Jump to content

Martyn's Chippie RCAF 671


Martyn K
 Share

Recommended Posts

Advert


I have just about finished with the fairings. Constructionally and emotionally. So, I have made a start on the cockpit. Following Danny's lead i have used aluminium foil tape for that realistic metal effect. It is quite tricky to get it into the corners without damage and i need to redo a few areas. Not a huge problem. However, i have noticed that Danny appears to have removed the two longerons and i wondered whether there is strength discontinuity as a result do I need to add a little additional reinforcement to compensate?

A couple of photos.

img_0396.jpg

You can see the foreshortened seat in this photo. I am not entirely happy with this. If i extend it then the diagonal sides are too close to the floor which is too high. Not sure what the best compromise is - I would welcome your thoughts and suggestions.

img_0397.jpg

The floor is very thin - about 2mm correx sprayed satin black from a rattle can. I am quite pleased with the effect and it chips quite easily for that nice used effect.

More to come

Martyn

Link to comment
Share on other sites

Thanks Danny. I was thinking of the large double longeron that links the top and bottom halves. I have simply reduced mine in width and painted it black.

I did a bit more on mine last night - started adding some detail and even worse - riv*ts..

cockpit3.jpg

There are a couple of pipes on one of the photos I have that are conveniently aluminium coloured and I used what appears to be appropriate thickness aluminium tube

I think it may actually be a closed loop throttle cable

cockpit2.jpg

Then started on a battered VHF radio. Not happy with this - except for the tuning knob. The switch heads are way too big so will probably get replaced. Stuff like this is quite tricky - especially as the image I am working from isn't especially clear. Black on black... with specular highlights to really wreck the contrast

Finally - riv*ts.. I am using a syringe with a green tip - once I get the flow rate right its quite quick and easy to dispense rivets and I can do three rows like this on one pressure charge. I am using 'No nails' PVA (Black bottle) which is slightly thinner that Resin'W' - green bottle.

Still need lots of practice though..

cockpit1.jpg

The riv*ts have dried clear overnight and have absorbed the black background. You can see them in the right light but I need to experiment with dry brushing to 'lift' a few.

So pleased with the resuIt that I did all the riv*ts for the seats and remaining stringers in the front and on the port side this morning..

Also done the joy stick and either the flap or brake lever. Not sure what it is. Mine are all black from the photos I have so are operating in stealth mode. Handles are from heat shrink.

Yes - I am enjoying this. Can't wait to start dong panel lines and even more riv*ts.. Not doing stitches though

Honest. laugh

More to come

Martyn

Link to comment
Share on other sites

  • 1 month later...

It was all going so well then I went on holiday for a week and since then its been a case of "errrrrr what do I do"? Mojo well and truly misplaced.

Still working on the cockpit detail but I realised I needed a couple of pilots. My seats are too high - as is the floor so scale things with depth just were not looking as right as they should

So I needed some pilots. Eventually at a local Antiques and Bric a Brac emporiums on one of the last stalls I found 2 Action Men and one Ken (Barbies other half). Poor Ken, looks such a wimp compared with the muscular AM but then I realised he has a better physique than me so I'll shut up.

Clearly - with the reduced height seat and floor they don't fit so they have had their lower torsos removed by the bandsaw. I didn't hear any screaming but my daughters will never speak to me again.

dsc_0103.jpg

and

dsc_0104.jpg

and

dsc_0106.jpg

Blood and guts have been washed away.

They look about the right size.Ken is definitely a hippy and I'd better get some clothes on the front one in case Ken gets the wrong idea.

More to come - but slowly.

Martyn

Link to comment
Share on other sites

  • 4 weeks later...

A bit more progress now the FF nationals are out of the way.

I have hit a mental block on cockpit detail so am parking that for a while.

Decided to bite the bullet and get the tailplane and fin glued into place. Ideally upright and horizontal as appropriate.

So carefully sanded the seat and glued and clamped the tailplane in place. I have used a bent rod and keeper for the elevator linkage push-rod.

tailplane1.jpg

Big clamps holding it all together..

 

One bit I was dreading was carving and fitting the tailcone. I tried using foam like Danny did but failed miserably so here is my balsa version. Laminated from balsa but with a liteply top deck to give a nice sharp edge. Extensively hollowed out - much more than shown on the plan.

tailplane2.jpg

Quite pleased with that.. I had to use a shim of 1/64 ply on one side to keep a nice even narrow gap between the elevator and the deck but it looks ok.

The fin was fitted. A slight mod to the plan though. My rudder tube was sandwiched between two small liteply plates and a block of wood behind the tube rather than bound to the fin post as shown on the plan. Made it less fiddly to assemble - although it was still quite fiddly getting it all to line up. Used slow set epoxy to keep it in place

I seem to have lost a bit of of left rudder in the process - and I have no way of investigating why...

 

Another change of powerplant.. I have acquired an OS70FS that has been converted to spark ignition. However, it still has a standard carb fitted so am not sure of its suitability for petrol (although it has been fitted with a Tygon fuel line)... Need to do some testing to decide what fuel I will run it on. Andy Green has suggested running it on glow which in hindsight seem seems like a good idea although for cleanliness I would have preferred petrol.

 

os70.jpg

It fits perfectly...

