BVM Super (Balsa) Bandit
10-08-2002, 03:59 PM
#1
BVM Super (Balsa) Bandit
This is a review and build-log of the new BVM Super Balsa Bandit. At this point, I have not yet completed the construction, so the review is an on-going process. So far though, I am very much impressed with the kit.
Please note that the kit that I am building is one of the very first batch (I supposedly have kit # 6), and as such I fully expect it to have a number of minor teething problems. I will report on these in order to try to help anyone else who has a very early kit, but please do not consider any such minor issues as a "real problem" - the folks at BVM are very willing and quick to address any such teething problems, and from past experience I can guarantee that these minor issues will already be resolved by the time the next batch of kits ships.
I hope to serve 2 purposes with this review:
(1) For people who have never had or built a BVM kit, give them an idea of what's in the kit, how well it builds, etc;
(2) For those who are about to embark on building this kit, offer some advice about areas that need particular attention - especially for the first batch of kits. In this case, you may want to skip most of the details and go just to the following areas:
Note - items shown in blue have been addressed by an updated manual page and replacement parts being sent out by BVM in Oct 2002. IMPORTANT - you do not need these parts for the composite bandit - only the balsa one..
Please note that the kit that I am building is one of the very first batch (I supposedly have kit # 6), and as such I fully expect it to have a number of minor teething problems. I will report on these in order to try to help anyone else who has a very early kit, but please do not consider any such minor issues as a "real problem" - the folks at BVM are very willing and quick to address any such teething problems, and from past experience I can guarantee that these minor issues will already be resolved by the time the next batch of kits ships.
I hope to serve 2 purposes with this review:
(1) For people who have never had or built a BVM kit, give them an idea of what's in the kit, how well it builds, etc;
(2) For those who are about to embark on building this kit, offer some advice about areas that need particular attention - especially for the first batch of kits. In this case, you may want to skip most of the details and go just to the following areas:
- Gear door cylinder mount size: http://www.rcuniverse.com/showthread...916#post365648
- Wing assembly sequence: http://www.rcuniverse.com/showthread...917#post365679
- Stab root-rib rear doubler: http://www.rcuniverse.com/showthread...914#post365600
- Doors for main gear: http://www.rcuniverse.com/showthread...922#post371505
- Swept-fin servo mount & access: http://www.rcuniverse.com/showthread...961#post455637
- Gear door horn: http://www.rcuniverse.com/showthread...973#post494388
- Tailpipe mounthttp://www.rcuniverse.com/showthread...986#post578872
Note - items shown in blue have been addressed by an updated manual page and replacement parts being sent out by BVM in Oct 2002. IMPORTANT - you do not need these parts for the composite bandit - only the balsa one..
10-08-2002, 04:08 PM
#2
Hits & Misses
Revisit this page periodically - I will be updating it throughout the build.
Hits
Misses
Hits
- Extremely high quality of parts.
- Very good parts fit - especially the fibreglass parts. With some other manufacturer's kits I've had canopies whose fit to the fuselage resembles the San Fransisco bridge - touching at the ends and having a gap in the middle that I could sail a boat through. Not so with the BVM kits - their fit is so good that you'd be hard put to fit a sheet of paper between the parts.
- Detailed manual, with very clear photographs.
- Ease of assembly. You can tell that BVM didn't just settle for making a kit that flies well once you get it built - they've clearly invested a lot of time in coming up with a design that makes it easy to assemble.
- Incredibly helpful and responsive technical staff at BVM, to help with any queries you may have.
- Lots of nice little touches that show attention to detail - even to the extent of including 3-view drawings of the model that you use for planning your paint scheme.
Misses
- No parts list.
- Some of the really neat ideas that made the Bobcat so easy to build, have not made it into the Super Bandit (e.g. wing-rib alignment tic-marks, aileron/flap horn alignment jigs, wing-tip alignment ribs)
10-08-2002, 04:17 PM
#3
Packing
I think the UPS guy had a bad day. The box looked as if it had been jumped on a few times, then reversed over with the delivery truck, and finally used as an attack dummy in a martial arts class. I cringed as I opened the box, and was amazed to find no damage on my initial inspection.
The condition that the kit arrived in, despite the condition of the box, is largely due to the great care that BVM has taken to protect the contents. Here's an example of what I mean - this photo shows the foam inserts which effectively suspend the major parts in the middle of the box. Other parts, and a lot of protective paper, are then used to surround and further protect the contents.
The condition that the kit arrived in, despite the condition of the box, is largely due to the great care that BVM has taken to protect the contents. Here's an example of what I mean - this photo shows the foam inserts which effectively suspend the major parts in the middle of the box. Other parts, and a lot of protective paper, are then used to surround and further protect the contents.
10-08-2002, 04:47 PM
#4
Getting started
I started by reading the manual through a couple of times.
The manual is very detailed, and contains 64 pages. Each page averages about 6 photographs, which are extremely clear - these are quality prints, not the photocopies of photocopies of photocopies that you get in some kits.
Although some are missing them, most of the paragraphs have a small check-box next to them so that you may tick each step off as you complete it. This definitely helps reduce the risk that you do something like closing out a wing without first completing all of the internals.
