Jet Provost Build by RedBaron

[RedBaron]

13/01/2014 - RedBaron starts posting on his JetProvost build.

 

Introduction: I am not comfortable with the traditional linear style of most build blogs. There is nothing wrong with that style it is just that I have another approach that suits me better. Also on this forum, for good reason, it is not possible to go back and edit stuff as things evolve, nor can one delete bits better left out.

 

My approach to build write-ups: I have started a NoteBook on my JP build using M/S OneNote. This NoteBook has a number of sections such as:

 

• Links to other parts of this Forum
• Prebuild decisions , much of this is gleaned from designer Andy Blackburn. Thank you Andy.
• A shopping list for stuff not in the cut-pack
• Fuselage build
• Wing build
• Etc.
• Eventually I will add a set-up section

 

No section is complete, it is work in progress.

 

How do I use the NoteBook: I tend to muse on options for approaching the next build task for my own benefit. Then I document how it went with suitable photographs. Perhaps some will find this a bit tedious, but I often wish other bloggers would document their thought processes as they are not always obvious. I know others will do it a different way, but at least I will give you some ideas to reject.

 

Where is the NoteBook: I have stored the NoteBook on SkyDrive in a public folder on my account. I will put the link below in a moment. I originally did this so that I could access it from my main PC and also from my iPad, that keeps me company in the hangar, as also do two of our cats who are often critical of my ideas. They also tend to sneak stuff from the build table and hide the booty around the house. I can edit the NoteBook, add to it, re-structure it easily if the whim strikes me wherever I am. It is also available "read-only" on Forums such as this one.

 

How will you know if anything has been added: Well the best way is to have a look. But when some interesting stage completes I will post some short notes on this Forum with a photograph or two as a tempter to look at the actual NoteBook.

 

Feedback: I would be pleased to get any feedback good or bad on style and content, posted here. Any good ideas I will sneak into the NoteBook with proper credit noted.

 

 

I thought that this was a good place to start my posting on this fine little model.

 

The link to my NoteBook:

 

skydrive.live.com/redir?resid=B02CB5DF3A04E5A2%21105

 

Should get you to a public folder on Skydrive. Click the Jet Provost icon. This should open an M/S OneNote file in your web browser.

On the left hand sides is a list of the included sections, click your choice to visit that page.

And finally for this first post a lot of thanks are due:

To

• The PSSA for organising this mass build and for being an inspiration to a lot of slopers
• Andy Blackburn for an extra-ordinarily good plan
• Traplet for a super cut parts kit and canopy
• ModelFlying for a fine Forum
• The forum moderators - unsung heroes (I am one on another forum).
• All the builders and flyers doing their bit
• Anyone who I forgot to mention sorry

 

Watch this space for more….

Edited By RedBaron on 13/01/2014 21:02:15

[IanN]

That's an interesting way of looking at it.

I'll be following this one

[RedBaron]

Where have I got to on the project today?: Whilst quertyuioping here the glue is drying on the completed battery box assembly, sides applied and squared up stage. Photograph of that stage of build, with Pete's Pilots checking it out, is here:

I thought that this was a good place to start my posting on this fine little model. For all the details check out my NoteBook, the link is above.

 

Edited By RedBaron on 13/01/2014 21:52:55

Edited By RedBaron on 13/01/2014 21:53:36

[RedBaron]

Whilst the fuselage is still open top and bottom, is the time to sort out control runs and all connections. It can be done later but you might need very small hands.

 

 

Today I added to my NoteBook some detailed information on how I connected the elevator and rudder servos to their respective control surfaces.

 

 

Experts of course will already know how to do this, but builders without many models in their build log may find the comments of some use.

Edited By RedBaron on 14/01/2014 20:40:56

[Alan Gorham_]

Looks good, I've had the plan for this for a couple of years.

What are you going to do for a canopy, Traplet aren't listing one?

[RedBaron]

Hi Alan,

Thank you for your comments.

I got my canopy from Traplet as part of the PSSA Jet Provost package - cut parts plus plan plus canopy.

Even if they don't list it I am sure it could be supplied if asked for.

Regards

RedBaron

 

 

 

Edited By RedBaron on 14/01/2014 21:01:02

[John A H]

Vortex Vacforms supplied a canopy for my build last year (it maybe that they provide the canopies to Traplet). If you want the "sliding canopy" effect you buy two canopies and cut the very rear section out of one and the middle/front section out of the other with them overlapping at the join, just like the real thing.

