Jocasta

[Paul Clay]

Posted by Paul Clay on 15/09/2014 14:50:29:

Posted by David Ashby - RCME on 06/09/2014 16:30:53:

A set of parts is in hand (RCME Plans Service) and should be a few weeks away.

Hi David,

I hope I am looking in the right place. Plese send me a link to the RCM&E Plans Service where I can find the Jocasta cut parts. Thanks in advance.

Sorry to trouble you David, I have now found the RCM&E Plans Service in "My Hobby Store". I asked them and they know nothing about the Jocasta or any parts. I guess I will just have to be Patient.

Paul

Paul

Edited By Paul Clay on 15/09/2014 14:51:02

[Den Moran]

Hi, Jim!

I was impressed by the 'Jocasta' idea. It's a long time since a decent four-channel trainer was available as a freeplan!.

I ordered the 'gubbins' this morning, using Turnigy for the powertrain. The reason for this was that 4-max deny all knowledge of the motor no. ......'PPO3548-110', and I tried really hard to locate it. As with most things, I turned to a reliable source, and got what I wanted easily.

I thought I'd let you know, it's some kind of glitch, and I haven't filed it in the ...' I found one handy in my granny's knickers drawer' section, that a lot of designers seem to think is great to say, without mentioning where us poor people can source one ( Another brahmer is...'you can buy it in B&Q'! Huh!).

I'm looking forward to the build, and will keep up to date here. Thank you for your time and effort , a really good looking aircraft.

One thing I am puzzled by is the tapering fuselage in the front - does one use water to bend the 1/4" sheet to meet the formers, or should it 'go' on its own?

Den

[WolstonFlyer]

Hi Den

You must have missed this on the 4-max website: PPO-3548-1100

It is the last motor listed on the page.

Turing are just as good though and as you know, much less expensive!

Edited By WolstonFlyer on 20/09/2014 08:35:40

[Den Moran]

Thanks for that! Wolston Flyer. It was the fact that 4-max 'search' wouldn't show it as in existence that put me off! Turnigy will do fine, as ever. Den

[Jim Newberry - Nuviation Ltd.]

Den - I am afraid I must hold my hand up to the error as regards the 110/1100 motor designation - while sending the files to RCM&E I mistyped the motor spec. I don't have the plan in front of me so I can't be sure but I think it shows it as the -1100 motor on the plan but the -110 motor on the description (or the other way around). Anyway, the fault is mine for being inept when emailing the spec through to Mr Ashby. Wolston Flyer has the correct spec on his post (thanks WF). I feel I must comment on WF's point about Turnigy motors being just as good but cheaper though - I use 4-Max exclusively because they turn orders around very quickly, their service is excellent (George is always on the end of the phone if you need him) and the after sales service is second to none. Whether or not Turnigy motors are identical, I can't comment but I heartily recommend 4-Max for the reasons I've given.

You shouldn't need to wet the fuselage sides before bending them - the curve is quite gentle and it certainly gave me no problems during the build.

Jim.

[Den Moran]

Ha ha! I thought it was my computer skills (lack of!!!)!

Thanks for the reply, Jim, I'm looking forward to the build, even ordered a SLEC building board to avoid the dreaded 'banana' fuselage. I know 4-max have a good reputation, from other people at my club. So, onward and upward, and keep designing those lovely aircraft.

Den

[Levanter]

Jim

I am just starting to cover my Jemima / Jocasta hybrid. I am going to make another wing from the Jocasta drawing and may even fit flaps and then I won't even need to do circuits. In a 5 mph zephyr I can just fly her in front of me and just slow down when I want her back!

Once upon a time, a long time ago in a previous issue you said Jemima would look good on floats and I agreed 100%. It may even have been one of my first posts. Knowing that you are such an obliging fellow I have fitted hard-points and captive nuts for the rear float mounts. You can't get away with such a temptation so you will simply have to publish a design for period floats. Please

[Jim Newberry - Nuviation Ltd.]

Den - thank you, that's very kind! I am always working on the next one so I'll be drawing up the next J class design soon - maybe a sesquiplane variant, low winger or mini park flyer - I have ideas for doing all three eventually.

