John Timmis Posted September 14, 2014 Share Posted September 14, 2014 Hi folks Don't wish to jump the gun but it's time to start the blog. It's a first so there may be some hiccoughs. Why two Chippies? Well the first one was started in 197? & then put away in the loft for the next 35 yrs or so. Danny's post provided the perfect incentive to resurrect the build & also up my game a bit. After quite a long gap, which included getting married again, involvement with schools karting, classic cars & full-size gliding I got back into rc modelling about 5/6 yrs ago following a visit to Western Park & seeing the EDF jets. At first the rescued airframe (90% built) looked quite good. Only small damage to an aileron trailing edge. However, by the time the flaps & ailerons had been removed from the wing they had virtually crumbled to dust. Some wing ribs were also very fragile. I don't think it's worth the hours involved in a proper scale build but it seems to good for the bin. So the plan is to finish this one off asap as a stand off scale model, converting it to electric & generally use it as a prototype to solve problems. I'll do the best build I can within the limitations of time but definitely no rivets on this one. Hopefully it won't be to shabby & should be flying soon. Second Chippie starts in October & will have whistles & bells, we will see about the rivets. I'll put up some photo's when I find out how. Cheers John Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted September 15, 2014 Share Posted September 15, 2014 Great news John I look forward to seeing your progress Cheers Danny Quote Link to comment Share on other sites More sharing options...
John Timmis Posted September 15, 2014 Author Share Posted September 15, 2014 Hi again Chippie no1 This is what came out of the loft after 36+ years. Some parts turned out to be very fragile, the flaps & ailerons have been rebuilt. Quite a few wing ribs needed repair also. I would like to know the reason for this degradation. I think that wood should last indefinitely if it it stored in good conditions. Only the thin bits seemed to be affected. Anyone got any theories? One area of the build that caused som difficulty was the wing root fairing. The plan seems to me to be a bit vague in this area. What is drawn doesn't quite agree with my 3 view or photos. In particular the trailing edge of the fairing where it curves up to the fuselage. I ended up cutting off my first attempt & having another try. Lots of eyeballing involved. More photos next time now I've discovered how. Cheers John Quote Link to comment Share on other sites More sharing options...
Nev Posted September 15, 2014 Share Posted September 15, 2014 I like your plan John and will follow with much interest. This one doesn't look too bad. Funny but seeing this one part built and my own build doesn't look so daunting either. Any photos you can post will be closely studied I'm sure, by me for one. Stand by for the requests for AUW, size of battery etc. Quote Link to comment Share on other sites More sharing options...
Nigel Day Posted September 16, 2014 Share Posted September 16, 2014 Impressive John. I'm with Nev sitting i the front row, writing everything down..... Quote Link to comment Share on other sites More sharing options...
John Timmis Posted September 16, 2014 Author Share Posted September 16, 2014 Hi Just looked up at the sky to see what was flying overhead (as you do). It was a Chippie. Had to tell someone John Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 16, 2014 Share Posted September 16, 2014 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
John Timmis Posted September 17, 2014 Author Share Posted September 17, 2014 Hi Danny, Nev, Nigel. Thanks for your comments. Tom. Watch this space. It won't be too long now. Back to the build. You can see from the previous photo that the wing fairings have been done & also tailplane/ rudder fairing has been made. Elevators & rudder have been hinged temporarily. Now is a good time to construct the fuselage end/elevator fairing. I built this up from several pieces of sheet. It was tack glued to the fuselage & sanded to shape. Next job is to glue the tailplane & then the fin to the top fuselage shell. The rudder horn assembly can be added next. you will need to cut a small hole in the underside of the tailplane that you can fiddle it through. Ensure that it aligns with the hinges before the glue sets. I Grooved the bottom or the rudder & epoxied a short piece of snake tube to accept the wire rudder arm. The slot you can see in the lower fuselage shell was to take the tailwheel. More of that next time. Cheers John Quote Link to comment Share on other sites More sharing options...
John Timmis Posted September 20, 2014 Author Share Posted September 20, 2014 Hi Still lots to do before the fuselage shells can be assembled. I wasted lots of time trying to do a steerable tailwheel. It was a simple mechanism that worked on the bench but couldn't be assembled in the fuselage.Some thing always fouled it wasn't possible to see what it was. In the end I gave up & settled for a fixed wheel. A possible solution might be a bobbin on the tailwheel pivot & a closed loop drive. This could all be assembled in the lower fuselage before they were joined. Next time we move to the front end. Cheers John. Quote Link to comment Share on other sites More sharing options...
Nigel Day Posted September 21, 2014 Share Posted September 21, 2014 This is useful stuff Kev and some good ideas for me to store away. Quote Link to comment Share on other sites More sharing options...
John Timmis Posted September 22, 2014 Author Share Posted September 22, 2014 HI again, I returned home from the LMA show at Cosford with all the bits for the power train. 6s Dynam lipo, 650 kv motor ( 1150 watts, 230 gms), 70 amp speed controller. A bit more butch than I expected but still in the right ball park. I'm told that nobody asks for 5s lipos any more? Anyway, the model can now be lashed up to determine the the CG & the disposition of the components. Note that this is only a lash up. the motor is held with duct tape & the fuselage is rubber banded together. It turned out quite nose heavy & a battery compartment had to be created with an access through F2. Next step will be to sort out the motor mount & plan the battery compartment/ cooling arrangements. Cheers John. Quote Link to comment Share on other sites More sharing options...
