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turtledeck form

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I like 3/4 birch plywood for forms and jigs and I would prefer to use this for the turtledeck form ( we do use all of them twice and have passed many along to other builders/wanna be builders.) Does anyone see a problem using 3/4 instead of 3/8'ths, I do have a 7 or so degree shaper bit that I could angle them all a little amount with?


maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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well, finally got around to finishing the jig today and it snapped together perfectly, used the "T" system again, like i did for the wing assembly jig. I used the 3/8 per plans and will have to measure a littly for the ribs, but the "t" system really makes assembly easy, wspecially when the "t's" are only 48 inches long, not 12 feet long as they are on the wing assembly jig.


maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Mike,

I am glad you actually worked on the jig today!! So we finish the wings the next two weeks, then start the turtle deck??? Awsome!! Better round up some more volunteers in short order. By the way, lamb chops WERE on your lunch menu that you missed Sunday!! You might get some next week. We will see. Dave


Dave Clifford

"The Metal Man" Musketeer

Vise grip hands and Micrometer eyes!!

 

Cozy MKIV Plans #656

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Well, the heat retained by a turbo has me concerned. Because of this we have decided to add an additional naca scoop in the turtledeck. We won't open it up now just bury it under the skin in the inside and if needed after engine testing, we can simply open it up and glass the edges and whalla, extra airflo to cool the turbo.

 

If we don't need it, hey a cool cieling in the passenger area and some extra ounces. I just know it will be easier now than later to install it.

 

Sounds easy, am not really looking forward to designing a turbo installation, but it will be a challenge.


maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Hi Mike

I really do not think you have to worry about the turbo unit getting to hot.

Consider the air intake will take a lot of heat, that is why an intercooler is of good use.The oil will also take away some heat plus there will probably always be an airflow around the unit.

The combiners as mentioned somewhere tends to work on the hottest possible days,they have no cooling arrangement.

It is essential though that the engine run at idle for a couple of minutes before shutoff.RPM off the turbo can be around 120.000/min.

And the turbo axle might go through the oil film,if not allowed to slowly slow down.


Plane will be called `Hugin`

After Odins raven

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Great info, it's just that if we do need the airflo for turbo OR interlooling it will be possible to easily, well relatively easily, obtaining it. Adding the little amount of foam and fiberglass when making the turtledeck on the floor is just so much easier than trying to do it inside and upside down in the plane later.


maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Actualy the intake will take very little heat from a turbo. The intake temp rises due to compression mostly. Engine heat adding to the intake air is a real problem to avoid. Detionation is bad.

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OK so maybe we duct this extra naca to intake and make it smaller, to stop preasure waves if we don't need all of the airflo


maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Largeprime has a point.

Usually when adding turbo to a gas engine the compression is lowered.

Popular you can say that turbocharging redundants other tuning.You can just raise the boost until you have got enough power.

The extra naca would sure be great for the intercooler.There might be some valvetiming that will need adjustment,to achive the most economical cruise.The entire breathing aerodynamics are involved.

Suggest that to be solved with co analysis during engine check.


Plane will be called `Hugin`

After Odins raven

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I dont know what you all think about going off topic. This should be about turtle decks I would guess.

 

I was gonna mention about back pressure changing bunches. But with a turbo motor you already got a turbo cam.

 

Perhaps dust should make a "Dust's turbo" post and we put all this in it.

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Hey john I over here, OK i wen to the Wayne Hicks site and read allot about making a turtledeck, but I didn't see anything so special, WHAT DID I MISS? I mean his write up is excellant, but doesn't seem to tell me much except i should have waited to carve the nose, too late now, and to get the joints perfect, always a goal and to use the hinge method of making the joints, always good advice, and to order canopy special if you want it bigger.


maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Things went a lot wrong for him on the first try, so he scrapped it and made the whole turtleback again. Maybe he took out all the errors, and just left the good stuff. If I remember right, it was the carving of the canopy deck foam that caused the problem.

 

Wayne - are you listening? You have more experience making turtlebacks than anyone else on this list :D

These guys want to learn from you.


I can be reached on the "other" forum http://canardaviationforum.dmt.net

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My Chapter 18 page "Why is he rebuilding?" pretty much explains it all. My main "error" was trimming too much acrylic to clear the instrument panel in an attempt to lower the canopy nose and get rid of the depression where the back of the canopy glass meets the turtleback. It's hard to explain in words. Maybe I can gen up a drawing that explains this.

 

If DUST and others need more info, please email me from the website?

 

BTW, my first canopy was functionally okay. I just wasn't happy with the results. So I rebuilt it. I still have the first canopy. My tech advisor couldn't understand why I rebuilt it. He muttered something about my standards being too high...

 

Wayne Hicks

Cozy IV Plans #678, Chapter 23 Engine and Cowls

http://www.maddyhome.com/canardpages/pages/waynehicks/index.html

 

PS---> A question for DUST: What is the T system for snapping the t-back jig together?


Wayne Hicks

Cozy IV Plans #678

http://www.ez.org/pages/waynehicks

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Talked to klaus at lightspeed engineering, the GOD of canard speed, and he thought the naca scoop in the turtledeck was a good idea


maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Put the foam in the form last weekend and used just three pieces lengthwise, only two joints instead of many doing it sideways. Seemed to work fine, will know more on plane day as we will lay up first inside turtledeck glass. Used carpet tape and weights on three inch foam (to spread load) to hold shape. hopefully the carpet tape and a few dabs of 5 min will bend foam and hold it during cure. This way the shapes are very uniform as there are no joints to change the material bending properties.


maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Length wise orientation worked great, next problem was drawing the cut line for later seperation. We followed the plans method and that worked ok, but to be honest with you, i wasn't thrilled with the quality of our work.

 

Tried to make a vinyl pattern, not good.

 

Tried to use the bulkhead pattern and a square

 

no good

 

Then put the top of firewall accross the form at an angle determined by the pattern ending up at the appropriate place (centered), put the bulkhead pattern on that from centerpoint to edge off the prosective line by 1/8 inch ( 1/2 the thickness of a carpenters pencil) Drew two near perfect lines by sliding side of pencil flatly against pattern and will be able to repeat it easily for next turtledeck.


maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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To better understand what Dust it talking about, take a look at Chapter 18 on my website. I have a picture showing how to use one of the semi-circular cut-outs from a turtleback jig to draw the cut line onto the inside of the turtleback.

 

A picture is worth a thousand words. This is an old trick that I picked up from Brian DeFord's website.

 

================================

Wayne Hicks

Cozy IV Plans #678

http://www.maddyhome.com/canardpages/pages/waynehicks/index.html


Wayne Hicks

Cozy IV Plans #678

http://www.ez.org/pages/waynehicks

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A number of people may want to build their turtleback larger for the larger canopies available for the Cozy MKIV. Attached are two PowerPoint presentations by Wayne Hicks documenting the steps needed to enlarge the turtleback. I do have a zip file with the viewer but it is over 2MBs and I could not upload that to this website.

Canopy Raising and Widening Process.ppt

CANOPY~1.PPT


Nathan Gifford

Tickfaw, LA USA

Cozy Mk IV Plans Set 1330

Better still --> Now at CH 9

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