To check the fit, I started removing fibreglass from the cowl - a pilot drill and then a dremel with a sanding drum. Much easier than expected. Since been cleaned up a bit more

os70-2.jpg

 

You can imagine a Gypsy Major in there is you squint very carefully

 

With all that done, it was time for a dry assembly shot.

assembled1.jpg

and from the front..

assembled2.jpg

and from the rear

assembled3.jpg

You can see the antispin strakes in the photo.

antispin.jpg

These are cut from 5mm spruce and carefully sanded. Which will be tricky is the junction from the strake to the tailplane. The blurb states that the strakes are perpendicular to the fuselage sides which makes for a messy tailplane junction.. Its hard enough doing things tidily. It will be very tricky to make them messy in a controlled fashion.. I'll worry a bit more about that after the fus has been glassed

Last night I covered the Flaps and Ailerons. Rib tapes next while I still check for things I need to do before the glassing starts

More to come. Getting far more enthused about this now..

 

Martyn

Edited By Martyn K on 05/06/2017 10:49:25

Link to comment
Share on other sites

I shouldn't worry too much about the strake/tailplane junction Martyn. On all the full size Chipmunks I've seen it's been different, there's always a gap ranging from 'not a lot' to 'quite a bit'. Many of the strakes were retro-fitted (I've made and fitted a few myself) so they're all a bit approximate.

Link to comment
Share on other sites

Hi Martyn

It's looking good. Glad to see that your back on the job again.

My chippie has been grounded for about the last 9 months with duff lipos. I flew it again last Sat with new batteries.

No problems apart from a tendency to tip onto it's nose. The new lipos are a bit bigger physically & about 4 oz heavier. Need to check the cg.

Cheers John.

Link to comment
Share on other sites

  • 4 weeks later...

A bit more progress. After digging out my mojo and giving it a good kicking and sending it back into the shed I cracked on with the fuselage.

I have glassed the Fuselage (and wing LE) but used eze-kote instead of resin. If you havent tried it, then I really recommend it it. No smell, no waste, wash out brushes in water and goes on so much more smoothly. Sands very easily as well. Basically, you prime the wood with a thin coat of eze-kote, allow to dry, lay the cloth down and stipple the 'resin' trough. Dries smooth and because its water based it looses weight. I needed two thin coats to fill the weave,

Which left me to prime with high build and sanded down with 320/400 grit wet and dry.

fuselage1.jpg

and

fuselage2.jpg

Anything needing filling was filled and then a thin coat of the eze-kote applied on top after the filler had been sanded smooth

While this was going on I was working on the wings. Same approach for the LE sheeting - except I haven't primed it yet.

The ribbed area covered in solartex and the edges sealed with eze-kote.. (getting monotonous now)

wing_tapes1.jpg

Wing tapes have started to be applied - except I have run out and now waiting for more from Mr Reeves.

So back on the fus, Everything sanded down smooth and then polished with 1200 wet & dry and then started marking the panel line locations.

panel-lines1.jpg

and

panel-lines2.jpg

I am not totally happy with the width of the joining band. Scaled from the 3v, but I think its too narrow so I'll try and get the size from a photo.

and

panel-lines3.jpg

The other detail addition that I added last night was the reverse venturi under the fuselage used (I think) as a cockpit ventilation. No shown on the plan and because the fairings and flap sizes are hopelessly non scale the location was a bit of a compromise. Its also a bit rough at the moment - needs tidying up a bit.

airoutlet1.jpg

Edited By Martyn K on 30/06/2017 10:23:09

Link to comment
Share on other sites

  • 2 weeks later...

Still cracking on with this. Last week, I bit the bullet and started on the panel lines. Something I have been dreading for a while..

Following Danny's lead I got some filler knives from Pound land (£1 for 4) and am using Isopon P38

panel0.jpg

Just a few photos to show how I am getting on.

I used some decent PVC insulating tape - double thickness - as the mask ,. Marked out the fuselage where I thought the panel lines should be and just did one or two at a time. Its been slow progress.

panel6.jpg

I used a dry white board marker for the markings, thee lines come off easily with a drop of acetone. On the piccie above the lower longitudinal line was marked in error, you can see the upper panel line above. Basically its a case of mark the line, add the mask, add the filler, let it harden, sand it down with very wet, wet and dry until the tape is showing again and feather into the fuselage then remove the tape.. Not really difficult, just time consuming

panel5.jpg

Wrong order, here is the shot with the tape still in place

panel4.jpg

Fuselage joining band overlaid, quite pleased with that. Same process

panel3.jpg

Now this is my oops. What I should have done is done the vertical panels first then the longitudinal line. It makes a lot of sense to assemble the panels lines in the order they would have been built on the aircraft.. I had to terminate the line at the horizontal join, mask what I had already done and then feather the vertical line into the corner in two directions. I think it will be OK

panel2.jpg

The wing fairings, After spending ages getting the fairings right, it hurt to plaster filler all over them..

Ignore the splodge on the fus, it's just sanding debris

panel1.jpg

Finally - and still in progress. The rear tailplane/fin fairing. Again same process but somewhat more tricky to sand. I actually did this last night, sanded its smooth this morning but I wasn't happy so have redone parts of it

It all looks like a lot of filler but I guess 90% will be sanded away. P38 is good for that.

More to come.. wind panels next then rivets..

Martyn

Link to comment
Share on other sites

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.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...