ArcherIIDriver

Yeah only 80 here "up north" [8D] They're saying 82 tomorrow, but windy (like today).

Well, got my new H9 Angle-Pro yesterday so now I can check my incidence(s). After that, all I have left is to fuel proof the inside of the stabilizers (forgot to do it before installing servos), hit the covering w/ an iron, double & triple check all my control surfaces/throws, lock-tite everything, weight & balance, and put another tank or two through the new DL. Then double & triple check everything again.

Oh yeah, and figure out how to make my throttle response more linear. I'm using a DX7, so I don't think I have expo or a throttle curve in "airplane" mode. Need to look into that to be sure, though. Anyone have any advice?

JoeAirPort

My Feedback: (41)

Set up your throttle right and you don't need it IMO. Mine throttles feel totally fine as is.

cjcyclesrc

My Feedback: (10)

Archer,

Post these things and I can tell you how to fix it.

[ul][*] Picture of the servo/ linkage at full and at low throttle.
[*]End points in your radio and subtrim if any
[*]Where the throttle comes on fast
[/ul]

A throttle curve is not necessary even with a pipe to get a linear throttle. The key is to not set the range of the servo in the center like you would on any other surface. The normal 90 deg of the throttle arm to the pushrod you want to be at about 75% throttle instead of 50%. This will offset the effect of the carb butterfly.

ArcherIIDriver

This is exactly what I was thinking. My "90 deg" is centered @ ~50% right now. Throttle comes on too fast from idle to half-stick, then it's pretty flat. I haven't even tried to fix it yet, but I'll post pics if I have any trouble.

Thanks for the replies!

JoeAirPort

My Feedback: (41)

Hmmm, I might learn sumthen too. [8D]

JoeAirPort

My Feedback: (41)

Please post you pictures too. I'd like to see how you set this up. Especially pic's of both sides with servo at 0, 50%, and 100% of rotation.

xtraflyr

My Feedback: (11)

So basically you have the butterfly open 3/4 the way about 1/2 stick position? Usually I have the servo at 90deg. and the butterfly at 50%..

ArcherIIDriver

I'll post pics when I get to mess with it. Probably this weekend, but no promises!

cjcyclesrc

My Feedback: (10)

The carb butterfly doesn't work linear so if you set it up linear you are not going to get a linear throttle response. Think about the servo arm and pushrod's movement. It is not linear which you can use to your benefit. The servo moves in degrees not inches. The movement of the pushrod is based on the length of the arm, but don't think about it in terms of just of the actual length of the arm. Consider the arm how far the line of the pushrod is from the servo screw. When the pushrod is in line with the servo screw if the arm moves 5 deg. you wouldn't even be able to tell the pushrod moved. Now at 90 deg the line of the pushrod is the farthest from the servo screw and if the servo arm moves 5 deg it will make the pushrod move a long way. What you do is set the line of your pushrod close to the servo screw at an idle and the farthest away at full throttle. The pushrod will move much less per stick movement at low throttle and faster at high throttle. This also means that when you move your idle trim a click it's going to change the rpm's MUCH less. Then it becomes very easy to dial in the idle trim. Another benefit is you can use a longer servo arm with your end points at 100. Let just say for example if you used a 1" servo arm and had to cut your endpoints down to 30. You can move the servo arm a few splines, change the length of the pushrod, and turn you end points back up to 100 where they should be for good resolution and still get the same throw on the pushrod. I have seen other methods one being manipulating the end points but you will loose resolution if you do that.

I found some of my 88" Yak. I went ahead and attached a few other pictures of the Brillelli. You will have to excuse the awful looking holes in the side of the motor box. I bought it used with only two flights on it, but the previous owner cut holes for zip ties with a sanding drum on a dremel.

xtraflyr

My Feedback: (11)

Thank You Charles!! I always say you should learn something new everyday..I even made a printed it out for reference.

So the servo arm and the throttle arm should be the same length? At idle closest to the servo screw,full throttle furthest away from the screw? I'll have to look at mine and see what I have.I know I usually have to fuss with the ATV's to get it right. If I do it your way,I should be able to keep my ATV's at 100%or can I go all the way to 150% on my JR,so I get full resolution?

Thanks again,
Frank

JoeAirPort

My Feedback: (41)

I get what you're saying and I'm pretty interested in trying it. Basically all I would do is shorten my push rod to make that relationship you're showing. Then I would make sure the end points are still at least both 100. Right now they are about 118. I'm not sure I can do that for certain though. For one my carb arm swing is fixed. I don't know that if I had my servo arm pointed almost totally forward that I would get the carb to fully swing from closed to open. This is one of those things I need to just go and try. It's hard to figure it all out just reading and thinking about it. Thanks for the idea though. I agree you learn something new every day on these forums. But to tell you the truth my throttles do feel pretty good right now but it could be that I'm just used to it. Maybe I don't know what I'm missing. I'll give it a try...not sure when but I'll report back.

cjcyclesrc

My Feedback: (10)

Your Welcome. I just hope I explained it clear enough.

