Here is a list of all the postings Brian Seymour has made in our forums. Click on a thread name to jump to the thread.
|Thread: Pegasus Models Hornet - HWDMAC Winter Build 2018|
Cheers Nigel, to be fair a few hours were put in at home between sessions but the model does go together nicely which helps keep the hours down.
Tapping the nut block rather than fitting T-nuts is a fantastic suggestion thank you, it gave me a heck of a Tefal moment! I'll definitely go for that on the next build, having fitted my ones and and assisted a few others with theirs I can't see how it could possibly take longer than messing around with T-nuts.
Cheers Richard, yes, she is a nice shape from the off, the only thing I changed whilst fixing my one was to round the front of the cowl to be marginally bigger than the spinner. That was partly due to the amount of wood that got pulverised at the front end.
For the build nights, folk tacked the wing trailing edge and ailerons to the false trailing edge so that they could be sanded to exactly match the wing profile, it's a neat idea that Guy came up with and a lot easier than the sanding than ailerons after hinging (which is what I had done). A couple of folk used masking tape on the wing veneer and the last 1/8" of the ailerons and trailing edge as a further guide for sanding and to prevent sanding too much - I'll definitely be using this technique on my next one.
With the ailerons and trailing edges still tacked on, the wing fixings were tackled. The dowel at the front was tackled first. Guy had simplified this by making some plates to go on the front of the wing from 1/16" ply, neatly cut to match the surface of the former with a hole drilled in for the dowel. The plate was tacked to the former (using the dowel to locate it), the wing accurately positioned, the wing then glued to the plate, and then the plate cut from the fuselage. The hole in the plate was used as drill jig to make the dowel hole in the wing and then the dowel was glued in place.
The wing nut blocks were glued inside the fuselage and their positions were marked on the top surface of the wing, this enabled us to get a good idea of where to put the wing bolt holes.
The wing bolt holes are drilled through dowels which are inserted into the wing. The dowels go in perpendicular to the underside of the wing so their position from the trailing edge was measured off the plan and marked on the top and bottom of the wing - due to the angle that they go in at, the top is a different distance to the bottom. Using the centre marks, the dowels were drawn onto the surfaces of the wing and discs of veneer were cut out and a hot wire melted through the foam to make the holes. This left a little bit of sanding to open the holes out to the exact size of the dowels. The dowels were dry fitted, pushing them flush to the underside and marking the excess on the top side The dowels were removed and the excess was cut off using a hacksaw as nothing else made much of an impression on them.The dowels were then glued in using epoxy.
The wing was then fitted to the fuselage and lined up by measuring the distance to the rear tip of the veneer on each wing to the middle of the back of the fuselage. Once the distance to both the left and right were equal, the wing was pinned in position. Holes were drilled through the wing dowels and the wing nut plates in the fuselage. The dowels are dead hard and most of us started with 4mm drill and then opened them out to 6mm. The wings were removed and the holes in the wing nut plates were opened out to 8mm to take the T-nuts.
The T-nuts were glued in from the back using G-clamps to force the prongs into the wood. This was a tricky stage for quite a few of us as the T-nuts didn't all go in straight and so they had to be drilled and re-tapped in situ.
As can be seen from the pictures, the drills wandered a little but, as the holes in the fuselage parts are drilled from the holes in the wings, the wings still locate perfectly.
Edited By Brian Seymour on 28/03/2018 13:55:03
The builds have been coming on, we had an extra build night yesterday and it was great to see the models nearing airworthyness.
There weren't quite as many as usual but the place still had a buzz about it and, with folk at the covering stage, we also set up a Solarfilm-ing station for folk crack on with covering.
Having: flown, crashed (after several flights), and repaired my one I can say that the Hornet is great flyer and stable enough in the gusty breeze that we have been flying in. She is a refreshing change from modern aerobatic planes with a good turn of speed and solid stability. Add to that, she is a tough model, given the speed that she went in at I was pleasantly surprised that she didn't end up as shrapnel and the repair wasn't too much like hard work.
The stats (pre-crash) for my one were:
Cheers Richard, credit to Guy really as I would have ended up something ludicrously complicated if he hadn't made a mock-up of the idea.
Geoff, building together as group is great, it tuns a usually solitary activity into a social one. Lugging the tools around is effort but when you get see how other folk are putting models together and you get to demonstrate your own techniques it is really good - a rich blend of picking up tips and showing off!
