Forward hing canopy people only need apply

[Big Steve]

I have pretty much built myself into a corner. Since I have decided to build a forward hinging canopy. My main question is for those of you who have done this did you strengthen your f-28 where you attached your hinges? What did you do to strengthen it? I have never done a forward hinging canopy so I am on new unproven ground. But others have been there so I know we can make it work. My idea for my hinge is a bit different I plan on putting them in the middle of f-28 instead of to the side. Thus necessitating a stronger f-28 Build on. STEve

[Lynn Erickson]

I have pretty much built myself into a corner. Since I have decided to build a forward hinging canopy. My main question is for those of you who have done this did you strengthen your f-28 where you attached your hinges? What did you do to strengthen it? I have never done a forward hinging canopy so I am on new unproven ground. But others have been there so I know we can make it work. My idea for my hinge is a bit different I plan on putting them in the middle of f-28 instead of to the side. Thus necessitating a stronger f-28 Build on. STEve

mine is a triangle cross section between the f 28 ,the top skin and the bottom of the F28. there is a foam wedge that is 1" smaller then the f28 and a glass to glass layup with the f28 on the bottom edge 1" wide running the full length of the f28 and tying into the fuselage sides. the skin has a flox edge on this layup of 6 plys. the hinge brackets are of glass and overlap onto the wedge layups

[Jerry Schneider]

Not sure of your reasons for moving the hinges inboard, but I'd consider moving them more outboard and figuring a way to tie them into the upper longerons. MUCH more stable.

 

If you can find other things to work on ( ) you may want to wait to see Ed Richards' design at the next Rough River. He's modified his side-opening canopy to forward-hinged very nicely just that way. (Better than mine...)

[Big Steve]

Jerry and Lynn:

 

Thanks for the replies. The main reason that I wanted to move my hinge to the center is for a better shape in the front cut out of the canopy I dont like the straite across cut that most seem to be doing. What I want is for the front cut out to be similar to the plans with a rounded nose. I will not be able to have it completely round it will have to be flat where the hinge is. My hinge is 8" wide enclosed is a picture of it not yet finished but it will give you the idea. I was actually thinking of using the canard as a stiffner for f-28 I would make a bracket similar to the ones we made when we installed the canard. I would make it the same widthe as the hinge. The down side to this is that I would have to unbolt my canopy to take the canard off. Maybe a trussed set up similar to Lynn's idea would be better. Thanks for the insiteful ideas. build on STEve

 

[argoldman]

Jerry and Lynn:

 

Thanks for the replies. The main reason that I wanted to move my hinge to the center is for a better shape in the front cut out of the canopy I dont like the straite across cut that most seem to be doing. What I want is for the front cut out to be similar to the plans with a rounded nose. I will not be able to have it completely round it will have to be flat where the hinge is. My hinge is 8" wide enclosed is a picture of it not yet finished but it will give you the idea. I was actually thinking of using the canard as a stiffner for f-28 I would make a bracket similar to the ones we made when we installed the canard. I would make it the same widthe as the hinge. The down side to this is that I would have to unbolt my canopy to take the canard off. Maybe a trussed set up similar to Lynn's idea would be better. Thanks for the insiteful ideas. build on STEve

 

 

 

 

Your hinge looks beautiful.

 

I do have a question, however:

 

What kind of diamond saw are you going to use go cut your radios down to size without injuring the electronics??? (especially when your canopy is open)

 

Seriously, When considering an alteration of this type, it is a good idea to think about 10 steps ahead. In my bird, the radios fit in a stack there and the radio rack is bolted to F28 which makes the instrument panel much stiffer.

 

Additionally, the F28 at that point is rather flexible. You might need to consider significant reenforcement to keep the canopy from "fighting with and winning" with it. When the hinges are at the outside, several angular layers of glass, tying the bulkhead to the sides give adequate strength.

[Edge 513]

It appears that the standoff in between Steves hinges would fit the radio stack in between. Nowadays with all the EFis' being so thin in depth the radio stack is really the only thing to be a player.

To answer you question,

Steve- you need to double up your F28 [i roughed up mine and flox joined them together.[i also took the opportunity to put in a taller F28 than the orig plans] And as Lynn points out put in a triangular gusset at the lower intersection between it and the longerons. Anyway that what I am using. The removable avionics cover should have the 5 point attachment along the top front sim to Nats original plans, and it would be good to have a removable canard cover to reach them [as Marc has just done on his plane]. This all contributes to the lateral stiffness needed up front. IMO.

