Big Ship - Plan in January 2009 RCM&E

[Hamish]

Rather than ARTF I am considering building the Big Ship as in the January issue.  Although I can understand how to build I get a bit lost on the terms used.  Grateful if more experienced can assist

 Wing shows "Rock Hard 1/4" sq spars     - What is rock hard?

"Soft sheet"  - As above

Former F5 is shown as "Litply" with all others just shown as ply   - Ply or liteply?

What do all the black arrow head and clear heads indicate?

A splice line is shown at the tailplane  - Is this because a 36" sheet has been used?

The dihedral braces show a mark "Front to here" and "Rear to here"   ?????

I appreciate a lot of the above will be basic and common within models but if you don't no, you don't no.

Grateful for any information

[Peter 'Ivanna Crashalot' Savage]

normally the little black triangles will represent linings on the main fuse sides like thin ply to reinforce, check next to the writing next to the fuse for what it means, actually, i think it may have accidently been left off for the black triangle, the white arrow is there though, that means hard 1/16" butt plate to.

on closer inspection i have discovered it underneath the rear window over the fuse

It means you make a 1/32" plate that you glue onto the inside of the 1/16" sheet fuse sides. To be honest i don't pay much attention to wood densitie.

anyway good luck on your build

[Peter 'Ivanna Crashalot' Savage]

also, this plane looks like you could make it into a seaplane

oh and the wing dihedral brace thing, it just means the rear one stops at the line above and the front one stops ant the bottom line

[simon barr]

Hello Hamish,

Rock hard 1/4 sq spars in the wings are necessary, if the spars are too soft, you will have no strength in the wing.

Soft sheet means just that, soft and light. You would only use this for things like leading edge sheeting where you need to curve the wood, and you wouldn't want hard and heavy wood here.

Liteply is used quite often now in all models, but depending what it is being used for, Like F5 for example, then firm balsa would be suitable, but keep the grain running vertical.

The black and white arrows just show the outlines of various sheeted areas and doubleres etc.

The splice line in the tailplane is just that. If you cannot get the correct lengh wood, then it needs to be spliced.

The dihedral braced are shown on the plan on top of each other, so they are the same length, but different depths, the rear one being shallower than the front, because where it is located, is a shallower part of the wing.

Hope this helps,

Simon.

[Hamish]

Thanks for the input

Having looked at balsa suppliers no mention is made of the grade of basla, hard, soft, etc.  I assume the best idea would be to visit the model shop and select.

I had assumed that by the name, liteply is lighter than normal ply, however is it as strong?  I would assume that liteply can be laminated to provide suitable thickness and would provide weight savings?

Slightly off subject but I would be grateful for advise on type of glues to use.  At the moment I use the following

A thin cyano glue for quick repairs where I have broken a bit.  My thoughts are that, unless in a break situation, my surface have to mate pretty accurately as the thin liquid will have little bridging effect.  At the moment I have used £/Land super glue and have had no problems

Where I do not trust the accuracy of my joints I use Evo-Stick weatherproof wood adhesive on the assumption it will take up my inaccuracies.

I have used epoxy which came with a wing bandage kit and have found OK.  For the odd bit where I have needed a small amount I have used £/Land epoxy.  I did have to dig out a ply servo-mount I fitted to a wing with this epoxy and it felt rubbery but was stuck solid'

I have recently purchased Gorrila Gum and not quite sure of its use.  I stuck ply into the base of a fuselage in order to screw the undercarriage on and found it very easy to work with and appears to have stuck solid.  I am attracted by my understanding that it expands when setting, which would be good for my inaccuracies.

I appreciate the replies and I am sure many others will learn from your replies.

Thanks in anticipation.

Edit  In for a pound in for a penny   How do you fill gaps.  I have seen balloons, but how do they work?

[simon barr]

Hello Hamish,

Yeah, I too mainly use a mix of cyano, white glue and epoxy, depending on the application...you seem to have it sussed...

[Stephen Grigg]

Im quite keen on this build also But like you im not sure of the different woods and phrasiology used so IM a bit unsure.Please keep this thread going on your progress because if I can pick up enough info I might have a go,thanks and good luck.

