suitcase

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Name me some outlets for World Models please. Is the only one in CA? How much is shipping on it??

opjose

Shipping to the East coast was a resonable $18.00.

Hmmm... not those super inflated shipping rates quoted on some sales....

badz

My Feedback: (1)

Take a garbage bag with you to collect the pieces. This is barely a 40 sized plane it's all but the same size as the 30....a Saito 100 will tear it apart. A OS52 is plenty for this bird.

badz

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I always order direct from Airborne ground shipping is $10.
[link=http://www.sheldonshobbies.com]Sheldon Hobbies[/link] carries them also they are in San Jose,California
and [link=http://www.hobbywarehouse.com]Hobby Warehouse[/link] in Kentucky carries World Models also.

opjose

I'm in the middle of building my WM 40S.

I'm wondering what to do about the fuel tubing.

I'm installing a side mounted .46 with a Bison Pitts style muffler.

I was planning on putting in a fuselage mounted filler valve, but then realized that there was no way to quickly remove the muffler pressure tube to be able to see overflow when the tank fills up... (non uniflow).

Is this something I shouldn't be worried about as the overflow will spill out the bottom?


Would it be a good idea or necessary, to go Uniflow on this plane (it is rather small...).

If so suggestions as to the vent location?

Thanks.

da Rock

A number of us at my field simply pump until we see fuel out of the muffler. The Slimline Pitts off a side mounted 46AX will put fuel out the muffler as soon as the muffler line overflows into the muffler.

In the past, I have routed an overflow line out one hole in a cowl and back into another just so it was readily visible.

And it's a common practice with some of the pattern flyers to route lines outside the cowl where they plug into a filter. Pull one line off the filter and fill there. When it's full, put the line back on the filter and good to go. It saves running a T in that line. It looks functional.... wouldn't look right on a scale airplane, but pattern planes don't look like a "real" airplane anyway.

opjose

Great thanks!

opjose

I noticed that the included mount had about a 1/16th" difference between the two "base" plates (the parts that are closest to the firewall). On is about 1/16th" thicker than the other...

In an inverted engine install, this would either angle the engine up about a degree or down by a degree dependant upon which plate you put on top or the bottom.

When I installed mine as a side mount, this difference all but cancelled out the right thrust produced by the angled firewall.

If I reverse them I'll get more right thrust than that given by the firewall.

So question...

How bad is the plane's natural left yaw at takeoff?

Does it need right thrust at all?

Does it need a bit more than given by the firewall.

Is it spot on, when the engine is inverted?

What about down/up thrust? Should it be a degree of down, a degree of up or none at all?

Thanks.

BTW: I don't like the idea of bending the pushrods as per the directions.

Cutting the cowling was a bear to get right. It was hard to get it looking good, and still permit you to remove and re-install it.

skoemba

I just finished my Ultimate last night, fitted with a ASP70FS up front. [>:]Plane balanced right on the money and weight in at 5lb. I will maiden it on Sunday and see how it goes.

elenasgrumpy

My Feedback: (4)

You'll like this. I live in Tracy Ca. Before I knew about Airborne Modles I ordered the WM Cap 232 46R from Hobby Warehouse in Ky. I payed another $20 for the shipping. When the box arrived I opened it up to find a sticker on the model box which read: Airborne Modles, Livermore, Ca. Well it turns out that Airborne is about 20 minutes away from my house & I payed someone in Ky $20 to ship me this model.[:@] I have since then just run over to Airborne whenever I want to buy a new plane.

I got my Ultimate 40 from them under scratch & dent for $90. Only damage was 2 small dents the size of your fingertip on the bottom side of the wing that you can't even see.

This planes fly great with an OS 46 on it & as MinnFlyer has already said standard servos is all that is needed on this little plane, it does build at 4.5lbs & the single servo ailerons work just fine!! The funnest plane in the fleet!!

cosmospho

Hello everyone, built my plane stock with a TT pro 46, and it has this tendency of yawing to the left on loops or whenever I apply engine, it is also snapping quite a lot when It gets a little low on speed, it is being quite a nimble hands full plane.... I have changed a little the thrust and added down thrust and my CG is on 3" from leading edge....

What props is everyone using for this ?? My TT 46 has a 11x6, tried placing a 12x4 for some vertical performance but it got much worse....

Thanks,
Cosmos

da Rock

cosmopho,
Your duplicate post on the other WM40Ultimate thread has answers. Don't want to duplicate them over here............

BTW, these forums had the answers all along. There is a thread that addresses them, complete with pictures and diagrams. It will show up in a search.

opjose

Yup, it will do this (any plane will) when the throws are set too high for what you are doing...then one of the wings or wing tips will stall.

You may want to set the throws for the tail a little lower, then try again.

Keep doing this until you find that the loop no longer causes a tip stall causing the seeming yaw...

When you get to this point, set this to be the low rate on your TX and return the elevator to the former rate for "high" rates.

Even with Darock's great fix for the aileron problem, this will occur with the throws at the recommended high rates, and it gets worst as you move beyond the recommended... he is pointing you to the thread where he illustrated his fix.... which I would recommend as well btw...

Leave the high rates on for things like hovers, then use the adjusted lower rate for everything else.


I'm using an 11x6 on my TH .46 (which is equivalent to the GMS .47 engine).

I have a second WM Ultimate .46 with an O.S. 46 LA engine using a 10x6 prop due to the lower output of this engine.

Super Splatter

I have a WM Ulitmate 40 S with a OS .46 AX.

I use a APC 12x5 it goes about 20 feet down the runway and then it goes UP as far as I wish.

I run the engine inverted with a stock muffler, with the weight of the muffler hanging to one side I have to add 3/4 oz leadweight the the opposite side interplane strut to keep it flying level through a loop.

