Zenith CH-701 thread

[eightyknots]

Hi Ek you are right but do a lot of flying in the sav and dont use the top window much i was also thinking down the lines of more strength in the air frame what do you think?

By all means block off the top window to shield against the hot sun if that suits you but not to make it part of the structure.

 

Personally, I would avoid trying to 'strengthen' the airframe at (with the exception of thin metal angle strips in parts of the fuselage to stop oilcanning in flight ~there's plenty of information around about this, e.g. http://forums.matronics.com/viewtopic.php?p=222645 ). The reason is that an aeroplane like the CH-701 has been designed with fairly fine parameters and works together as a whole. It's, as they say, a semi-monocoque construction which means the strength is in both the frames and the skins. By suddenly strengthening one part of the plane you create the risk of transferring a force to another part of the plane which may have been initially designed to have some flex to cope with buffeting forces. Ideally, any design change needs to be analysed as a whole and it's a fairly complicated field. One thing you could do is to email the Zenair people and tell them what you have in mind. Before he retired, often they would flick the suggestion to Chris Heintz (who now lives back in France) and he will do the calculations to ensure it doesn't compromise the safety of the whole aeroplane. Perhaps they can still do this?

 

 

[eightyknots]

There's also this more recent idea to prevent oil canning: http://www.zenith.aero/photo/anti-oil-canning-t-bar-on-ch-750

 

And, for people concerned about oil-canning in their wings: http://www.ch701.com/Builders%20Resources/false_rib/here_is_a_picture_of_an.htm

 

 

[Phillip King]

Hi Ek thanks for the info i like the idea of the stiffners in the wings also wonderd about the effect you have on the airframe when you add little bits here and there, always had the idea of building a 75% scale single seat version of the 701 may be will not work Cheers Phil

 

 

[Phillip King]

Hi Ek thanks for the info i like the idea of the stiffners in the wings also wonderd about the effect you have on the airframe when you add little bits here and there, always had the idea of building a 75% scale single seat version of the 701 may be will not work Cheers Phil

 

 

[skyfox1]

But, you'd lose the advantage that 701's have over the Sav: upward visibility!

visibility[ATTACH=full]19597[/ATTACH]

Hi l would be happy to lose visibility than to get back what l have taking three years to get rid of.

 

 

[skyfox1]

Hi Ek l have spoke to a few aeronautical engineers and have learnt a lot about the transfer of loads when stiffening up areas of an aircraft changing compression loads to tensional loads on aircraft components the area that the top bennie mod needs strengthening anyway as Zenith have advised people that use rough runways needs to be done as some have had trouble in this area.

 

cheers Geoff.

 

 

[skyfox1]

Hi Geoff spoke to the instructor today he is keen depending on the weather , would you offer him 10k for the pup i was thinking 7k done a few hours and has been bent a couple of times .Paint on my plane is rough have picked up some striper that you used will try a bit and see if it comes off easy then make a decision. Funny what you are going to do about blocking out the sun i was thinking the same thing the savs have only a small window on the roof i was thinking replacing the roof lexan with a aluminium stop sun and glare Cheers Phil

Hi Phil you can only offer he will only say yes or no .

Depending on the type of paint used will determine if that citra strip will work good or not when you do it paint it on an area then get some glad wrap lay over the top stops it dying out gives it more time do do its job l normally leave it on all night l is not harmful and it is biodegradable once on all night i take it outside and pressure wash it off my pressure washer is 3500 psi does the job .

 

Yes l am going to use some 2024T3 aluminum sheet on top going to make some ribs and keep the same contour as the wing .

 

the only thing about that that it stops the airflow getting to the rudder and that's part of the 701 design l have spoke to some other 701 owners in the US that have a similar mod and they say it doesn't affect the handling.

 

cheers Geoff.

 

 

[fly_tornado]

watch one get built http://zenith750project.com/

 

 

[skyfox1]

watch one get built http://zenith750project.com/

Thanks FT very interesting .

 

 

[Phillip King]

Hi Geoff finally got some work done on the plane tonight started to refit the header tank and found an off cut painted the same as the plane so have painted some citra on see if it comes off easy.What paint scheme you going for? I like cub yellow with a black stripe.Cheers Phil

 

 

[skyfox1]

Hi Phil

 

My paint scheme is going to be red and white, red slats white wings white airframe with some sort of stripping haven't decided on that bit yet don't want it to hard so its easy to mask up and red rudder and elevator half white and red cowlings.

