RE: ASM F-7F Tigercat
 

Very Nice Cat Rickavery !!

Mine is just finished and i hope the Maiden before the end of june.

Could you tell me what engine and propellers youre using ?

RE: ASM F-7F Tigercat
 

Thanks elojim,
She's an electric cat. 2 E-flite power 60s. 2, 6s, 5000mah batteries, one for each motor. She flew her maiden flight with a pair of EMP 15 X 10 props but I have since installed some APC 15.75 X 13 props cut down ~ 1/4". Good luck on yours. Blue skies!

Rick

RE: ASM F-7F Tigercat
 

Rick, Have you flown yours with the APC props yet? I haven't, yet. Have wanted to, but wind been hurricane strength around here for almost two months.

I did get one flight in on a rare nearly calm day last month, flew well, but I'm thinking maybe a little more with the APCs.Pretty sure I'll have to drop the batts to 5S on the rimfire 1.20s. I need to leave acouple planes at home when I go out, so I'll spend more time doing the test, lol.

Good to see you've got her flying well.
Don

RE: ASM F-7F Tigercat
 

Hi Don,
No I haven't flown the Cat with them, but I do fly my H-9 Spitty & P-40 with the same motor & APC props. The Spitty has an uncut prop and the P-40 has been trimmed a bit. I think the P-40 performs better and is probably getting a few more RPMs, but, she also weighs 1.75 lbs less. Comparing apples & oranges. You can always trim the props down to suit your power output. They always unload some once in the air, especially props with big cuts. I'm hoping to get to the field this Sun. to try out the APCs. Blue skies!

Rick

RE: ASM F-7F Tigercat
 

Rick,

I have the BH .90size P-40 with a Scorpion 4025-12 on 5cells turning the APC 15.75x13 and love it on there. Have a set cut down and ready for flight, just haven't installed them, yet. I've taken them to the field a couple times, just haven't mounted them. Keep getting busy with other stuff. Have the 5 cell setup available, if ground test is to high a draw.

I guess I should do a balance check with 5cells each on board. Those 2 cells would affect it the way I mount them. Just in case. I did screw the nose cone on so I could add weight quickly, if necessary.

RE: ASM F-7F Tigercat
 

Last weekend the Tigercat had it's annual outing in the sun light at the Plum Island Airport fly-in. I used the word "annual" because it hadn't been flown in a year. I need to join a club with a field that allows for a safer approach and landing for this plane so I won't have to wait for fly-ins at airports.

It was breezy but the F7F flew great, as usual. When I thought it was safe to raise the landing gear they wouldn't retract because the plane was traveling too fast and the airstream was exerting too much force on the gear locks. Those OS 1.20AX engines pull the F7F along quite fast even with the gear down. At the time I didn't know what was causing the problem and it didn't occur to me to slow down. It got windy and I didn't fly again.

When I got home I held firm hand pressure against the nose gear and there was a hesitation then a very pronounced metallic "clank" sound as the lock released and permitted the gear to retract. The gear in my ASM F7F is a modified set of ESM F7F retracts. Next time I'll retract the gear sooner.

Another peculiar thing happened while I was tuning the engines before flying. The left engine kept quitting when both engines were accelerated from mid range to full throttle. It never quit when it was running alone. I thought, oh oh, vibration and bubbles in the fuel are causing it to go lean. Well, it was just the opposite, it was going rich. Richening it only made it worse. Leaning it fixed it.

Hey, is anyone else putting flying time on his Tigercat? It will be interesting to hear about your experiences. Don't worry, I don't think that anything you say about an F7F Tigercat will be boring.

RE: ASM F-7F Tigercat
 

Congrats on the annual.

Want to fix those retracts so they'll work, up or down? A couple drops of lite oil, "3in1" ,WD-40, whatever. Applly it to the lock slides and the pivot points. Very little required! Viola! No more stubborn retracts! AND, they don't wear the points out so fast! Mine have been flawless since I did this.

Mine has been out twice this season, 3 flights. Last flight I tried my cut-down 16x10x3 MAS blades on 5 cells. Cut down to 15". NOT impressed. Have already tried 15x13.5x3 APCs on 5 cells. Also NOT impressed. I still have not tried the APC 15.75x13x3 blades yet. Also cut down to 15". I'm thinking I won't be impressed here, either. The MAS 14x9x3 on 6 cells seems to be by far the best setup. I have to run the bigger blades on 5 cells, because 6 cells draw to many amps. Over 100 on the ground, for all three blades. The 14x9s only pull 85amps on 6 cells. well within limits.

