Jump to content

Jet Provost 1.5metre Andy Blackburn PSS Plan


Peter Garsden
 Share

Recommended Posts

Well this project all started when Phil, who flies his smaller 39 inch JP all the time said how great it would be to fly a larger version which wasn't quite as twitchy as the small one.

My JP has had so much airtime and crashes that it is starting to look a bit tired. It was only my 2nd PSS build and I have learned a lot since. For one, I think I am going to paint this time. My previous JP was trimmed in flourescent orange which has faded a lot in the sun. The pilots in the cockpit keep misting up - can't think why but they are both male! - and the canopy has been off and on about 6 times.

So I contacted Andy Blackburn whose designs are always ace and asked him if he could let me have some enlarged plans thinking he would just blow them up and that would be it. I would have to work out the rest - not so - Mr B is a man whose attention to detail is awesome and he could not do half a job.

So somewhere in the mix we ended up with an enlarged plan which Andy has redesigned, and offered to PSS to sell on their site! - Bigger result than I ever imagined. So BIG THANK YOU TO ANDY B.. Here is a link - https://www.pssaonline.co.uk/product-category/pssa/

This is what my old JP looks like - I will be selling it at a much reduced price if anyone is interested. Still flies very fast.

img_20150621_111429.jpg

 

Edited By Peter Garsden on 02/08/2019 22:57:09

Link to comment
Share on other sites

So Phil has organised a short wood pack for 12 of us which is great via SLEC. I have ordered one. He has volunteered to do a plug for the canopy which is also great. I have ordered some plans from Vintage Models of Buxton. Good job Any has put a scale on the side because they have been reprinted to the correct scale - good idea Andy.I have put a wood list together (one does not get the fin or tailplane because of the wood thickness being unsuitable for laser cutting. Here it is

Link to comment
Share on other sites

Jet Provost 1.5metre Version

Wood List

3/8 x 3/8 x 2 Leading Edge x 36"

3/16 x 3/8 Wing Spars 2 off x 36” (each one 27&rdquo

3/32” x 4” – 12 sheets medium

3/32 x 3” – 1 sheet medium

3/8 x 4” x 9 sheets Light

3/16 x 4"x 1 sheet medium

½ x 3" x 2 sheets light

1” Triangular x 5

¾” x 4" x 3 Light

1/8” x 3" x 2 sheet

3/16 x ½ Spruce x 36” x 2

2.5mm wire

6mm id brass tube

1 x Elevator Snake

4 Channel Receiver

3 Hitec HS85mg Servos

1 x 2000mah Eneloop Battery

I Halls Electronic Switch

2 x small Aileron Horns

Link to comment
Share on other sites

Jet Provost 1.5metre Version

Wood List

3/8 x 3/8 x 2 Leading Edge x 36"

3/16 x 3/8 Wing Spars 2 off x 36” (each one 27&rdquo

3/32” x 4” – 12 sheets medium

3/32 x 3” – 1 sheet medium

3/8 x 4” x 9 sheets Light

3/16 x 4"x 1 sheet medium

½ x 3" x 2 sheets light

1” Triangular x 5

¾” x 4" x 3 Light

1/8” x 3" x 2 sheet

3/16 x ½ Spruce x 36” x 2

2.5mm wire

6mm id brass tube

1 x Elevator Snake

4 Channel Receiver

3 Hitec HS85mg Servos

1 x 2000mah Eneloop Battery

I Halls Electronic Switch

2 x small Aileron Horns

Link to comment
Share on other sites

Jet Provost 1.5metre Version

Wood List

3/8 x 3/8 x 2 Leading Edge x 36"

3/16 x 3/8 Wing Spars 2 off x 36” (each one 27"

3/32” x 4” – 12 sheets medium

3/32 x 3” – 1 sheet medium

3/8 x 4” x 9 sheets Light

3/16 x 4"x 1 sheet medium

½ x 3" x 2 sheets light

1” Triangular x 5

¾” x 4" x 3 Light

1/8” x 3" x 2 sheet

3/16 x ½ Spruce x 36” x 2

2.5mm wire

6mm id brass tube

1 x Elevator Snake

4 Channel Receiver

3 Hitec HS85mg Servos

1 x 2000mah Eneloop Battery

I Halls Electronic Switch

2 x small Aileron Horns

Edited By Peter Garsden on 02/08/2019 22:49:55

Link to comment
Share on other sites

Hiya Pete, good to see your blog underway - and if the photo at the top represents your chosen scheme for this bigger JP then that's a beauty!

Regarding the wing spars, they definitely come as part of the woodpack - they are slotted for rib position and tapered from root to tip so are quite intricate in form - hence the laser approach!

Edited By Phil Cooke on 03/08/2019 18:11:52

Link to comment
Share on other sites

Posted by Monz on 03/08/2019 18:17:45:

Ooooh, I always fancied a JP but the mass build one was a bit small for me. Any details on the short kit? The link above doesn't have the JP?

Hiya Monz,

As Pete described - the 150% idea was born from within the PSSA ranks and is now being realised in short kit form through SLEC. Although the initial bulk order has helped us spread the one-off cost of laser and CNC machining, these short kits will be available to order on an ongoing basis through SLEC I'm sure. I don't have any details (woodpack ref etc) at this time as the first parts are still being made.

Once productionised, plans will be made available for purchase or download through the PSSA website and I will reference the SLEC woodpack there. At the moment its all a bit prototypical and not yet available to buy. Watch this space!