BTW- this is an industrial 2 part urethane that Jason Heath He uses in his business. It does not morph and change shape after 10 hours. It is the bomb of pour foam. Very fast mixing and acting though. Just what I needed for the irregular surface that I was pouring over on the premade avionics cover and preset hinge pads.

[Big Steve]

Rich says:

What kind of diamond saw are you going to use go cut your radios down to size without injuring the electronics??? (especially when your canopy is open)

My reply:

 

Radios!!!! What radios Who the heck needs radios. This is Idaho Getting serious I plan on a very small radio fit is not a problem I will also be using a portable as a backup. I put in a nav antenna but will probably not use it. Just gps and the ground. All I need is my ity bity radio and my gps and lots of engine monitoring stuff and I can fly happy as a lark that way. I was not planning the big huge IFR radio stack that most seem to like. I want a 1050 lb or under bird.

 

Thanks for the replies guys you are all the best. Build on

 

STEve

ps. The weather sucks here today it snowed last night.

[jpolenek]

What are you really building???

[Edge 513]

Just call IT 'the fly'. I brushed on 3 coats of that coating stuff on my canopy inside and out, and then figured that the rising foam would be so sticky that I need a separate barrier from it- [so as to not destroy my brushed on protection]....hence the bubblewrap fly look. It worked.

[argoldman]

Steve- you need to double up your F28 [i roughed up mine and flox joined them together.[i also took the opportunity to put in a taller F28 than the orig plans] And as Lynn points out put in a triangular gusset at the lower intersection between it and the longerons..

I don't know about your F28, but mine is rather flexible. Doubling it although making it less flexible still retains a lot of flex.;

 

Now lesssee---

 

You got a semi-flexible member (??? no comments) on which you are putting a hinge device which contains lower lips to which are connected two pneumatic cylinders, each producing about 100 PSI (because of the small lever arm necessitated by the hinge construction.) The other ends of these cylinders are connected forward to F22 or whatever, also a somewhat flexible (although doubled) structure, and then you close The canopy. The pneumatic cylinders will try to push F22 forward (in the middleish) and the F28 backwards (in the middleish because they are connected to the hinges. The canard lift tabs are connected to F22 which will ad some resistance, but the lift tabs, instead of resisting mainly vertical forces, in their normal state, now must resist bending forces also, as f22 flexes.

 

The entire assembly is subjected to engine and flight vibrations, seemingly making things worse.

 

Now any change in the dimension between F28 and where the canopy hits the longerons or front of the rear turtle will result in binding or chafing or not fitting.

 

I am full of questions about this approach as I would like to use it but see many downfalls to it.

 

Please understand that this evaluation is from an armchair engineer (more of the dental persuasion) with little true engineering training. As a matter of fact the armchair that I designed lost it's arms.

 

Marc, or other engineer types, bail me out, or put my concerns to rest. My slide rule is rusty.

 

Thanx,

 

Rich

[rickh]

Radios!!!! What radios Who the heck needs radios. This is Idaho Getting serious I plan on a very small radio fit is not a problem I will also be using a portable as a backup.

X-Com makes a small remote head VHF, and Micro-Air makes a remote head transponder. Am sure there's others.

 

Rick

[Edge 513]

I am full of questions about this approach as I would like to use it but see many downfalls to it.

Thanx,

 

Rich

You are right- Don't bother with it. It works, but I don't want to convince others. I'm happy.

[steve]

I don't know about your F28, but mine is rather flexible. Doubling it although making it less flexible still retains a lot of flex.;

 

Now lesssee---

 

You got a semi-flexible member (??? no comments) on which you are putting a hinge device which contains lower lips to which are connected two pneumatic cylinders, each producing about 100 PSI (because of the small lever arm necessitated by the hinge construction.) The other ends of these cylinders are connected forward to F22 or whatever, also a somewhat flexible (although doubled) structure, and then you close The canopy. The pneumatic cylinders will try to push F22 forward (in the middleish) and the F28 backwards (in the middleish because they are connected to the hinges. The canard lift tabs are connected to F22 which will ad some resistance, but the lift tabs, instead of resisting mainly vertical forces, in their normal state, now must resist bending forces also, as f22 flexes.

 

The entire assembly is subjected to engine and flight vibrations, seemingly making things worse.

 

Now any change in the dimension between F28 and where the canopy hits the longerons or front of the rear turtle will result in binding or chafing or not fitting.