With the wings shaped the next step was to glue them together. The top surfaces are kept flat so the dihedral is no more than the tapering of the wing. I used epoxy to join the wings and laid a sheet of cling film over the building board to prevent sticking the wings to it.
Next up was the aileron servo box, I am using a pair of 9g servos for the ailerons so the pre-cut recess for the servos needed extending slightly. The box is lined with 1/8" balsa, where possible I ran the grain of the balsa across the wing join, I know it doesn't do much for the strength but it is simple enough to do.
For the aileron torque rods, I set them slightly into the false trailing. I hadn't used torque rods for a long time but I did recall that setting them into the false trailing edge made their operation smoother. The centre section trailing edge has a slot pre-machined in it to clear the torque rods so it only needed small sections cutting out to clear the torque rod bearings (for want of a better word). Annoyingly, I managed to glue one of the torque rods in pace so the trailing edge had to come off, the IPA deployed, and the trailing edge glued back on - turned out to be a simple fix.
The wing is located at the front with a dowel that is fixed in the wing and locates in the former in front of the wing. The hole in the wing was made with a power drill, it was tricky to keep the drill from wandering either side of the glue and, although the hole in the leading edge was snug, the rest of the hole was somewhat baggy. I used Gorilla glue to fix the dowel in the wing in the hope that it would expand enough to hold it tight - it seemed to do the trick.
Cheers men, there are a few alternatives to get the turtle deck on, the contact adhesive and aliphatic method sounds like an excellent method. The turtle decks are covered with obechi but no reason that UHU contact adhesive wouldn't work unless it eats foam - the contact adhesive that I had eats foam so we couldn't go down that route.
I'm with you DD, once I got the hang of sanding (and a decent set of abrasives) I began to find the shaping stage very rewarding.
I haven't got many pictures of the rest of the build so I'll see if I can get some of the other builds as my one is pretty much ready for flying strip.
With the fuselage sanded the hatch and cowl were liberated with assistance from the razor saw. Ply tabs were glued to fuselage sides and bottom to bolt the cowl to. The pictures below are of my fuselage, I have a sheet of lite-ply so I made the tabs from that but there is enough scrap poplar ply in the kit to use that for the tabs.
With the tabs glued in the cowl was re-fitted and holes drilled trough to the tabs. Screws were fitted and then removed and then thin CA was run into the holes to toughen them up a bit.
Thin CA was used on the cut edges of the of the cowl/fuselage spit to toughen them up. Once the glue had set the cowl and hatch were re-fitted and the front end was given another once over with abrasives to blend them back in line.
I must confess that splitting the front of the fuselage off to make a cowl on the electric models was Guy's idea, possibly obvious to everyone else but it hadn't crossed my mind. He made a mock-up of the font end to demonstrate it complete with the motor mounted so it was dead easy comprehend and copy.
With the fuselage well underway I switch back to the wing, gluing the halves together. I used epoxy and left them overnight.
Edited By Brian Seymour on 01/03/2018 13:51:15
Cheers Richard, I think that we have left a few for other folk...
I went back onto the wing to fit the undercarriage blocks. Slots are pre-machined into the wing which need the ends squaring off to take the blocks. The blocks were laid in position as a template and the veneer was score with a scalpel until it was cut through.
The foam beneath was cut to dept and the corners picked out.
The undercarriage blocks are doubled up in the end closest the wing root so the foam needs to be cut deeper to accommodate it. I used a scalpel to make a grid of cuts to depth, picked out the squares of foam and then finished the base with a bit of sand paper - a bit OTT but I couldn't help myself.
The blocks were glued in with epoxy.
With that curing, I switched back to the fuselage. The top deck and underside of the nose were planned back to be flush with the fuselage sides so that the split line for the cowl could be marked on and pre-cut before sanding. The cut on the top deck forms the front of the flight pack hatch and, as it hooks in at the back, needs to be at an angle - 45° seemed as good as any. The pictures below are of my brothers fuselage, annoyingly, I hadn't realised that the front needed to be at an angle so I have got a slight gap on my one.
