The problem is the amperage difference between battery types. Volts is volts and not an issue. Go with two batteries of the same type. Your plane is worth it. Another Fromeco or Troybuilt lion battery is pretty close to the same as a good nimh and weight would not be a factor. If your running out of receiver ports you can add a Wye to a servo port. Run the servo out of one side of the wye and connect the battery through the other side.

Back to channels. If you really need more and your transmitter doesn't support mixing two channels to drive a paired servo installation, A Matchbox or two is a lot cheaper than a Power Expander.

Remember the battery sequence. Battery to switch, switch to regulator, regulator to receiver.

Keep in mind that you may end up putting the rudder servo in the tail. I have the plane with a 3W80, aluminum spinner, wood prop, dual NiMH RX batteries behind the cockpit area, and stock tailwheel assembly. The rudder servo, a Hitec 5955, is in the tail on a push-pull set up.

Dan

Here's what happens.

The two voltage regulators will have slightly different voltages, they always do. Let's say one is 6.00v and the other is 6.02v.

When the plane is sitting there with everything idle all the current will be coming from the one with 6.02, that's the way they work. The other one won't start to let current through until it's output goes below its set value of 6.00. This means that the one with the lower voltage is actually both a backup and a "fill-in".

In high current draw situations (which happen more often that you might think) the lower voltage regulator kicks in and adds its supply to the other one. If the higher voltage one fails altogether the lower one then flies the plane alone.

So either have both batteries the same capacity or have the bigger one on the regulator with the higher voltage. But don't try to mix Nimh and Li chemistries.

And on the next flight turn on one battery pack at a time and test each pack alone before you fly. It is possible with this setup, if something went wrong on the previous flight, that you could have landed on one pack without knowing.

TF

makes sense.... i will get another regulator then. It feels good to have insurance

so if i have to put the rudder servo in the tail, you can still just run one? this is all pending balance of course

Yes, you can. A push-pull installation using two rudder servos in the tail is the absolute best to equalize forces on the rudder post and hinges but I've used many single servo tail mounted installations and never had an issue or failure. If you don't need the weight or torque of a second servo in the tail a single servo installation works just fine. My 35% Giles still uses a single tail mounted rudder servo and it's doing just fine. I make it a point to use 10-32 hardware for the rudder horns instead of 8-32 for a safety factor. I've managed to bend, in flight, every 8-32 rudder horn screw I ever used.

I haven't had any problems at all with mine. I did add an extra hingpoint down towards the bottom of the rudder. I now have a hingpoint slightly above the control horn, which was originally the lower-most hingepoint as drilled at the factory, and I have a hingepoint, the one I added, just below the horn. I imagine it would have been fine without the additional hingpoint, but, because of my set up, I liked the idea of having a little extra strength at the horn.

Dan

ok here comes another question:

the 260 i bought from a guy came with an anodized tube, much longer than the stock tube. my 2 questions are, what length should i cut it to, and how do i cut it? someone told me a dremel is a no no. if i cut it as stock length, what methods/tricks do you use to keep the tube centered?

I was very disappointed today. I finally got a chance to fly the 260 after moving the CG back to 4 inches. There was absolutely no change in the amount of trim required to to fly level. I have 10 clicks of up trim to hold the nose. The airplane did fly better. More responsive on the controls. I am going to get an incidence meter and check the wing and horizontal. It is hard to understand how that could be off due to the laser cut kits these days. Anyone have any other suggestions? Stumped John

I'm surprised there wasn't at least some change. I would look at the incidences on the wing panels and horiz stabs. Does the nose drop like a rock when inverted if you don't feed in lots of down elevator?

I've had the same thought before about ARFs by various manufacturers. In an RCU thread for a popular ARF that is touted at being at the top of the heap, some posters have said their horiz stabs' incidences are not the same on each side, and that in some cases the horiz stabs are off by 2*. How can that happen when these things are jig-built??

Dan

I was so P.O.ed today I did not think about flying inverted to see what happens. I knew from the way it flew I was not going to move the CG back any further. That would have told me if I could have continued to move the CG. It was very responsive. Enough that I will have to tone it down for IMAC. John

John:

I have a thought about this situation.