I don't worry about getting the arms the same length. It's setting up the linkage the way a linkage shouldn't normally be set up. I guess it's kind of like two negatives make a positive. You have a carb thats not linear and you have a linkage that's not linear and when combined they turn out to be linear. It's really simple when you do it a couple times.

[ul][*] Attach the pushrod to the carb[*] Set the endpoints to 100 in the TX[*] Position the servo arm on the correct splines to get the desired angles[*] Now line the linkage up over the servo arm and Make a mark on the pushrod over the hole that looks to be the best. Then move the throttle stick and pushrod to full throttle and idle. If the servo arm isn't moving enough go out one hole. If its moving to much go in one hole. I can usually find a hole that hits it very close.[*] Set the length of the pushrod to the correct length. Don't bolt it down yet. Hold the ball link over the hole and move both to full throttle and idle. Adjust the length of the pushrod so that its equal distance from lining up both sides.[*] Adjust the endpoints in the TX until the bolt will will screw in while the pushrod is at the end of its travel on both ends[*] Bolt down the pushrod.
[/ul]

I don't turn up the end points to 150 because then you don't any room to adjust the idle without taking it apart again. When you start the motor adjust the idle endpoint to get the correct idle with the trim in the center. It works great for me. I find I have to make very little to no throttle curve adjustments with this setup and I always have great idle trim resolution.


Joe,
If your set up is linear don't worry about changing it. All this is just to get the throttle as linear as possible. I like for all of my planes to hover at about 65-70% stick. That way you have good amount of control at lower throttle settings which is what you use doing harriers, elevators, high alpha KE, rolling harriers, etc. I always find it funny when someone talks about how much power their motor has and that it will hover below half throttle. The motor could easily be at 80% power at less than half throttle.

JoeAirPort

My Feedback: (41)

I've always done the traditional "throttle butterfly a 50% swing, throttle servo arm at 90 degrees to the servo case" method. Your idea totally makes sense. It moves the throttle butterfly closer to the 70-80% swing when the servo arm is at 90 degrees to the case correct? I have noticed that my throttle response is always flatter near WOT. I think I've gotten used to it. I would like to try this.

cjcyclesrc

My Feedback: (10)

Correct. If your throttle seems to be flat on top it's quick on the low side and you will likely tell a big difference if you change it.

cjcyclesrc

My Feedback: (10)

Check this out.

JoeAirPort

My Feedback: (41)

Is that a custom job or a new scheme?

cjcyclesrc

My Feedback: (10)

New Scheme

diamondave

My Feedback: (29)

russian thunder, i heard it was coming, looks better than i thought it would actually, very nice

edge540je

My Feedback: (190)

Well I got the front of the plane pretty much done. Engine mounted, ignition,tank etc. It is looking pretty good so far. -J

JoeAirPort

My Feedback: (41)

Yeah, looken really good. Nice engine install.

torqmeister

Edge540, you are going to have some fun with that bird.

cjcyclesrc

My Feedback: (10)

Looking good!! One tip. You might want to consider securing the tank where it can't creep forward. I've had it happen with that same set up before. Now I put a piece of foam behind the tank and run a piece of velcro around the front of the tank just below the stopper and back to the velcro on the other side.

xtraflyr

My Feedback: (11)

I've also just put some velcro under the tank,attach it to the tank floor..

JoeAirPort

My Feedback: (41)

Double sided servo tape on both sides of 1/4" foam under the tank. Then velcro straps to hold it down. Doesn't go anywhere.

JoeAirPort

My Feedback: (41)

Man I love Hitec programmable servos. I converted my Yak and Extra over to Spectrum and had to move one of my elevator servos to another channel since it's only a 7 channel receiver (AR7000). For some reason the new channel (5 gear) would not let the servo go to full up deflection like the old channel (8). Instead of having to take the entire stab apart and move the servo arm to the next spline all I did was reprogram the center and end points on the Hitec servo programmer. Fixed it. That alone saved me hours of frustrating work. Did you ever try to take a servo arm off while it's in a stab? That would have sucked. The reason I think it would not go to full up deflection was that I had -40 subtrim on that servo. The thing is why did it let me go that far on channel 8? This same thing happened on both planes. That was weird.

Hitec rocks.