bluestratos

After I flew my plane, I had moved the trims to correct flight characteristics. Of course now the trims are slightly off center so I want to rezero them while retaining the trim changes. On my other radios this is straight forward but I cannont figure out how to do it on the 14MZ. I post this to Futaba's direct support but the answer is either wrong or missing some info. Would appreciate any help,
Randy

huey-pilot

My Feedback: (17)

You can use the sub trims to move the servo center without moving the trim switches.

bluestratos

I see...recenter with sub trims then slide the trims back to zero.. that will reinstall the correct offsets for trim. I thought my 9z could do this for all trim settings automatically with the push of a button. Is that not correct?


Regards,
Randy

Silent-AV8R

Yes, the 9Z did allow you to do that with the "trim memory" feature. The 14 MZ does not allow that.

My question is, why the worry about the trim being centered?? I just set it and forget about it. If it really becomes an issue I would just play with the linkage to get the proper trim mechanically when the radio trim is centered. But again, having the little tick mark on the TX showing "centered" isn't a big deal to me.

Bax

My Feedback: (11)

Actually, that won't work. If, for example, you put in 14 points of "up" elevator trim, it will take several points of "down" to recenter with the sub-trim. Then, if you recenter the main trim, you'll add another 14 points of "down" elevator, and end up with more points of "down". You'd need to go the other way. You'll still have to measure the amount of deflection physically so that you can zero the main trim and then add the appropriate amount of "up" sub-trim. Please note that 10 points of sub-trim equal 1 point of trim.

This isn't the best use of the sub-trims, though. The sub-trims are intended to be used to make very small adjustments in the centering of your servo after you've gotten the best setting you can by adjusting the servo horn, linkage, and control horn. If you've put in so much trim that you're almost out trim adjustment available, then you should work on your linkages...better yet, try to find out why the model needs to carry so much trim...balance, thrustline, weight, alignment, and so on.

The Trim Memory of the 9Z saved the trim settings, but did not change the indication. If, for example, you had 14 points of "up" trim, your transmitter would indicate 14 points of "up" trim. What trim memory did was save that 14 points of "up" trim. Then, if you moved the trims on later flights for some reason, you could reset the transmitter to the 14 points of "up" with a few keystrokes. It did not "recenter" the trim indicator while keeping in the 14 points of deflection.

bluestratos

I like to have the trims set to zero so I can tell if I accidently changed them before a flight. I am shocked to see that this $2,200 radio cannot do such a simple function that the 9Z could. I sure blew it by spending the money.. it was just so hyped up and as I have always had Futaba's I thought it was the best choice.

bluestratos

Sorry Bax, we must have both answered at the same time because your response was not there when I responed to the last e-mail. My trim changes are very small, so I guess I will put the deflection guage on the surfaces, measure the angle, reset the trims and use the sub trim or linkages to re-establish the new trims.

Regards,
Randy

mc3854

My Feedback: (6)

Read Bax's response!

The 9Z doesn't do what you are talking about either! It only recalls the saved trim settings! Doesn't reset the indicators!!!

Besides, the 14MZ, like the 9Z, has digital trims! You can't change them unless the radio is on! Surely you can't turn the radio on and accidently change the trims before you take off!!

bluestratos

Read my response, lol.... I did not get Bax's response untill after I read the last post prior to his. I appreciate your thoughts, they don't agree with mine though. I can still move the trims after I have the radio turned on so I always do a quick visual before I take off to be sure I have the trims neutralized. Now if you do it differently thats cool. Now losen the bone Wilma.. its only a hobby. LOL.

Regards,
Randy

gnichola

The other thing to note about excessive use of sub trims is that it can mess other things up. I had a situation where my sub trim had to be adjusted too far out on my 9Z with a CCPM heli and basically that servo stopped early on full deflection. I second, or third, the statements earlier that you should setup your servo horns as close to their desired postion and then only use sub trim to do final adjustments. Doing this you should only need, at max, half a servo arm notch of travel, which would be probably less than 30 or 40.

Regards, Guy

ww2birds

My Feedback: (14)

Maybe what some people are thinking about is the Robbe/Futaba FC28 .. that's kinda-sorta the European version of the 9Z. I used one quite extensively while living in Switzerland. Very nice radio .. more of a "tray style" TX that is really not well designed for hand-held use .. much like the high-end Multiplex. Software is somewhat unique .. not the same as the 9Z .. and has old-style analog trims .. and has a very nice feature that will set the subtrims to whatever value would bring the analog mechanical trims back to zero .. so it makes trimming a new plane very fast indeed .. fly, trim to satisfaction, land, push the "magic button", and recenter the analog trims. Some adventurous pilots even use it in the air! Not that I would personnaly know about that, of course!

Had another nice SW feature I have yet to see on other radios .. the ability to offset the zero position of channel. Imagine a situation where you have very different ATVs on + and - travel .. so the servo graph of input vs. output goes through 0,0 but has a "vee" shape, or a kink in it .. by offsetting the zero position you can make it into a straight line that connects full + ATV point to the full - ATV point without a kink. I don't think the 9Z can do this (I have owned one for a while now, so I suppose it's possible and I haven't discovered it....), and I don't see it in the 14MZ manual .. but I haven't really studied that thoroughly yet...

Dave

HarryC

My Feedback: (1)

The Multiplex Profi 3000 series, Profi 4000 and Royal Evos can all do this. I would be very surprised if other brand high end radios can't do this, it is simply altering the centre point of a multi point curve.

H

ww2birds

My Feedback: (14)

Yes, fair enough .. the 9Z and 14MZ can both do it that way too .. but what a hassle .. have to re-enter all the points whenever you change an endpoint.. I just found it convenient that the FC28 had an extra parameter on the ATV screen to offest the zero .. much simpler .. maybe the radios you mention do it the simple way too...

Dave

HarryC

My Feedback: (1)

It's very simple, you are presented with a graph of the points on the curve and you choose which one you are going to alter, in the example you gave you would choose the centre point and adjust it up or down to make the curve a straight line. When you adjust any point it doesn't affect the position of the other points. Surely radios from the JR8103 and Futaba 9C and upwards can also do this with their multi point curves?

Harry

ww2birds

My Feedback: (14)

Ah, good thinking, just use a 3 point curve ... guess I get the dodo award for the day :-) I was thinking of multipoint curves with lots more than that..