Ron Gray Posted March 6, 2018 Share Posted March 6, 2018 This is what can happen when a bulkhead has not got sufficient support from the surrounding fus, in my case a lack of attachment area / lack of factory applied glue: And that was before it flew! I added this strengthening as I would rather have the bulkhead firmly secured what happens in a crash is something that I will deal with when (if) it happens! Quote Link to comment Share on other sites More sharing options...
simon burch Posted March 6, 2018 Share Posted March 6, 2018 I had my Dual Ace for 10 years and sold it a few months ago (wish I hadn't). Had hours of fun over the years and always drew attention when it was flown. Only mods I made were to double up that front former so you have more glue area with the surrounding wood. Mine was 1/4 ply from memory. If you have a landing on the nose wheel, it will easily rip out and make a mess. Not essential, but for longevity I'd do it before you stuff the nose with batteries. Also, do your instructions look modified with regard to the cg position (like someone has modded the text) , because it was wrong on the original instructions. Great plane. Regards, Simon Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 6, 2018 Author Share Posted March 6, 2018 Ron, while I completely agree with you regarding the build quality or lack of glue used I think there is a difference between mounting the nose wheel and a 240V in this case. As mentioned I would prefer the captive nuts to rip out of the bulkhead than pull the bulkhead out of the fuselage. Simon, Are yes the C of G according to the on line manual its 95 to 110mm back from LE, but the manual supplied with the kit states (in bold) 105 to 115mm so I'll go with the 105 initially. Where was the C of G on yours? Quote Link to comment Share on other sites More sharing options...
simon burch Posted March 6, 2018 Share Posted March 6, 2018 From memory I was towards the rear of that range on mine. It doesn't take much to rip that front former out on a dual ace. One bad landing on the nose wheel and she will be out. It is not strong enough to stay in place if the t-nuts were pulled through. Simon Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted March 6, 2018 Share Posted March 6, 2018 If the landing was hard enough to pull the T nuts out then it's quite a hard 'landing'! Maybe better off mounting the nose wheel gear with nylon bolts then they would break first? Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 6, 2018 Share Posted March 6, 2018 Just checked my nose leg fixing. I put a 10mm thick ply doubler directly behind the blind nuts for the nose wheel. It’s about 2”x3”. It’s the largest single piece I could get in , space is a bit tigh Bown there. I have given the nose wheel some abuse a few times and it shows no sign of breaking away.....there, that’s gone and done it, now it will come loose the next time I fly it !! Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 7, 2018 Author Share Posted March 7, 2018 Update time! Finished off the elevator linkage and closed loop on the rudder (it was no where near as much grief as I presumed) plus made a start on the nacelle bulkhead. Having internet issues so photos will follow! One question regarding the "pitch" of the aircraft when its sitting on its U/C, is it best to have the underside of the wing horizontal or nose up or nose down. Its just once I cut my nose leg to suit it will be tricky adding something back if needed later Edited By Chris Walby on 07/03/2018 23:58:16 Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 8, 2018 Share Posted March 8, 2018 Check prop clearances first. Allow a few inches, that’s why I have bigger wheels on, also helps with landings as mine are quite soft so take up some of the touchdown stress. If anything mine is slightly nose up main gear slightly trailing back. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 8, 2018 Author Share Posted March 8, 2018 Cymaz, I took your and others advice and have larger wheels plus nose leg upgrade so was just wondering apart from aesthetics if there is a technical reason for either nose up/nose down with respect to take off and landing. My Speed Air seems to ground handle better with a longer nose wheel (only because the engine mounts clashed and I didn't want to cut the leg down however it has loads of power and thus the transition to flight is very prompt! Landing roll out seems better as it seems to resist the nose wheel tucking under even on long grass or over the bumps. Edited By Chris Walby on 08/03/2018 06:56:48 Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 8, 2018 Share Posted March 8, 2018 I found that a slight nose up the plane is more readily able to take off. You already have some positive AOA. I did have a plane that had a nose down attitude, never took off and I had to raise the nose! Also worth noting, taxiing - I have a bit of up elevator, this gets the nose wheel into the ground and helps me steer without it skidding about Landing...with some nose up , you have prop clearance. Edited By cymaz on 08/03/2018 07:05:48 Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 9, 2018 Author Share Posted March 9, 2018 Progress update Tinkering along with aileron linkages, U/C fixings and prop clearance (looking at just over a inch although it was tricky hold lots of loose bits so I'll do it a gain once the nacelle boxes are finished and fixed in. While I was at it I had a play around with the carb and exhaust orientations to see if I can obtain easy access to both carb needles . Those with OCD won't like the fact that the carb and exhaust are at different angles, but its works for me as both needles will be outside of the cowl and accessible without me touching the exhaust to get to one! Other progress was making the spinner back plate spacers and gluing the nacelle bulkheads in. This will allow me to