BVM Super (Balsa) Bandit
12-12-2002, 03:38 AM
#76
Horns
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:
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:
12-12-2002, 03:40 AM
#77
BVM Super (Balsa) Bandit
... 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.
12-21-2002, 05:27 AM
#78
Pushrods
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
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.
This is mildly misleading, as
- 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.
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.
12-21-2002, 05:34 AM
#79
BVM Super (Balsa) Bandit
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 !)
Here's a couple of photos of the completed assemblies:
From the front (there sure is plenty drag there !)
12-21-2002, 05:42 AM
#81
Fuel cells
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.
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.
01-09-2003, 04:55 AM
#82
Bypass & tailpipe mounting
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:
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:
01-10-2003, 01:11 AM
#83
BVM Super (Balsa) Bandit
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.
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.
01-10-2003, 01:19 AM
#84
BVM Super (Balsa) Bandit
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.
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.
01-10-2003, 01:29 AM
#85
Nozzle fitting
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.
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.
01-28-2003, 04:25 AM
#86
Elevator pushrods
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.
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.
01-28-2003, 04:40 AM
#87
BVM Super (Balsa) Bandit
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
Elevator
Rudder
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
- 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
Elevator
- Measure at root
- No high & low rate info - one travel amount only.
- 1 1/8 inch up
- 1" down
Rudder
- 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
03-02-2003, 02:29 PM
#88
Paint
Well - I know it's been a month since I last posted any updates here, but I have not been totally lazy ... as well as being very busy at work, I've been doing work on the aircraft that is very time consuming, but without much to show for it ... all the pre-paint prepwork.
I've almost finished with the color paintwork now - some parts need a little more paint applied to get the color's closer (metalics can be a real pain to match from one part to another, when you coat one a bit heavier than the other, and the colors come up substantially different!)
Anyway, here's a quick shot giving an idea of the paint scheme. I've also been working on some artwork for decals. The decals, panel lines etc will come next.
I've almost finished with the color paintwork now - some parts need a little more paint applied to get the color's closer (metalics can be a real pain to match from one part to another, when you coat one a bit heavier than the other, and the colors come up substantially different!)
Anyway, here's a quick shot giving an idea of the paint scheme. I've also been working on some artwork for decals. The decals, panel lines etc will come next.
04-06-2003, 03:23 AM
#89
Cockpit
I purchased the cockpit & clear canopy option for my Super Bandit.
I didn't like the idea of just putting a sticker on a flush instrument panel, so elected to make a few minor changes. I decided to make the instrument panel area look a bit more realistic, without going the whole hog of doing an extensive detailed cockpit.
First change was to put a "lip" around the main instrument panel, as well as the upper area, as shown in the attached photo.
This was done by using a 1" strip of thin carbon fibre matt to make the lip, attached with Pic Plasti-Stick. The I used a small amount of putty to fair the lip in.
I didn't like the idea of just putting a sticker on a flush instrument panel, so elected to make a few minor changes. I decided to make the instrument panel area look a bit more realistic, without going the whole hog of doing an extensive detailed cockpit.
First change was to put a "lip" around the main instrument panel, as well as the upper area, as shown in the attached photo.
This was done by using a 1" strip of thin carbon fibre matt to make the lip, attached with Pic Plasti-Stick. The I used a small amount of putty to fair the lip in.
04-06-2003, 03:39 AM
#90
Instruments
Next, I decided that the instrument decal that came with the kit was a bit "old fashioned" for a modern aircraft like this, so I replaced that decal with something that looks a bit more "glass cockpit" like.
In thread http://www.rcuniverse.com/showthread...hreadid=609277 you can see the original, as well as my first attempt at reworking the panel, plus info on the tool that I used for the design.
Below is the main panel that I ended up with. Another small panel will be added in the upper area later..
In thread http://www.rcuniverse.com/showthread...hreadid=609277 you can see the original, as well as my first attempt at reworking the panel, plus info on the tool that I used for the design.
Below is the main panel that I ended up with. Another small panel will be added in the upper area later..