Some of these planes had the elevators built with a twist in them. Most of the time it was just in one elevator, so that if you had the counterbalances lined up with the h-stab one of them was off from the other one. Check yours for this.

Look at it from the rear with both counterbalances lined up with the stabs, it will be obvious of one of them is off.

If this is the situation contact me and I'll send you another set (if I have the right color in stock).

TF

I have not check for that. Will let you know. Thanks John

hmmmm had my first flight on mine today, it was amazing. just putted around mostly, but my cg is right around 4" or 3.80 ar somethin like that anyway it was almost hands off inverted and wow i didn't even get around to mixing anything out today cause it was flying so nice. i could fly this thing all day long.

btw no one ever answered my wing tube cutting question

Just checked. They are both the same. From a flat table, they both check 8 inches with the counter-balances centered. John

Here is what the trim looks like for level flight. John

hey john, how does the 3W pull yours around? mine is 24 lbs even, and it seems pretty good so far, but haven't 3d'd it yet

Measure the length of each wing panel's tube and add that to the width of the fuselage as measured at the fuse's wingtube. The total of mine is 44".

You might consider taking it to a machine shop. For something simple like cutting a wingtube on a bandsaw, they would probably charge a very small amount.

I was able to get a hose clamp between the tube in the fuselage and the former behind it. Put in the tube and tighten down the clamp.

Dan

thanks Dan. i think i'll just have the tube cut the extra two inches (longer than the stock tube) so i don't have to use a clamp. i'm suprised a hack saw wouldn't work if you kept it straight

I'm sure a hacksaw will do the job too; it just might try to wonder a little bit. If you take it slow though it shouldn't be bad. Plus, as long as it is cut just a little shorter than your total width, you should have enough wiggle room if the tube isn't cut exactly perpendicular.

For the 3W80Xi, I've heard that the Vess 26" prop is a nice match. I picked up a 26A and hope to try it within the next week or two. May try a 26B also. The Vess I got was balanced perfectly, tips and hub, right out of the package.

Dan

cool thanks

The 3W80 is plenty of power. Running a 3w 26x10 for break in but I know it will pull a 27x10. John

The incidence meter says the leading edge of the horizontal is to high. It is one increment on the meter. I don't know if that is a degree. It is about 1/2 bubble off. That is what is causing the dive problem or at least most of it. I am wondering if I can loosen the attach bolt holes at adjust it down any. It could induce a twist but it is worth a try. Both sides are the close to the same, but the right side is worse than the left. It would be an easy adjustment with only one tube but with two it becomes more difficult. Does anyone have anything else to try without taking the tube sleeves out if I can't adjust with the bolt holes? John

You can't adjust the incidence on that plane. And 1/2 degrre would not account for your problem.

I still think the elevators are twisted.

Let me ask you this; if the elevators did not have counterbalances would you even know there was a problem?

I mean what difference does it make if you are carrying a little up or down elevator if it flies ok? I may have a set of non-counterbalanced elevators/stabs, what color is your plane?

TF

Where you will notice the incidence issue most is on KE.

Even though your stabs are not adjustable it can be done... I just finished doing it on a Yak and the difference was night and day.

First take off your canopy and put a level on the canopy line... raise the tail till you are perfectly level. Check your wings and they should be at 0. From there check your stabs.. they should be at 0 as well.. if they are at 1 or 2 then you should consider spending maybe an hr to fix the issue.

All you need to do is enlongate (sp) the anti-rotation pin holes and maybe the holes in the tab that keeps the stab in plane. Take a rat tail file and slowly length the hole in the direction you need to go. Then just get it so you are at 0. Harden the holes with CA and then take some epoxy and make the dowel slightly larger on top or bottom so it's a snug fit and keeps your incidence at 0. Take your time and sand it so its a perfect nice and tight fit.

You will spend maybe an hr or 2 depending how fast you work and in the end with 0-0 incidence you will be closer to where you want to be and the plane will fly even better.

what he said