work out where the throttle servo can go and recheck the prop to ground clearance. TTFN Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 14, 2018 Author Share Posted March 14, 2018 Update time again! Although progress seems to come to an all time slow I think I am making so headway! Nacelles are more or less finished and now just need gluing into the wings, then a coat of fuel proofing and they will be complete. Pilot and crew ordered form HK plus a fail over regulator (I really can't see the point of a switch as it just another thing to go wrong) and was just going to do a same as the Speed Air. Plug the battery into the UBEC and lock the canopy down, then control checks and start the engine. I'll see where the C of G ends up and can always go with a couple of RX batteries if I need a bit more weight Lastly on the subject of overly long nylon wing bolts I went through my dad's nuts and bolts collection only to find some UNF cheese head screws. Small washer and some epoxy hey presto these should do the trick! I really don't know why Seagull are using UNF, but perhaps that's for another thread? PS I ended up with the carbs vertical again, OCD now at a new state of karma Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 16, 2018 Author Share Posted March 16, 2018 More slow but sure progress, honest things will get more exciting soon. Nacelle boxes are in and they just need fuel proofing before everything can be fitted back in, Saturday job Fitting up of the nose for the C of G check List of things to do: Collect tank No2 Cockpit crew – on order from HK Plumb clunk line on No2 Make and install vent pitot tube Aileron leads to servo Mount RX, switch/BEC and batteries Make spinner adaptors Centre aileron servos on RX Nose, cutting wheel opening and fixing screws C of G check Control surface throws and throttle settings Club inspection Fly Its not looking too far off being complete (thanks for the advice chaps) and we will see how it goes with a pair of Lasers in it! TTFN Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted March 17, 2018 Share Posted March 17, 2018 Posted by Chris Walby on 14/03/2018 22:08:56: I really don't know why Seagull are using UNF, but perhaps that's for another thread? I doubt that another thread would be needed (although there is already at least one) to conclude that Seagull see their major market as the USA, which persists in using the more flexible imperial system. If only the human race had evolved with 6 digits on each hand it would be a no-brainer that we'd all be using it... Edited By Martin Harris on 17/03/2018 10:45:00 Quote Link to comment Share on other sites More sharing options...
CARPERFECT Posted March 17, 2018 Share Posted March 17, 2018 Chris Walby. Not sure what radio you have. But i had my Dual Ace on Futaba 8j. Each engine on different channels . the 8j has 6 trim switches, most only have 4. This enables you to adjust each engine so they are in harmony. I also had the rudders and engines on a mix, operated by a switch.(ground only) When i applied right rudder the left engine would increase in revs and vice versa. It helps turn it on the grass. I also fitted two rx switches the second was in between one engine and the servo, ( must be 3 wires though) this allows you to start one engine, get it tuned, set the revs to just over tick over , then turn the switch off. now start the other engine and tune. when happy turn switch back on. You can see me do it on my link earlier on this thread. Quote Link to comment Share on other sites More sharing options...
CARPERFECT Posted March 17, 2018 Share Posted March 17, 2018 You Tube Seagull Dual Ace x 2 SC52 FS engines Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 17, 2018 Author Share Posted March 17, 2018 Carperfect, Thanks for the information, I have an electric twin with no rudder where I mixed rudder into throttle, but had some grief with and RX that would not throttle down one channel (not the throttle channel) on loss of signal so I used a lemon RX. The model passed range checks and flew once okay and crashed 3 times. I thought it was me, but the last time it crashed it didn't launch the lipo out of the fuselage and the RX was flashing. Its sitting in the naughty corner and I have a feeling its something to do with the "electrics". I have my suspicion as to what it might be, but I want conclusive evidence which will take time. Its flight envelope was very disappointing as well so might just put it down to experience! I am looking to keep the Dual Ace as I simple as I can (the less things to go wrong) as I am new to the IC side of things. Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 18, 2018 Share Posted March 18, 2018 It’s an utter pain to get the idle end points to match as the linkage is not easy to get at. I posted the Tx mixes I used for my Futaba 9c on page one....it may not help at all if you use another Tx make. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 18, 2018 Author Share Posted March 18, 2018 Great news !! Its all coming together and today was the first go at C of G. Spinners, props tanks and RX batteries (not the nacelle covers) and C of G is good at 105mm back from LE! In fact I need to move the batteries back to make an easier method of install/changing plus the RX can sit on the middle tray which will help even more! News getting better! Weigh in again without nacelle covers comes in at 4.789 Kg and Seagull AUW is approx. 5 Kg so those big Laser 70 are not weighing it down Last be not least with the modified nose wheel gear and bigger wheels I have 2 inches of prop clearance which hopefully will be enough for our patch on the basis that it is tri-cycle so should not tip over. Thanks guys for the advice, its been a big help and now to scratch my head around setting the throttles up with separate trim.. Quote Link to comment Share on other sites More sharing options...