My personal approach here is to put a diagonal line through the check-box in one direction when I do the step for e.g. the first wing, then put a diagonal line in the opposite direction for the second wing, and when I can confirm that every check-box on the page has been completed in both directions I cut the corner off of the page. That way I can very easily pick up the manual, put my thumb on the corner, and flip the manual open to the first page of a given section that still needs work.
Do be careful to ensure that you have fully completed each paragraph before checking it off though.... in most cases the check-box applies to a single step, and you get kind of used to that... then all of a sudden you will find a single paragraph and check-box that contains a whole load of separate steps. (e.g. Stab instructions on the right-hand side of page 27). I would have prefered to see these separated to help ensure that you don't miss anything. A trivial issue - but do take the time to ensure that you don't get caught out by it.
The rolled plans that come with the kit are also very good quality - clear printing and decent quality of paper that can be repeatedly rolled & unrolled without tearing. There are "detail" sheets that show a lot of detail of the construction (to augment the manual), and there is also a sheet that is used for you to build on top of. The latter contains portions for each wing, stab and the rudder, so that as you are ready to build a given part you simply cut out the appropriate section from the plan, attach it to your building board, and off you go.
Speaking of building boards - you actually "use up" your building board with this kit, as you glue the parts to the building board. (Just like the BVM Bobcat,BTW). I was unable to find a source of the Armstrong ceiling tiles that BV typically recommends - and instead I use a couple of 2' x 4' sections of drywall. If you choose to do the same, be careful not to use the outer 3" or so of the drywall slab - a 3" or so strip down the edge of the drywall is lower than the centre-section (for taping), and if you try to build on that you will not like the results !
The manual is very detailed, and contains 64 pages. Each page averages about 6 photographs, which are extremely clear - these are quality prints, not the photocopies of photocopies of photocopies that you get in some kits.
Although some are missing them, most of the paragraphs have a small check-box next to them so that you may tick each step off as you complete it. This definitely helps reduce the risk that you do something like closing out a wing without first completing all of the internals.
My personal approach here is to put a diagonal line through the check-box in one direction when I do the step for e.g. the first wing, then put a diagonal line in the opposite direction for the second wing, and when I can confirm that every check-box on the page has been completed in both directions I cut the corner off of the page. That way I can very easily pick up the manual, put my thumb on the corner, and flip the manual open to the first page of a given section that still needs work.
Do be careful to ensure that you have fully completed each paragraph before checking it off though.... in most cases the check-box applies to a single step, and you get kind of used to that... then all of a sudden you will find a single paragraph and check-box that contains a whole load of separate steps. (e.g. Stab instructions on the right-hand side of page 27). I would have prefered to see these separated to help ensure that you don't miss anything. A trivial issue - but do take the time to ensure that you don't get caught out by it.
The rolled plans that come with the kit are also very good quality - clear printing and decent quality of paper that can be repeatedly rolled & unrolled without tearing. There are "detail" sheets that show a lot of detail of the construction (to augment the manual), and there is also a sheet that is used for you to build on top of. The latter contains portions for each wing, stab and the rudder, so that as you are ready to build a given part you simply cut out the appropriate section from the plan, attach it to your building board, and off you go.
Speaking of building boards - you actually "use up" your building board with this kit, as you glue the parts to the building board. (Just like the BVM Bobcat,BTW). I was unable to find a source of the Armstrong ceiling tiles that BV typically recommends - and instead I use a couple of 2' x 4' sections of drywall. If you choose to do the same, be careful not to use the outer 3" or so of the drywall slab - a 3" or so strip down the edge of the drywall is lower than the centre-section (for taping), and if you try to build on that you will not like the results !
10-08-2002, 04:53 PM
#5
Stab construction
Wing construction is typically done first.
Due to a camera malfuntion, I am missing a series of photographs from the early stages of the wing construction. These are virtually identical to the stab construction though, so I will start by showing the stab construction here, then go back to wing construction a bit later.
The "construction" plan sheet is cut up into its constituent parts, and the wing or stab part is taped to the building board. I chose to lay wax-paper over the top of the plan, but that is really not needed. Note that there are a number of diamond shapes shown on the plan. Cut these diamonds out with a sharp X-acto blade, but control the depth of the cut - you don't want the building board surface cut too deeply otherwise the ribs can move later.
Due to a camera malfuntion, I am missing a series of photographs from the early stages of the wing construction. These are virtually identical to the stab construction though, so I will start by showing the stab construction here, then go back to wing construction a bit later.
The "construction" plan sheet is cut up into its constituent parts, and the wing or stab part is taped to the building board. I chose to lay wax-paper over the top of the plan, but that is really not needed. Note that there are a number of diamond shapes shown on the plan. Cut these diamonds out with a sharp X-acto blade, but control the depth of the cut - you don't want the building board surface cut too deeply otherwise the ribs can move later.
10-08-2002, 05:15 PM
#6
Prepare parts
Next - prepare the ribs and other parts for assembly. The parts are separated into multiple bags, and most (though not all) of the parts for each separate assembly can be found in one or more bags that are labelled for that part - e.g. a bag of stab parts.
All ribs include "location" tabs which stay attached to the ribs for the first part of the assembly process. The ribs are all laser-cut, and simply need to be freed from their sheet by cutting the small portions that hold them into the sheet. Note that since the areas by which the ribs are held into their sheet includes the bottom of the location tabs, you should very carefully sand the bottom of these tabs to ensure that you don't have small amounts of extra material attached (which would change the relative height or incidence of the rib during assembly). Don't overdo it tho - otherwise you will affect the rib's alignment. It might be a slightly better idea if BVM used other less critical areas of the rib to hold the part into its sheet, but as long as you take just a little care here, it's really not an issue.