The razor plane was deployed again to chop the radii roughly onto the corners and, whilst I was in "the zone" for razor planning, the balsa work on the wings (tips, leading edges, and false trailing edges) were planed roughly to shape which made for a nice little pile of savings:
The balsa was then finished off with sand paper so this stage was rather messy but also rather nice to see finished shapes coming through.
Thanks for the encouragement men, the Scorpion looks ace with a cracking finish.
Most of us have gone for power setups that are capable of more than 700w so we have got reasonable scope to turn up the wick. That said, the Hornet is a bit smaller than the Scorpion (52" wng span) and the AUW on my one is a shade under 4lb so we are in with a chance at 500W.
In between the first and second build meetings folk cracked on at home to get the fuselage blocked out:
The turtle decks were glued on as described above:
The one below was glued with PVA and left over night - held just as well as epoxy glued ones.
The back of the cockpit is supplied a little over size so the actual size is marked on, trimmed roughly to size, glued on, and then sanded to size.
The firewall was marked out with the location of the front nose leg, as my one is electric I have mounted it slightly lower to give a bit more clearance for the prop. I made shallow grooves in the front face to help locate the nose leg.
The location of the firewall was marked on the inside of the fuselage to help align it correctly. Elastic bands were used to pull the fuselage sides in and clamp the firewall in place and it was glued in with CA.
The underside of the nose section was glued on next, the front end needs to be pulled in to match the nose ring. The nose ring was dry fitted to gauge how tightly to clamp the front end, the underside sheet was glued in place with the clamp holding the fuselage sides.
The firewall has got reinforcement strips that run down the edges, these were sanded to make them a perfect fit and glued in with CA.
The cockpit sides glued on along with the cockpit floor.
The top deck sides have an area which is left un-glued so that it can be easily cut off to form a hatch. The top deck is glued on the length of the sides.
That little lot of jobs is very satisfying as it only takes around an hour and transforms the fuselage.
Edited By Brian Seymour on 26/02/2018 22:29:26
Quite a few of us are going for electric, we are aiming for ~500W using 3s or 4s packs. The kit is design for ic but making adaptations for electric aren't particularly taxing and you'll see how we went about in the ensuing posts.
The build isn't complicated but we aimed to get the bulk of the build done in 3 sessions of 4 hours so 5min epoxy and CA were the order of the day but we used PVA for anything that could be pinned, clamped, or otherwise retained and left overnight.
I haven't got any pictures of the early stages of the build but a few of my fellow builders may post pictures, for now a bit of imagination will be required. The build starts with gluing an extension to the left hand fuselage side at the front, the right hand side is left short to allow the cylinder head of the engine to protrude. Electric powered model need the right hand side to be modified to be the same the left hand side. Guy cut out the pieces required to extend the right hand fuselage sides in preparation so that on the build night just the scarf join needed cutting into the right hand fuselage side. The extensions were glued in using CA.
Next up is gluing ply doublers to the balsa fuselage sides. For this we used a spray contact adhesive, the extents of the doublers were masked off to prevent overspray and the adhesive was left for 10mins before the parts were joined.
Whilst the contact adhesive was drying we switched to the wing panels and glued the wing tips on with 5min. epoxy.
With the wing tips curing we switched back to the fuselage and stuck the ply doublers in. The fuselage formers either side of the wig were next. For this stage we marked lines on the inside of the fuselage side to assist with getting in the right position and perpendicular to the top edge of the fuselage. 90° blocks were used to ensure that the formers were square to the fuselage sides and CA was used to tack them in place. With the 90° block removed beads of CA run down either side of formers to ensure a good bond.
Guy had setup and brought along his fuselage jig so the fuselages were put in the jig and the formers and rear end glued in situ. Whilst in the jig, the underside sheeting was glued on to ensure a dead true fuselage was built by all.
The turtle deck is veneered foam part ready to be glued on, this is a bit tricky although a darn sight quicker than builder and sheeting one. For this we put rows of pins down the top edge of the fuselage sides to make the deck conform to the profile of the fuselage and then either: used 5min epoxy and held the turtle deck down until the glue cured, or used PVA and rubber bands to hold the turtle deck down and left it to set over night. Both methods were tricky but effective.
The leading and false trailing edges were glued on using PVA and held in place with either masking tape or pins and left over night to dry.
That was about all we had time for on the first evening, I had thought that we would get further but almost all of my fellow builders hadn't ever built an rc model kit before so in hindsight I think that folk did rather well.
