Paul Marsh Posted February 27, 2018 Share Posted February 27, 2018 Four strokes are usually more reliable than 2 strokes, I found, although one recommendation I would recommend is that run and fly each engine in another airframe first, such as a trainer, get them nicely run in and when happy with both put them back in the Dual Ace. When new, engines may not be totally reliable, even a Laser, it would be prudent to do that, Having a engine quite, as discussed does not bode well for a test flight... Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted February 27, 2018 Author Share Posted February 27, 2018 Paul, Thanks for the advice, it would not be too difficult to pop them in in the Speed Air for run in and setting up (just keep the run time the same) as the speed air 70 was a little tight, but then again I didn't do much taxi testing before it took to the sky! Having said that I only got a dead stick by my rubbish tuning and repeatedly doing big stall turns until it quit (don't think I'll be doing that on maiden for sure!). The point made by Jon and others is that it will be well over powered so take off and cruising around will not need full throttle, plus I'll seek advice from a very experienced club member (if he doesn't mind?). Progress tonight consisted of gluing the aileron, elevator and rudder hinges plus ordering the SLEC tanks and closed loop parts for the rudder. Hopefully they will arrive before being snowed in (can only hope, but unlikely with three four wheel drives in the family!). I'll post the nacelle box modifications once I get to the workbench! Quote Link to comment Share on other sites More sharing options...
Jon H Posted February 27, 2018 Share Posted February 27, 2018 I wouldn't bother messing about flying them in the speed air. Its a different model with different tanks and a different installation so its not really going to tell you much about the reliability of the engine in the twin. I would just go for gold but make sure you take some time to set the engines up on the ground. Do them one at a time and then just get it in the air. If your club test pilot has no twin experience then you might as well just do the maiden yourself. If you do want someone with twin experience to give you a hand you are more than welcome to pop up to my club for a day. Wouldn't be any trouble. Edited By Jon - Laser Engines on 27/02/2018 21:09:13 Quote Link to comment Share on other sites More sharing options...
dave windymiller Posted February 27, 2018 Share Posted February 27, 2018 You will enjoy it! Mine could do many maneuvers like outside bunts which all tracked lovely. I junked the red spinners in favor of ally ones (less vibes) and make sure the engines are rigid. I used LA40s which had to be on the ends of the mounts to protrude enough. The mounts are quite flexible so the engines shook at certain revs (making it loud). I extended the mount on 1" blocks of wood so the engines were mounted further back. Make sure the nose wheel steering is sound (mine was a constant problem until i replace some bits with heavier ones) Dont do like i did and cut out the nacelles as mirror images of each other if you have sideways mounted engines (Dohhh). Fortunately, the tops and bottoms are reasonably symmetrical so got away with having one pair upside down Edited By dave windymiller on 27/02/2018 21:45:21 Quote Link to comment Share on other sites More sharing options...
cymaz Posted February 28, 2018 Share Posted February 28, 2018 I will get some photos done soon....but it’s too damn cold in the garage, can’t think why! Quote Link to comment Share on other sites More sharing options...
CARPERFECT Posted February 28, 2018 Share Posted February 28, 2018 Have a look at mine. I sold it after a couple of years, had some great fun no dead sticks. https://www.youtube.com/watch?v=IM1sDiCvA7s Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 1, 2018 Author Share Posted March 1, 2018 Hi Carperfect, Thanks for the post, your video and a couple of others have been very interesting (including the Seagull one) as it seems to come in a bit quick, but stops once on the ground (might just be camera angle), anyway a bit late now to be considering a slow fly! I think I'll go for either ali back plate spinners or all ali, just see how I go with C of G and AUW. Inwood parts turned up a day after I ordered (less than 24hrs!) so I have plenty to be getting on with. Progress last night was slow due to lack of time (hinges checked and aileron servos in) so hope to get on with the nacelle boxes soon Quote Link to comment Share on other sites More sharing options...
dave windymiller Posted March 1, 2018 Share Posted March 1, 2018 One more thing ive remembered, some of the 4 wing bolts are a right pain unless you have little hands. I cut the heads off the bolts and wound M6 nylocks onto them to make a bolt that can be undone with a ratchet spanner or similar (the thread isnt m6 but it made for a good tight fit). Also make them just the right length. They are far too long as standard (more turns to fit / remove!). Dave Quote Link to comment Share on other sites More sharing options...