Link to comment
Share on other sites

There are a couple of points that I feel really should be made at this juncture;

  • It's obviously a bit big, but I can't help that; Peter was quite insistent that he wanted a bigger one, I did try and convince him that size isn't everything but he wouldn't be dissuaded.
  • I haven't built one, I've just drawn the plan. Peter is - courageously - going to do the first build.
  • Every plan I've ever drawn has had some sort of c*ck-up somewhere on the first version of either the plan, the parts or (usually) both. Obviously, the member of staff responsible is always ritually tarred and feathered but this doesn't seem to have hand any effect on the error rate.
Link to comment
Share on other sites

I have the rare privilege to be a Pioneer (didn't they used to make matches). Like all brave Pioneers I will take all the risks and let you chaps benefit from my fool hardy bravery. Whilst size isn't everything, my mother always told me that it is not the measurement from the ground to the top of your head that counts (my grandfather and all his brothers were under 5 foot tall but made up for it in their argumentative behaviour) but the distance from your eyebrows to the top of your head, so there!

My balsa order is on its way from the Balsa Cabin and so are the plans. Thanks to Andy for putting the measurements on the plan top left corner so I could check scale. They had to be reprinted by Vintage Models. I tried to buy some wood from our local Model Shop in Macclesfield, Cheshire Models but sadly it has gone the way of all other models shops. So I am planning to make the lower wing sheeting to await the parts from SLEC.

I have had a look at the plans Andy, and can't see any errors anywhere, mind you they only reveal themselves when you start building IMHO.

The version at the top of the page is the colourway I am going for in that my previous version was silver with luminous orange trim. Steve has bought it. Hopefully he will give it some much needed TLC.

Link to comment
Share on other sites

Posted by Peter Garsden on 02/08/2019 22:48:38:

Jet Provost 1.5metre Version

...

3 Hitec HS85mg Servos

Pete - I think you're going to need a bigger servo for the elevator unless you're running on 6 volts; the estimate on the plan is 3.2 kg/cm for the elevator, which I'd regard as an absolute minimum.

> I Halls Electronic Switch

you choice, of course, but I would encourage m'learned friend to carefully consider the mean time between failure (MTBF) of the hall-effect switch when compared to that of a purely mechanical switching device (e.g. a large toggle switch), which according to MIL Handbook 217 F is likely to be somewhere around 500,000 hours.

Link to comment
Share on other sites

Posted by Andy Meade on 07/08/2019 16:01:39:

...

Surely the MTBF for the switches are 10,000's of times greater than a slope model's lifespan? I'd wager we aren't even breaking into the 100's of hours use per year.

Are they, though? If the MTBF of a hall switch is of a similar order of magnitude to an ordinary switch then there probably isn't a problem, but all I'm saying is that I've not seen any actual evidence.

Link to comment
Share on other sites

Posted by Andy Meade on 07/08/2019 11:32:53:

Pete - 9 sheets of 3/8" x 4" surprise that's quite a bit. Do you know if that's for the tip tanks? If so, I'll drop that off my list as I'll be 3D printing them for lightness.

Good point well made my learned friend, and a point also made by Steve the Scottish Lothario (not sure of spelling). The sheets are for:-

  1. Fin
  2. Tailplane
  3. Underneath and top sheeting for Fuselage - it is so wide that one width of 4 inches won't cover it.
  4. Not sure if I calculated for Tip Tanks - maybe actually - yes I think so

Link to comment
Share on other sites

Posted by Andy Blackburn on 07/08/2019 17:08:54:
Posted by Andy Meade on 07/08/2019 16:01:39:

...

Surely the MTBF for the switches are 10,000's of times greater than a slope model's lifespan? I'd wager we aren't even breaking into the 100's of hours use per year.

Are they, though? If the MTBF of a hall switch is of a similar order of magnitude to an ordinary switch then there probably isn't a problem, but all I'm saying is that I've not seen any actual evidence.

Another good point well made my very learned friend (not the use of the superlative!). I started using the electronic switch after trying to create a scale type switch with a piece of wire threaded through a normal mounted switch inside the fuselage in my BAE Hawk which Tim Mackie is now refurbishing after a crash!

  1. I launched the model in a 35mph wind up Leek.
  2. The lift wasn't good because it isn't a good slope.
  3. The lack of elevator response produced an unintended landing.
  4. I picked it up and bunged it off again only to discover it had switched itself off! The mechanism had not engaged properly with the switch and it was "on the cusp".
  5. The plane was blown back and hit the ground with a crack. The fuselage broke in 2 - you can read more on my Hawk blog

Before anyone says anything I know this was not the switch but the mechanism, but in fear of the Scale Police I started using the electronic switches which I use on my mouldies without failure. You can buy them from T9 here - **LINK** They are more expensive, admittedly, in fact they have risen from £20 to £28 recently.

Link to comment
Share on other sites

Posted by Andy Meade on 07/08/2019 16:01:39:

Ejector seats and instrument panel modelled up last night yes

progress 1.jpg

Surely the MTBF for the switches are 10,000's of times greater than a slope model's lifespan? I'd wager we aren't even breaking into the 100's of hours use per year.

Edited By Andy Meade on 07/08/2019 16:04:14

Can I order one please? I think I worked out we are working on 1:7.17 Scale - roughly

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...