The laser cutting also leaves a soot residue on the parts - especially the ply parts. Clean this off of the sides of the ribs, but do not clean it off the perimeter of the ribs at this time - the soot marks will later be used to help gauge how much sanding to do on the completed framework prior to sheeting.
All ribs include "location" tabs which stay attached to the ribs for the first part of the assembly process. The ribs are all laser-cut, and simply need to be freed from their sheet by cutting the small portions that hold them into the sheet. Note that since the areas by which the ribs are held into their sheet includes the bottom of the location tabs, you should very carefully sand the bottom of these tabs to ensure that you don't have small amounts of extra material attached (which would change the relative height or incidence of the rib during assembly). Don't overdo it tho - otherwise you will affect the rib's alignment. It might be a slightly better idea if BVM used other less critical areas of the rib to hold the part into its sheet, but as long as you take just a little care here, it's really not an issue.
The laser cutting also leaves a soot residue on the parts - especially the ply parts. Clean this off of the sides of the ribs, but do not clean it off the perimeter of the ribs at this time - the soot marks will later be used to help gauge how much sanding to do on the completed framework prior to sheeting.
10-08-2002, 05:25 PM
#7
Glue ribs to building board
Okay - now we get to see why we cut diamonds out of the plan earlier.
Place the rib on the plan, ensure that it is aligned properly, and is vertical (1-2-3 blocks are great for this), then apply glue to the rib location tab in order to glue it to the board.
I have received so many enquiries about where to buy the 1-2-3 blocks, that I figured I may as well add that info here. I got mine from http://www.penntoolco.com/catalog/products/2245.cfm
With the BVM Bobcat, the wing construction plans included small marks that indicated exactly where to position the rib (in the fore & aft sense) in order to ensure that all ribs would be properly lined up. Unfortunately, for some reason the Super Bandit is missing this really handy refinement, so a little more care and time is needed in getting the alignement correct. In fact, in this case I got it wrong at first, and had to remove the rib from the board and try again.
The photo shows the attachment of the rib to the building board.
Place the rib on the plan, ensure that it is aligned properly, and is vertical (1-2-3 blocks are great for this), then apply glue to the rib location tab in order to glue it to the board.
I have received so many enquiries about where to buy the 1-2-3 blocks, that I figured I may as well add that info here. I got mine from http://www.penntoolco.com/catalog/products/2245.cfm
With the BVM Bobcat, the wing construction plans included small marks that indicated exactly where to position the rib (in the fore & aft sense) in order to ensure that all ribs would be properly lined up. Unfortunately, for some reason the Super Bandit is missing this really handy refinement, so a little more care and time is needed in getting the alignement correct. In fact, in this case I got it wrong at first, and had to remove the rib from the board and try again.
The photo shows the attachment of the rib to the building board.
10-08-2002, 05:30 PM
#8
Stab parts alignment
As mentioned in the last post, I found that the initial placement of the root rib was not perfect, so I removed it form the board and used the following approach to get better alignment.
I placed (not glued !) the carbon fibre rod through the hole in the root rib, then used a couple of 1-2-3 blocks to effectively project the location of the rod upwards from the plan. This ensured that the root rib was correctly positioned w.r.t. the rod placement. A couple more 1-2-3 blocks ensured that the root rib was located in the correct side-to-side position as well as being vertical. I then reglued the rib to the building board.
I placed (not glued !) the carbon fibre rod through the hole in the root rib, then used a couple of 1-2-3 blocks to effectively project the location of the rod upwards from the plan. This ensured that the root rib was correctly positioned w.r.t. the rod placement. A couple more 1-2-3 blocks ensured that the root rib was located in the correct side-to-side position as well as being vertical. I then reglued the rib to the building board.
10-08-2002, 05:36 PM
#10
Stab ribs
...then used the 1-2-3 blocks again - but this time in conjunction with the stab spar - to ensure proper location of the remaining ribs.
The assembly thusfar was certainly far from challenging (despite my initail mistake in locating the rib), but it could definitely have been easier and quicker if the plans had included the really useful location marks that BVM used on the Bobcat wing. Hopefully, future Super Bandit plans may include this refinement.
The assembly thusfar was certainly far from challenging (despite my initail mistake in locating the rib), but it could definitely have been easier and quicker if the plans had included the really useful location marks that BVM used on the Bobcat wing. Hopefully, future Super Bandit plans may include this refinement.
10-08-2002, 05:56 PM
#11
Stab closure
Addition of the LE and TE are trivial.
Next - there is one important step that the manual doesn't seem to tell you to do (either that, or I'm going blind ! ;-)... and if you get too far before noticing this, you can not retrofit it after the fact. The part in question is a plywood doubler for the rear portion of the root rib. It needs to be installed before the carbon fibre rod is installed (page 27 of the manual).
If you look closely in the attached photo, you will see that this part is missing from my stab, because I slavishly followed the written sequence in the manual without double-checking it against the plans or photographs
If you should find yourself in the same situation, use some scrap balsa block to make fillets between the root rib and the shear webbing - this will help spread any loads over a wider area. I discussed this "fix" with BV himself, and he seems happy with it.