[Alan Gorham_]

Ah, ok! A canopy IS available then, just not listed on either Vortex or Traplets websites...

Thanks for the info both of you. I might just have to ring up and ask for prices then.

[John A H]

Think I sent vortex an e-mail asking if they could still supply them (the original article in QEFI mag 2006 gave them as supplier). Got a response within a day with price etc.).

[Alan Gorham_]

Just for info of anyone else building a J.P. traplet now list the canopy.

It's CA3182CY and the cost is 5.40 GB pounds plus postage.

[RedBaron]

Thanks Alan,

For that helpful bit of research.

Rgds

RedBaron

[RedBaron]

Today I installed servos, connectors, snakes etc. into the fuselage wing bay. I also painted the inside of this section a light grey acrylic. I have a weakness for painting insides where they will be seen, I guess it is a consequence of a lifetime of full size flying especially high performance modern gliders. Here is how the wing bay looks now, all the connection stuff about as simple and easy as I can imagine. Snake supports will be done later.

 

 

Contemplating all that balsa sheet work and shaping to do, I decided to complete the nose section horizontal and vertical shape with 1/16 hardish sheet as per plan. This was just tacked with cyano. It does mean a few more cuts when doing the sheeting but at least it does make a shape guide right at the front.

 

 

What next, hmm I fancy having a go at that aileron torque tube, very interesting. Also perhaps I may make a start on the wing. The fuselage sheeting can be done in sections whilst wing stuff glue is drying.

 

For more detail see my NoteBook, the link to this on SkyDrive is in the first post of this thread

Edited By RedBaron on 17/01/2014 00:02:55

Edited By RedBaron on 17/01/2014 00:04:13

[Stevo]

Well done RB.

I nice IT solution to the limitaions of a build log on a forum such as this - I applaud you. I did set up a forum once with a similar solution - proper edittable galleries, proper blog facilites with editting of previous postings etc and of course a forum.

I directed everyone to post thier builds on the blog part of the website - after 24months of trying I gave up - it all went on the forum!

Might be good to get a more friendly URL and point it to the Skydrive URL - at least we could remember it!

Your doing a grand job - I wish I had your time!!!

Steve

[RedBaron]

Thank you Steve for your kind words.

It can't be easy running a forum even being a humble moderator as I am on another forum takes effort.

I have found it a good solution just to be able to iPad in the hangar and see the same stuff on my main machine. Linking it to a forum was an added bonus anyway it is work in progress.

I like your idea of a snappier link name. I must admit that I did not think about that as I imagined folks clicking the link the first time and then bookmarking that file on Skydrive (folk can name the bookmark as they personally wish). Thereafter using the browser bookmark?

On the time thing, believe me I am fitting this stuff in between acres of other things.

Thanks again

RedBaron

[Stevo]

There is another solution - write a book

I know with my Be2c Thread on here, Traplet are interested...!

There is probably a need for a dedicated build website somewhere, however thats such a niche product!!!

If you set up your own URL, you may well drive others to your skydrive by way of the META Tags of course?

[RedBaron]

17 January 2014 The torque tube and fittings: For me the words and measurements on the plan do not quite work. Certainly not the fault of the plan, probably due to dimensions (particularly inner diameters) varying depending on where you shop for materials. After a bit of fiddling with stuff in the hangar I can note that my definitive set of materials is as follows:

Wire 16swg which is about 1.6mm diameter

Aluminium tube, K&S external diameter 3/32in

Carbon tube external diameter 4mm

Blue snake outer for the bearings with external diameter 5mm

The aluminium tube is a slightly loose fit in the carbon tube I intend to "centre it up" with a thin shim of masking tape around the aluminium. Concentric-ness will be critical for smooth operation.

Where the aileron horn fits into the aileron I intend to use a sliding fit in some of that aluminium tube (epoxied into the aileron) to give some forgiveness in the setup. The wire horn will also be shorter than on the plan, 18-20mm as recommended by Andy.

The parts for one torque rod are in the top row and below is the other one temporarily assembled to check against the plan and check free movement. I can't say that that was the fastest aileron connection that I have ever made but it was certainly the most interesting. I think that I will leave any gluing here until the wings and ailerons are constructed, just in case any modifications are necessary. How will I connect the servo end? I am beginning to feel a ball joint coming on.

[RedBaron]

I haven't renamed the NoteBook link yet so I will repeat it here:

skydrive.live.com/redir?resid=B02CB5DF3A04E5A2%21105

Maybe you could bookmark it in your browsers for now, thanks.

