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SLEC Chipmunk build blog


Tim Flyer
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Hi fellow flyers ! Today I started the build of my SLEC Chipmunk I had bought at Wing and Wheels in June. The first thing I did was pencilling the numbers on all the parts to avoid confusion. I started with epoxying the undercarriage supports on the ribs. It is the RAF trainer version which many are familiar with in full size . I chose it as my first 1:5th scale substantial size build as it seems relatively simple to build rather than some of my other favourite war birds plus the Chipmunk is a great easy to fly plane not requiring retracts etc. I decided to buy the kit as it gives extra control of the build rather than having to put up with an ARTF build that has been finished to hit a price level. I must admit I’m no expert builder at all and don’t really like painting. The kit is well cut from quality wood, and the plan and instructions quite detailed . The cowl is really substantial fibreglass and the canopy good quality. There is decent hardware supplied but I’m going to use some spare Oleos on the legs. It’s a nice big model which still just fits on the bench. I’m pleased the wings are two piece! Spares are also readily available at SLEC Which is great to know and a BIG plus versus ARTFs. 49197768-5e26-4ac4-a78d-f543d0c9e257.jpegI did build a Warbird replicas LA7 just over a year ago and I like that so hopefully this one might be better. I’m still debating whether in painting this or film covering it but that’s further on. It will be powered by my trusty Laser 180 I have spare, so there will be no shortage of power!

Edited By Tim Flyer on 16/09/2019 13:13:31

Edited By Tim Flyer on 16/09/2019 13:16:05

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Cheers Ash good to hear , we can compare notes . I will post photos as I go . I’m looking forward to getting into this one. I’m also looking forward to flying it as I used to really enjoy my smaller 60 sized Blackhorse ARTF Chipmunk. The two piece wing uses a ply brace which certainly looks very solid. So far I’m just doing the early stage u/c bits on the wings

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2b4e1fdd-9c7f-4f99-aa41-4fa37d779ba0.jpegA bit more done today . I partially assembled the right wing. Instructions say left first, I’m not quite sure why though. The wood fits well together but doesn’t seem to exactly match the plan. The tabs underneath the ribs and central spar web do help it all to line up . Some bits of the instructions don’t seem quite right but I will have to see. Here is how far I am now . I will add stringers tomorrow.

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  • 2 weeks later...

d74c1dd5-2059-4a37-95b1-28b00021317c.jpegI’m slowly soldiering on with the build. It’s been fairly straightforward so far. It’s definitely worth making sure the inside ribs are dead flat when building as they are made from light-ply and can easily twist despite the centre jig. Mine needed a bit of sanding as there was a slight twist. I also added a small bit of reinforcement.
I’m in the process of sheeting the left wing at the moment. As I use Aliphatic resin, drying is best overnight. I used long aluminium bars , elastics and clamps to hold the sheets in place .
Putting in the hinge blocks was a little fiddly and needed plenty of sanding. After they were glued in with Aliphatic I added gorilla glue to fill some of the void and prevent them coming loose when I cut the hinges. I will be using flat hinges that I bought from SLEC. One interesting point is that the plan states just 3.3kg BB servos are recommended on flaps and ailerons so expensive gear isn’t really necessary. Next task is cutting out the wing joiner bay.

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a5a4a162-9bbf-434b-8d81-1562d9d31eb0.jpegThe wing joiner box is finished . This is left open for access to the bolts. The ply joiner spar is glued into the right hand wing at a later stage. Next job is fitting capping strips on the ribs and servo bays. I also fitted paper guide tubes for the servo leads . I’m also sheeting the right hand wing .

Edited By Tim Flyer on 04/10/2019 10:07:54

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Hi Chaps.

Rich the two piece wing is standard on the SLEC version. As I mentioned above the wing joiner is Ply . It has removable bolts one side and is glued on the other . It’s a strong arrangement that holds the ply between the two hardwood wing spars.

Hi Barryt im afraid I’m not familiar with the Bryant version. The SLEC version is a newer version of the old Apache Models Chipmunk that was well known and well flown I believe. I chose the SLEC version due to easy access to spares and SLEC are very easy to deal with being large wood suppliers. If is a “sport scale” model rather than a full on scale kit for the specialist scale modeller. I’m sure though it could easily be built to far higher scale standards than standard. My build will certainly be sport scale . I’m look to build a durable easily flown model that can be flown in most conditions rather than a masterpiece. I’m afraid I’m certainly no building expert but so far this kit seems quite straightforward. There is slight variance to the plans i have noticed in that the outer wing rib cut out spacings are not quite perfectly mirrored by the plan but I have found that immaterial and doesn’t cause any issues. All in all I’m very happy so far . I plan to cover the model in film rather than have the hassle of painting.

