ZIROLI 96" F6F HELLCAT BUILD
 

Just picked up an Aeroplane works full wood kit.
If it's like the aeroplane works kit that I had for the P-61, it will be an excellent kit.
The kit is all hand cut (no laser).
I retracts are robarts as are the wheels.
I had a GT-80 that fits inside the large cowl.
I also have a custom muffler for a tigercat that I'll modify for the hell cat.
The stab was already started but it looks straight and of good workmanship.
I've always liked the hellcat: reminds me of a linebacker; not pretty but effectively gets the job done.

RE: ZIROLI 96
 

Your killing me SAM!!!!!

Working on my Bates F4F..... Still. The F6F is another favorite of mine. I will be watching!!

Regards,

Flakbait

RE: ZIROLI 96
 

Sam,

You are sicker than me. I have 3 builds going and now you add another one. You are just plain crazy!!!:) Build the Z P-40 first.

Barry

RE: ZIROLI 96
 

Flakbait,
I like the wildcat, too: love those gear.
===

NCIS:
Winter's coming and I've got to have something to do.
It's either my hobbies or woman: my hobbies are cheaper and lower maintenance so it's a no brainer!

RE: ZIROLI 96
 

Hey Sam. Looking forward to this one. I have most of the parts for one of these myself and having flown Phil's a couple times it's a great plane I look forward to.

RE: ZIROLI 96
 

You wouldn't want to sell that Tigercat Exhaust ring would you? I have a 121" Tigercat that I have been collecting parts for.

RE: ZIROLI 96
 

Jeff,
Giant scale twins sells the mufflers for only $300 a set:
http://www.giantscaletwins.com/accessories.htm

RE: ZIROLI 96
 

I have talked to them, as they seem to be great guys. The exhaust is what I consider a luxury at this point. Sometimes scale and fancy exhausts cause more trouble than they are worth. I have two 3W 106's and the Robart gear. I just need some time and the woodkit from GSTs.
back to the Hellcat...I will be watching.

RE: ZIROLI 96
 

Hurry up Sam as we need all the warbirds at the field we can get in 2011!!

Mike

RE: ZIROLI 96
 

Sorry, all building is on the back burner for about a month (or so) to work on my daughter's house.
Previously, (last month), I finished cutting up and varnishing all the new oak trim for the upstairs of my daughter's 90 year old house (downstairs was done, last year). Doors still have to be done plus install this Fall.
Presently, I've also got to prep 4800 linear feet of beveled western red cedar siding for her house.
They won't get installed until next Spring, but, for this Fall, each board has to be sanded to remove the 'fuzzies' plus ends cut square and then primed and then painted. I started out with 80 bundles (six 10 footers) and am now down to about 18.
(not counting just putting a new water heater in her house plus fixing up two antique dressers that she just found!)

RE: ZIROLI 96
 

Fuse.

As usual for Nick's stuff, the crutch was first made,
the wing support plies FWS-1 and formers were next.
NOTE:
If anyone has the 3-5 page instructions,
please email me at [email protected] (thanks).

pic 1:
Crutch using 1/2" high balsa.

pic 2/3:
Wing supports glued while crutch is still attached to the plans.

pic 4:
Crutch moved to risers.

pic 5/6:
Formers F-1 to F13 dry fitted to crutch.
I'm glad that I dry fitted the formers as I started
at F-5 to F-13, thinking F-3 to F-4 would slide on
via the front (au contraire!).
I also thought my risers were high enough:
I'll need to add another 1/2" to clear the front three formers!

RE: ZIROLI 96
 

Fuse and wing

Fuse:
Former F-11 supports the retractable tail wheel, the kit had 3 ply so I re-enforced it with some 5 ply.
Most of the formers were glued to the crutch using carpenters glue.

wing:
Using the plans, I checked where 5 ply is required and cross checked the kit parts for any parts that used 3 ply and re-cut them.
The main spar needed to be re-cut using 5 ply as the kit had them as 3 ply.
Surprisingly, the center ribs have 5 ply where needed.

pic 1:
Former F-11 has the bottom half sistered with some aircraft ply so the tail wheel doesn't break off on a bad tail landing.

pic 2:
Ripped some 1" high pieces of 3/4" thick ply to add to the risers as they were too short to hold the crutch at the proper height.

pic 3:
Most formers glued to the crutch.

pic 4:
New WS-1's cut from aircraft ply.

pic 5/6:
Center wing dry fitted with main spar, ribs and 1/4" square and 1/4X1/2" spruce spar supports.

