Montague

It depends on the engine and airframe. For a 2610 plane and an OS .25FX, it's not going to be that critical, since the plane can't really pull that many Gs, and the FX has pretty darn good fuel draw.

However, in general I try to get my tank as high as I can, since a low tank will tend to lean out late in a round if you pull a really hard turn. Mounting the engine sideways really helps as well, though it makes a lot of other things a real hassle, so I tend to mount my engines upright.

flyguyeddy

alright i can work with that. i have my engine mounted at a 30 degree tilt to the right anyway (as if u were sitting in the pilots seat, muffler lower than normal)

how does everyone do the bidi tape? chordwise or spanwise for the strips? i picked up some and i wanna give it a try.

Alex Treneff

The Bi-Di is always done span-wise (wing-tip-to-wing-tip). Going spanwise also keeps the wing from snapping in a crash or mid-air. Bi-Di is great stuff, and as long as you don't get heavier than you'd like, use as much as possible. You only need to overlap each strip by about 1/4" though.

flyguyeddy

alright so i got the tank about as high as i can go on the airframe which is pretty close to engine centerline. maybe a little bit above it. i dug a pocket in the two halves so that it fits nice and tight. should i make the tank moveable? like with softer cushion foam or would hard mounting it be alright? on all the other models i have the tank usually gets hard mounted so i will probably do it that way as well. im going to cut a big oval in the top of the firewall for the lines to pass through, then seal it up with silicone caulking. that way if i ever have to remove the lines or change them all i have to do is peel the silicone off and im good.

now where does one get 1/8" fiberglass rod? i will be needing some in the future.

sgilkey

My Feedback: (180)

in the last couple of years i've gotten all my 1/8 fg rod from www.hattrickrc when I get my wing cores. in the past i got it from kitebuilder.com. it's also available from mcmaster-carr. there are other sources, i suspect.

Montague

Most kite suppliers have the fiberglass rods. I personally get mine from kitebuilder, but Mike from HatTrick was talking up a new supplier last time I ran into him that is apparently cheaper with rods that are at least as good if not better in quality, but I've spaced on the name of the place. McMaster-Carr is expensive, but when I order stuff from them, it shows up FAST.

flyguyeddy

so i just bought some HS-45 servos from my local hobby shop. i plan to use them on the wing. the guy said that they are pretty strong and they dont have nylon gears. i forget what they are, but seems to be alright.

anyway, would you:

A: tape the wing then cut holes and channels into the tape for the servos and then retape
or
B: put the servos in first then tape the wing?

i still would like to see just how people are doing the trailing edge.

Montague

Aren't the HS-45's really small, like about the same as a HS-55, or smaller? Even if they are karbonite gears, I think they might break a bit easy. If nothing else, they might not have much torque, and I'd worry about the pot holding up. But I could be wrong, I've not used that servo myself.

personally, I cut the holes for the servos and glue in plywood or hardwood mounting strips, then tape the wing. Then I cut open the hole and install the servo. If I'm using a Y-harness, I put the Y-harness into the wing before taping, and leave the ends of the Y in the servo cutout so I can connect the servo easily. Other guys just cut through the tape to put in a Y-harness then run a strip of tape over the cut. I also cut the Y-harness into the bottom of the wing, which makes it easier to get to, remove, repair, or install with out hurting my paint job. I use white packing tape on the under sides of the wing anyway, which works for me.

sgilkey

My Feedback: (180)

hs45 is karbonite. i mentioned in an earlier post to AVOID KARBONITE for combat use. i tried them and they stripped easier than resing gears. i called hitec and they admitted that karbonite is not good for "shock" loads. I asked them what the heck do they advertise that they're so much "stronger" for if they don't take "shock"? he agreed that karbonites are not a good match for combat where you have a lot of impact loads. frankly, I don't know WHAT they're good for as the only planes i ever strip servo gears in is combat planes. it's not like i strip gears in my sport planes. but i digress

that hs45 is teeny. it'll probably work (assuming you use dual ail servos) for a combat plane that never actually crashes or midairs with anything. if you plan on actually combating with it, i think you will be disappointed. i think it will be inadequate for elev. throttle will be fine.

for me, tradoff of cost/weight/durable gears, you can't beat the hs81MG if you insist on a mini servo. folks say they have centering problems or various other issues but i've used them for years and never had problems. hs85MG and 225MG are also very good but expensive, and in my experience strip just as easily as the 81MG, all the hitec MGs have one plastic gear (the smallest one) and they all strip if you hit 'em hard enough.

mostly i use all standard servos, S3003, they are fairly tough and are cheap and durable, but a bit heavy

flyguyeddy

indeed they are karbonite. i will probably take them back and exchange them for something else.

i hear good things about the GWS servos. thoughts?

Montague

I personally don't use the GWS servos, but make sure whatever gear you use, that you can get parts for it. Arms and gears, as you'll be wanting to repair them sooner or later.

Like Scott, I think the HS-81MG is about the best bang for the buck in terms of cost, reliability, and repairability.

I'll also add that it pays to use lots of the same kind of servo once you get a fleet of combat planes going, and I try to always have at least 1 spare servo kicking around in my field repair box.

Alex Treneff

The HS-81MG, or CS-12MG (Hobbico equivalent) are really the ideal servo for combat. They are tough, not a much more expensive than an S3004, light, and strong. I've talked to a few guys that saved a couple bucks by going with the no-name Chinese equivalent, but if you're going to fly combat, the Hitec and Hobbico warranties are nearly invaluable.

Although I've stripped my fair share of servos in the last 5 years, I've probably had at least as many clevises, horns, and pushrods break or bend (easier fixes). They are tough little servos, and when they do strip and Hitec and Hobbico have always backed up their warranties exceptionally.

sgilkey

My Feedback: (180)

i have a bunch of GWS but i wish i had never bought them. they work... but have poor centering. centering is not THAT critical on a combat plane since the surfaces are just about always flapping, but if you're using them for elevons, it will be noticeable (got some from a friend who tried them on a Predator, NO GOOD). their arms are extremely weak and break easily. the cases are flimsy. they work, but are a headache.