Next, the assembly is sanded lightly and sheeted on one side.
The black soot marks on the plywood ribs (and to a lesser extent the darkened laser-cut marks on the balsa ribs) act as an excellent way of determining whether you have sanded the assembly sufficiently. Gently sand with a bar-sander, and the color change of the parts will show you which parts have been sanded so far, and which are still low points. Sand just enough to remove the soot from all parts.
Next, I sprayed the sheeting with a fine mist of water and laid it on the assembly to let it form itself, then attached it with thick CA.
The stab assembly can then be removed from the building board.
Note that for the wing construction, you do not re-use the location tabs, so you can saw or break these off in any way you wish - but for the stab, you must cut these parts away carefully because these tabs will be used as a cradle to hold the stab when the second side is sheeted.
In case you can't make out the size of the parts from the photo, the stab ribs are very small (almost like building Guillows again!), and with small parts like this it can normally be very easy to get the parts misaligned. Fortunately for us, BVM always finds ways of making the build process easier for customers, and this use of a "cradle" is a really neat way of ensuring correct alignment.
Once the stab has been freed from its cradle, the carbon fiber rod, shear webbing, hinge blocks, etc are all glued in and then you simply sand and sheet the second side.
The photo shows the assembly which is just awaiting the hinge blocks before being sheeted.
Next - there is one important step that the manual doesn't seem to tell you to do (either that, or I'm going blind ! ;-)... and if you get too far before noticing this, you can not retrofit it after the fact. The part in question is a plywood doubler for the rear portion of the root rib. It needs to be installed before the carbon fibre rod is installed (page 27 of the manual).
If you look closely in the attached photo, you will see that this part is missing from my stab, because I slavishly followed the written sequence in the manual without double-checking it against the plans or photographs
If you should find yourself in the same situation, use some scrap balsa block to make fillets between the root rib and the shear webbing - this will help spread any loads over a wider area. I discussed this "fix" with BV himself, and he seems happy with it.Next, the assembly is sanded lightly and sheeted on one side.
The black soot marks on the plywood ribs (and to a lesser extent the darkened laser-cut marks on the balsa ribs) act as an excellent way of determining whether you have sanded the assembly sufficiently. Gently sand with a bar-sander, and the color change of the parts will show you which parts have been sanded so far, and which are still low points. Sand just enough to remove the soot from all parts.
Next, I sprayed the sheeting with a fine mist of water and laid it on the assembly to let it form itself, then attached it with thick CA.
The stab assembly can then be removed from the building board.
Note that for the wing construction, you do not re-use the location tabs, so you can saw or break these off in any way you wish - but for the stab, you must cut these parts away carefully because these tabs will be used as a cradle to hold the stab when the second side is sheeted.
In case you can't make out the size of the parts from the photo, the stab ribs are very small (almost like building Guillows again!), and with small parts like this it can normally be very easy to get the parts misaligned. Fortunately for us, BVM always finds ways of making the build process easier for customers, and this use of a "cradle" is a really neat way of ensuring correct alignment.
Once the stab has been freed from its cradle, the carbon fiber rod, shear webbing, hinge blocks, etc are all glued in and then you simply sand and sheet the second side.
The photo shows the assembly which is just awaiting the hinge blocks before being sheeted.
10-08-2002, 06:15 PM
#12
Wing construction
The early stages of the wing construction are very much like the stab construction - except that the main spar is used as an alignment aid. It is pinned to the board (with a 1/16" spacer between it and the board), and the ribs are lined up on it.
The photo shows the LE and TE attached to the ribs, with judicious use of straight edges to ensure that the assembly is straight. Note that it is not uncommon for the large plywood ribs to have a very slight curve to them, so it is important that every time you glue any part to the root rib (upper or lower fore or aft spar, etc), you double-check to ensure that the rib is straight and at the proper 91.5 degree angle (a 91.5 degree gauge is provided). Doing this will ensure the best possible fit of the wing to the fuselage without the need for lots of filler.
The photo shows the LE and TE attached to the ribs, with judicious use of straight edges to ensure that the assembly is straight. Note that it is not uncommon for the large plywood ribs to have a very slight curve to them, so it is important that every time you glue any part to the root rib (upper or lower fore or aft spar, etc), you double-check to ensure that the rib is straight and at the proper 91.5 degree angle (a 91.5 degree gauge is provided). Doing this will ensure the best possible fit of the wing to the fuselage without the need for lots of filler.
10-08-2002, 06:22 PM
#13
Cylinder mount - IMPORTANT
There seems to be a minor issue with the mount that is used for the gear-door cylinder. This is typical of the kind of teething problems that kits have in their very first release (remember - this is something like the 6th kit produced), and my past experience with the Bobcat (where I also built a very early model, as well as 2 later kits) shows that BVM is extremely good at fixing these issues in very short order.
Here's the problem. I went to install the cylinder mount as excplained on page 13 of the manual... and found out that the part is about 3/16" shorter than the space it fits into. A quick sanity check to see whether I had screwed up found that the part is indeed undersized, as can be seen by comparing it to the detail plan (as seen in the photo below).
Furthermore, not only is the part too short - it also has the doubler positioned where it would interfere with W3.