RE: ZIROLI 96
 

Fuse (cont)

The fire wall (FW) will be removable so the thin 3 ply former F-1 was re-enforced with a 5 ply duplicate epoxied to it.
Most of the upper half of the stringers were glued to the formers as well as the stab supports SS-1/2. SS-1/2 rest right on top of the crutch so the correct stab incidence is automatic.
Carpenters glue was used on all the stringers.
The stringers are dry fitted, tick marked by each former, the stringer is removed, carpenters glue put in the former slot as well as on the stringer and then the stringers are re-inserted into the formers stringer slots. Excess glue is wiped off with an acid brush as, unlike epoxy, gobs of glue adds no significant strength and the glue dries quickly in a thin state.
The stringers were added alternately on each side to reduce the possibility of inducing a longitudinal warped fuse. About 20 lbs of lead were also put on the crutch to insure no vertical warpage.
The stringer slots on each former is also numbered to insure proper stringer install.

pic 1/2:
New 5 ply 1/8" thick F-1 cut and epoxied to original F-1.

pic 3:
Stab supports SS-1/2 glued to the crutch.

pic 4:
Acid brush used to remove excess carpenters glue.
Excess stringer spliced to next stringer to reduce waste.

pic 5/6:
All stringers slots on each former is numbered to insure proper alignment of each stringer.
This worked well, early, as the 2nd stringer did not go to the third last former.

pic 7:
Tick marks indicate where to apply glue after removing the stringer.

pic 8:
F-1 epoxied to the end of the two wing supports.
Looks like the wing supports has the built in 3 degrees down thrust needed for the engine.

pic 9/10:
FSW-2 epoxied to the formers since a compound curve exists.
A straight edge was put along FSW-1 to insure FWS-2 was aligned with FSW-1.
Some sanding of the slots were needed to get them aligned.
Best to have all four wing supports in alignment to get maximum support along the wing.

pic 11/12:
Most of the top stringers glued in.

RE: ZIROLI 96
 

Center wing

After dry fitted the center wing with main spars and ribs, I checked the wing tubes.
I found the two short ribs that support the retracts had no holes in them for the tubes.
After cutting the holes, the tubes were inserted to insure all was aligned.
Some sanding was required but now I was ready to epoxy the center wing.

First, the bottom spruce spare was pinned to the plans as this spar insures everything is straight.
The 1/2" risers were also pinned to the plans to support the back of the ribs and keep all of them in the same plane.
The main ply spar was first epoxied to the bottom spruce spar.
A 1/4" square spruce spar was also put along the back of the plans.
Each rib, starting from the center, was then epoxied to the main spar and back 1/4" spar.
The outer two ribs were saved for a later glue up.
The top spruce spar was then epoxied to the main ply spar, the front LE spruce spar was put in the front of the ribs to insure they were aligned and weight was put on all the back of the ribs to insure they made contact with the 1/2" riser.
After all this cooked for an hour, the outer two ribs were epoxied to the main spar.
Some straight pieces of wood were clamped to these two ribs to insure they are perfectly straight.
A square was also used to insure they are also perfectly vertical as these two ribs need to match up and be flush to the outer wings.

pic 1:
Bottom spruce spar pinned to the plans.

pic 2:
Main ply spar epoxied to the bottom spruce spar and each rib was then epoxied in their respective positions.

pic 3:
All ribs, save the outer ribs, epoxied.

pic 4:
1/4" LE spruce spar dry fitted to ribs to insure alignment.

pic 5:
All ribs aligned to the plans.

pic 6/7:
Outer ribs, last, epoxied to the main spar.