Levanter - Oh go on then, I've been meaning to do it for a while anyway so I might as well get on with it. I'd like to come up with one set of floats that would work for both Jemima and Jocasta. The only problem I have is that it's all a bit theoretical - I don't have a water patch to fly from so I'll need to find somewhere suitable to test whatever design I come up with before releasing it into the public domain.

Thanks for the encouragement chaps!

Jim

[Levanter]

Jim

You will only need a paddling pool and a hairdryer to create a headwind!

[Den Moran]

Funny how things come together - I too will be fitting floats to Jocasta - the odd bit being that I've just realised that a pill (tidal creek - Gower) where I was brought up is large enough at either side of high water to provide a really sheltered , safe flying site - the gulls will have a bit of a shock, I expect!

Also, I have a pair of skis of the right size, so I'm hoping for snow, as well! Good luck,Jim, with the Sesky... pesky... er, next series of aircraft!

[Den Moran]

Has anyone any idea about how to replicate the impressive decals shown in the article, or the name of a decal printer to order a set, please?

Den

[Jim Newberry - Nuviation Ltd.]

Den - Glad you liked my chosen scheme! Here's how it went - fuselage, blue Solartex. I hadn't intended it to be quite as translucent as it turned out so if you don't want the structure to show through, make sure you get opaque 'tex. For the wings, I had the brilliant idea of using natural Solartex (no pigment at all) and then painting it yellow. Failed! Painting it proved to be a nightmare as yellow, being a light colour, needs a lot of coats to make it opaque - in fact I even had to apply a couple of coats of white primer to get it opaque. It ended up costing me a fortune in Halfords spray paint and of course added a fair amount of weight. Do yourself a favour and buy yellow Solartex! The rudder stripes were painted with spray paint and masking tape - after applying each layer of tape, give it a couple of passes with spray polyurethane varnish to seal the edges of the tape before applying the colour. The decals all came from Pyramid Models - it's basically their Stearman set but at slightly reduced size. If you email Lee at Pyramid he may still have my original order on file and be able to help you. If not, get back to me and I'll check exactly what size stars I ordered.

Jim.

[Den Moran]

Brill,Jim!

You had me laughing about the 'multi-coats', had a similar experience before I chose the spray can route!

I already have the Solartex colours as shown in the pics, and everything else has arrived , so, once I build the SLEC fuselage jig, it's onward and upward - but don't hold your breath! The decals I want are the same with one exception, the number code - I use 'DYSG' then a number for my trainers, DYSG being the first four letters of the Welsh for 'Dysgwr' - learner!

Many thanks for youe help, I will keep you posted as to the build,

Den

[david shaw 3]

hi jim, just completed my jocasta.she weighs in at just under 5 lbs with e-max 2820,70 amp red brick speed controller dynamic 3200 li-po 11x7 prop.hoping to test fly on sunday. just question,why is my models wing span 69 inches when I built it off the plan?

[Levanter]

Hi Jim

I did a dry run with all the gubbins today to see roughly where the balance point was coming to. Very pleased to say it came out right on the money and I have sufficient movement in the flight battery to make the final trimming changes once the covering is complete.

To do this I had to fit the wing. I thought I had some suitable bands "in stock" but because of the wide chord it would have been a good stretch and without the covering I was scared off breaking something so I tied two together. Is there a designation for the correct sized band. I have seen them advertised in places and a size is quoted. How are they measured? Is it the circumference or the length of the loop laid out but not under tension? Another question sorry - roughly how long do you expect them to last?

I will try and get some photos up in the next couple of days.

[Jim Newberry - Nuviation Ltd.]

Hi Levanter,

Glad the CG location is looking promising without the need for lead! I used the 8" white rubber bands from SLEC. It is quite a stretch to get them over the wing but I haven't had any drama with them. Before fitting them to the model I always give them a good stretch in my hands first. Whether or not this makes any actual difference I really couldn't say but it can't hurt! As for how long they are likely to last - that's almost impossible to answer. Store them away from sunlight in a sealed container. The SLEC website suggests rubbing them with washing up liquid after use for prolonged life - I must say I've never tried it but it must work! In any case, they are about £1.75 for 8 bands so you should find a packet lasts a while.

