Mr. Smoothie for Q-40  
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Mr. Smoothie for Q-40 - 4/19/2003 4:33:50 AM   
PylonWorld



Posts: 1346
Joined: 12/29/2001
From: Monroe, NC, USA
Status: offline 		I received the 3 views of the Mr. Smoothie today from Duane Gall (DHG), and I went ahead and drew it up. Here is a JPG of the drawing.

The JPG conversion is not perfect, but it will give you an idea of what I have in mind. Let me know what you think.

The cowl ring to LE is 7", and the engine cowl is right at the max height allowed especially at the rear of the cylinder, at least for a Nelson. I better check it for the JETT.

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Don Stegall
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Mr. Smoothie for Q-40 - 4/19/2003 5:10:41 AM   
PylonWorld



Posts: 1346
Joined: 12/29/2001
From: Monroe, NC, USA
Status: offline 		After posting the first version, I realized that I didn't capture the essence of the tail end of the fuselage on the bottom, so I did a minor reworking of the bottom, and the rudder.

Note that you have to click on the photo to be able to see anything.

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Don Stegall
RCPRO Chairman of the Board

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Mr. Smoothie for Q-40 - 4/19/2003 5:50:52 AM   
PylonWorld



Posts: 1346
Joined: 12/29/2001
From: Monroe, NC, USA
Status: offline 		Good thing I checked a JETT. They are only 2.5" from centerline to top of the head. The Nelson is 2.65". So I'll have to make a change to the nose area.

I think I also have to make a minor change to the Hughes H-1 because of this. I was going by the Nelson, and had not though about them being different in height.

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Don Stegall
RCPRO Chairman of the Board

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Mr. Smoothie for Q-40 - 4/19/2003 11:44:57 PM   
PylonWorld



Posts: 1346
Joined: 12/29/2001
From: Monroe, NC, USA
Status: offline 		This is version 3 of the Mr. Smoothie. The nose has been lowered to accommodate the shorter cylinder of the JETT engines. Also, I lowered the canopy 1/4" and added the 1/4" to the bottom which results in a more realistic bottom shape. Plus the bottom can be tapered way down, and the canopy looks more realistic being smaller.

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Don Stegall
RCPRO Chairman of the Board

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Allright!!!! - 4/20/2003 8:09:00 AM   
matchlessaero



Posts: 1288
Joined: 1/6/2002
From: Cordova, TN, USA
Status: offline 		Now that is a good lookin plane..... I like version 3 much better.

Considering the configuration of the landing gear on the real one, I bet you could use one of the available carbon fiber gear options from a Q500.

Too bad you can't do the scale spinner on this one, it is real interestin' looking if I remember right.

_____________________________

Go fast turn left-----3D is life-----Fly S.M.A.L.L. I'm having an RC identity crisis!!!!!!!!!

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Mr. Smoothie for Q-40 - 4/20/2003 8:18:24 AM   
PylonWorld



Posts: 1346
Joined: 12/29/2001
From: Monroe, NC, USA
Status: offline 		It has a vent in the middle like the Swee' Pea had. Until I got the three views and article from Duane, I thought the spinner was part of the fuselage because of the [URL=http://www.aeroaces.com/smoothie.htm]No-Cal[/URL] FF model.

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Don Stegall
RCPRO Chairman of the Board

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Smoothie front end - 4/21/2003 8:50:06 PM   
DHG


 

Posts: 896
Joined: 4/24/2002
From: Arvada, CO, USA
Status: offline 		Don,

That looks real nice! For the front end treatment, may I suggest not trying to have the fuselage contours meet the engine cylinder perfectly. I tried to make the cheek cowl meet the engine cylinder on my earlier version Stinger and it just didn't work. Jerry Small's TRC-1 "Sidewinder" also does this, with what I consider less than ideal results.

My 2 cents' worth is, do what I'm doing on the cheek cowl of the new version of the Stinger (kitted by Ed Smith): Have the fuselage contours come up behind the cylinder and end in what looks like a very flat & blunt wing leading edge, leaving the area behind the cylinder basically open but very smooth -- large radii on everything, no cutouts or hollows. This gives almost as good aerodynamics as a tightly fitted installation, but you'll get better cooling on the backside of the cylinder and there's room to fiddle with your fuel lines, etc.