RE: ZIROLI 96
 

Center wing (cont)

The 1/4" square LE spruce was epoxied to the ribs which makes the wing sturdy enough to remove from the table and check/dry fit the retracts.
I dry fitted the wood mounts and there's not a lot of room for fitting the retracts.
In order to make the gear removable, I had to put a small notch in one of the wood mounts for the rotating rod that sticks out one side of the gear.
I rested one end of the wood mounts on the bottom spruce spare and adjusted the front until the edge of the gear frame is just below wing sheeting.
This position is good for the down position but part of the oleo protrudes in the up position.
The gear door has a large recess in it so I'm guessing that this is the proper location in the up position.
Moving the wood mounts so the oleo would be completely in the wing would not give the correct incidence in the down position.
I'll have to sleep on this and do some research.

RE: ZIROLI 96
 

You got it Sam, that's the way Grumman handled the issue on the big one! :)

http://www.cybermodeler.net/aircraft...asm_f6f_10.jpg

http://www.cybermodeler.net/aircraft...asm_f6f_04.jpg

RE: ZIROLI 96
 

Chad,
thanks for the great pictures.
Last night, I looked through my pictures and found it difficult to find good shots of the belly of the plane with the gear up.

RE: ZIROLI 96
 

Center wing (cont)

Thanks to Chad, I was able to epoxy the gear mounts to the ribs.
Prior to the epoxy, I aligned the gear on the mounts, clamped the wood mounts to the ribs and drilled holes and screwed in some hex head servo screws at each end of the mount to insure the mounts didn't move during 'glue up': If the mounts aren't parallel to each other, it can cause the gear mechanism to bind as two epoxied parts tend to slide when they are clamped together.
I also epoxied the wing tubes, the cardboard wire extension tubes and the two wing to fuse mounts.
The wing tubes were a little short to 'my liking' so I cut some new ones. I think the tubes were cut on the horizontal distance but the tubes are slightly angled in the wing so the end edges were a little too close to the ribs.
Chuck Gill (aeroplane works) made this wood kit: too bad he passed away as he made some nice kits.
Chuck would sign the motor mount and write who the kit was for: I just want to thank Jim Nicosia (if he's still in the hobby!) for buying this kit and not building it!

RE: ZIROLI 96
 

Center wing and fuse (cont)

Center wing;
I epoxied some 1/4" square spruce into the bottom TE of the wing and also the 1/8" thick ply to the LE, which makes the wing pretty ridged.

Fuse:
engine area:
Didn't realize this plane has an engine box so no need to have a removable fire wall since I can easily mount the servos on top of the engine box and the gas tank lines will be easy to route.
The four sides of the engine box had 3 ply so I cut new 1/8" thick sides and 1/4" thick top/bottom pieces.
I have a GT-80 with a tigercat exhaust: I'm thinking I can get some 3/8" flexible copper piping and route the side exhausts to each top side and the bottom exhaust to each bottom side and crimp the top exhaust closed.

pic 1:
1/4" square spruce epoxied to bottom of TE.

pic 2:
1/8" thick ply epoxied to the LE.

pic 3/4:
Wooden wing mounts epoxied to fuse.

pic 5:
new motor box.

pic 6/7:
motor box dry fitted.

pic 8-10:
Hoping to route the tigercat exhaust to the four exhausts on the hellcat.

RE: ZIROLI 96
 

Sam,

Did you fabricate the headers yourself (between the motor and the exhaust ring)?

I have the Tigercat.... and the exhaust rings... and two DLE111's, but I'm not sure about the best way to get these rings mounted and functional.

Any suggestions?

Sorry for the digression.

Regards,

Noah

RE: ZIROLI 96
 

Noah,
I bought them and the engine from the owner of the tigercat that was featured in the IMAA mag, last year from giant scale twins. They sell them. The owner lost his plane and was selling the engines and I bought them.
http://www.giantscaletwins.com/

$300 for a set:
http://www.giantscaletwins.com/accessories.htm

Mine has what looks like a stainless steel tubes connecting the exhaust to the muffler with some auto hose clamps to secure everything.
Seems like you could also buy some of that gray flexible tubing with hose clamps.
B&B specialties also sells some flexible steel piping.
http://bennettbuilt.com/index.html

My exhaust has some L brackets on the muffler: I plan to epoxy some wood to the engine box by the L brackets and secure them with some screws.

here's a picture of the setup:

One thing that I just realized was that maybe the exhaust ports on the engine cylinder are not included with the mufflers. If not, then the previous owner must have made the ones in the picture.