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Hi Tim. Thanks for the feedback and explanation. I recently started looking for a future Chipmunk project and came across your build thread which is excellent. I also came across this Bryant build thread which would certainly present a challenge for me. **LINK**

A slightly simpler sport scale model would probably be my preference.

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The thing I really like about the Chipmunk (apart from looks) are it’s great flying characteristics. I used to own a Black Horse ARTF Chipmunk that was really fun. I would say they are an almost halfway house between an Acrowot and a Warbird and are a great trainer for warbird flying . My old Chipmunk would tip stall if provoked but could handle crosswind landings well due to the large rudder. It was also very capable of terms of aerobatics. The simple fixed undercarriage is also a really big plus( I do plan to fit oleos on this one just like the black horse version)  . In terms of building this big model is actually fairl simple. As this kit is big it’s less fiddle than many smaller planes . I’m not a hugely accomplished builder by any means but I would say this kit isn’t that difficult. It certainly requires some thinking and time for “dry assembly” in order to check fit and adjust. The wings build straight on top of the plan and the ribs are specially built with tabs so if can be built flat on the plan. I put a plasterboard sheet on my building bench to pin it on . It works well.

 

Edited By Tim Flyer on 06/10/2019 14:45:18

Edited By Tim Flyer on 06/10/2019 14:46:45

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The build seems to be going quite well now . I’m just catching up the left hand wing with the right hand wing . I’m putting in the capping strips on the ribs and have to finish the last small bits of sheeting on the right hand wing and aileron and flap servo installation. As I use Aliphatic glue overnight hardening stops are often used . Now and again I have used cyano but due to its short working time and tougher sanding properties I use it far less. I bought a couple of bottles of Titebond aliphatic which is good value. For finishing the plane I plan to water down the titebond and paint the plane with it . The titebond aliphatic will act as a sanding sealer. Film adheres well to aliphatic as when heated it becomes sticky again . Anyway it will be some time until that point!
My next major job is cutting the aileron and flaps. The good thing on this plane is that it is one long straight line that needs cutting as the leading edge of the flaps and ailerons are in line . Once done this will require facing and hinge cutting. I’m using flat hinges which I bought from SLEC . My reasoning is just that I find them a bit easier to install and set up than Robart hinge point hinges. I find it easier to see whether the flat hinges are square and central due to their shape. On this model if one chooses to use Robart hinge point hinges on the flaps the plans recommend recessed hinge fitting which does slightly increase the work.
Once I get to the aileron/flap cutting I will add photos.

Edited By Tim Flyer on 10/10/2019 14:19:57

Edited By Tim Flyer on 10/10/2019 14:21:21

Edited By Tim Flyer on 10/10/2019 14:22:02

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One other thing I might mention is that I haven’t yet totally finished the wing tip and leading edge profiling. I only partly completed this as due to its large size it’s very easy in my small workshop to slightly damage the surfaces so I wanted to try and do the finishing at the last stage . It’s also worth noting that the centre wing profile needs to match the wing capping on the fuselage, plus the front centre section of the leading edge needs to be flat where in meets the fuselage and wing dowel recess area. That’s why I have been conservative with sanding so far .

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Here are the flap and ailerons cut out . It’s not too difficult. Firstly a narrow cut is made and widened slightly along the line between aileron/flap spars with a scalpel on both sides followed by carefully running the razor saw along the line to separate. I purposely did not finish the trailing edge as the square edge makes sanding and alignment easier at a later stage . The same goes for the leading edge and wing tips . Leaving them square on the edges protects them and will allow easier blending in later .

I will be using flat hinges which makes the flap installation easier, with no recessed hinge line required.

4e55a787-a465-4780-b08e-33b72f0534ae.jpeg

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Hi Ron and Rich . Thank You very much for the encouragement. Much appreciated. This is my first large 1:5th scale build so it certainly is a new challenge in terms of its size. In some ways the bigger build is much easier as it’s far less fiddly than a smaller plane. The Perma-Grit tools and razor plane are coming in very handy. The other tools I have used are aluminium square rods. These are great as straight edges and for clamping. I bought them on line a while back when I was bus new extra long wing tube for my Hurricane. The aluminium supplier wanted just abou £5. For a long length of wing tube but their minimum order was £20 so I added a number of aluminium angle lengths and tubes that come in really handy. A whole load only cost me £25😊

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