If that leaves you cold, take a look at Dan Kane's Pole Cat. He's got a very nice wraparound cowl (excuse me, crankshaft hole cover) that ends "short", leaving the head fully exposed as required by the rules. This might require you to rework your side view yet again and it is more work, but it would be very clean.

Just my thoughts. Again, the project looks great so far.

DHG

(in reply to PylonWorld)
       Post #: 7

Mr. Smoothie for Q-40 - 4/21/2003 10:15:04 PM   
PylonWorld



Posts: 1346
Joined: 12/29/2001
From: Monroe, NC, USA
Status: offline 		What I was planning was to use a piece of fiberglass to restore the contours. Since the engine compartment is a little bigger than on many planes, I thought it would be good to enclose everything that can be enclosed. The dashed line on the front from the thrustline up to the top of the cowl represents the back side of the cylinder and I currently have it at 1.75, which is the max for a JETT. I would still need to lower the cowl by 1/32" or so, to accommodate the .020" piece of material that restores the cowl shape.

If cooling on the back side of the cylinder is an issue, I can easily rework the nose shape. We're only on Rev 3 ... the El Bandito is on on Rev 16 and that doesn't include the .1 revs.

I'll save the full size plan to a JPG and email it to you so you can mark up what you think would be best.

The cooling matter is new to me. I was used to the F1 cooling and RIRE air supply issues, and that's a whole 'nother ballgame.

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Don Stegall
RCPRO Chairman of the Board

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Mr. Smoothie for Q-40 - 4/22/2003 12:01:20 AM   
kane


 

Posts: 255
Joined: 6/28/2002
From: Arlington Heights, IL, USA
Status: offline 		I cannot take credit the crankcase cover. This concept was copied from Jerrett Cangie. He designed the first El Bandito/Shoestring QM40. His design flew great and was super fast.

I did the polecat because I liked the lines, and was so so on the bandito. Bruce designed the wing and tail. I just put the pieces together in the middle.

So major KUDOS should go to Jerrett for his forward thinking.

Don, if you have access to sheet wax you can make a crankcase cover easily, simply mold the wax around the engine to the desired shape and make a mold from the shape. Then from the mold make a part that can be filled and sanded to fit your plug keeping reference points solid like the position of the venturi to the crankcase, and position of venturi to spinner ring. Sounds easier than it actually is but, this is the way to do it. Then make a mold for the cover from the plug, this way it will match the fuselage exactly.

Dan

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Dan Kane

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Mr. Smoothie for Q-40 - 4/22/2003 12:40:52 AM   
bl10


 

Posts: 303
Joined: 12/29/2001
From: Chatsworth, CA,
Status: offline 		Don:
Seems I heard you were planning on a vertical mounted engine. If so where are you planning on putting the tank? Tank placement relative to the engine is critical. If the centerline of the tank is to high, like the original Sidewinder with a tetra tank, The engine will go rich (particularly in the corners). The flat tank made the sidewinder better but you still must set a Nelson pretty close to kill on the ground unlike the typical Mustang type which can be left fairly rich on the ground. (Tank is lower due to low wing). Most think tanks should be as close to cg as possible, which can be a problem on a mid-wing design. In my opinion the tank installation in the Pole Cat (mid wing) leaves a lot to be desired. Are you planning on notching the wing for tank clearance? The European F3D guys actually raise or lower the tank to control mixture out of the corners. Something else you might consider is the landing gear mount. The reason tank installation in the pole cat is difficult is the huge hump inside the fuse for the gear mount. You might consider mounting the gear on the sides of the fuse rather than through the fuse.




Barry

(in reply to PylonWorld)
       Post #: 10

Mr. Smoothie for Q-40 - 4/22/2003 12:42:03 AM   
DHG


 

Posts: 896
Joined: 4/24/2002
From: Arvada, CO, USA
Status: offline 		Dang I wish I were smart. Sheet wax, of course. I be usin' oil-based modeling clay. The fiberglass won't stick to it, but it's a mess to get off the engine fins & stuff after you've made your mold.

One nice thing, though ... the bits that get into the cylinder really shorten your break-in time.

Primitive Pete

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       Post #: 11

Mr. Smoothie for Q-40 - 4/22/2003 1:29:45 AM   
PylonWorld



Posts: 1346
Joined: 12/29/2001
From: Monroe, NC, USA
Status: offline 		Barry,

Thanks for the tank info and the gear idea. I was really wrestling with the gear installation. Irwin Funderburk's F1 El Bandito had a similar installation as the Pole Cat, and you're right, it is a big hump.

DHG had recommended the upright engine installation. And that's what I was thinking, but different positions could be used.

Since I'm going to do a new wing for this one, I can design a notch into the wing, and use plenty of CF in the front of the saddle area.

I'm going to scan the Mr. Smoothie three view and article and put it on PylonWorld.com.

Plus, I'll be glad to email the full size profile in GIF and JPG form to anybody that wants to see it or mark it up for suggestions.

_____________________________

Don Stegall
RCPRO Chairman of the Board

(in reply to PylonWorld)
       Post #: 12

Mr. Smoothie for Q-40 - 4/22/2003 2:33:53 AM   
kane


 

Posts: 255
Joined: 6/28/2002
From: Arlington Heights, IL, USA
Status: offline 		DHG,

Wrap the engine with packing tape first.

Barry,

I am confused with your comments. Are you saying that the Pole Cat tank is too high? too Low? or can't get it into the airplane? Please shed some light on the POLE CAT problem. I don't see anything as a problem only as a challenge. Yes it is a challenge to get the tank in the Pole Cat.

As to the sidewinder issue??? I have flown one with a Nelson for the past 3 years. What is the problem, the tank is too high? Or too low?

On a side mounted engine (with the airplane sitting on its wheels) the tanks position relative to the venturi is different than when the airplane is on it's side while in a turn. While in a turn this type of airplane, has the cylinder head upright. The tank position here is dead center on all airplanes in terms of up and down. IF I move the tank up or down relative to the top of the airplane I have moved the tank to the left or right. Is this what causes a difference?? I am not trying to be funny here I am truly trying to understand what is happening by changing the tank position. I am trying to understand why it would go rich in the turns with tank too high (to the inside of the turn). Does it go lean if it is too low (to the outside of a turn)? Most F3D airplanes have the engine mounted inverted, does this cause differences when turning on engine settings?




Dan

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Dan Kane

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Tank position in the turns - 4/22/2003 3:05:08 AM   
DHG


 

Posts: 896
Joined: 4/24/2002
From: Arvada, CO, USA
Status: offline 		Dan,

I hope Barry doesn't mind my jumping in here, but I think I understand your confusion. When the airplane is on its side, preparing to turn, the tank is indeed just a little below the venturi (in relation to gravity, i.e., the ground) with the cylinder sticking up vertically. And of course there's little or no perceptible change in the mixture ... as long as the plane keeps on flying steadily in knife-edge flight, relying on the fuselage for lift. It doesn't need much lift at that speed, and the forces on the airplane are rather mild.

However, when you hit full elevator, the effect of ordinary gravity is overwhelmed by the artificial gravity (G-force) as the wing "lifts" the airplane hard in a [COLOR=orangered]horizontal[/COLOR] direction. Now the airplane is sustaining a force of 20 or 30 Gs perpendicular to the wing, which you'd consider an "upward" force if the airplane were parked stationary on the ground, sitting on its wheels.

If the tank is 1 inch below the venturi when the airplane is parked stationary on the ground, sitting on its wheels, then in a full-up-elevator pylon turn it will [COLOR=blue]act[/COLOR] as though the tank were 20 or 30 inches below the venturi. That's why the tank position makes a difference to the engine mixture in the turns.

Capisce?

Dude the Obscure

(in reply to PylonWorld)
       Post #: 14

Mr. Smoothie for Q-40 - 4/22/2003 4:48:14 AM   
Ed Smith