NORMAL and then make AUX 2 the secondary channel for the left wing. Aux 1 would be the flap channel because that is the default set up