Here's the problem. I went to install the cylinder mount as excplained on page 13 of the manual... and found out that the part is about 3/16" shorter than the space it fits into. A quick sanity check to see whether I had screwed up found that the part is indeed undersized, as can be seen by comparing it to the detail plan (as seen in the photo below).
Furthermore, not only is the part too short - it also has the doubler positioned where it would interfere with W3.
10-08-2002, 06:38 PM
#14
Gear door cyliner mount - continued
I spoke to Dana (at BVM) about the part, and he has agreed to look into it.
I decided to just make up my own part to replace the mount, making it 3/16" longer. That's when I hit another minor snag. The larger part can not be installed at this late stage, because the tab that locates it into W1 makes the part too long to be maneuvered into place.
I simply cut the part and provided a doubler for strength. This replacement part is shown in the attached photo, along with the original for comparison purposes.
The correct approach is that the cylinder mount not only needs to be slightly larger than in the kit - it also needs to be installed much earlier - I would recommend doing it in the step on page 10, just before you position W1.
Once again this is a really minor issue - but if you know about it in advance you may be saved a little hassle.
I decided to just make up my own part to replace the mount, making it 3/16" longer. That's when I hit another minor snag. The larger part can not be installed at this late stage, because the tab that locates it into W1 makes the part too long to be maneuvered into place.
I simply cut the part and provided a doubler for strength. This replacement part is shown in the attached photo, along with the original for comparison purposes.
The correct approach is that the cylinder mount not only needs to be slightly larger than in the kit - it also needs to be installed much earlier - I would recommend doing it in the step on page 10, just before you position W1.
Once again this is a really minor issue - but if you know about it in advance you may be saved a little hassle.
10-08-2002, 06:51 PM
#15
Wing assembly
In the next photo, the lower wings spars have been installed (note - the wing is built upside down, so the lower spars are at the top during initial construction).
The gear plates have also been installed. One really neat point about the BVM kits is that even if you do not already have the gear available, you will not be held up at this stage - the kits include a plywood template that has the correct gear bolt-holes etc in it, allowing you to glue the assemblies in place in full confidence that the gear will simply drop into place perfectly once you do buy them.
The geodetic ribs have also been installed at this point, and the assembly has been sanded ready for receiving the bottom wing skin.
You may notice, if you look carefully at the image, that I have not removed the section of rib W-4 above the retract. If you build exactly per the manual, you will remove sections of ribs W-4, W-5 and W-6 on the bottom only, for the retract to fit into the wing. Removal of the W-6 portion is not absolutely necessary however, so I left it in.
By the way - when you get to the plywood parts that act as the base of the servo mounts, be aware that the flap ones are handed - check the wing detail plan to ensure that you use the correct one in each wing, otherwise the mount may interfere with the flap actuator pushrod.
The gear plates have also been installed. One really neat point about the BVM kits is that even if you do not already have the gear available, you will not be held up at this stage - the kits include a plywood template that has the correct gear bolt-holes etc in it, allowing you to glue the assemblies in place in full confidence that the gear will simply drop into place perfectly once you do buy them.
The geodetic ribs have also been installed at this point, and the assembly has been sanded ready for receiving the bottom wing skin.
You may notice, if you look carefully at the image, that I have not removed the section of rib W-4 above the retract. If you build exactly per the manual, you will remove sections of ribs W-4, W-5 and W-6 on the bottom only, for the retract to fit into the wing. Removal of the W-6 portion is not absolutely necessary however, so I left it in.
By the way - when you get to the plywood parts that act as the base of the servo mounts, be aware that the flap ones are handed - check the wing detail plan to ensure that you use the correct one in each wing, otherwise the mount may interfere with the flap actuator pushrod.
10-08-2002, 06:56 PM
#16
BVM Super (Balsa) Bandit
I use a long aluminum straight-edge during sheeting - using it to press the sheeting down onto the ribs, spars etc. This ensures that I don't introduce low-points into the skin.
This photo shows the first skin on, as well as showing the flap and aileron assemblies partially built.
I deviate slightly from the BVM manual in constructing the aileron and flaps. My preferred method is that instead of lining all ribs up with a line that you draw on the flap / aileron skin, I do this only for two ribs - the second one in from each end. Then I put the LE on to the flap / aileron, and use a straight-edge to ensure that it is perfectly straight - then I glue it to the skin. Once that is done, I can simply slide the other ribs snugly up against the LE without having to check them against some line.
WARNING - the flap has no rib # 2. For some reason the ribs are numbered 1, 3, 4, ... so don't get caught out by gluing the wrong rib in the wrong place !
This photo shows the first skin on, as well as showing the flap and aileron assemblies partially built.
I deviate slightly from the BVM manual in constructing the aileron and flaps. My preferred method is that instead of lining all ribs up with a line that you draw on the flap / aileron skin, I do this only for two ribs - the second one in from each end. Then I put the LE on to the flap / aileron, and use a straight-edge to ensure that it is perfectly straight - then I glue it to the skin. Once that is done, I can simply slide the other ribs snugly up against the LE without having to check them against some line.
WARNING - the flap has no rib # 2. For some reason the ribs are numbered 1, 3, 4, ... so don't get caught out by gluing the wrong rib in the wrong place !
10-08-2002, 07:09 PM
#17
Hinge blocks etc
Now you just need to add the upper spars (BTW, I forgot to mention that the spars are all made from balsa that you attach a carbon fibre strip to), add the mounts of the aileron and flap servo, and the hinge mounts.
