sodbuster 1

The fuel getting sucked out the carb venturi is a common problem on side draft carbs when the cowl's off.
Most people never figure out what's actually going on and chalk it up to " I can't seem to get my motor tuned right"
Or..."piece of junk carb"

They set their carbs up and they get the engine to run somewhat Ok then put the cowl on ,take off, and find the engine keeps stalling.
It's due to it now being extremely rich since the carb venturi is no longer under a negative vaccuum once the cowl is on and the plane is in the air.

Here's how I figured it out. After screwing around with a "Problem " engine like this
for a few outings to the field, by sheer luck upon going to tune the damn thing for like the umpteenth time,I pulled the cowl off started it up and for the first time snuck my hand up screwdriver in hand from BEHIND the carb and was shocked by how my hand was absolutley soaked in gas.
I was lucky in that the mixture screws pointed out the side of the cowl so was able to finally get it tuned right by cutting some mixture screw holes in the side of the cowl and tuning the engine with the cowl on.
Never had the problem again.

You're right on the diapghram hole fix being an old one too...

rcpilotva

things at the personal hangar and our collective shop site made the wing/gear re-build having to be done by a fellow flyer. sorry there are no photos to go with this. wing-tip salute to my friends neal and andrew for getting it done.
I was told that the wing tube was 'loose' in each section. we have at least 150-200 flights on the bird, so vibration is the rule here, but the repair team stated very little adhesive. built light, but prob too lite. this is why the wings were 'banana-ing'?
no existing beef or real reinf for the gear.

existing skin removed completely, bottom only at first. new aircraft ply ribs were cut at each end of the wheel bays, hardwood blocks for gear mounts replacing the 'hardwhatever' that was original. re-attached the wing tube and several spars that had come loose. fit new robart gear, then checked the fit to the plane. a bit of skin tacked in to hold ribs in place to re-do the top.
top stripped. all re-skinned, reattaching wing tube and center spar. ready to be glassed.
we considered adding washout to the wing to get it to land even sweeter, but (a) neal did a beautiful job sheeting and (b) don't fix what ain't broke, we'll prob leave it as it was.
 if i were to buy another arf chinese bird, i would probably cut the wing skins off the bottom in the spar/tube area and check/fix. we have been finding this to be a real consistent issue with china kits across several mfgrs. looking at the hidden areas may save your bird, tho fixing may add to your build time. my personal experience has proven this on two large scale birds, now, + direct knowlege on at least two more. fwiw, mike

sodbuster 1

Glad to hear you guys will have yours back in the air again.
Looking forward to seeing Andrew "stress" test it in the coming season.

Think they'd consider doing the same for my wing if I shipped them down?

rcpilotva

I don't know, but i'll ask him.  the guy who repaired mine augured in his fifth scale P 39 last sunday. apparent metal fatigue on the 4 40 threaded link at one of the elevators - clean crystallized  break'. i suspect he's already working on the replacement (I know he ordered it, probably from the field on his phone). Chinese metal, not Du Bro (or sim).
my 'cat has not been glassed or painted, and the way things are going around here, probably won't be for a while. I even had to farm out a 50cc sized areobat to get another clubmember to cover it. ( a grandbaby lives in the home hangar now, so literally nowhere to work or leave work in progress. our offsite shop is no longer available(where we did most of our work), and my business is closing down.) I haven't touched any project/repair/or foamie since the fall, and it's 'iffy' if i am going to make it to Delaware - i may go, set up a tent and work on my B 25 just to get out of the cauldron for a few days.

SJN

Got back to assembling my Bearcat, and then I found this video of one with a moki 150cc in it......man it sounds good, and goes well

http://www.youtube.com/watch?v=Cx3w51mKQDw


There is also an alternate use for jumpstarting cars

http://www.youtube.com/watch?v=HsDy3yScWLQ



Everybody still enjoying their F-8F ?

bob62

My Feedback: (28)

That fellow would feel funny if his rope broke

GeorgiaFlyer

Has anyone bought one of these Easy Tiger Bearcats recently?

GeorgiaFlyer

anyone?