Hope that helps!

Jim.

[John Taylor 14]

Morning Jim..Please can you give me some advise on the Centre section of Jocastas wing..I am returning to model building after 40 years or so..now all you experts out there please don't laugh!! is the Centre section flat..it seem from the dihedral braces the it is..but on the photos it looks in line..how does the main spar bend to accommodate this..rest of the build is going fine..all parts being cut by hand..not as neat as your good looking model..regards John T

[monty2]

Just seen the email edition of the mag, Good idea putting the motor along side the wood pack, only query, what is the additional pack beside the cnc pack. Excuse my ignorance but would be nice to know.

[Levanter]

Jim. What did the AUW come to in the end. I know you said you designed her heavier than Jemima.

[Andjo]

Hallo Jim,

Your Jocasta is the first free plan that I really liked and want to build. I have ordered the wood packs from My Hobby Store and am awaiting delivery. This will be my first build, however there is one thing that doesn't seem clear to me (perhaps because the plan is in English) how are the ailerons and elevator and rudder hinged?

My native tongue is Vlengels by the way, a mixture of English and Flemish. Also because of the exchange rate things from England are very expensive to buy from here, can anyone recommend the best E Flite motor for the Jocasta?

My local hobby shop Aerobertics (www.aerobertics.be) keeps these in stock and Bert is very helpful, they also export to UK.

[Andjo]

Calling all Budding Jocasta builders, wood packs here'

http://www.myhobbystore.co.uk/search.asp?k=jocasta&x=27&y=15

Hopelijk gaat deze link werken! or, hope this link works.

[Jim Newberry - Nuviation Ltd.]

Sorry folks, it looks as though I missed a couple of posts on this thread so I haven't answered your questions for a couple of weeks.

Firstly, John, well done for spotting the difference! The original Jocasta had no flat centre section to the wing and worked well - this is the model that was used for the photographs. However I tweaked the design slightly when I gave a kit to my dad and incorporated the flat centre section shown on the plan. This brings the benefit of simplifying the shape of the fuselage formers below the wing centre section as they no longer need to be notched to fit around the V of the centre section, however it makes wing construction very slightly more complicated. Whether you decide to incorporate the flat centre section or not is entirely up to you in the end - it won't affect the flying characteristics at all.

Monty - The CNC pack will contain all the shaped parts, i.e. the wing ribs, forward fuselage sides and forward formers etc. It will not contain strip wood parts used to make up wing spars and fuselage stringers, or sheet wood for the wing leading edges. These are an optional extra as many builders will either have sufficient stock of sheet and strip wood already and so will not want to purchase these items along with the cut parts.

Levanter - about 4.5lbs.

Andjo - I used the fuzzy cyano type hinges fitted into slots cut in the control surfaces and glued in place with thin cyano. If you're not sure how to do this then you may find an instructional video on Youtube but if you can't, get back to me and I'll draw a sketch to send to you - it's very simple indeed so it won't take long to sketch.

Best wishes everyone,

Jim.

[John F]

For anyone interested here is the video for furry hinge fitting:

[michael latham]

To Jim Newberry,

I am new to model making but when I saw the free plan in the magazine, I thought yes i Will have to have a go.

Having never built a balsa model before and you state that there are no tricky bits, i went out found a model

shop

bought a load of balsa and have after a lot of trials have built the fuselage.

my problem now is the wing. i have cut ribs R1 R1B R2 R3 R4 but there is a rib at the top of the plan with 4

holes in it but no number on it , where does this rib go ?? i am enjoying the build, but think i should have gone

for a simpler first try. I am 74 but i don,t have any problems with starting a new hobby.

thank you

mr M Latham

[Crunch1]

Hi Jim,,,,i am building the jocasta myself and cutting all the ribs etc, the drawing at the top of the page is a view of the cross section of the wing only, and not a rib in itself, (ie , eyeline from wing root or tip, hope that helps Jim