ColinB

More work on bulkheads

this is the nose bulkhead, i forgot my usb drive when i came to work today so ill add it into the assembly tonight

Which CAD program are you using?

I am using the Delcam Powershape and Powermill system

If you're going to create a CAD model of an aircraft, please use a standard aircraft coordinate system so that anyone else using the models will have a consistent coordinate system.

 

The X-axis goes out the nose, the Y-axis goes out the right wing, and the Z-axis goes down. Standard right hand rule.

Dont worry too much i can add in a separate work plane if i release the cad files, you may well see workplanes pointing in funny angles depending on how iv drawn the part and the workplane i have active at the time of the screenshot so i wouldnt read too much into it

Well im always open to sugestions, however i dont want to sit around too much discussing and debating ideas id rather just get on with it

also i am designing this aircraft for myself and i have a pretty clear idea of what i want for the most part

also you have to remember everyone has different prioritys and needs when they come to building there aircraft, as it is for me im not worried about having any more than 2 seats, and extra baggage room can always be taken care of with wing pods

Are you going with the standard width of the fuselage?

it will be close, the shape may be slightly different, good thing about CAD is its a damn sight easier to change the shape if im not happy with it

nosegear bulkhead added

in the message box there is a little icon (little square box with what looks like a mountain picture) thats for insert image

i host my images in photobucket and then insert the direct link into the box that comes up when you click insert image

a quick knock up of the spar exterior edges havent been radiused yet

The basis for the CAD, will be to setup the datums for the waterlines and flight stations

with this done the next logical step is to start work on the firewalls and bulkheads enabling me to construct the fuselage around these points

here is the picture of the firewall, the vertical line is the CL and the horizontal lines are the various waterlines im using as references for engine mount holes ect

Welcome to my own little subsection for my aircraft,

Ill start with the name (From wiki) The Garuda (Sanskrit: Garuḍa गरुड, eagle; Pāli Garuḷa) is a large mythical bird or bird-like creature that appears in both Hindu and Buddhist mythology.

What it is, is an EZ based aircraft, i have compiled lots of information on the EZ and other canard aircraft and i will be constructing CAD models and subsequently machining patterns and creating molds from these, the aircraft will be constructed out of modern hi performance composite materials and processes (such as prepreg and modern core materials and autoclave use)

As i am in the UK, there will be some PFA (now called LAA) hoops to jump through, however i am not departing from the original design in any great way so this shouldnt be an issue

The initial specs of the aircraft will be

Retractable undercarriage

Mostly carbon construction

Engine choice at the moment is looking likely to be the Wilsch diesel (as the company is only an hour drive away from me) and there is already an ez flying with it and so approval shouldn't be a problem

Other additions i am looking at are a ballistic parachute and while not cheap, will give some peace of mind

one other project possibility i am considering is to release the CAD files as open source or some other similar license but ill need to have a think about the pro's and cons of that

Its ok Bob you can post away im just as interested in your project as anyone else

infact i have no intentions of repeating your work if you are able to sell a berkut fuse, it means i can concentrate on other areas like wings and canard ect

just to answer a few questions on rohacell, one of the previous posters was correct, you cant hotwire it, you can however cnc machine it, i do this on a daily basis

its certainly not as cheap as floation foam, however i do have quite a few boards of it already so im covered there

so really for me in the time it would take me to make the templates and build a hotwire i could already have them cut, and while it certainly wasnt in the EZ philosophy when rutan designed it, or even for you at home, for me personally this is actually an easy and cheaper option (read free) because i already have the tools and material to cover the build of my aircraft and if im honest its also the method im most familiar with

also as sometimes is the case there is out of date materials, maybe no good for making the parts from, but to make a mould out of? perfectly acceptable and again, reducing my costs

so there is no unlimited budget, infact its no different to most other builders possibly even less, im just in a fortunate position to be able to do this project in this way