SJN

Marc wanted to see my progress.
It has been slow

I have only painted the trailing edges of the wings and tails, and installed all the control surfaces, and flaps.
Also installed the servos,
Got my header silver soldered together, and my exhaust installed.

Here are a few pictures of my canister install.

There will be a cooling tunnel installed oner the canister.
Fresh air will be brought in from the front, and past the canister through the tunnel, and vented out of the scale exhaust`s on the side, and the rear tail wheel well.
Also some air should flow out the trailing edges of the wings, as the by design have open bays in them.

We will see how that turns out

GeorgiaFlyer

looking good! keep up the progress. couple questions, how are you going to get to the wing bolts under that plywood next to the canister? What type of glue are you using to adhere the wood to the fiberglass?

SJN

Im not going to use the stock mounting system.

I am going to remove the plastic threaded/dowl locator pins from the LE and TE, and glue in carbon fiber pins instead.

Then install a blind nut just after the wing tube about in the center of the wing, and just use a hex bolt to hold hte wing on.
I can get to the easily in the center section.

I useR&G epoxy mixed with micro baloons to get more fill, and thixo to make it stick like gel, so it does not run.

You can buy an allready mixed product called Hysol if you are not comfortable with mixing yourself.......just a lot more expensive, but a great product.
Ofcouse you have to scuff up the fiberglass and clean well to get the best bond.

GeorgiaFlyer

cool thanks for the info. I have heard of Hysol on other threads looks to be good stuff. I saw on some of you pictures glue that looked like a white silicon in the joints and around them or something like that based on pictures.

GeorgiaFlyer

dang I am having a hard time finding landing gear that will fit into this bird without "major" modifications. I was hoping Robart would have them but still looks like what they have will not fit

SJN

Yea, I also plan on upgrading my struts at least......will see how the stock retract units hold up.
But I will try the stock bits first.
Otherwise I will but some quality german Behotec stuff for it....easy to get hold of on this side of the pond.
http://www.behotec.de/xtcommerce/index.php?page=index

GeorgiaFlyer

From all I have read on here the stock retracts are not strong enough to hold up this plane. Those Behotecs look really nice!

SJN

Got a bit more done.

servo operated tail wheel
servo for the tail wheel steering installed.
adjusting the retracts and gear doors so they will be troublefree
Servos and lonks installed on all of my control surfaces.
Built an insulated duct to go around my exhaust. Im ging to install 2 500cc fuel tanks, one of each side of the exhaust. I bet the 90cc 2 stroke is thirsty


Its getting there slowly....

GeorgiaFlyer

looking good! keep the pictures coming, love to see the progress being made!

SJN

Got my gear doors done, and retract cover plates installed.

Now I need to find a location for the 2 valves and servos to control the gear and doors...and a space for my door sequencer........and do the plumbing...then paint the wheel wells.....lots to do still

GeorgiaFlyer

very nice! looking good. Keep the pictures coming

SJN

moving on to the door and gear air valves......also have a sequencer to time the doors.

Im trying to keep all the weight I can up in front of the CG.

Im going to set my CG on the panel line just at the rear end of the silver painted exhaust panel.

GeorgiaFlyer

Here is a link to my build thread for the ETM Bearcat http://www.rcgroups.com/forums/showthread.php?t=2006415

SJN

very nice looking landing gear.
Looks like your bearcat is another version than mine with the all plastic cockpit/hatch ?

Mine has a fiberglass hatch, and a seperate clear cockpit canopy.

GeorgiaFlyer

Mine does have the fiberglass hatch and clear cockpit, it was an extra I ordered with mine. It is not in the first pictures I posted. Those are stock pictures.

GeorgiaFlyer

Bump http://www.rcgroups.com/forums/showt...2006415&page=3

SJN

Thanks for the update.

I too am binning my 2 stroke, and getting a moki 180 :-)
Just have to save up a few months more, or get some stuff sold.

I was also looking at the Evolution 160 7 cylinder.
But Im not sure it will fit the cowl with its 29cm diamter vs the mokis 25cm.