04-06-2003, 03:42 AM
#91
Seat
The seat is an ABS part with a 1/8" balsa stiffener for the seatback. A couple of plastic extrusions form the ejection seat rails, and then a large O-ring is painted to have black & yellow stripes, and will be glued to the top of the seat assembly.
04-06-2003, 03:43 AM
#92
BVM Super (Balsa) Bandit
There is also a largish area behing the seat that remains kinda empty, so I decided to make up some odd parts to fill that area. Here's an example - a simple fire-extinguisher made out of some pieces of balsa, ply, & wire
04-07-2003, 12:11 AM
#96
BVM Super (Balsa) Bandit
This one shows the size of the speedbrake on the fuselage underside.
It also shows that I did a poor job of getting color paint all the way inside the intakes ... but that's a lot of work, and I'm lazy. If you want any tips on how the intakes should be painted, ask John Redman - he's the expert.
It also shows that I did a poor job of getting color paint all the way inside the intakes ... but that's a lot of work, and I'm lazy. If you want any tips on how the intakes should be painted, ask John Redman - he's the expert.
04-07-2003, 12:18 AM
#98
BVM Super (Balsa) Bandit
The kit includes two plywood trays for the various components (switch, ECU, smooth stop, retract valve etc) to be mounted to.
I prefer the flexibility of doing my own layout, to accomodate the variances between my installation and the "stock" BVM one - e.g. including two switches & RX battery packs instead of one, hard-mounting the air fill valves, including a DVM and a couple of digital air pressure meters (from CJM), etc.
Here's a shot of the upper tray that I fabricated.
I prefer the flexibility of doing my own layout, to accomodate the variances between my installation and the "stock" BVM one - e.g. including two switches & RX battery packs instead of one, hard-mounting the air fill valves, including a DVM and a couple of digital air pressure meters (from CJM), etc.
Here's a shot of the upper tray that I fabricated.
05-16-2003, 12:14 AM
#99
BVM Super (Balsa) Bandit
Sorry for the delay in finishing this review - I opted to wait for a Jetcat P160 for this aircraft, and the engine's demand far outstips its supply right now, hence the delay - it was well worth the wait though - this engine is a beauty - throttle response is fantastic.
BTW, before anyone starts getting in a panic about the fact that I'm putting such a powerful engin in the Super Bandit, be aware that it is very heavily detuned.
Here you can see the engine with the fod-guard attached. Given the debris that is frequently on the runway at my new primary club (Tracy Skyliners ), I figured that the fod guard is a must.
I had heard about people using RTV to hold the FOD guard in place, but when I checked with the good folks at Jetcat they advised me that that is unnecessary. The rubber washer prevents the FOD guard from going anywhere when the engine is not running, and when it is running, the suction holds it on perfectly well.
I had also been concerned that the rubber washer was too wide, thereby blanking out a significant area of the air intake - I thought about reducing its size to minimize the area involved, but again Jetcat told me that my worries are unfounded, and I should leave the washer exactly as is.
BTW, before anyone starts getting in a panic about the fact that I'm putting such a powerful engin in the Super Bandit, be aware that it is very heavily detuned.
Here you can see the engine with the fod-guard attached. Given the debris that is frequently on the runway at my new primary club (Tracy Skyliners ), I figured that the fod guard is a must.
I had heard about people using RTV to hold the FOD guard in place, but when I checked with the good folks at Jetcat they advised me that that is unnecessary. The rubber washer prevents the FOD guard from going anywhere when the engine is not running, and when it is running, the suction holds it on perfectly well.
I had also been concerned that the rubber washer was too wide, thereby blanking out a significant area of the air intake - I thought about reducing its size to minimize the area involved, but again Jetcat told me that my worries are unfounded, and I should leave the washer exactly as is.
05-16-2003, 12:16 AM
#100
Engine mounting straps
The engine mounting straps that come with the Super Bandit engine installation kit are too long to be used "stock".
A length of shim material is supplied by BVM, and I cut this into four pieces - one each for top & bottom of each of teh engine straps.
The shim is inserted underneath the engine mount strap as shown below:
A length of shim material is supplied by BVM, and I cut this into four pieces - one each for top & bottom of each of teh engine straps.
The shim is inserted underneath the engine mount strap as shown below: