Phil Winks Posted November 13, 2012 Share Posted November 13, 2012 I'm starting this some time before I intend to comitt to balsa as I want to throw my ideas out there for discussion etc. 1stly I've spent a little time this evening going over the plans and have come up with some suggestions for modifications some for ease of construction some to make the model easier to transport and one because as has been disscused in the gen chat thread there is a minor flaw / printing error on the plan that is causing some confusion.. Plan alteration / modification suggestions The fuselage sheet limit marks along the lower edge of the turtle deck are incorrect on the plan and should be one line lower down. basically the triangles filled out blue are the originals and I've redrawn them on the correct line The height of the fuselage sides at F3 taking into account of the curve is 4 ¼” . This is easily addressed by the addition of a ¼” x app 1” triangle of 3/16” sheet at this point. F4 can be doubled with one attached to the fuselage as per plan and one attached to the canopy floor to help with the fixing of the canopy. This will make the joint between the front of the canopy and the fuselage easier to get neat. F5 could be doubled up with one fitted 1/8” inside the rear canopy line and one fitted to the fwd edge of the turtle deck above F3. Then magnets could be let in to these formers to hold the canopy secure and make it less fiddly to remove. I will definitely fit Shorts style exhausts hollowed through into the motor bay for some cooling air to pass, just slightly higher than scale to prevent losing them when grass landing with out U/C, I will almost certainly be modifying the wing seat and aileron servo position to allow me to make the wing removable (smallish car syndrome) on the plus side this will mean all the radio gear can be forward of F3 to help with C.o.G. due to lighter LiPo's and the belly hatch can be omitted, thus by putting some triangle stock along the inside of the lower fuselage side / belly junction I can also round the bottom of the fuselage of more to make that area rear of the wing seat a little more scale like finally for the moment I think I might consider engineering a castor mechanism for the front U/C leg to ease ground handling when using the U/C. These points are just my 1st thoughts and I welcome a full and open disscusion Phil Quote Link to comment Share on other sites More sharing options...
Tim C Posted November 13, 2012 Share Posted November 13, 2012 Hi Phil, A few comments (based on experience with Tuc no 1.) 1. Yes your correct, a small filler piece takes up the space ii .No need really, F4 forms the front of the canopy base to which the canopy is glued, just a case of getting the profiles of the front of cowl right and matching that of the canopy molding iii again no real need it a matter of matching up the fuse and canopy profiles, I used a couple of magnets on a small block on the fuse sides, works just fine. Doubling up might make sense if your using this as a wing attachment point iv. I did the same to avoid losing them in a landing, not hollow though!! v. I moved the servos fwd as the RX went in the forward fuse, still a weak area immediatly behind F3, as I cracked the fuse sides immediatrly behind F3 on a hard landing, the tail section causes stress in this area not suffered on U/C versions, I will certainly change this on Tuc 2 v1 - No comment still going for belly version Also used a 1.75inch spinner, I think it gives a better nose prifile Edited By Tim @ ModelMarkings.com on 13/11/2012 22:24:38 Edited By Tim @ ModelMarkings.com on 13/11/2012 22:26:34 Quote Link to comment Share on other sites More sharing options...
GrahamC Posted November 13, 2012 Share Posted November 13, 2012 And on iv. I would say, no real need. Mine has a fixed nose wheel and is an absolute peach on the ground. It's easy to steer as the rudder and a blip of throttle easily turns it, but its stable when you want it to be - on the take off run. I might even go as far as to say the best taxying plane in my fleet! Quote Link to comment Share on other sites More sharing options...
kc Posted November 14, 2012 Share Posted November 14, 2012 The line of the fus sides top could be cut oversized by perhaps 3/32 to allow sanding down to a flat ( curving in will otherwise produce just a point contact ) to match the flat on the triangle. Consider making the canopy and entire front lift off for access to Lipo & motor etc? In this case the addition of a liteply tray with Velcro strap for the lipo will stiffen the fuselage. Backplate mounting motors will need an F2 which is further forward ( smaller too ) which could connect with the liteply tray. All depends whether you use 1 Lipo or 2 as discussed elsewhere. Edited By kc on 14/11/2012 11:50:38 Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted November 14, 2012 Author Share Posted November 14, 2012 Many thanks for the replies lads all points have been taken on board for consideration the sugestion at iii. to double up on F5 for beefing up to allow a wing fixing is a cracker Tim I kinda thought maybe a block on top of the wing to fit inside the fuse and butt against a similar block fixed inside the fuse with a dowel locator at the front and wing bolt at the rear. the aileron servo attached to the wing with a fixed socket accessable through the canopy hatch for the servo lead, or even having the tx positioned so it would be easy to plug/unplug said servo. Glad to hear that a castor for the front u/c leg is not really req Graham as that was one mod I saw being a problem to get right. KC your 1st point is I would say a must as your quite right about the issue of a knife edge join. As for the canopy and front being one hatch I don't see why not. as there is already an access hatch detailed forward of the canopy though to be truthfull this area will most likely be so full of motor as to not allow much extra access for batteries Phil Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted November 17, 2012 Author Share Posted November 17, 2012 Power system and servos ordered this morning I've gone for the following NTM propdrive series 35-42 motor Motor accessorie pack Turnigy plush 60A esc Turnigy MG90S metal geared servo just another step towards the start of the build in January Drawings coming soon for a removable wing and a firewall to rear mount the motor to Phil Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted November 17, 2012 Author Share Posted November 17, 2012 For those interested I've completed my wood shopping list and from slec its likely to be the best part of £40 I have allowed a generous 15% wastage rate as any over order will be absorbed into my "Stock pile" it desperately needs building up lol here is my estimated requirements Soft 4"x36" 3/16" 4 off 3/8" 2 off 1/2" only 6" but as I have none in 1 off Med 4"x36" 1/8" 1 off 3/8" 2 off Hard 4"x48" 3/8" 1 off 1/8" ply 1 piece app 12"x3" however not having any in I'll need to get a 12"x12" piece still it'll come in lol Next up control links u/c wire weels etc Phil Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted November 21, 2012 Author Share Posted November 21, 2012 Just aquick update the powertrain and servos arrived this morning and being forced to stay at home due to some serious flooding on both possible routes to work this morning I've been able to solder the relevant connectors on and test all the bits. THE MOTOR my 1st impression is the motor is just as described on the HK website and in many other reviews, a solid lump that runs smoothly and quietly, all you can ask really however I would've prefered to see a more flexible wire used for the esc/motor wires the fitted ones are incredibly stif probably to help keep them away from the rotor, however any amount of rough handling could see the joints inside the motor being weakened, THE ESC once again a sturdy well made item with very smooth throttle control and simple to set up pretty much plug and play for most applications on Li|Po btys. THE SERVOS I expected these 13g metal geared servos to be a little larger but pleasantly they're little, if any, bigger than your average 9g servo with a much better torque and smooth in operation Also one for WF my motor accesorie pack fits perfectly so it looks like yours is a one off bad Item, I would get HK to replace it mate though just check the diametre of the boss it fits over. On mine it is 10.96mm according to my digital calipers. not that I expect that to be the prob but prob best checked before complaining also it may be that the recess on the prop driver is not turned square to the bottom of the recess. Phil Edited By Phil Winks on 21/11/2012 14:47:54 Quote Link to comment Share on other sites More sharing options...
WolstonFlyer Posted November 21, 2012 Share Posted November 21, 2012 Hi Phil I agree with you about the motor wires being very stiff, I think they just extend the enamel coated winding wires out to the bullet connectors so that there are no solder joints inside the motor that could fail?.. [Edit] No they must join the wires somewhere inside the motor?? Good to hear that your prop driver fits OK, I must have just got a "friday afternoon" one I am not going to bother sending it back, it would cost more in postage than the part is worth, besides I added a couple more to my servo order that has been delivered to work today.. while I am at home with the kids because school is closed (flooding). Edited By WolstonFlyer on 21/11/2012 14:56:19 Quote Link to comment Share on other sites More sharing options...
kc Posted November 21, 2012 Share Posted November 21, 2012 You need a spare prop driver or two because they are very soft alloy and bend at the slightest noseover etc. My model was caught by a gust of wind whilst on the club outdoor bench, just dropped 30 inches to the grass and bent the prop driver! Giant Shark are good for motor mount prop driver sets at around 1.14 pounds. Same with motor shafts they bend so easily, buy a spare to keep flying. Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted November 21, 2012 Author Share Posted November 21, 2012 this style of prop driver (bolt on) is prob the most robust and I've never managed to bend one KC however I agree its good practice to have a spare along with motor shafts and having them is prob why I've never bent one (Sods law and all that lol) Phil Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted November 21, 2012 Author Share Posted November 21, 2012 for those interested here's the hardware. the rx pictured is a 6ch radio link rx currently bound to a 4ch tx and may not be the one it flies with depending on budget as the build progresses Phil Quote Link to comment Share on other sites More sharing options...
Lucas Hofman Posted November 22, 2012 Share Posted November 22, 2012 Phil, how heavy is soft, med and hard balsa.? I can take a scale with me to the local shop but have to know what are acceptable weigths... Regards, Lucas Quote Link to comment Share on other sites More sharing options...
Tim C Posted November 22, 2012 Share Posted November 22, 2012 Lucas, This chart will help, 6lb is light, 8lb med 10 lbs+ is heavy as a rough guide, for 3/8 sheet double up the 3/16 Edited By Tim @ ModelMarkings.com on 22/11/2012 12:33:59 Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted November 22, 2012 Author Share Posted November 22, 2012 Thanks for that chart Tim I have to admit I would've had to do some maths to answer that one lol Phil Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted November 27, 2012 Author Share Posted November 27, 2012 Just a quick WIP report I have as posted on the general chat thread, drawn the tail fin decal if anyone wants a copy to print themselves I have it full size in PDF format for A4 paper/waterslide/vinyl sheet or when I get round to printing mine I can print a limited run at cost orders in a pm please ! Also for those waiting I'm about 45% complete with the drawings for a removable wing modification Phil Quote Link to comment Share on other sites More sharing options...