also just as a side note, i do actually have some CNC machines of my own in my garage, i have 2 CNC mills a bridgeport and a hurco (the bridgeport is for metal work and the hurco is for the dusty stuff), and a large CNC lathe also for the composite side i have a homebuilt autoclave i built from a propane cylinder, 1m in length and aprox 300mm dia and uses domestic cooker fan and element

the CNC machines btw were old machines i bought cheap with broken controls and retrofitted with EMC2 controllers (linuxcnc.org) and i use Delcam powermill (borrow the key from work) to program the toolpaths

and at work i have free use of large 3mx1.5m 5 axis mill and several VMC's and i can use the big autoclave as long as i pay for the electricity, also when a large order for material goes in i can add onto that for my own stuff and get the material at the bulk price

i hope this helps to understand why i want to approach the project in this way

but you already know all this because you have a set of the plans and have studied them. right

No, but i have seen a few pictures of an ez and it looks very pretty

you know constructive comments are always welcomed, however there is no need to be so condescending

if you do change the type of foam you will be flying an untested wing that you don't how it will act in the air. but you will be doing flutter analysis on the wing before you fly it. right. there is a plane that was built with a "better foam" and that airplane was falling apart and delaminating and was to cut up into pieces before it killed someone.

And how exactly do you think the flutter will change at all? the core is of the same density, its just capable of handling a higher heat, will the flutter calculations take in to consideration the colour of the core material too?

actually the center spa is the first thing that will be built via autoclave

also yes you are correct about your foams not being upto clave temps if you read back to some of my posts i explained i will be using a different foam (rohacell) with the same density as the one you use

i don't doubt that it can be done with a full crew of experienced people. but the glider wing is engineered to be built that way and the ez wing is not. so i doubt anyone can re-engineer the ez wing, build molds, build a spar and wing skins and assemble it in a few days. assemble it in a few days, Yes and all the other work required did not count because it was done in your free time?

actually all i said was the wing patterns could be machined and molded in a few days

i never said anything about re-engineering, or even making the wings in that example

also completely re-engineering it isnt necessary if a foam core is used, as the construction will actually be very similar, just think of it as having your existing foam core, then laminating your sparcaps and outerskins in one operation, then enclosing it between 2 wing shaped molds and squeezing it around the core with a hundred or so tons of pressure and heating to cure, causing the outside to be the exact shape of the wing without need for sanding and floxing to get it smooth

and if in the future i do want to try build a ribbed wing the existing molds do not require altering either as the outside shape is unaltered

Hi just to set a few things straight

i am not remaking the berkut so i dont see why i would need to involve them unless they somehow have some patent on using molds to make aircraft parts and somehow i doubt that, i only used berkut as an example of molded components, it could just be a molded open ez if that makes you feel better

and to answer the question of will it be a kit then i dont know, probably not, will most likley just be selling the main moulded components that people could use to complement an existing open ez or whatever build

where the line is drawn when an aircraft stops being an ez and becomes something else im not sure, but it would be upto the builder

also i dont belive i have underestimated time or money needed to make the moulds, i do this every day for my job and the stuff we do requires very quick turn around, and a wing mold is actually a very very simple shape to laminate (its almost flat), and i it would depend on what materials i used to make the molds, but i do belive it could be done in a couple days, however as its my own parts you are probably correct that i will take a bit more time and care on them

also i have not yet decided on the exact construction of my wings yet either, and just because its molded it doesnt mean it has to be made of skins and ribs, i can still use foam as a core (albeit better foam called rohacell) that i will machine up, the foam is then compressed against the skin inside the mold, (also 31IG rohacell is the same density as the foam you are already using)

or i could reengineer it and use a ribbed and honeycomb construction that is bonded together, but the mold will be the same either way so thats not an imediate concern

also i dont belive the previous poster who said the molds would be free meant it litterally, i belive he meant i am making them anyway for my own bird, and thus for future use for making parts for others they are already essentially "paid for", and this i belive to be true also

and yes as im still in my mid 20's i do belive im still young enough and have enough energy for it

anyway as they say the proof is in the pudding, and i do realise you have probably had a lot of people come up with these ideas before, i have been around this forum for a few years now reading and researching so i dont belive im coming in to this blind

ill keep you all updated on my progress, at first it will be with CAD drawings and then ill start the machining

Save yourself a lot of time and buy a Mobius (manned version.)