With a 12 in prop it has lots of left pulling torque when I apply full power, that's what right rudder is for.

With a 10 in prop it will do radical snap rolls. the gyro effect of a 12 in. prop really kills how hard it will snap roll.

Nice model for a sport type ARF, I like Bipes because they slow down nice for landing and the presentation of a model bipe is just plan cool

opjose

... though even latterally balanced planes will yaw during a loop if the loop is too tight for the lift generated by the wings... e.g. a stall occurs.

Great little plane.... throw it in the trunk and fly.

cosmospho

Thanks everyone, great answers, I have just flown it about 10 times and I am dialing in every aspect to get the best out of this plane.... I have followed your aileron discussion daRock and have changed the ailerons, I will also check the lateral balance cause my engine is also upside down with muffler hanging to one side...

About the elevator throws, they are not over the recommended, what I think is that because of the yaw to the left due to torque the plane ends up finish the loop a little twisted and not tracking right... I am going to dial in some right thrust just so that the rudder doesn't need that much use....... This is really a great plane, the best of all is the looks you get in the field from such a small beatiful plane

Thanks guys

opjose

Try doing what I've said. It will cure it.

The stated throws in the manual are too much for a tight loop.

I lessened the throws and my plane stopped doing it, although the loop size is bigger.

BTW: My plane was laterally balanced from the start and also had DaRock's fix, and it still did it, even when the engine was at idle (little torque effect) during a nose entry into a loop.

I tried going nose down at full speed, then cutting the throttle and entering a loop, and it still did it... however with the engine at idle it will yaw in either direction as the wings stall.

With the engine going it will tend to yaw left.

---

Yes it's a great little plane, and fairly sturdy too...

One of mine has over a dozen crashes on it, mostly due to engine/fuel problems, and I just patch it up and throw it back in the air.

I used very inexpensive components on mine so I'm not too worried about crashing it... leading to far more fun at the airfield...

My little "fleet" of WM 40S Biplanes has just gained it's third member.

cosmospho

Hi everyone, just some updates, I have decreased the throws in the elevator and its helped.... I increased my right thrust but its still yawing to left, guess I will have to dial some rudder, since if I use right rudder the loop is perfect.... This plane has some tendencies but its a great plane and no complaints here, its a bipe so im not expecting a pattern plane ....

How about those snaps ?? Hell I tried some snaps and the thing rolled so fast I had no idea which way it was turning when it stopped..... About hanging on prop, I can do it fine, no problem with the small area of ailerons, it hangs and holds quite well.... I guess when hanging we don't really need ailerons, just steer with the rudder and the elevators... Great little beast this plane, if you have experience its one of the best planes you will ever fly....

Keep em flying

da Rock

About the yaw to the left.........

As long as we have a prop on the front and it's turning clockwise (from the pilot's perspective) we will have P-effect. And that pulls the nose left when the nose is pitched "up". Balance can't cure it. Lessened throws can't cure it. Reducing the throttle also slows the plane and that means the lessened P-effect from the reduced throttle has less to contend with, so that might or might not help. It might actually be in the prop's favor and you see more yaw.

And then there's gyroscopic precession. And it's purely a function of the spinning mass of the prop. Throws and balance does nothing to it.

da Rock

I've actually not got an airplane I'm flying now that won't yaw left in some situation. And thinking about it, I think almost everyone of them has the tendency to go left at the top of an inside loop at some airspeed and loop tightness.

And one of our pattern guys was fussing the other evening. He was trying to decide which right thrust he wanted in his $5,000 worth of perfect pattern airplane, the right thrust that worked right away or the right that worked after the plane slowed down some.

BTW, I'm glad this question came up. Ever since it's been a topic, I've thought to watch for it whenever I'm flying one of my better flying airplanes. And it's made me a better flyer. I've noticed that the little Ultimate won't do it if I relax the elevator where it happens. I relax a bit and then move it back if it needs it. Most often it doesn't need it. Depends on the speed. Glad the question came up. OH yeah.... My CAP does it too. And same cure.

cosmospho

Hello darock I agree with you but some planes handle it much better, and maybe I guess the smaller planes suffer a lot more ... But I have gotten used to using the rudder and if you work your fingers right it ends up in a perfect loop.... Its strange why there is an offset on the firewall which should help and maybe it does with a weaker engine. But as all planes and flying pilots, some user rudder and others change thrust and some even build planes more bulky on one side to enduce more drag.... Its a very theoretical and depends on plane, thrust angle, prop size etc.... Its not inherently a plane problem but a physics and logical issue, I was just looking for some help and see what people have done on their planes....

Keep em flyin straight this time [:-]

opjose

Yes exactly.

This is why lessening the elevator throws DOES help.

It prevents us heavy fingered flyers from moving the elevator too much.

You've done it the "correct" way, lessening the loop radius to stop the yaw/stall.

My other planes also do this dependant upon wing and fuselage length characteristics, coupled with the elevator limits.

Ugo Ferrari

My Feedback: (1)

I lost it this past weekend ! I let it stall by slowing down to much turning on final, and it fell like a brick ! I did not have enough elevator travel to recover, and it spiraled in... It had the recommened max travel. I got six great flights before I goofed ! Keep the speed up !

Ugo

da Rock

What's interesting is that there is no obvious "lessening" of the loop radius. And you know what that shows..... that the elevator deflection isn't working "good". It might be stalled, but more probably it's just not got the lift working but does have the drag working. Yeah, less full travel is a good solution. And there are two good ways to get it.

Ugo,
Awwww mannn....... hate to see that!

Ugo Ferrari

My Feedback: (1)

Thanks darock....SNIFF ![] LOL !
Ugo