RE: ZIROLI 96
 

I thought yours looked familiar. Those headers and connectors were fabricated by the two guys who built that Tigercat, not the most recent owner, who unfortunately lost the plane (an engine-out, as I learned second-hand).

Looks like I'll have to get measurements and have something welded-up for me... as I'm not equipped to weld.

Thanks for the quick reply, though.

Noah

RE: ZIROLI 96
 

Noah,
That's what the owner also told me: I'm surprised on the engine out as I have about 10 zenoah's and I find them very reliable. I wonder if it was maybe a tank problem. Don't have all the facts: how many flights, doing any acrobatics, properly tuned, etc. (There's a lot of variables).

Maybe you can get a local welding shop to do the work or buy some straight pipe mufflers from B&B and modify them. JB weld is some pretty tough stuff.

RE: ZIROLI 96
 

Fuse and center wing (cont)

Fuse:
The front 1" thick motor mount was cut at an angle on two sides to snugly fit inside the motor box and then everything was epoxied. Some extra hardwood triangular pieces were also epoxied between the formers and engine box for extra strength.
I still need to drill and install dowels from the edges to re-enforce the motor mount.

Center wing:
#6X32 bolts and blind nuts were used to hold the retracts to the wooden mounts.
Whenever I mark and drill all the holes at once, there's always one that is a little off so I drill and install a bolt/blind nut for one hole, secure it and then do the opposite 'catty corner' hole, drill and install the bolt/blind nut and, after the two corners are secured, I can do the remaining four holes, all at once.
While doing the retracts, I noticed that I might as well re-enforce the front wooden mounts by epoxying some 1/4" thick ply to the 1/8" thick LE ply and 1/4" square LE spruce. I used three pieces which should help as any ground loops can put a lot of force on those mounts.

pic 1-3:
Engine box epoxied to fuse.

pic 4-6:
#6X32 bolts/blind nuts installed.
I first drilled about a 3/32" bit pilot hole and then enlarged it with a same diameter bit as the OD of the blind nut. Those prongs on those blind nuts are rarely straight so I use some needle nose pliers to straighten them so they'll go into that hard maple.
Sometimes I have to re-tap the blind nuts as they sometimes distort under pressure when installing them in the holes.

pic 7-9:
Some 1/4" thick ply used to re-enforce the front retract mounts to the LE.
Blind nuts also epoxied.

pic 10:
The excess waste of all the spars/wing tubes were cut/sanded flush with the outside ribs.
mmmm: looks like I missed some gobs of epoxy on that rib!

RE: ZIROLI 96
 

Hi, Sam.

I feel a little like a stalker on RCU.

Every time you start building a plane, I seem to start the same plane at the same time or slightly afterwards ! Works OK for me, since your RCU threads are like instruction manuals on steroids. Thanks for that.

The only ones I can claim to have beat you to are the Yellow-38 and the Z-61's, but I didn't build either one of my 61's and my Yellow died 2 years ago :(
We must have pretty close to identical taste in RC models.

Anyway, my good friend and custom builder Chris and I went nuts and bought all the fixin's for the Ziroli Hellcat at Toledo 2007. Life gets in the way sometimes and he is just getting started on it. I have mentioned this thread to him. I'm sure it will serve as great inspiration and you may hear from him occasionally.

Only difference is we went with Sierra gear and I thought I might put a Moki 150 radial in it (the cowl fits it easily!) I never bought the 150 and glad I didn't since I've heard a lot of rumors about it being persnickity. I want this Hellcat to be sort of a workhorse, so I like your idea of the Zenoah twin.

On the Giantscaletwins website, they say something about "custom-fitting the exhaust ring to your engine needs." I wonder if that means they would do the welding?


Mark


R.I.P. Yellow