The flap hinge mounts are to be cut from 1/2" x 3/4" balsa. It was unclear though, whether the aileron hinge mounts were also cut from this material, or from smaller stock. The plan shows the blocks, but without identifying the material, and the manual similarly fails to identify them. The wing parts do include 1/2" x 1/2" stock in addition to the 1/2 x 3/4 - however I was unsure at this point whether the 1/2 x 1/2 was needed anywhere else, as well as whether the remaining 1/2 x 3/4 was needed elsewhere. Head-scratching time !
This has long been my biggest gripe about the BVM kits - there is no parts list provided. If there had been, I could easily have looked it up to find out the answers to the above. Instead, I finally gave up and hedged my bets - I went in search of spare material in my scrap box - leaving both the 1/2 x 1/2 anbd 1/2 x 3/4 available in case they were needed elsewhere.
BTW - if a missing parts list is the biggest thing I can find to complain about, that speaks volumes for the rest of the kit ! However, this same issue has bugged me with every single BVM kit I have built, and it seems such an easy problem to fix...
The flap hinge mounts are to be cut from 1/2" x 3/4" balsa. It was unclear though, whether the aileron hinge mounts were also cut from this material, or from smaller stock. The plan shows the blocks, but without identifying the material, and the manual similarly fails to identify them. The wing parts do include 1/2" x 1/2" stock in addition to the 1/2 x 3/4 - however I was unsure at this point whether the 1/2 x 1/2 was needed anywhere else, as well as whether the remaining 1/2 x 3/4 was needed elsewhere. Head-scratching time !
This has long been my biggest gripe about the BVM kits - there is no parts list provided. If there had been, I could easily have looked it up to find out the answers to the above. Instead, I finally gave up and hedged my bets - I went in search of spare material in my scrap box - leaving both the 1/2 x 1/2 anbd 1/2 x 3/4 available in case they were needed elsewhere.
BTW - if a missing parts list is the biggest thing I can find to complain about, that speaks volumes for the rest of the kit ! However, this same issue has bugged me with every single BVM kit I have built, and it seems such an easy problem to fix...
10-08-2002, 07:21 PM
#18
Closing out the wing
The method used for jigging the wing for the second wing skin originally had me a bit worried, but needlessly so.
Not all of the rib location tabs are removed at this point - two ribs have the tabs left on (they were never glued to the board). A straight edge placed on one rib's tabs should be exactly parallel to a straightedge placed on the other rib's tabs. You then put the rear edge of the wing flat on the building board and place a 3/8" balsa stick under the forward part of the wing. By moving the stick around differently at the wing tip than the root, you can effectively twist the wing slightly and get the straight edges parallel. Then you pin the wing to the 3/8 stick and do the sanding and sheeting.
My concern at this point was that the 3/8" stick's edge would unnecessarily dig a groove into the lower sheeting, especially when the assembly was pressed down on during sanding. After I did this step though, I checked for damage and found absolutely no sign of dents.
Not all of the rib location tabs are removed at this point - two ribs have the tabs left on (they were never glued to the board). A straight edge placed on one rib's tabs should be exactly parallel to a straightedge placed on the other rib's tabs. You then put the rear edge of the wing flat on the building board and place a 3/8" balsa stick under the forward part of the wing. By moving the stick around differently at the wing tip than the root, you can effectively twist the wing slightly and get the straight edges parallel. Then you pin the wing to the 3/8 stick and do the sanding and sheeting.
My concern at this point was that the 3/8" stick's edge would unnecessarily dig a groove into the lower sheeting, especially when the assembly was pressed down on during sanding. After I did this step though, I checked for damage and found absolutely no sign of dents.
10-11-2002, 02:22 PM
#19
Retract doors (wing)
After sheeting the 2nd side of the wing, the next step is to make the necessary cutouts in the bottom skin to allow the retract units to be fitted, and then to adjust these cutouts as necessary for the doors fitting.
At this point, another note is necessary for anyone else who has an early kit. There are two things that you might want to take note of here - one part missing from my kit, and one part supplied slightly differently than is shown in the manual and detailed plans.
First, the missing part. Kinda hard to identify just by words, so I'm attaching a photo of the plan. The photo shows the strut cover (on the right) and the retract cover (on the left). It is the retract cover that was missing from my kit. I spoke to Dana at BVM about it this morning, and not only are they immediately sending me the parts - they are also going to check whether mine was a fluke omission, or its an omission in their "bill of materials". Either way, they will take care of you. If you have an early kit and the part is missing - either they will contact you, or you should just call them and they will fix you up right away.
At this point, another note is necessary for anyone else who has an early kit. There are two things that you might want to take note of here - one part missing from my kit, and one part supplied slightly differently than is shown in the manual and detailed plans.
First, the missing part. Kinda hard to identify just by words, so I'm attaching a photo of the plan. The photo shows the strut cover (on the right) and the retract cover (on the left). It is the retract cover that was missing from my kit. I spoke to Dana at BVM about it this morning, and not only are they immediately sending me the parts - they are also going to check whether mine was a fluke omission, or its an omission in their "bill of materials". Either way, they will take care of you. If you have an early kit and the part is missing - either they will contact you, or you should just call them and they will fix you up right away.