 

http://beanddi.com/

you could say the same to anyone here then,

infact why bother building at all? just go buy a share in a piper

i am curious to know why some of you are so negative about the way im planning to build my aircraft

but thanks to the messages of support i have recieved in PM

well just to clarify, a lot of what is requiered i am going to do anyway, the plugs and moulds for the fuse, wings and canard i will be CNC machining and molding from anyway for my own aircraft

so the question of looking to alter what im doing ie high performance 2 seater i cant really change that to suit what others want because it defeats the intentions of what i want to do for myself

a lot of what im doing is to save time for myself aswell, i can machine and mould the wings in a couple of days, and for me that is a worth while aproach and it has the added bonus of ending up with a better finished article, and the fact that i can just setup the machine and come back in the morning and have a wing pattern sitting in front of me beats the hell out of sanding, floxing, sanding floxing ect

so yes for most people this would be a very very expensive venture, for me im just using the tools and facilities i already have to my disposal

so i think quite probably be best bet would be to just carry on with the build, document and photograph and if people like the parts then i can think about offering them for sale

just so you have a background on me, I spent 5yrs in the airforce and now i work in the composite industry mostly making parts for F1 cars

if anything you guys are the ones i have to thank, you have done the hard work for me, i have no intention of reinventing the wheel im just refining it a little with more modern teqniques

i think the only issue would come if sold as a kit is as soon as you do that you become responsible for the care of people building it, and having to write documentation for it all

i will start a topic/thread soon once i have more to show people in the next coming weeks

I think your possibly right in regards to the kit, maybe id be better off just selling the parts as separate items and also helps in not having to support a kit as well

so the other question is would there be an interest in prepreg or wetlay moulded parts ?

Just out of curiosity and possibly a bit of market research

would there be a market demand for a molded kit aircraft ?

the reason i ask is because im going to build mine is this manner as i work for a composite company and have full access to CNC, claves and lots of other things

so the options i have available range from fully claved and molded wings ect ect, to the lower tech bucket and brush were all used too

so really im curious to see if its just something to do for myself or if its worth making the extra effort to make the tooling extra durable for the extended usage of making parts for others aswell as possible clave usage

Hi, no longer going to build the long/open ez as im building a molded version (have the berkut drawings and manuals) so im currently CNC'ing up the plugs ect for that

so the TERF CD is pretty redundant to me now as i have the information i needed

Im in the UK so obviously factor in postage if your not

open to offers

Thanks

-Colin

Take a look here http://www.mgs-online.com/en/products/air.shtml

they make the MGS epoxy that a lot of people are using these days

make sure there the recent drawings current to 2006 if you can

and make sure all the pages are present especially the spar layup and construction ones as you will more than certainly want those

for the price of that you could get a bigger old machine and retro fit it with EMC (www.linuxcnc.org)

this is what i have done in my workshop

http://img.photobucket.com/albums/v280/rallyslag/31012007175.jpg

your only issue is space and available power really but the larger machines tend to have much better motors (servo's and encoders instead of cheaper steppers)

and ball screw motion

shouldnt be too bad

id imagine it to be available in a 5 gal drum tho i doubt that would last too long anyway

since i have to make patterns, moulds and then make the final article anyway

not entirely sure yet i asked for a catalog and just got tech sheets with no pricing

i guess it might be variable or something

its probably just the same figures but replacing the $ for pound sign making it 2x the price as seems to be the case with most other things

found a place that sells it

PRF composite materials

01202 680022

dont know if this is likley to help anyone from overseas but a good number if your in the UK