John Timmis Posted September 22, 2014 Author Share Posted September 22, 2014 HI again, I returned home from the LMA show at Cosford with all the bits for the power train. 6s Dynam lipo, 650 kv motor ( 1150 watts, 230 gms), 70 amp speed controller. A bit more butch than I expected but still in the right ball park. I'm told that nobody asks for 5s lipos any more? Anyway, the model can now be lashed up to determine the the CG & the disposition of the components. Note that this is only a lash up. the motor is held with duct tape & the fuselage is rubber banded together. It turned out quite nose heavy & a battery compartment had to be created with an access through F2. Next step will be to sort out the motor mount & plan the battery compartment/ cooling arrangements. Cheers John. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted September 22, 2014 Share Posted September 22, 2014 What size prop are you using for those figures John?CheersDanny Quote Link to comment Share on other sites More sharing options...
John Timmis Posted September 22, 2014 Author Share Posted September 22, 2014 Hi Danny I got a 14/7 but haven't tried it yet. It is one of the recommended sizes for the motor. Cheers john. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted September 22, 2014 Share Posted September 22, 2014 Hi John well as you no doubt know the Chipmunk has a 6'10" prop so at 1/6 the scale size would be 13.666" so you are very close to the money Personally I like to reduce the prop/motor noise and would go for a coarser pitch and drop the revs for cruise perhaps a 14 x 10 but you will be fine I am sure with your set up. Look forward to seeing how you get on, loved your tailwheel set up, shame you couldn't get it to work in situ. Cheers Danny Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 22, 2014 Share Posted September 22, 2014 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Andrew Price 2 Posted September 22, 2014 Share Posted September 22, 2014 All good stuff. Quote Link to comment Share on other sites More sharing options...
John Timmis Posted September 25, 2014 Author Share Posted September 25, 2014 Hi folks. Just logged on to update the blog & found that the ipad is playing up. I can't upload photos from the ipad library to the Model Flying album. The software was updated a couple of days ago. Anyone got any ideas? Cheers John Quote Link to comment Share on other sites More sharing options...
John Timmis Posted September 26, 2014 Author Share Posted September 26, 2014 Hi again, The ipad seems to be working again so lets get on with the fuselage. As you can see from the photos. The engine bearers were retained but needed to be spaced out to allow the battery to fit between them. They were also cut away from the upper fuselage shell & glued into the lower half. The battery compartment will be the rectangular hole in the former. The rounded hole below it will be an air cooling duct. The photos also show the servos in place in the front cockpit. I used standard size servs which do encroach a bit into the cockpit space but the hope is that they will be covered by the pilot. The receiver battery will be installed below the seat in the rear cockpit. Next instal the rudder & elevator linkage. I used snakes. Don't forget to secure the clevises and ensure that thy won't unscrew. You may want to build in some cockpit detail at this stage. When you really can"t think of anything else to do, only then think about joining the fuselage halves. To join the shells I linked together a long string of rubber bands. Starting at the tail, over the elevator & then work round the fuselage up to the front . The roll of newspaper protects the soft fuselage spine. Quote Link to comment Share on other sites More sharing options...
John Timmis Posted September 28, 2014 Author Share Posted September 28, 2014 Hi folks About this time the canopy & cowl arrived from Traplet enabling further progress to be made in the motor / battery area. A motor mount was cut from 6mm ply, the cowl drilled for the motr spindle & the air intake sanded out with the dremel. The whole thing was now assembled for a tril fit & a photo. Cheers John Quote Link to comment Share on other sites More sharing options...
Terry Walters Posted September 28, 2014 Share Posted September 28, 2014 Hi John - just catching up with your 'finishing off' build which I'm sure a lot of us will find useful. Keep it up Terry Quote Link to comment Share on other sites More sharing options...
John Timmis Posted October 1, 2014 Author Share Posted October 1, 2014 Hi folks, Sorry to interupt the building. The ipad is playing up again so the text will be brief, the photos will have to explain themselves. This shows what is under the cowl. The start of the motor mount & the battery compartment. The 2 pegs locate the top cowl. The rounded hole is for the battery cooling duct. Thats all for now. Heads down again. Cheers John. Quote Link to comment Share on other sites More sharing options...
Nigel Day Posted October 1, 2014 Share Posted October 1, 2014 Really useful, thanks John. Quote Link to comment Share on other sites More sharing options...
John Timmis Posted October 1, 2014 Author Share Posted October 1, 2014 . Hi again Here are a few more photos of the cowling. Getting this right with a good fit to the cowling halves is crucial. Don't rush this, time spent here will pay off. I don't know what experience others have had, but I found that epoxy didn't work to well on the cowl moulding ( which is polyester). I ended up using Ronseal wood filler. Cheers John Quote Link to comment Share on other sites More sharing options...
John Timmis Posted October 1, 2014 Author Share Posted October 1, 2014 . Hi again Here are a few more photos of the cowling. Getting this right with a good fit to the cowling halves is crucial. Don't rush this, time spent here will pay off. I don't know what experience others have had, but I found that epoxy didn't work to well on the cowl moulding ( which is polyester). I ended up using Ronseal wood filler. Cheers John Quote Link to comment Share on other sites More sharing options...
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