10-11-2002, 02:45 PM
#20
Strut cover improvement
The next thing to take note of, is that there has been a very recent improvement incorporated into the retract strut cover, but that the manual and plan still need to be updated a bit to match the parts.
The plan shows that the strut cover is a single piece of 1/16" ply, with a small 1/32" shim applied at the top. If you look at the parts you received, you will see that there are four parts supplied that match the outline of the strut cover - not just the expected two. Two of the parts are 1/32" plywood and are "solid"; the other two are 1/16" plywood, and have a number of lightening holes cut into them, as is shown in the enclosed photo.
The inner 1/16" part acts as a stiffener for the outer 1/32" part, and should be glued to it. When you do this, make sure you make one left-hand and one right-hand part. (What ? You never make that kind of mistake ? Me neither !!)
Personally, when I'm gluing one piece of ply to another like this, I like to give the glue something to bite into, so I use an Xacto knife to score diagonally hashed lines across the gluing surface. BTW, you may notice in some of the photos that one of my Xacto knives has masking tape on it, while another has not. I use the tape to identify the knife that has been blunted by use on plywood. A truly trivial tip that you might find of use. Or not.
The plan shows that the strut cover is a single piece of 1/16" ply, with a small 1/32" shim applied at the top. If you look at the parts you received, you will see that there are four parts supplied that match the outline of the strut cover - not just the expected two. Two of the parts are 1/32" plywood and are "solid"; the other two are 1/16" plywood, and have a number of lightening holes cut into them, as is shown in the enclosed photo.
The inner 1/16" part acts as a stiffener for the outer 1/32" part, and should be glued to it. When you do this, make sure you make one left-hand and one right-hand part. (What ? You never make that kind of mistake ? Me neither !!)
Personally, when I'm gluing one piece of ply to another like this, I like to give the glue something to bite into, so I use an Xacto knife to score diagonally hashed lines across the gluing surface. BTW, you may notice in some of the photos that one of my Xacto knives has masking tape on it, while another has not. I use the tape to identify the knife that has been blunted by use on plywood. A truly trivial tip that you might find of use. Or not.
10-11-2002, 03:55 PM
#21
Fuselage
Well - the wing isn't finished yet, but I will come back to it later. Let's have a look at the fusealage.
Like all fiberglass assemblies, this one should be thoroughly sanded on the inside. This gets rid of the odd strands of glass that may be sticking up here & there, and more importantly it prepares the surface properly so that when you glue formers in, the glue will actually stick properly.
One of my clubmates has an unusual way of doing this - he takes the fuselage into the shower with him, and sands it there. That way, all the loose fibres and dust get washed away rather than sticking the fus or to him. I thought this was a great idea, but my wife vetoed it... so I just sanded in the garage.
Next, we cut out the forward nose gear door and hinge it. (The bandit has two doors for the nose-gear - the forward one hinges fore & aft, while the rearward one hinges to the side.)
Instead of just surface-gluing the plastic hinge to the fibreglass, this kit has a neat approach whereby the hinges are "captured" between the fuselage surface and a plywood cover. First, you glue one piece of 1/32" ply to the fuselage - this piece has a hinge-sized cut-out in it which effectively locates the hinge for you. Then you glue the hinge half in, followed by another piece of 1/32 ply so that the hinge is sandwiched in place. Pretty neat.
I did find, however, that the two screw-holes in these plywood parts were just a little bit too close together, and needed to be opened up. These holes will be used for the screws that retain the front of the nose-gear flex plate, and it almost seemed as if the space between the holes was the straight-line distance between the screws rather than being slightly larger to take account of the curved surface that they attach to. Two seconds with the Minicraft sorted that out tho.
The photo below shows the hinge retention for the forward nose-gear door. The small extra 1/32" plywood shim that you can see on the left hand side is used to align the gear in such a way that the nose gear strut is perfectly vertical when extended and viewed from the front.
Like all fiberglass assemblies, this one should be thoroughly sanded on the inside. This gets rid of the odd strands of glass that may be sticking up here & there, and more importantly it prepares the surface properly so that when you glue formers in, the glue will actually stick properly.
One of my clubmates has an unusual way of doing this - he takes the fuselage into the shower with him, and sands it there. That way, all the loose fibres and dust get washed away rather than sticking the fus or to him. I thought this was a great idea, but my wife vetoed it... so I just sanded in the garage.
Next, we cut out the forward nose gear door and hinge it. (The bandit has two doors for the nose-gear - the forward one hinges fore & aft, while the rearward one hinges to the side.)
Instead of just surface-gluing the plastic hinge to the fibreglass, this kit has a neat approach whereby the hinges are "captured" between the fuselage surface and a plywood cover. First, you glue one piece of 1/32" ply to the fuselage - this piece has a hinge-sized cut-out in it which effectively locates the hinge for you. Then you glue the hinge half in, followed by another piece of 1/32 ply so that the hinge is sandwiched in place. Pretty neat.
I did find, however, that the two screw-holes in these plywood parts were just a little bit too close together, and needed to be opened up. These holes will be used for the screws that retain the front of the nose-gear flex plate, and it almost seemed as if the space between the holes was the straight-line distance between the screws rather than being slightly larger to take account of the curved surface that they attach to. Two seconds with the Minicraft sorted that out tho.
The photo below shows the hinge retention for the forward nose-gear door. The small extra 1/32" plywood shim that you can see on the left hand side is used to align the gear in such a way that the nose gear strut is perfectly vertical when extended and viewed from the front.
10-11-2002, 04:20 PM
#22
Nose Gear
The landing gear has received a major upgrade, compared to the original Bandit.
This is the new nose gear unit, which can not only be used in the Super Bandit, but also fits into the Bobcat - a much better solution than the unit in which the cylinder was separate and you had to solder brass tubes and clevises on etc. (I'll be tearing the old unit out of my Bobcat soon, to replace with one of these beauties).
This is the new nose gear unit, which can not only be used in the Super Bandit, but also fits into the Bobcat - a much better solution than the unit in which the cylinder was separate and you had to solder brass tubes and clevises on etc. (I'll be tearing the old unit out of my Bobcat soon, to replace with one of these beauties).
10-11-2002, 04:35 PM
#23
Nose Gear installation
Here we see the nose gear mounted into the fuselage.
All three gear in this model mount to carbon fibre flex plates. (I know that aluminum versions of most flex plates are available from BVM, but have not specifically checked on the Super Bandit gear yet).
The plates are tapped to allow the nose gear unit to screw to it, and it has two holes at the front - a couple of machine screws are inserted into dimples on the bottom skin of the fuselage, through the thin ply hinge mounts we just discussed, and into the flex plates. The plates are then also retained at the rear of F1, and inbetween these two mounting screws they are able to flex up & down a little so as to absord some energy from landings.
This is where I made a mistake. The small maple blocks that attach to the rear of F1 are supposed to be on top of the flex plates, so that not only do you attach the flex plates to them, but they also serve as a base for the lower equipment tray.
I somehow managed to indulge in a moment of brain death, and glued them below the flex plates instead of above. I fixed this oversight by adding a separate strip of 1/2 x 1/4 hardwood above the flex plates to support the tray, and cutting holes in this hardwood strip to get access to the screws which in my case attach the flex plate from above instead of below. I'm explaining this only so that anyone else building the Super Bandit can understand why the photos of the fuselage interior may look a bit odd.
All three gear in this model mount to carbon fibre flex plates. (I know that aluminum versions of most flex plates are available from BVM, but have not specifically checked on the Super Bandit gear yet).
The plates are tapped to allow the nose gear unit to screw to it, and it has two holes at the front - a couple of machine screws are inserted into dimples on the bottom skin of the fuselage, through the thin ply hinge mounts we just discussed, and into the flex plates. The plates are then also retained at the rear of F1, and inbetween these two mounting screws they are able to flex up & down a little so as to absord some energy from landings.
This is where I made a mistake. The small maple blocks that attach to the rear of F1 are supposed to be on top of the flex plates, so that not only do you attach the flex plates to them, but they also serve as a base for the lower equipment tray.
I somehow managed to indulge in a moment of brain death, and glued them below the flex plates instead of above. I fixed this oversight by adding a separate strip of 1/2 x 1/4 hardwood above the flex plates to support the tray, and cutting holes in this hardwood strip to get access to the screws which in my case attach the flex plate from above instead of below. I'm explaining this only so that anyone else building the Super Bandit can understand why the photos of the fuselage interior may look a bit odd.
10-11-2002, 04:45 PM
#24
Nose gear doors, continued
On the forward nose gear door, attach the small plywood parts that form the door standoff. Do this exactly as directed in the manual - do not pay too much attention to the detail plan, which shows the stand-off in a position that is further up the door. If you position the standoff per the plan instead of per the manual, the door will not close. How do I know this ? Ummmm... somebody told me .. I swear !!
Next, the nose gear rear door may be cut out and hinged. The enclosed photo shows both doors hinged and open, and you can see the plywood hinge mount. I made a slight change here - the manual indicates that you should insert the hinge pin from the rear. I found this to be slightly akward, as the hinge kept hitting the fibreglass when I tried to remove it. (Perhaps my alignment was just slightly off ?). However, I found that if I simply reversed the direction of the hinge pin (and consequently relocate the retaining screw & washer to the front of the hinge instead of the rear), then the hinge pin can be removed and replaced with the utmost of ease.
Next, the nose gear rear door may be cut out and hinged. The enclosed photo shows both doors hinged and open, and you can see the plywood hinge mount. I made a slight change here - the manual indicates that you should insert the hinge pin from the rear. I found this to be slightly akward, as the hinge kept hitting the fibreglass when I tried to remove it. (Perhaps my alignment was just slightly off ?). However, I found that if I simply reversed the direction of the hinge pin (and consequently relocate the retaining screw & washer to the front of the hinge instead of the rear), then the hinge pin can be removed and replaced with the utmost of ease.
10-11-2002, 04:49 PM
#25
Nose gear door, continued
Some strips of poly-ply are glued to the inside of the area where we cut the nose-gear doors out, and these act as a sort of door-stop and former that keep the door properly aligned and shaped when closed.
At this point I simply taped up the doors to prevent them from flipping open and catching on something while I'm working.
This photo of the outside of the doors shows the initial fit, and the screws that we use to help retain the hinges.
At this point I simply taped up the doors to prevent them from flipping open and catching on something while I'm working.
This photo of the outside of the doors shows the initial fit, and the screws that we use to help retain the hinges.