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Joined: 1/30/2002 From: San Jose, CA, Status: online
The flap horn and linkage is entirely internal, whereas the aileron linkage is external.
One of the things that I really liked about the BVM Bobcat kit, is the way jigs were supplied for aligning the horns on the ailerons and elevators. This handy refinement has not made it into the Super Bandit, but now that the Bobcat has shown us how easy these jigs are, we can very easily make up our own jigs if we wish.
I just placed some tracing paper over the wing detail plan, traced the outline of the aileron cross-section and the horn centre-point, then glued that piece of paper to a scrap of 1/16" ply, cut it out and glued in a small piece of wire at the horn centre location.
The result is shown below, and took just over a minute to throw together:
< Message edited by Gordon Mc -- Dec 12 2002 4:38AM >
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Joined: 1/30/2002 From: San Jose, CA, Status: online
... and here you can see the jig in use. This ensures that not only do I have the horn installed in the correct position, but both ailerons (and both flaps, done similarly) move the same amount for the same servo input.
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Joined: 1/30/2002 From: San Jose, CA, Status: online
Notches: Page 24 of the manual tells you to make notches in the wing skin as necessary to get clearance for the control horns.
This is mildly misleading, as [list]
This statement is made in the section about Ailerons, yet the ailerons need no such notches - just the flaps may need it. The photo is in fact of the flap - it's just under the wrong section heading.
The instruction appears twice - once it clearly states that its for the flap, the other time it doesn't. Don't let this confuse you into thinking that both the flap and the aileron need notches - only the flap. [/list]
Next, the wing detail plan shows that all pushrods use 2-56 clevises, and that some are solder clevises and some threaded clevises. This is incorrect.
There are in fact 4 x 2-56 clevises and 4 x 4-40 clevises - all threaded. The 2-56 clevises are for the flaps, and the 4-40's are for the ailerons.
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The built-up surfaces are now all double-checked for the correct fit to the fuselage, since they are completed to the point where they are ready to glass. (In fact the rudder & fin are already glassed in these photos).
Here's a couple of photos of the completed assemblies:
From the front (there sure is plenty drag there !)
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Joined: 1/30/2002 From: San Jose, CA, Status: online
There are three kevlar fuel cells in the Super Bandit, plus a UAT.
The fuel cells come in two parts each, and are simply glued together with Aeropoxy, after adding the plumbing fittings.
The instructions tell you to rework the opening in fuselage former F-3 to make it squarer (to fit the tank cross-section) instead of rounded as the former is supplied. I guess the tank shape was changed after the formers were designed & cut (otherwise they would have been cut to the right shape in the factory?).
If you're building this kit, and haven't installed F-3 yet, you might want to reshape it before you install the former, as this will be slightly easier than once it is installed, primed, etc as mine already was before the tanks arrived.
BTW, the detail plans show the centre tank having three fittings - that's wrong - there should only be two (as is shown on the separate plan that comes with the tanks).
There is also one part which (to me) was unclear what it was for. This is a straight brass conector & two nuts. Turns out this is the overflow vent that vents to the outside of the aircraft through the fuselage bottom.
Here's a shot of the fuel cells.
< Message edited by Gordon Mc -- Dec 21 2002 2:13PM >
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Joined: 1/30/2002 From: San Jose, CA, Status: online
The Super Bandit manual gives more than adequate detail for the vast majority of the assembly of the aircraft... but when it comes to the fitting of the bypass & tailpipe, written details are for some reason pretty scarce.
However, don't forget that the kit also comes with a number of large and detailed plans too. The Fuselage plan shows some of the detail for the mounting; other details can be gleaned from the photos in the rear of the manual.
Here's what I did. Hopefully it's right !
First, the bypass. Cut the supplied 1/4" plywood strip in half, then sand the appropriate contours on it to allow the part to fit snugly under the engine mount tabs on the carbon fibre bypass. Glue it in place and then install 4-40 blind-nuts on the underside so that 4-40 bolts passed through the engine mounts will anchor into these blind nuts. Glue them in place too.
Cut and/or grind away a portion of the upper section of the bypass (hatch) in order to allow it to fit over not only the lugs in the lower portion of the bypass, but also the aluminum engine mounts once they are installed. The inside of the bypass hatch actually has a scribed line showing you where to grind, though this will give you a slightly larger cutout than is strictly necessary.
Next, I took the two carbon fibre angle brackets, and tapped them 4-40, then used 4 x 4-40 SHCS to attach these to F-5, as shown on the fuselage detail plan. I drilled out the holes in f-5 very slighty oversize to allow a free but close fit. (I guess you could tap these holes if you wanted, but I figured a free-fit hole would allow the angle bracket to be drawn closer to F5 than if both components were tapped.)
Then I put the bypass assembly into the aircraft, with the 2" fibreglass bypass extension added to the front of the bypass just as a push-fit for now (will be glued later), and then inserted the tailpipe from the rear of the aircraft and pushed it forward until the inner pipe was pushed as far over the outside of the rear of the bypass as it could go.
I then rotated the inner pipe until the two straps on it seemed to be symmetrically placed about the bypass, and marked through the holes in the straps. A 4-40 clearance hole was then made at each of these marks, and the inside of the bypass scuffed slightly at these points. A 4-40 nut was glued to the inside of the bypass using PIC plasti-stic (will be Aeropoxied later). This allows the two straps to be bolted to the end of the bypass.
Some of this can be seen in the photo below:
< Message edited by Gordon Mc -- Jan 10 2003 1:21AM >
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At the rear of the fuz, there are a couple of dimples on the outside of the rear-end on the surface that butts up against the removable nozzle.
These marks are intended to show where to use screws to secure the outer tailpipe, via the two right-angle brackets that are spot welded onto the outer pipe.
IMPORTANT:
These marks are in the wrong place. Originally, BVM had the angle brackets on the outer pipe in slightly different positions, and these matched the dimples on the fuselage. They then decided to put the brackets in a slightly different position, but did not revise the positions of the dimples.
The correct position for the screws can be arrived at by some trial and error. BVM suggested that I start by aligning the top of the brackets with the bottom of the dimples. I did that, and taped the brackets in position, put the removable nozzle on and checked for the tailpipe being centred. I ended up dropping the pipe slightly more to get the position reasonably close, then drilled the holes in the fibreglass and screwed #2 screws in to hold the pipe. A recheck of the tailpipe centering showed that a slight adjustment still needed to be made, so I extended the holes to suit, then put a couple of small 1/4" ply pieces behind the fibreglass lip and drilled the (by now correctly positioned) holes again.
In the following photo, you can see the original dimple positions above the brackets shown here in red, giving you an idea of how far you may need to move the screw holes. Use this only as a rough guideline though - you should fine tune your own installation to get a properly centred tailpipe.
< Message edited by Gordon Mc -- Jan 10 2003 1:39AM >
Posts: 6709
Joined: 1/30/2002 From: San Jose, CA, Status: online
The bypass is additionally secured in place by having two small (#2) screws go through the bypass from the inside, and into the 2 carbon fibre brackets that we earlier mounted to F5.
I tried to take pics showing the screws in place, but the glare from the all-black innards caused some odd results.
Anyway, for the positioning of the screws, the simplest thing is to drill from the outside. Since the bypass is still free to rotate at this point (until the screws are in), align it centrally (side-to-side wise) in the fuselage opening, and then use some tape to secure the bypass to the bypass extension etc at the front. This will keep the bypass in the correct position while you turn the fuselage upside down so that you can drill the screw holes as shown below. I drilled a 1/16" hole right through the middle of the bracket, then enlarged the hole in the bypass only, for screw clearance.
< Message edited by Gordon Mc -- Jan 10 2003 4:52AM >
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Joined: 1/30/2002 From: San Jose, CA, Status: online
Since the outer-tailpipe brackets mount to the outside of the fuselage molding, these brackets and the screws that retain them will interfere with the 1/16" ply former that is at the front of the removable nozzle.
I mounted the nozzle, and marked the positions of the brackets and screws, then used my Minicraft (kinda like a Dremel, but better ) to recess the plywood as appropriate for the bracket, and make a suitable hole all the way through where the screw will be.
< Message edited by Gordon Mc -- Jan 10 2003 4:51AM >
Posts: 6709
Joined: 1/30/2002 From: San Jose, CA, Status: online
The elevator pushrods are kinda interesting....
There is an outer tube (fibreglass or CF) which is secured in place inside the fuselage - pretty normal stuff there. The inner, moving, portion however, is rather novel.
Inside, is a music wire (which we will solder the connectors to). That music wire fits inside a Nyrod inner, and then there are a series of small o-rings spaced along the outside of that Nyrod inner. This whole assembly - wire, nyrod and o-rings - slides along inside the outer.
Perhaps a photograph will make this clearer.
< Message edited by Gordon Mc -- Jan 28 2003 4:40AM >
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Joined: 1/30/2002 From: San Jose, CA, Status: online
I have now done two rounds of the prime-sand-fill, prime, sand, fill repetition, and need only to do final touch-up on the primer before shooting color.
You can also see here that I have cut out the canopy to allow for the cockpit & clear canopy option.
A double-check of all parts-fit and control surface travels is also in order here, to make sure that the filling etc has not interfered with the parts fit in a way that reduces throw.
This is where I find one of the few areas to complain about the manual.... I like a manual that puts all of the info where you can find it easily. I would like to see the BVM manuals include a table (or even just an extra column in the servo selection table), that shows what the throw(s) of each surface should be. If all that info is put in one place, then tasks like setting up the radio requires you to find just that one page of info.
Instead, that information is scattered, and consequently more awkward to find. The manual says things like "Check plan for control throws" for the rudder. The Fin & Rudder plan (comes separate with the straight fin) has no throw info on it, so then I dig out one of the fuselage plans ... not there either, next I try the other fuselage plan, and now find a small diagram that says the rudder should have 1 3/8 throw.
It's the same for ailerons, elevator etc - more hunting around to find out where the info is, and each is on a different plans sheet. This really is not a big deal, but it's a little frustrating just because the rest of the manual is so good, and then this one area is neglected like this. Same with the Bobcat, BTW.
(I have since talked to David Shulman at BVM, about putting this info in a table at the back of the manual in future... it may happen.)
Also, the info about the rudder throw did not state whether that was for the straight fin or the swept one (or both?), and does not tell you whether that is as measured at the top or the bottom of the fin (big difference, especially on the swept fin).
In case it helps anyone else, here's some of the control throw info collated from the various plans, plus a phone-call to BVM:
Ailerons [list]
Measure at junction of flap & aileron
Hi-rate: 1 1/8 inch up
Hi-rate: 1 inch down
Low-rate: 9/16 inch up
Low-rate: 3/8 inch down [/list]
Elevator [list]
Measure at root
No high & low rate info - one travel amount only.
1 1/8 inch up
1" down [/list]
Rudder [list]
Measure at the base of the rudder.
No high & low rate info - one travel amount only.
1 3/8 inch left and right
Required travel is the same for swept and straight versions [/list]
< Message edited by Gordon Mc -- Jan 29 2003 8:23PM >
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