We couldn't have got the builds done as quickly or as well without the help of a few of the club's seasoned builders lending a hand so many thanks to Guy, Graham, Charles (who was also building a kit), and Steve.
This year the High Wycombe and District Model Aircraft Club is having series of club meetings to get together and build Pegasus Models Hornets (used to be Galaxy Models Hornet). This blog has been started a little late as our final scheduled meeting is tomorrow night and a couple of models are almost ready for their maidens.
With the assistance and encouragement of Richard Wills of Warbirds Replicas we decided that the Hornet is an ideal combination of build simplicity, flight performance, and price for our group build.
The pictures below are Richard's and Glynn's completed (and regularly flown) models. I'll follow up with pictures of the my build and, hopefully, a few of my fellow builders (there are 12 of us) will share their experiences.
|Thread: Warbird Replicas Bf 109 club.|
The '109 is looking sweet as you like.
It's great seeing the, generally taken for granted, details come to life.
Very nice build.
|Thread: The Warbirds Replicas Macchi C.202 is Landing!|
Nice tip thanks Dave, I noticed that about torn edges when some of strips ripped as I was smoothing them out but I didn't have the bottle to do it deliberately - I will next time
Cheers Martyn, a 1/6 scale version isn't out of the question but it'll take me a couple of years.
I'm putting this to one side for a few weeks to get on with the club Winter build but I am still hopeful of getting her finished and flying before April.
Cracking job, she looks grand.
She looks sweet, I intend to build one eventually. The anti-vortex wing tips and the cockpit made it stand out from the other slope soarer designs of its time.
I have kept the plan and the magazine that featured it:
|Thread: The Warbirds Replicas Macchi C.202 is Landing!|
Cheers Paul, credit to Glynn, he applies a finishing technique to smooth rippled surface.
Cheers fellas, the overlaps are easily visible due to the paper being slightly transparent but I expect a coat of primer to make them invisible.
Good point about the camouflage, my current Macchi has a multitude sins that are beyond the keen eyes of my fellow flyers.
The covering is well under way, I used brown paper for the fuselage. This was a bit trickier than the wing as it is a big compound curve but four strips (top, bottom, left, and right) did for the section from the tail to the cockpit. The wing fairing and cockpit fairing were quite tricky due to having concave surfaces and I struggled to get the iron involved but a few chopped up strips were glued on and smoothed out by hand - in hindsight, a dry brush may have been better for smoothing out.
I eventually got round to lining the cockpit with balsa and covering it. Again, the iron couldn't be used so the brown paper was applied with just glue and hand smoothing.
As covering was the order of the day, the ailerons, elevators, and rudder covered with Solartex. Cover Grip was used to aid adhesion of the Solartex and it was breeze to apply.
The next stage of covering/finishing is applying a coat of thinned (50/50) cellulose dope (non-shrinking). A coat was applied to the wings, I had forgotten just how quickly it goes off and the wing was soon given a swift buffing up with 400 grit sand paper. I'll give the wing another coat or two of dope before I applying the primer.
I couldn't resist putting her together for a sneak preview:
This is my first go at brown paper covering and there are few rough bits for sure but I reckon that a few coats of dope and sanding between the coats will smarten her up a treat. On the plus side, it has been much quicker, easier, and less messy than skinning with fiber glass.
Next job will be to get the fin and tailplane glued in and their fairings made.
There were a couple of other jobs that came to light before I could get on with the covering: the nose ring and hinging the inner gear doors.
The front of the nose ring needed a facing put on it to blend from the back of the spinner plate to the fuselage. I have built in 3° right thrust into the motor mount which leaves a gap of ~5mm on the left hand side. Scrap from the 6mm thick components was chopped up and glued to the front face of the nose ring:
Then the motor was fitted along with the spinner back plate and 80 grit sand paper was run behind the the spinner back plate to gradually sand the the face to be a perfect fit to spinner back plate.
The diameter of the spinner back plate was marked onto the front face of the nose ring and the outer edges of the nose ring sanded to match it. I sanded a bit too much in a couple of places so a couple of dabs of filler were applied and sanded back to make a nice blend:
You can see from the picture that the cowl has been covered with brown paper. This was pretty simple although I did try to use a single sheet first of all but once I saw that it wasn't going to work out I binned that and completed the job with 3 sheets.