Enjoy your bird. Way to windy here, when I don't have to work. Over 100 degrees and 25mph+ winds today and next three.

RE: ASM F-7F Tigercat
 

Hey Staggerflyer, it is good to hear that you're still flying and experimenting with your Tigercat and it's power system. You're being very thorough with your prop experiments and it appears that you're getting close to a conclusion. I started with the MAS 14x9 3-blade because that is what was available at my local hobby shop and I was in a hurry to get the F7F flying. I haven't yet changed to any other brand or size because they seem to be working OK on my OS 1.20AX glow engines.

I don't know if anymore oil will help the actuators to overcome the effect of the high speed air loads on the retract mechanism. All of the moving parts were lubricated with silicone oil when the retracts were installed. Maybe they need to be re-oiled. Maybe a grease would be better.
I know that these retracts have a very secure locking action and they could probably be torn out on a crash landing without releasing the locks.

The Robart adjustable air valve had been set for a slow sluggish retract action but now I have it set for a rapid retract action and that may help the actuators shock the locks loose.
My initial air tank pressure is set for 100-110 psi. Is anyone starting with a higher pressure?

RE: ASM F-7F Tigercat
 

Rocketman,

I forgot, you are using ESM retracts, not the ASM units. Mine wouldn't extend all the way, especially the nose gear, until I oiled them. No trouble now. I have also given up on the nose gear door, finally just removing it.

I'm pretty sure I'm going to end up staying with the MAS 14x9x3 props in the end. Solid flight, motors do not get warm, nor do ESCs nor batteries, and she has plenty of speed and vertical performance. The higher pitched props have a noticeable drag on performance, and even on 5 cells, the motors are slightly warmer, as well as the batteries. I need to download the logs before they fill up, to see how things are going.

I use two medium sized tanks, at 100PSI. I get almost ten cycles, so only have to fill once. Unless I don't get a fitting properly connected, that is.

RE: ASM F-7F Tigercat
 

The tank that came with my retracts has a diameter of 2 inches and a length of 6 inches but I don't know if that is considered to be small or medium.
Are both of your tanks on top of the wings or is one underneath?

RE: ASM F-7F Tigercat
 

Both my tanks are same size, the ASM and Robart. One above wing and one below.

RE: ASM F-7F Tigercat
 

On mine, I always fill to 100 PSI, but I replaced the tank with a standard Robart.

For props I use MAS 16 x 10, right out of the package with no trimming or balancing. Since mine is the earliest turbine version I may have more clearance. I could have fitted a larger DIA prop, but this was the largest I could get form MAS with counterrotation.

Electric has many drawbacks but one of its advantages is the ease of achieving multiengine opposite rotation. In addition to eliminating Torque, P factor, etc to get straight runs and flight, it increases the odds of surviving the dreaded loss of one motor. That overrides everything for me since the biggest failure of my RC career was loss of my Yellow Aircraft electric P-38 on maiden due to motor out.

RE: ASM F-7F Tigercat
 

softshell29,
Did you replace your air tank because the Robart tank was larger or did you feel that the Robart was better?

Electric motors will certainly make it easy for you to set up counter rotating props and test those theories. Judging from how well this Tigercat flies I don't believe that modifying a glow engine for clockwise rotation and finding a counter rotation prop would be worth the effort.

Have you had an occasion to find out if that really helps in an engine out situation?
It is difficult to visualize that enough torque can be derived from the one running engine to counteract all of that weight and drag of the fuselage and the dead engine side of the wing, especially since you can only run the engine at a lower throttle setting.

RE: ASM F-7F Tigercat
 

Rocketman,

I used the Robart since the ASM tank looked small and Robart was a known entity and fit nicely. I like touch and goes so use the tank a lot. Maybe the ASM one is adequate; don't know.