Edited By RedBaron on 17/01/2014 21:01:36

[RedBaron]

19 January 2014 Not a lot done this weekend as nice weather and flying all day hmmmm. Well I did get the lower wing skins joined, ribs and spars and webbing glued up (R1s not glued yet). What a beautiful little structure.

 

 

I decided to build on the complete lower wing skin. Hopefully making the wing join - dihedral work simpler as root shapes will be truly identical. The thought being that I would cut a narrow V cut-out in the centre to accommodate the curve-up of the sheeting. Also at the point of setting the dihedral to score a shallow cut underneath the wing to facilitate the dihedral, and that the wing halves were never be completely separated.

 

The other thought I had was that I would like to do built up ailerons, fit pinned-hinges and the torque rods getting them lined up properly before the top skin goes on. This may seem like a lot of trouble compared with the simpler sheet aileron idea, but I just like engineering in wood.

 

Use the link to my NoteBook for all the details.

 

 

 

Edited By RedBaron on 19/01/2014 21:57:49

[RedBaron]

21 January 2014 Flying has been interferring with building, but I am not complaining. Basic wing structure done and one built up aileron installed. In my NoteBook link earlier in the thread I have included the extended wing tip ribs for anyone going this route.

Having got this far with the wing it seems natural to use the lower wing skin as the wing trailing edge adding two staggered laminations of 1/32 inch hard balsa. I intend to keep the t/e quite blunt, not less that 1/16inch and with a sharp vertical edge. In theory this will control the boundary layer better (not sure at this size?) but whatever don't try to round off the t/e.

Next will be finishing up the other wing and installing that interesting torque tube.

[Matt Jones]

Is the gap at the inboard end of the aileron deliberate and if so, why?

[RedBaron]

Thank you for your question Matt,

Yes the gap is deliberate - as per plan.

The tiny rib at the inboard end of the aileron is at right angles to the hinge line. The main ribs are not.

After the top skin is applied a small piece of balsa is shaped to fit the gap (glued to wing) and is faced with 0.4mm ply.

Hope that clarifies things

Best wishes

RedBaron

 

 

Edited By RedBaron on 22/01/2014 12:37:36

[RedBaron]

25/01/2014 - I have had a busy week on other activities, but have still accomplished some progress on the wings. Nothing picture worthy yet, but you might want to see the detail notes in the build notebook:

**LINK**

[RedBaron]

28/1/2014 - I have installed the first torque tube now. No problems here just mark out the tube centre line on the top of the ribs, this being inline with the aileron hinges. Using this as the datum mark out the cutting lines to suit your torque tube bearings and cut almost to the bottom of the rib. Use a sharp knife blade to remove required amount to line up the torque tube and hinges in this plane. Here is what it looks like now, note the aluminium tube in the aileron to take the wire snuggly.

I still have to put the scrap balsa over the torque tube slots. Then repeat everything for the other wing, design the servo box / mount and I will be ready to fit the top wing skin.

[RedBaron]

29/01/2014 Both wings now to the same state of build. The servo box frames have been installed, a last clean up over the spars done and also a careful shaping of the top edge of the false leading edge accomplished. Do keep the taper even and symmetrical for each wing. I can't think of a reason not to make up the top skins and fit them now. Maybe a play and check with the dihedral brace and the actual dihedral amount first. Here is what it looks like at this stage assembled with the fuselage to check adequate clearances inside.

The Rx will probably be mounted with Velcro on the top of the fuselage servo plate between the two servos.

If there is anyone reading this who has never done a scratch build before, then it is time for my first confession…. This is my first scratch build for forty years. Modern glues and materials are quite new to me in modelling applications. What was I doing for those forty years? Well I got side tracked into serious full size gliding and have only very recently caught the r/c bug again. This really is a beginners model to build, at least in my opinion.

Here is my Skydrive Notebook link again to find all the updates:

**LINK**

[RedBaron]

PS - A small accident:

When I fitted the scrap balsa over the torque tubes I had a small accident with the Cyano!! A drop of Cyano ran down over the blue bearing and onto the carbon rod……. Ouch, luckily I spotted it as the drop was still running and spreading. Quick work stopped the bearing being seized. After a careful clean up with Cyano cleaner I decided to secure the blue bearings not with Cyano but with UHU (POR was all I had to hand) this gives good risk free grip for this job.