SLEC Chipmunk build blog

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. I 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

Hi Tim, I have the same Chipmunk made by Apache Aviation which I bought already built, so I'm looking forward to your build. Mine has the one piece wing.

Good luck

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

Looking forward to following your build Tim, I bought the same at the nationals and have made a start on the undercarriage supports. However the build will pick up more pace once the nights draw in and flying is restricted.

A 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.

I do love the Chipmunk

Edited By Rich too on 17/09/2019 20:56:11

I’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.

Oops double post and thank you Rich for your comment 

Edited By Tim Flyer on 30/09/2019 15:58:10

Edited By Tim Flyer on 30/09/2019 15:59:49

Watching...

The 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

I doubled the thickness of the centre part of the inside rib using spare liteply from the kit as I thought the single thickness wasn’t that durable with the open joiner bay .

I like the square tubing to keep the sheeting straight. Is there the option of a two piece wing?

You've got me looking at getting one of these, as you never know how long they will be available.

Following with interest. Does the SLEC Chipmunk have advantages over the Bryant Chipmunk from Sarik?

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.

Ah, I see, got it

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.

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

Here are a couple of recent photos of the wing build, first the aileron hinge blocks that are sanded then glued in to fit between the aileron spars. This is done before the bottom spars are added, the second photo is of gluing the leading edge.

Gluing leading edge

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