Fauvel AV48

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Doug Diener
Posts: 8
Joined: 25 Aug 2017, 00:44
Location: Seal Beach CA

Fauvel AV48

Post by Doug Diener » 25 Aug 2017, 01:25

I love weird and old classic gliders so I bought plans and a short kit for the Fauve AV48 several years ago from Traplet Publications. The plans I believe were drawn by Vic Steel and an article was published about the build and flying in RC Model World July 2009. The build has gone well having mostly completed the vertical stabs, rudders and inboard wing sections as well as the spars for the outer wing sections. The fuselage is well along with the formers and longerons installed and aligned. However, in setting up the wing incidence I discovered a major problem. The position of the main spar rod and incidence pin is a disaster. The main spar and incidence rods were accurately located and bolted onto the formers as shown on the plans. However, the fuselage side view shows these rods in a different location with the main rod protruding through the middle of one of the main fuselage longerons! I doubt if this is the correct way to build the model. As shown on the side view the wing incidence is 8 degrees, which looks about right for the Fauvel flying wings. However, as positioned on the formers I would end up with an angle of about 13 degrees. The best fix appears to be lowering the main spar rod by 1/4inch and raising the incidence rod about 1/8 inch, which will give just about 8 degrees of incidence. Of course the issue is that the fuselage in difficult to access for locating and redialing the holes for the clamps holding the main and pin incidence rods. I'm wondering if anyone else has had this problem and whether changing the wing location on the fuselage while holding the 8 degrees of incidence will affect the flying of the model. There was nothing mentioned in the article about this problem and looking at the poorly reproduced pictures in the article it looks like Vic built his model using the modifications I mentioned above. I just wish I had discovered this before I glued all those longerons onto the formers. Thanks Doug
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Trevor
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Joined: 19 Jul 2016, 16:29
Location: Hampshire
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Re: Fauvel AV48

Post by Trevor » 25 Aug 2017, 08:43

I built the AV36 from Gordon Waite's plan last winter but it has a three piece wing so, although I too had issues with wing joining, they are not the same as the problem you're grappling with.

However, since it's a flying wing, surely the only effect of changing the rigging angle of the wing will be to alter the 'sit' of the fuselage in the air - the wing will fly just the same regardless, as long as the cg and elevator trim are set correctly.

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Barry_Cole
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Joined: 10 Mar 2015, 09:30
Location: Hampshire UK

Re: Fauvel AV48

Post by Barry_Cole » 26 Aug 2017, 10:09

Drawings added.

BC

Doug Diener
Posts: 8
Joined: 25 Aug 2017, 00:44
Location: Seal Beach CA

Re: Fauvel AV48

Post by Doug Diener » 28 Aug 2017, 00:38

Hi Barry and Trevor
Thank you for the reply and the info related to the Fauve. I will move the main rod and incidence pins to give me close to the 8 degrees incidence. Barry informs me that the 8 degree angle is more to help get the glider off the ground for a power take off rather than the angle they fly in the air, which I believe is essentially zero degrees incidence. Now if I can find a source for a 12-8 folding pusher prop and how to set up dual rudders with differential throw I could by flying by spring. thanks Doug

Sean Fitzgibbon
Posts: 21
Joined: 11 Oct 2017, 18:53
Location: Mitcheldean

Re: Fauvel AV48

Post by Sean Fitzgibbon » 21 Oct 2017, 08:46

Hi Doug,
Read this post with interest as I have this model in the the building queue, hopefully to be my winter project.
Thanks for flagging this potential issue, forewarned is forearmed, as they say!
Do you have any progress updates?
Sean.

Doug Diener
Posts: 8
Joined: 25 Aug 2017, 00:44
Location: Seal Beach CA

Re: Fauvel AV48

Post by Doug Diener » 18 Nov 2017, 03:10

Hi Sean
I only build in the winter and I have built several scale models but I am still a novice builder. Do you have a copy of the construction article that appeared in one of the model magazines? My copy came with the plans and short kit? It is helpful but I still had many questions and issues with the build. If needed I could scan the article and send you a copy. I started last year with the vert stab and rudders. No major issues, however, the attachment of these structures to the outer wing panels is vague. I used the suggested screw location as a locating point, fiddled with the angles, and then glued them on with reinforcements. I was not clever in mounting the rudder servos, they are sort of built in and if they need to be removed it will require drilling holes through the bottom of the vert stab to have access to the mounting screws. Otherwise the servo hatch cover on the side provides access to the linkage. The outer wing panels went together well but again the issue with the attachment of the vert stab is not clear and required some head scratching to figure out what the designer intended. The multiple ribs, ply and balsa, rib parts that are stacked together to form the mounting surface for the vert stab took some time to figure out. There was some adjustments needed to make it fit together well, trail and error fitting. At this point I thought about finishing the wings so I built the main spars for the outer wing panels. Nothing special here but getting the angle of the spar joiners correct took some careful alignment. I then realized I needed to have the fuselage completed to make the inner wing panel connections to the fuselage (incidence pin locations, wire and antennae runs) and so I could finish the bottoms of the inner wing panels. I followed the suggestions in the construction build article and made a jig to hold the formers in the proper position. Some adjustments were needed and formers 2 and 3 needed some realignments. I custom made spar clamp holders and wheel housings out of aluminum. I had to steam bend some of the 1/4 inch spruce longhorns as the curvature near the nose is extreme. I am now in the balsa infill stage and trying to figure out how to mount the motor so it is removable. I'm wondering if the motor location should be mover further forward? I also ordered airbrakes for the outer wing panels and will add these rather than just faking them. I am now back into building and will continue with the balsa infill and dealing with mounting the motor. This is by far the largest model I have attempted to build and looking forward to seeing the parts come together. Good luck with your build. doug

Sean Fitzgibbon
Posts: 21
Joined: 11 Oct 2017, 18:53
Location: Mitcheldean

Re: Fauvel AV48

Post by Sean Fitzgibbon » 26 May 2018, 18:35

Hi Doug,
Hope your AV 48 is still progressing! After some delays I have eventually made a start on mine, it's being built in our clubroom, so it'll only get worked on one evening a week in the summer.
I'm still pondering the wing incidence issue, but my present thinking is to add another former in front of the main joiner tube and box in and epoxy the tube itself. This will be in the location shown on the side elevation and the longeron will be cut to butt up to it.
I'm figuring that as the structure is infilled with balsa and glassclothed it will be sufficiently strong!
Sean.
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Sean Fitzgibbon
Posts: 21
Joined: 11 Oct 2017, 18:53
Location: Mitcheldean

Re: Fauvel AV48

Post by Sean Fitzgibbon » 10 Nov 2018, 15:47

Hi Doug,
Thought I'd post a picture of the current state of my AV 48. I'm at the infill stage of fuselage construction, which is time consuming but oddly therapeutic! As I said before, it's being assembled in our clubroom, so construction time is limited to four hours a week at most. My clubmates have been fascinated by the progress, which speaks volumes because as a group we tend to be drawn to the unorthodox prototype! The last model that emerged from our room was the IS5 canard, designed by Frank Skilbeck and built by himself with Roger Spragg and Andy Parsons.
How is your model coming along?
Sean.
IMG_20181025_205136001.jpg