Jon H Posted March 19, 2018 Share Posted March 19, 2018 In the interest of keeping it simple chris i wouldnt do anything complicated with the throttles. Just use a y lead and take a little time making sure the mechanical setup of the servos is as close to identical as possible. If small adjustments are then needed to the idle rpm of one engine, or more importantly its half throttle rpm, you can adjust the throttle rod length by unscrewing the clevis. The two engines i sent you are a matched pair and as close to identical as i can make them. You shouldnt have any trouble. I dont recommend throttle/rudder mixing either as it can produce huge yaw if you dont get your curves right. If its only for taxiing then ok mayb, but certainly not for anything else. I have owned 5 twins and a 4 engine model. All of them had y leads and no mixing and flew without any trouble for many years Edited By Jon - Laser Engines on 19/03/2018 08:35:32 Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 19, 2018 Author Share Posted March 19, 2018 Hi Jon I think the servo and throttle arms will both be outside of the nacelle cover so can be adjusted at initial set-up plus as the rudder and steering are on separate servos so I could do something there if taxing is an issue. The train of thought was more along being able to adjust the tick over separately without resorting to mechanical adjustments. The experience with the rudderless electric thing was a bit weird as it yawed around the C of G rather than turning in (didn't look very scale and gave the impression if pushed it might spin!) then again it didn't give me much time in any department apart from the long walk with the bin liner 3 times! (its in the naughty corner awaiting for more time and will perhaps). Anyway back to the throttles and the RX I have in mind may not allow for separate throttle channels with throttle cut in both which will mean a Y lead and keeping it simple (suits me!). Main thing is to have it ready for the "better" weather Quote Link to comment Share on other sites More sharing options...
Jon H Posted March 19, 2018 Share Posted March 19, 2018 Dont get too caught up worrying about the tickover. You fly at much higher power settings and its more important to have the engines together at your normal flying power setting. What you could do is get all the servos in stalled and do a test run with the servos on a y lead. See how the engines behave, if a small mechanical tweak is all you need, and then if its all as you would like you can save the time spent on the more complex setup. Quote Link to comment Share on other sites More sharing options...
Alve Hansson Posted March 20, 2018 Share Posted March 20, 2018 I have a dual ace kit that I planned to build now this spring. Engines become Asp 52 FS and I will use Microsens Glow 4 L for onboard glow. Will follow the thread with great interest. Edited By Alve Hansson on 20/03/2018 09:40:16 Edited By Alve Hansson on 20/03/2018 09:40:38 Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 20, 2018 Author Share Posted March 20, 2018 Alve, All the best with your build and please keep us posted on progress. I am new to IC thus wanted reliable engines and Laser are local with great support from Jon. The other thing was that some of the Dual Ace builds needed lead in the front to achieve correct C of G where I have not needed to add any (my C of G is forward so batteries etc are rearward). Plus Lasers don't need on board glow or pressurised tanks so the install is simple There is one last minor thing....I want to really run these engines in before they are moved to another airframe I have in mind but that's for another thread. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 28, 2018 Author Share Posted March 28, 2018 Been a bit busy at work and with some decent weather (nearly another 1/2 gallon through the Speed Air Laser!) progress has slowed. After 10 hours at work Sunday I drilled and tapped the spinner engine adaptor nut M5, doh original was M3 and needed to be M4. Plan B and stood in front of the lathe and made two the right size. Dremeled the nacelle cowls and it seemed to go okay, still need to fit the cowl spinner ring and a couple of screws down the sides to finish off. Second thoughts about the throttle linkage and have come up with a better way with a z bend and a metal clevis. Plumbing and control throws at the weekend with just the crew to finish things off (plus a load of other stuff). Then it will close to running the Lasers up for a few ground runs. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.