motortommy

long time no update...

work, family, house refurbishing and flight lessons are only few excuses why my bird is not flying yet again. Honestly had disillusioning moments during the rebuild. But fortunately finally all the small achieved objectives puzzles together so hopefully there will be a flying plane again someday...

partial success

rebuilt 582 with all new cylinders, pistons, crankshaft,...

new wingtips

reworked fuselage, blasted, painted and smoothened out for Oratex

next put back header tank/fuel lines, wires for trim, ACL and antenna and lots of reaming prior installing all new AN hardware...

Thanks for taking care!

Good point to start from. No need for too strong springs as only purpose is preventing slack, right?

I need new rudder springs, but unfortunately have no usable samples.

Has anybody rough spec. (dia./length/spring rate). I`m located in Europe, so ordering via mothership isn`t an option... Thanks!

Dusty, any updates regarding the PU pucks setup? 

I like to get back to the PU spring strut and its setup...

Using 5 pucks (4x red 90shore + 1x yellow 80shore) should give attached results according to manufacturer spec.

As a base I used coil spring data. I`m worried that this PU setup might be too stiff, means only minor movement and or no comfort at all! The data would result in 0.548" strut travel during normal landing. This means approx. 1" vertical movement of the gear (w/o tire deflection)...

Would be interesting to know, how much movement there is with a classic bungee gear.

So far, i have only rough data at least also inaccurate due to metric/imperial transformation. I will put a test strut into a hydraulic press to measure travel according to applied load.

Any thoughts or hints?  

Thanks Jim for your helpful insights! Not always easy to make right decisions at an early stage of a rebuild (even for a less experienced pilot with no idea of Kitfox flying). As long as I´m limited to 80hp (by ultralight approval) I decided that an engine swap is too much of a task at he moment. First I want to finish my rebuild and get the Kitfox back in the air. Second I want to build up/improve my TW skills (pure newbie). Later I will see how to proceed...       

I know that this topic has been discussed several times, but anyway I would like to ask for some real life experiences. There should be folks who meanwhile have experience with both 2 and 4 stroke powerplants…
Due to microlight regulation I`m interested mainly in comparison of 65(582) vs. 80 hp (912). So no focus on 912uls, zipper, edge,… options
Is the swap worth the effort? Why/why not?
Aside from short following pro and con list, how did your Kitfox IV changed? What real life numbers did you gain?

con
 

• cost (engine, mount, prop, accessories,…)
• additional weight
• no ideal installation with early mount (oiltank, carb position, …)
• approval procedure needed
• no quick and easy swap (cowling, cooling System, avionics,… are affected)
• …

pro
 

• improved reliability
• simplified operation procedures
• better resale value of the plane
• increased performance (cruise/climb)
• …

Thanks for any insights!

Nice Jim, following along...

would you mind telling the measurements roughly (width)?

Thanks Marc

like this? (sorry written numbers are metric conv.)

maybe you want to get in contact with FredStork aka Mr. Avid/France 

http://avidsimhttp://avidsimonini.blogspot.co.uk/

overhauled 2 Rotax C gearboxes.

Cleaning, glass blasting, Propshaft checked. All bearings and sealings new. Hope they`re good to go again ...

Thanks, great! I will study. Looks like a more modern abstract of

http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43.13-1B_w-chg1.pdf

thanks for any help

Unfortunately I have to replace some sections due to wrong dia./poor welding...   

hmm, thanks!

Looks like a combination of bowed part in the middle and straight ends, tail and baggage area...

anybody out there with a genuine (not crashed) fuselage?

I want to replace some parts of the lower longerons due to improper repair. Questions:

- are the longerons one piece till the tail?

- is the longeron shape gently bowed (like #1) below or is the longeron divided in sections with straight tubes angled (like#2)

Hope you got what worries me... 

would be great to have some measurements as a cross reference…

Thanks!

Thanks!
Unfortunately 4130 tubing is sold out at the moment (Germany)...have to wait.

Like more pics? Here is the bent mess...

previous repairman added triangle braces and steel stringers side and bottom, maybe to strengthen his welding skills

I have a crashed and repaired fuselage. Although the plane has been in service flawlessly for years since then, I don`t like the workmanship of previous owner. Welding is awful, no splices and metric tubes were used. Further additional `improvements´ were made
Goal is to get the fuselage back in original state as much as possible referring to AC43.13

1. What is correct tube size (green) of the longerons. OD is 1/2", but unsure about wall?
2. Does anybody have a bare, undamaged IV fuselage handy and could help me with some measurements in case? No rush!

to keep the fire alive, I just throw in the possible candidates, probably some out of the same same mold ;-)

(combo 582, c-Box 3:1)

- NR SR83 dia. 1720mm

- Luga/Kool? dia. 1750mm

- kiev 183 dia. 1800mm (STOL)

- kiev 163 dia 1710mm

Would have already ordered, but so far not clear what`s best replacement for my aged wooden GSC!  

Vladimir,

what ist the best fit for Rotax 582 using 3:1 gear? your opinion?

nice progress. Thanks for sharing!

Would you like to share some more info regarding your landing gear, like width and especially tube dimensions front and rear legs...

…after some more research, I understood that with fuselage both leveled and loaded a slight positive camber of 1-2deg is desired while the wheels should be straight or show minimum toe-out. Not decided, if I will go with welded axle tube or adapt a bolt on axle like Grove which would be much easier to adjust via shims…

…so besides the easier fairing issue wrapped bungees also maybe offer more range for adjustment. I really like to build a cub style landing gear as it should be a proven design and knowledge is spread open. What I´m not fully aware of is the correct strength/tension of the bungee setup. To clarify my question I spared no effort and created this high end drawing

Most airborne cabane gear looks like #2, means there is some ´sag´ when unloaded. Maybe intention is to offer some kind of progression as load builds up? How to find good setup? Do you agree that plane on the ground should more look like #1 (straight) than #3 (empty weight already compressed the gear). Adjustment depends on strut travel, no. of wraps, bungee strength and –preload…

Hope you get my point...

(could explain better in native language)

....glad it worked out well for you!

Please share some pics/insight of your wing rebuild (if you like)