Doug Diener
Posts: 8
Joined: 25 Aug 2017, 00:44
Location: Seal Beach CA

Re: Fauvel AV48

Post by Doug Diener » 30 Nov 2018, 16:11

Hi Sean
I'm back to working on the Fauvel. Your progress looks good and the infill process is interesting but tedious. I guess I'm about 75% complete on the fuselage, see photos. A couple of suggestions: leave open some space behind the cockpit for access to the back of the plane as you will find there is much to do in the aft fuselage e.g. servo wiring, battery tray, controller and electronic positioning, and motor installation. I also suggest you do not glue in the aft plywood former. I found it much easier to fit the motor, make the cooling vents and adding the hardwood motor mounts before gluing it all together in the back. There is much fiddling to make it all fit, removable and I found myself trial fitting all the pieces and parts many times before it was finally installed and epoxied into position. Once I removed the fuselage from the building jig I infilled the aft lower parts and did some creative shaping. I left the front lower area open as there is much to do in the cockpit area, wheels and working on the battery tray and electronics platform. See photos as this may help you see where I am with the build. I elected to use a Axi 4120/14 ver2 for power and 6s battery with an 80 amp controller. A turbo folding prop, 12/8 if i remember correctly, need to run this to determine final prop size. Get your motor and start figuring how it will fit together in the rear before getting too far on the fuselage build.
I found the building of the wing stubs onto the fuselage to be creative sculpturing and difficult to get everything lined up and fitting. To do this properly you will need to build the inner wing panels. I tried to use foam infill but didn't like the support and so I used balsa infill and then sheeted in balsa. I made a filet between the wing stub and inner wing with some spackle and epoxy/microballon mixture. I still have much sanding and contouring to make it look good. Be sure too allow for servo wire access, antenna, and connecting rods and incidence pin. I will have two different servo wire access into then fuselage: the aft one will have the elevator and rudder servo wires and the forward one just aft of the main spare will have the ailerons and airbrake wires. I will add functional airbrakes.
In building the inner wing panels I followed the build article and used the suggested jigs. I built the inner wing spars first and then used them to build the outer wing panel spars and setting the dihedral angle. I have not built the outer wings yet but I will start this soon as I need to complete the outer wing panels to finish the inner wing panels, mainly for the retaining clamp holding the inner and outer wings together. Once this is done I can finish the bottom sheeting on the inner wing panels and finish them. Leading edge yet to complete.
The elevators, vert stab and rudders are mostly finished. Again I am struggling with servo wiring and how everything is held together and taken apart for transport and flying. There is a photo showing the vert stab attachment to the inner wing panel. The construction of the junction between the inner and outer wing panels and the vert stab was a mystery puzzle. The photos show both sides of the right vert stab and rudder, note the cut outs needed to make the wing connections and fitting of the vert stab. This is creative modeling at best. I'm a little worried about the strength of the connection holding the vert stab to the inner wing??? I think there could be much torque at this point when landing and the vert stab skids dig in. I found some cool little wing wheels that I will try instead of aluminum skids. I hope my comments are helpful and good luck with the build. As you can see in the photos the model is large just putting together the right half and outer wing spar covers must of most of my 8ft building board.
Note in third photo the two bolt ends holding the vert stab to the inner wing panel, I hope this is how it is supposed to be?????

Regards to you and your build team, as you can see once it starts coming together it really is a cool model.
Happy holidays
doug
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rear fuselage, cooling vents, right inner wing, elevator, stab,
rudder
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Sean Fitzgibbon
Posts: 21
Joined: 11 Oct 2017, 18:53
Location: Mitcheldean

Re: Fauvel AV48

Post by Sean Fitzgibbon » 06 Dec 2018, 21:48

Hi Doug,
Your 48 is looking great!! Gives me incentive to push in with the infilling!
Great to read your insights on potential issues, I can at least sidestep the motor installation headaches because I'm building mine as a pure glider. My intention is to use it primarily at aerotow events and possibly slope it as well. Guys in the clubroom are intrigued by the construction methods, not sure if they fancy having a go themselves though!
I'll post some photos on the thread I started as I progress, I'm hoping to build the fins next. I'll bring the fuz home to sand and shape it, I'm thinking it's going to generate a fair bit of of sawdust.
Look forward to seeing your model progress, got any idea of a completion date?
Sean.

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