I'm not sure about the magnitude of counterrotation benefit in an engine out situation, but think you are correct. It does not outweigh all the problems or assure safety. The benefit is only marginal, perhaps 20%, but thats enough to make me a big fan given the gravity of engine out situations.
My only experience is with the takeoff runs and flight tracking straight, proving some effect of counter rotation. My understsanding is the engine out advantage is only partial and only if it is the left engine you lose. If you happen to lose the right engine the remaining (port) engine rotation direction creates a vortex automatically pushing the vert fin toward a left turn. This partially corrects and counteracts the powerful right turn tendancy of the single remaining engine. That is, it automatically, immediately and constantly fights against the normal death spiral even if the pilot's human reaction isn't so quick or correct.
If you lose the left engine, however, you have none of the countervailing force, only the death spiral force from the remaining (star) engine, unless it counterrotates to give the correct pressure on the vert fin (correct torque, correct p factor ,etc.).
One of the contributors to this thread who has great workmanship may also be expert in the dreaded engine out . On RCG he recently posted a video of his Tigercat crashing after engine out. His skill may explain the minimal damage for the most part. But it looks as if his right motor was the one lost, in which case the remainiing motor would have worked with him to a limited extent, in overcoming the greater force of the death spiral.

RE: ASM F-7F Tigercat
 

LOL@ "expert in the dreaded engine out". Hopefully I will never gain enough engine out experience to be given that label.

It happened to me once with my Tigercat. On the second flight with those brand new engines, the right one quit.
I wanted to test the retracts so I throttled back to the mid range and the plane slowed much more than I expected it to. I figured it was an engine problem but I couldn't determine which engine it was until the Tigercat got wobbly, dropped the right wing and turned right. I throttled back to idle and since I had enough altitude I gave it lots of down elevator to avoid a stalled spin (death spiral). As the air speed increased I eased in some up elevator and added throttle and made a 180 degree right turn into the dead right engine to line up with the runway and land. I carried a small amount of throttle until touch down.

So there you have it, support for the points that you raised, or maybe not. After all, one Tigercat didn't survive a right engine failure.

RE: ASM F-7F Tigercat
 

Gents, I have read thru most of this forum with interest. I recently purchased the ESM 83" Tigercat & intend to power it with 20cc or 30cc gas engines.
Most ARF kits these days require a good inspection of security of formers stringers & trays to insure they are glued properly on both sides. I always re-epoxy or glass resin all timber sI can access.
On most occassions I use a large syringe with fuel tube attached to get the resin to the required point. once in place dip your finger in metholated spirit & smooth it out. Works a treat.
Gas engines seemto be the way modelling is going & most engines are very reliable & easy to get into sync.
There is a wealth of information in this thread to enable anyone to get all the right answers to put a Tiger in the air. Not much talk on electric retracts though.
Will stay in touch as the project progresses as I work away from home Fly in Fly Out basis.

RE: ASM F-7F Tigercat
 

Main reason, that I know of, there not being much talk on electric retracts is the current low availability of units in this size class, and, for most of us, the price of the few units that are available. None of which, to my knowledge, fit this aircraft. Most units I've found/investigated, require you to buy the air units, ($300+) then send them in for retrofitting of the electric conversions, another $300+! When electrics become generally available, pre-built, in the $300 range TOTAL, my ears will perk up, but not until. For those of you who can afford it, more power to you, (without prejudice, by the way.) Let those of us in the cheap seats know what you find.

I have been investigating somewhat in the conversions, but have found nothing in the general hobby lines, yet. Most everything I find is for smaller models, but more companies are entering the market everyday, and even companies like Robart are beginning to partner with some of the conversion companies to make the gear available in a one step process, for lower prices. More of this will only be good for the hobby.

RE: ASM F-7F Tigercat
 

Troy Built Models out of USA is selling Electric retracts for $319 USD. A couple of the guys in our club have used electric version 2.5 on other models with good results. There is a set for the Tigercat which I believe respond quite well. Cheers.

RE: ASM F-7F Tigercat
 

Hats Off!
to pilots like Rocketman, Brad, Staggerflyer and Rick Avery.

Most pilots can't land a twin with one out, even though they know the theory of opposite rudder and turning away from the dead engine. With electrics, its even harder since you can't hear and often don't know that one is out.

Turbo Cat debuted at War Birds Over Delaware this week . Never would have thought we'd get a flightline position for our tent when so many were 6 to 10 tents back from the flightline at this enormous show.

I've never in my life flown a model airplane with SIX others at once and wasn't about to start here. So it fell to my fearless 18 year old to do the honors.

RE: ASM F-7F Tigercat
 

Congratulations! Everything went well, we're a guessing.