 

I am full of questions about this approach as I would like to use it but see many downfalls to it.

 

Please understand that this evaluation is from an armchair engineer (more of the dental persuasion) with little true engineering training. As a matter of fact the armchair that I designed lost it's arms.

 

Marc, or other engineer types, bail me out, or put my concerns to rest. My slide rule is rusty.

 

Thanx,

 

Rich

you hit on some very good points.

and i have seen many (2) bail from the FHC. so before i go on................

................bail...............

if you want to fly soon

i ran in to many things, a fun one was after the hinging and water seals were done and it was time to do the shock (4 try=4 months) , i had a fool prof set up and it worked Gr8 but when i closed the canopy and it got warm out, the shocks closed the gap at the t/b and the dam thing got stuck closed

so in the trash it all went. but on the good side it all works good now and I'm happy to help others do the same

[ErlendM]

I just bought the plans for the FHC for the Cosy Classic from Ulrich Wolter in Germany. It consists of the entire chapter 18 for the CC. I plan to extract the essentials from this and adapt the MKIV-plans with the changes needed to make the FHC.

 

Reading the plans made me wonder: Does anyone know why Nat changed from FHC in the Classic to the side-opening in the MK IV?

[Wayne Hicks]

It's the other way around. Nat had the side opening canopy. Uli changed it to front opening.

[ErlendM]

It's the other way around. Nat had the side opening canopy. Uli changed it to front opening.

Ok, I see.

I thought the Cosy Classic was the predecessor for the MK IV. My mistake.

 

What is the difference between the Cozy III and the Cosy Classic then? I guess the Cozy III also has the side-opening?

[raiki]

Ok, I see.

I thought the Cosy Classic was the predecessor for the MK IV. My mistake.

 

What is the difference between the Cozy III and the Cosy Classic then? I guess the Cozy III also has the side-opening?

In the early days there was the Cozy, when the Cozy IV was born the Cozy became the Cozy III to differentiate it.

 

When Uli got the rights to the Cozy III in Europe he called it the Cosy Classic (not sure if that was pre or post IV). Certainly the Cozy III had the side hinged canopy. The first Cozy I ever saw in the flesh was Tony Rothwells III here is Australia around '98 at the SAAA flyin and that was side hinged. (and had to be built exactly to plans back then in Australia (ABAA rules or 101.28), experimental was introduced about that time).

 

Other than the FHC, I am not sure there are any differences between the III and the Classic however I don't have the plans for either so I am not 100% sure.

[Edge 513]

Erlend,

To answer your question, I dont know what was in Nats mind about a side vs FHC. But I will say that many feel the FHC is a safer canopy. Maybe that is why you are starting on it. Anyway, there is a LOT of info in the various forums to read, and Uli's plans are talked about. Uli's hinges would be better if a bit longer so that there is more distance to the cut, from the mounting point on the canopy. AND, this is a BIG and, put the hinge pivot as HIGH UP as you can on F28...to the point of removing foam on the canopy up to the "top skin". Big Steve and I just didnt like the gas shocks out where you can see them so that is why they arent where Uli mounted his. Buly and a few have gone the whole turtleback canopy lifting route, but it sure seems like a LOT to swing up there. Be good to see what Buly did and get his input. I went with FHCing just the front and swinging the whole rear sideways like per plans so it's easy to get bags in and out and people back there. No "clamshell" door back there for me. THe ULi whole turtleback method would be tons easier...due to all my thinking mocking up parts, and fabbing, and...but I am happy with my solution. Whew!

The Uli method seems to be working for several though so, so, as always, YMMV.

Good luck!

[TMann]

Erlend,

To answer your question, I dont know what was in Nats mind about a side vs FHC.

I think it's as simple as this.

 

The original plans called for the worm gear crank style of nose gear deployment. This requires you to lift the canard while you crank up the gear. I don't know if it is possible to do that with a front hinge design but the EZ-NoseLift style of gear deployment makes that a non-issue.

[ErlendM]

Thanks, guys.

I've been looking at various solutions on the turtleback but I haven't come so far that I have given it much thought. I have more or less decided to go the FHC-route, I have an E-racer "nearby", and I will study how he have done the hinges.

[steve]

Thanks, guys.

I've been looking at various solutions on the turtleback but I haven't come so far that I have given it much thought. I have more or less decided to go the FHC-route, I have an E-racer "nearby", and I will study how he have done the hinges.

my hinges are in the removable dash cover.

so i can remove(or install) the fhc with the pull of two piano hing pins