[Myron Beaumont]

 I ,like many others I suspect DONT like liteply . It's very brittle in bending/stretching applications . Personally I stick very thin proper plywood to a balsa sheet  of about  four or five times the thickness to produce a much better strength to weight ratio for formers & the like  Even ply on one side only is a vast improvement ! Bet you've never seen what happens to lite ply & structure around it after an "arrival" Basically -more difficult repair work to be done -Don't ask me how I know 'cos I once bought an ARTF  Never again --What you've built from scratch you can rebuild easier !

[Peter 'Ivanna Crashalot' Savage]

PVA or white glue is good for things that need to be acurate, eg bending wing sheeting. put pva on the curved bit of the rib then put a dab of cyano on the tip, then pin it on

i normally only use epoxy on things that really need a lot of strength like engine bulkheads, because it is heavy and will make another weak part break as opposed to this one.

[IanN]

There's one thing on this plan I can't work out.

 Bending 8g u/c wire takes a certain amount of force. Is there any special trick to forming the Big Ship u/c without bending or squishing the 8g brass tube that it runs in?

[Peter 'Ivanna Crashalot' Savage]

isnt the tube a tight fit over the wire? put the bit that isnt covered in tube in a metal jawed vie then bend it, you could use a hammer

[Peter Miller]

It looks as if most of the early questions have been answered.

 

You can order a pack of wood and/or precut parts from SLEC, this will come in the correct grades of wood.

 

Hard spars are essential. I have seen a Little Ship wings fold because the builder used soft wood.

 

I like liteply because it resists splitting and takes loads better while being almost as light as hard balsa. This is especially useful when there are cut outs in the former.

 

I use a proper wire bender but a good solid vice and a hammer will do the job, Make the bend just outside the tube. IT won't sqaush the tube because that is supported by the wire.

 

The little arrows indicating sides and doublers are actually shown with their definitions on my original plan. I have also found that the magazine plan has stretched and distorted a bit compared to the original. Still, everything seems to cancel out and fit.

 

Grades of wood. You can tell by the weight. Hard wood is heavier. also the fingernail test but model shop owners are not too happy with people gouging their finger nails into the wood.

 

I use Deluxe products Aliphatic Resin glue and some five minute epoxy.

[Peter Miller]

I have just received a sample from SLEC of the pre cut parts plus full balsa and ply pack. Looks really good. Should save hours.

[Doug Ireland]

Hi Peter,

 

I've searched the SLEC site and can't find any references to pre-cut wood packs. Could you point me in the right direction?

 

Cheers,

 

Doug.

[Braddock, VC]

I too am planning to build this one, some time ago (1983? ish) I built a free plan of the scaled down one called the "Little, Little ship" it was a fantastic flier with an AM 10 up front and two mini servos that cost  £19.99 each all those years ago. I still have the wing (36" span) and tailplane but cannot for the life of me figure out where the fus went, I know I sold he engine at the 2004 nats so it probably got trashed in my garage.

Any way I've a rake of balsa left from my prolific days and an unused OS 26 SF, so I'll be starting shortly and watching this thread with great interest.

[Peter Miller]

The plan pack is not listed yet. Just phone them for price etc I don't know it. They will be very helpful.

 

John.

 

The big one is even nicer to fly. One club member is going to do an electric version. (Don't hold,your breath, he took 3 years to build one of my designs. Mind you, it was more complicated,)

 

Another member is thinking of an even bifgger one to use an irvine 40 diesel in it. Should be nice.

[Braddock, VC]

Peter, I'm a bit like goldilocks, diesels too mucky, electric too clean, glows just right.

[Peter Miller]

I agree. I like diesels but the smell stays on ones clothes for days if left.

By the way folk, the first one or two SLEC packs  are short of 1/4" square,There should be ten in the pack.

 

DON'T BLAME SLEC! It was my fault when doing the cutting list. Any other shortfall will also be my fault.

 

It is senility creeping in.

[Peter 'Ivanna Crashalot' Savage]

Just keep the planes coming Peter!!!

[derek critcher 2]

Re big ship wings and hard square balsa, if hard balsa is not available will 1/4" square

spruce be suitable, or will it be too heavy. Derek Critcher 

[Peter Miller]

NO, 1/4" sq. spruce will be OK. IT is not much heavier than really hard balsa.

 

What power are you using?

[derek critcher 2]

Thankyou Peter, I expect to use a 30 two stroke. Derek.

[Peter Miller]

SHOULD BE FINE BUT KEEP IT AS LIGHT AS POSSIBLE.