Jon H Posted March 1, 2018 Share Posted March 1, 2018 I have noticed that many models come with wing bolts that are way too long. Its not an issue as they are easier to shorten than lengthen! Models with 2 piece wings wind me up too. I just find them such a faff to assemble Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 1, 2018 Share Posted March 1, 2018 Posted by dave windymiller on 01/03/2018 11:01:47: One more thing ive remembered, some of the 4 wing bolts are a right pain unless you have little hands. I cut the heads off the bolts and wound M6 nylocks onto them to make a bolt that can be undone with a ratchet spanner or similar (the thread isnt m6 but it made for a good tight fit). Also make them just the right length. They are far too long as standard (more turns to fit / remove!). Dave You are so right. I replaced mine with m6 bolts and captive nuts.... Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 1, 2018 Share Posted March 1, 2018 Just for you Chris.... Fuel fill and some painted grill to decorate the top The American nose wheel... Main wheel.... Some poor pictures of the closed loop on the rudder.. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 1, 2018 Author Share Posted March 1, 2018 Cymaz, thanks for the photos, is the grill/mesh just for checking the tank level or for ventilation as well? PS I have a nose wheel leg on order just like that Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 1, 2018 Share Posted March 1, 2018 Just for ventilation. And for a bit of decoration Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 1, 2018 Author Share Posted March 1, 2018 Minor progress with main U/C, aileron servos and a spot of head scratching with where to locate servos. Not difficult for the standard arrangements, however I have a question for the collective regarding the closed loop for the rudder and the push rood for the nose wheel. Photo of servo bay with steering push rod laid in and missing the clevis's for the rudder (centre) and elevator servos on each side. Is there an elegant solution where I can use the clevis's for the closed loop and at the same time use type of connector that is used on the elevators? One "cop out" would be to use another servo, but I am not keen unless I have to. Thanks for your time and idea's anyone? Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted March 1, 2018 Share Posted March 1, 2018 Rudder and steering are usually on one servo arm Chris The closed loop on the end holes of each side of the arm And steering further in as this only needs a small throw Edited By Denis Watkins on 01/03/2018 22:01:20 Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 1, 2018 Share Posted March 1, 2018 Posted by Chris Walby on 01/03/2018 21:37:47: Is there an elegant solution where I can use the clevis's for the closed loop and at the same time use type of connector that is used on the elevators? That’s the one I went for...works well. Picture tomorrow all being well Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 2, 2018 Author Share Posted March 2, 2018 Friday update, the Inwood parts ordered one day turned up the following day so great service there and only equalled by Bob Fults sending the nose gear form the USA on the 26th and arriving today! With this many bits there was only one thing to do, divert my attention to the nose gear as what can I say. Well engineered and easy to install. While ordering from Inwoods I just could not resist an ali spinner or two. With any luck I'll get on with the nacelle box modifications and then be ready to fit the engines this weekend. Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 2, 2018 Share Posted March 2, 2018 See...told you the Fults nose gear was worth it. I heard sometime ago that they used to make parts for banjos. How true it is, I have no idea Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 5, 2018 Author Share Posted March 5, 2018 Decisions and progress over the weekend. I took advice which concurred with my dislike of attaching the nose wheel steering and the now closed loop rudder servo and it was a bit of a no brainer as there is plenty of room in the servo tray. I didn't like the idea of having the steering inside of the closed loop clevis's based on servo arm failure resulting in no rudder and uncontrolled nose wheel. The remaining time was spent fixing control horns, gluing horizontal and vertical stabiliser and on making a start on the nacelle boxes! Before After The bulkhead needed to move back about 25mm with the loss of the servo tray (no real loss as the linkage looks like it could be quite contorted). I need to make a new bulkhead as the existing engine mounts are in all the wrong places and it looks like a tea bag already, plus some tidying up for the tank bracing. Once its all glued up and the engines mounted I'll look to mount the micro servos behind the carb/in front of the tank. Cheers guys and thanks for the help Edited By Chris Walby on 05/03/2018 08:50:01 Quote Link to comment Share on other sites More sharing options...
Jon H Posted March 5, 2018 Share Posted March 5, 2018 Posted by Chris Walby on 05/03/2018 08:46:54: Once its all glued up and the engines mounted I'll look to mount the micro servos behind the carb/in front of the tank. Cheers guys and thanks for the help Edited By Chris Walby on 05/03/2018 08:50:01 Good idea Chris but make sure you use the best servos you can. i have done this a few times and little HS55 types really dont cut it. The heat/vibration/oil kills them off pretty fast so get something good. You might even have space there for a full size servo so if you do i would use one of those. Its worth the effort as one throttle servo on my old twin scorpion suffered from the jitters on its way to the grave and that made for an exciting takeoff! Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 5, 2018 Share Posted March 5, 2018 Chris as promised... Edited By cymaz on 05/03/2018 17:52:55 Edited By cymaz on 05/03/2018 18:00:33 Quote Link to comment Share on other sites More sharing options...
simon burch Posted March 5, 2018 Share Posted March 5, 2018 Have you doubled up that front former? Simon Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 6, 2018 Share Posted March 6, 2018 Posted by simon burch on 05/03/2018 23:35:42: Have you doubled up that front former? Simon I don’t recall doing it..let me take a look later Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 6, 2018 Author Share Posted March 6, 2018 Simon, I am not sure what you mean by "front former" (its not in the The Model Flying Glossary) do you mean the bulkhead that steering leg bolts to? It is quite thick ply and has an additional support on the inside and my thought was to space the fixings to spread the load coupled with a decent nose leg strut the problem would be resolved, perhaps not? I'll take some photos and measurements then post. Edited By Chris Walby on 06/03/2018 06:53:23 Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 6, 2018 Author Share Posted March 6, 2018 Simon, Bulkhead is 8.5mm thick with a rib (if its the same as the others) is 2.5mm. Those with more experience can no doubt comment regarding the bulkheads suitability, but I would say if excessive force was applied to the nose wheel then the entire bulkhead would fail, by beefing it up anymore there is a chance of ripping the complete bulkhead out of the fuselage (a mess I would prefer to avoid). Quote Link to comment Share on other sites More sharing options...
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