WolstonFlyer Posted November 27, 2012 Share Posted November 27, 2012 Hi Phil For your removable wing design, are you thinking of adding a third dihedral brace towards the leading edge with a lug on it to insert a dowel rod, along with a lug on the middle brace so the rod is fixed to the wing. Like this picture but with the wing dihedral the other way up. I have started drawing up my own idea for what this might look like but got a bit stuck with where and how the aileron servo would fit on top of the wing. Also trying to get the other two servos further forwards so I can get rid of the rear radio / servo hatch and strengthen the tail inside with triangle stock along the lower decking. Edited By WolstonFlyer on 27/11/2012 22:17:07 Quote Link to comment Share on other sites More sharing options...
Tim C Posted November 27, 2012 Share Posted November 27, 2012 For my 10c worth, I plan on sticking with the rudder/elev servos behind F3, instead of a whole width hatch there room for a smaller central hatch, easier with the smaller servos than on the orginal plan, mount them centrally as a pair with the snakes going outboard on each side, and that enables you to have the lower triangle doublers, again based on my experience to beef up the area behind F3 as mine MK1 Tuc cracked aft of F3, there a bit of a stress point there. As for the Aileron servo that will now have to go fwd of the torque rods, easy to mount some cross rails, I would make a small lite ply box for the removable wing version to hold the servos. Quote Link to comment Share on other sites More sharing options...
WolstonFlyer Posted November 27, 2012 Share Posted November 27, 2012 That is worth much more than 10c Tim. I had not thought of a smaller servo hatch behind F3, yes that would allow the triangle doublers as well, thanks I cannot quite picture how a lite ply box would fit? So would you just shape a couple of short servo rails/blocks to match the dihedral and fix them directly to the wing surface in front of the torque rods, alowing just enough space for two short linkages? Quote Link to comment Share on other sites More sharing options...
Tim C Posted November 28, 2012 Share Posted November 28, 2012 Giving it more thought, the servo will have to be recessed into the wing to maintain the angle onto to the torque rods. Ideally the servo needs to be 90 deg square on, if the connecting rpds are too high up the torque rod arm, you will not get enough airleron movement without super long servo arm extentions Quote Link to comment Share on other sites More sharing options...
WolstonFlyer Posted November 28, 2012 Share Posted November 28, 2012 How about installing the servo upside down so the arm is just clear of the wing surface? It would need a very small front servo rail, probably only just wider than the servo so that the linkages clear each side of it. Quote Link to comment Share on other sites More sharing options...
Tim C Posted November 28, 2012 Share Posted November 28, 2012 why bother complicating it, a recessed servo will be fine and some simple blocks to screw into. See pic (thats a 9gm servo I had hanging around for size) Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted November 28, 2012 Author Share Posted November 28, 2012 I think I've got the gist of all those postings basically I'm fitting a 3mm ply plate hor in the fuse above the wing with a central hole to allow torque rods servo etc to prtotude through when the wing is fitted with the servo fitted centrally on the wing. a tongue fitted to the rear of the wing and a bolt to fthe front the elevator and rudder servos will be fitted above this plate forward of F3 to eliminate the belly hatch and move weight forward well thats the plan at the min the drawings are about 45% done just a few details to check before completing not too sure how soon as work is going manic seeing as we have three cottages to complete so the owners can move back in before xmas Phil (Joiners desperately needed dept) Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted November 28, 2012 Author Share Posted November 28, 2012 Here we go chaps and chapesses the preliminary drawings for the removable wing seat. Whats not shown on the drawings yet is new dihedral braces and the re-enforcing to F3 prob by laminating, cross grain, 2 x 1/8th sheets. the centre sect of the wing is built flat as one piece and not shaped. also a modification to the attachment of the wing root fairings will be needed they will be, I think attached to the fuselage but to be fair I'm holding that detail open untill I have to tackle it Phil James pm me your email and I'll send you the pdf mate same goes for anyone who wants a copy Edited By Phil Winks on 28/11/2012 20:18:46 Quote Link to comment Share on other sites More sharing options...
Chris Bott Posted November 28, 2012 Share Posted November 28, 2012 Phil the Whizzza is very similar in construction and the plan shows a removable wing option. That is achieved using two dowels glued into grooves on the underside of the wing at the rear. Then two bolts are used at the front. What I had to be careful with was the fus former directly behind the wing. This had to be cut out to accommodate the movement of the aileron pushrods. Had the dowels been above the wing like your tongue, they would have sat in that cutout and would have had nowhere to locate. My bolts go up from inside the fus into captive nuts that are above the wing. This leaves more space in the fus. Of course theres a battery hatch underneath, through which the bolts can be reached. Quote Link to comment Share on other sites More sharing options...
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