Going to have to forgo Owatonna Electric this year, but may be able to make it to Cedar Rapids Iowa for their big Warbird Weekend. The Tigercat is ready to go. Hope to have the gear fixed in the BH P-40, along with new battery hatch made for the Ryan STA-M, and maybe the P-6E Hawk will be ready, just some minor stuff needed on it. Would like to take the Waco YMF, also, but, it's not a warbird, so we'll leave it home.

RE: ASM F-7F Tigercat
 

Ian Rehbein,

Thanks for pointing out the ESM electric retracts as sold by Troy Built for the less painful price of $314.95. I don't need them now but I'll keep them in mind for future projects. The struts appear to be the same as those in the pneumatic set of retracts that I bought from them.
Like Staggerflyer, in the past I considered the electric option but was totally unwilling to dish out the kind of cash that they were asking just to raise the wheels when a pneumatic system could do it for only $169.00. When I was looking for retracts Troy Built was selling a complete set of pneumatic F7F Tigercat retracts, including metal hub wheels, for $169.00.
Sure, pneumatic retracts have their problems but you can pay a lot of money an buy a new set of strange, weird and quirky problems with electrics.

RE: ASM F-7F Tigercat
 

Quoting Rocketman "Sure, pneumatic retracts have their problems but you can pay a lot of money an buy a new set of strange, weird and quirky problems with electrics."

And since electrics use the same framework for the mechanical section of the gear, only replacing the pnuematic part, (air cylinder itself,) any problems with the mechanicals remains, in this case, the soft metal in the bearings and moving parts. I now have enough wear in mine, after less than a dozen flights, that I need to make some washers from very thin plastic/mylar to take up the play in the main block where it rotates on the pins against the side frames. I have almost a 1/4" side "wiggle" movement at the wheels when gear extended. And all screws and pins are properly tightened and locked. And I oil all pivot and sliding points regularly.

RE: ASM F-7F Tigercat
 

Hi everyone, man it is great to see all this action in the tread. I have had a bit of a 'powered' rest since returning home from my trip, enjoying some electric and gliding fun and ,Oh,,, another holiday away!!:)
It has been a bit windy up here as well as the flying field being used for other stuff like ,,, horse racing and cricket. I shall be getting my Cat ready through the week (charge batteries and put wing on :) and taking it for a fly on Sunday if the wind holds off.
I'll report back later. I am so looking forward to seeing it in the air again and hearing those two OS engines on song.

Cheers,

Brad

RE: ASM F-7F Tigercat
 

Hi everyone!

I am new to this thread, having just purchased an ASM Tigercat ARF, NIB, with retracts. You guys have done great things with these cats and I would be greatful for your help with mine.

My first question is; where can I get decent looking, inexpensive dummy engines that fit the cowls. I saw the "Top Flight 1/7 scale" cowls mentioned near the beginning of this thread, but apparently Top Flight doesn't offer those anymore. Can anyone point me in more productive direction?

Second question; has anyone run across a scale or scale-like color scheme that is more visible than all Navy Blue, but not as garish as the stock blue, green, and white?

Thanks,
Jim

RE: ASM F-7F Tigercat
 

Jim,

Hi, I'm sure you'll like you Tigercat. Be sure you do ALL the fixes shown in this thread. Almost every kit out there needs them, if not immediately, then after just one or two flights.

The dummy motors are still available through Tower Hobbies. http://www3.towerhobbies.com/cgi-bin...&I=LXHY66&P=SM They are shown as in stock.

As for the color scheme, the Tigercat was only in service for a very short time, from the very end of WWII into Korea. The only color scheme it ever carried was the Dark Sea Blue, The Grren & White markings were carried by the Marine trainer aircraft training the backseater in the radar use for intercept duties. Any other schemes are "fictional" in nature.

You could do a fictional drone controller scheme, which would be rather colorful. A Navy "grey/white scheme (Vietnam era) could also be done, but again, it would be fictional. The Navy/Marines did not have that many different basic schemes. Or, you could go earlier, using the Navy's WWII three tone blue scheme. Just some suggestions.

Again, be sure and do all the fixes, except the wing center section, altho it probably wouldn't hurt to do if you are ambitious. The one mentioned is the only one that has occurred, so far. All the rest have been found in all aircraft, so far.

Enjoy,
Don