Hinging the inner gear door was a bit fiddly but not too traumatic. A pair of small hinges were glued to either side of the lower keel. I tired to bind these by drilling 4 holes through each pair of hinges and threading fibre glass tow through them but it ended in a right mess. Instead, I used CA filler in the holes to act as rivets, possibly a bad idea but I'll drill it out and try again if it doesn't work out.
On the doors, recesses were made in the the outer face and the face on the hinge line to accommodate the hinges. Given the experience fitting them to the fuselage, I followed the same procedure and then ran a skim of filler over the mess to cover it up!
I'll sort out the FMS/Graham Stone style wires/linkages when I have got a bit further on.
You never know I might get round to doing what I planned and lining the cockpit, I did run a seam of filler around the cockpit fairing but haven't taken any pictures.
I think that I'll crack on with covering the fuselage next but you never know.
The sheeting on the radiator was up next, cross grain sheet was chopped from hard 1/8" balsa, butt joined, and sanded. The curve is quite drastic for hard balsa so water was liberally brushed onto the external surface and left for a few mins to allow the balsa to absorb it. The wet balsa was most compliant and the skin was stuck on using CA. Once set the wood was dried out using my filming iron.
Wit the air dam fitted and the duct slots cut in the fuselage, the oil cooler needed little more than gluing in position. I used a combination of gorilla glue and CA to stick it on. I used the Gorilla glue on the gappy edges (where I had cut the a bit too much off when I liberated it from the scrap) as well as on the air dam to ensure that it was sealed. For those who have not used Gorilla glue, it expands as it sets.
A reasonable batch of epoxy and fairing compound was mixed up for the radiator, oil cooler, and wing trailing edge fairings. Before applying the filler mix the wing was fitted to the fuselage with cling film around the trailing to isolate it and prevent the filler mix from gluing the wing in place.
Once the filler had set, the wing was removed, the cling film discarded, and fairings sanded.
As I was in the mood for fitting fairings I stuck the cockpit fairing on. With the cockpit fairing on it seemed rude not to apply a bit of effort to the cockpit itself: the cockpit aperture was cut from the skin, the floor glued in, and the cockpit prepped for fitting.
The masking tape and paint were used visualise where the vac formed canopy should be cut - possibly not the best the method but its looking OK. The razor plane inside the cockpit is holding the cockpit floor in place as the glue goes off.
During the summer I had a go at making a 3d printed tail wheel and leg:
The tire is 3d printed rubber which took a bit of effort to get the right settings, the pivots and axle are Ø2mm steel pins running inside PTFE tubes. There is a bit of spring in it but I haven't finalised making it castering or steerable yet.
Next up will be a run of fairing compound around the cockpit fairing and balsa lining on the back of the cockpit and then covering.
This is a diagram of the inner gear doors on the real plane from a truly excellent book "The Macchi MC.202 Folgore, a Technical Guide" by Maurizio Di Terlizzi.
In the meantime a few bits and pieces on the fuselage have bee done.
The front underside of the fairing has been filled and sanded. I used Bucks Composites fairing compound with 30min epoxy, this is first time that I have used and it exceptionally good. It really can be sanded to a feathered edge without crumbling and it sands easily.
The oil cooler and radiator have also been started, both are used to help move air around to aid motor cooling. The oil cooler has an air dam half way along to channel air from the front into a duct which leads to the front of the motor and the rear draws air out the fuselage from behind the motor. The radiator has an air dam at the front and is used to draw air out of the fuselage.
The oil cooler is a supplied vac formed component but to make it aid cooling a little prep has to be done. First off the fuselage skin was cut to allow air to flow in and out. The air dam is made from off-cut balsa, a basic rectangle was cut and then trimmed to fit inside the oil cooler and then a slot was cut in it to fit over the fuselage keel. After a bit of trial fitting and fettling it was glued to the fuselage formers exposed through the duct holes.
The radiator is built up from balsa, the assembly starts with laminating the sides and sanding the external profile. The sides are then glued to the box section inside the fuselage. Once the radiator sides are glued in place an air dam is cut from scrap and glued into position and then scrap balsa can be cut to shape and fitted around them.
Next job is to sheet the radiator and glue the oil cooler on and then blend them into the fuselage with sweet fairings.
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