 

l did see this really nice metallic midnight blue that l saw on a car .

 

l am starting to unpick the rivets on the horizontal stabilizer to see why the brackets that bolt on to the fuselage are loose an other job .

 

and l don't like the hinge bracket to the elevator l am changing that also as the one that is on it is elongated to thin no bearing surface for the bolt and sleeve .

 

cheers Geoff.

 

 

[Phillip King]

Hi Geoff she will be like new when you finish, mine has red slats also and gostgum white fus the citra worked alright but see going to be big job cheers Phil

 

 

[skyfox1]

Hi Phil another set back today l am rebuilding my 912 my replacement piston for the one that had the broken oil ring is 15 grams heavier than the rest so l have to stop the rebuild till l get the right one another two to three weeks to get it sent out , at least l can still continue on the aircraft .

 

Is your 701 painted in two pack .

 

cheers Geoff

 

 

[Phillip King]

Hi Geoff hows it going? has been a big weekend for me nearly got my all navs done no work on the plane though had a look on the Zenith web site can not find anything on the open day what do you no. Cheers Phil

 

 

[skyfox1]

Hi Phil

 

Glad to see you have nearly done your navs no excuse not to fly up here .

 

Will have to check on the date 17/11/12 that's the date Allan Barton told me months ago .

 

cheers Geoff.

 

 

[Kyle Communications]

But, you'd lose the advantage that 701's have over the Sav: upward visibility!/QUOTE]I have full visibility in my Sav the roof is totally clear...I use it regularly

[Kyle Communications]

The view of mine on top

 

 

 

[skyfox1]

Hi Mark

 

Thank for the pics l cant have the sun coming in on me that's why l have to cover mine or reduce the UVs l was trying to find some tinted lexan .

 

cheers Geoff.

 

 

[Kyle Communications]

Hi Geoff

 

If you look hard enough mine is tinted. It has the UV filter tint on it. Its done by a car tint place I took the sheet down to them and got the best tint put on it to block the UV but not a lot of light so I can alway see through it. It cost $100 to get that tint and it to be put on professionally...I am very happy with it....it makes a huge difference tinted also cuts out a lot of the heat

 

 

[skyfox1]

Hi Mark

 

l might do that l have a mate who owns tint a car l wasn't sure if that would last your tint is on the inside how did the tint go when you drilled the holes did if lift off any where.

 

cheers Geoff.

 

 

[Kyle Communications]

Mine was already predrilled and the tint guy cut small holes out of the tint so when he applied the film it was completely glued to the sheet and around the holes so it shouldnt lift. Mine has been done for around 1 year so far and it is still perfect

 

 

[skyfox1]

Hi again Mark l will do the same pre drill first thanks again,l notice in the pic you have a emergence chute where did you put the actual chute ,l have a chute that l was going to install while testing l was looking to fined the best place to mount it is a canister type from parachute Australia.

 

cheers Geoff.

 

 

[skyfox1]

Hi Phil the Zenith open day has changed it is on the 23/02/13 at Bendigo airport .

 

cheers Geoff.

 

 

[Kyle Communications]

Hi Geoff

 

I have all the straps and trays fitted but have not got the chute yet...it is US$4000 so will get that soon. Mine is slightly different attached are pics of the installation manual it mounts in the baggage compartment and the rocket goes inside the left aileron control cover. you should get an idea by the pictures. You could do the same with yours in a similar fashion. I got the kit of parts from ICP for my aircraft all except the chute and will get that direct from magnum. I have no fear of structural failure of the aircraft mine is being fitted to take care of some of the numbskulls flying around...I have had a couple of near misses already and one really scared the crap out of me recently at our local field with a gyro dude...so getting the bucks together now to order the chute but it will be on sea freight so will take maybe 2 to 3 months to get it as the rockets can not be airfreighted I am told

 

 

 

 

 

 

 

 

 

 

[eightyknots]

But, you'd lose the advantage that 701's have over the Sav: upward visibility!

The view of mine on top

Savannah XL (and S) have plenty of upward visibility, perhaps not as much as the Zeniths because of the way the wing joins the cabin.

 

 

That remark was really meant for the non-XL (and non-S) Savannahs.