wathoshebumps

Thanks for your comments Brad. The tail dragger idea is based on the concept that the Wellington bomber was a tail dragger with a single fin. I'm not sure if a single fin would have enough steering authority at ground handling speed on a model. I won't rush into it unless I am satisfied !!

Staggerflyer

The Wellington Bomber had a completely different wing position and cg/main gear mounting position. Also, as a model design, this model does not have the internal structure needed to support a taildragger design. Any weight added to the tail to allow this change would require large amounts of weight in the nose to compensate.

I have done tail dragger conversions on other aircraft, but those were sport/GA style aircraft, where the structure and basic design allowed for it, including room for the main gear to be moved forward of the cg, as well as supporting structure in the fuselage/tail section. This model has none of that.

Good luck.
Don

wathoshebumps

Thanks Don. I included the preference for a tail dragger design to see if I got any feedback. Your comment about the strength and weight at the rear end of this model is a major consideration.

Staggerflyer

Welcome. I hope you don't think I was trying to stop innovation, far from it. I love taildraggers myself. In fact, this aircraft is one of only two trike geared aircraft in my present flying inventory, which totals 14, plus two mini copters.

Even with the structural repairs/strengthening we've done throughout this thread, the tail section is still extremely weak, as there is no continuous framework inside. The skin is literally all that holds the tail where it is. I keep my manuevers big and open to keep the "G" stresses low on the tail, for this reason. I believe it is weak enough that a hard elevator pull/push at speed would rip the whole tail section off the fuse, right behind the wing. Some of those stresses occur just in taxiing a taildragger on rough ground.

Your other ideas sound great. Because of your conditions, if you follow the strengthening suggestions in this thread, before the first flight, you should be able to really enjoy this aircraft. One thing I would suggest, as you intend to go with fixed gear, is leave all the gear doors off, or better yet, glue them in the closed position.

Enjoy
Don

I might add, that as you are going with the fixed gear option, which does not have the shock absorbing oleos that are available with the retracts, you may find a lot more sresses in taxiing. so keep a close eye on the structure, especially after any hard landing. There are more and more add-on oleos becoming/already available. Maybe something to look into?? The beautiful "greased" landings you see in the videos posting are 95% the effect of these oleos we (the other pilots on this thread) have on our models. I have made a few landings that would have resulted in major relaunches back into the air if I had standard fixed gear, but looked real good with little or no bounce because of these oleos. Just a suggestion.

wathoshebumps

Your reasoning is good Don. I've just been studying the threads on strengthening the fuselage and I can see what you mean !! I'll concentrate on sourcing some good glue for now.

Staggerflyer

If you come up with some better ideas, or additional ones, be sure and post them. We can use all the help we can get.

wathoshebumps

My ASM Tigercat arrived today and a brief inspection of the fuselage shows that the glued joints between the wood and the ABS skin are pretty good. The wood to wood joints are quite good with some missed areas. Overall the build quality is quite good for an ARTF but I get  the impression of a very light construction for a plane of this size. So the first target is to get some more strength into it without significant weight increase - which requires a lot of thought. 

wathoshebumps

After studying all 26 pages of this subject it stands out that the joint between the tail and the fuselage on the Tigercat is weak. On the full size aircraft the hatch over the wing is part of the main structure, whereas on the model the hatch provides no strength at all. Therefore I decided the change this by making the hatch cover part of the structure. I have run a 4mm dia carbon fibre tube almost the full length of the fuselage as high up as possible, attached to the skin with flexicyano glue ( from 5 star adhesives ) - . The hatch cover has been strengthened with 10mm x 3mm spruce and the whole structure is connected by bolt on wooden plates. The front plates are completely removable to allow the wings to be removed. 

elojim

Hi all,

Iam pleased to send you this video. This is the second flight of my Cat. http://youtu.be/kc1B1LQ4TvE
Thank you to all the contributors on this forum who have helped me to improve the construction of my plane.
Do not hesitate to contact me if you would like information on the sliding glass (show on the video).


Elojim

Staggerflyer

Very nice. Excellent camera work too. I like the slow motion for the landing. Love how the struts work on damping the bumps!
Thanks for sharing.

Sliding canopy very nice!

Don

Oh, good airmanship on the sticks, too.

Rocketman_

Sounds like a video worth watching but I'm in Hawaii for 3 weeks with just a tablet on wi–fi and no PC. I tried to watch it but You Tube sald "the owner has not made this video available on mobile".

Lebus1

I have fixed gear and would like to install the robart straight and offset struts . The wire size is 5mn for the mains and 4mn for the nose gear. What size would I need?

Staggerflyer

The Robarts come with an insert to fit the strut. If I remember correctly, both sizes are in the package. If not, they can be drilled to fit. I had to drill mine on my P-40. Order them to fit the plane first, then strut size. Since they do not come as a set, but rather individually, and if they also list strut size, in each class, (my memory failing me at the moment,) then order them that way.

They are worth every penny. I always thought they were to expensive, but after using them on one plane, I've pinched the pennies to afford them for two more. They really soak up the bumps and protect the airframe on rough fields. And, they really make your landings look better!!

Don

Lebus1

Thats what I need. Some help in the survive the landing area.

Staggerflyer

Just went and measured mine. I have the ASM retracts and strut kits on mine. (BTW, Hobby People still have the retracts available, for $199.00, but, as far as I can tell, no strut kits. Thinking about ordering a set myself as spares.) The struts are 0.47 nose and 0.48 mains, so you want to get the 1/2" Robart struts, which are rated 18-25 lbs, which is correct for this plane. Get 1 each straight for the mains. The axle can be mounted either way for left and right. For the nose, you want an offset one. Measure your wheel, and get the one that fits. Or, you can order a complete steerable nose gear strut assy with nose mounting block. Hope that helps.

Don

Lebus1

Thanks. I want to get this plane in the air more this year and enhancing the landing gear will help. DB

elojim

Hi,

thank you pour your comment.
Indeed, slow motion lets see how the aircraft landed. How the struts work is very instructive !

Elojim

Brad330l

My Feedback: (1)

Seven more excellent flights with the Cat under my belt. I have been a bit quiet lately in the way of flying but I know I can drag the Cat out and go fly it any time.
Still loving it and I even had helicopter guys applaud my last landing.

Cheers,

Brad

Rocketman_

Elojim,
Back from a 3-week vacation and I'm now able to see your F7F video on my PC. That was a good show especially with the sliding canopy and smooth landing. It appears that you did not use the flaps for takeoff and landing and the plane performed very well without them. I used the flaps once for a takeoff and the plane leaped into the air after a very short run from a paved runway. I never used them again for takeoff or landing.
Can you tell me the title of the song that played during your flight and name of the artist?

Brad,
It is good to hear that you're still trying to wear out you Tigercat with all of that flying.

Eyeguy

My Feedback: (1)

Just starting to build my ASM Tigercat. Does anyone know if the Century Jet retract set (intended for the KMP(and ESM ?) Tigercat will fir the ASM Tigercat ? I will try to get a photo with measurements uploaded

Rocketman_

Just wondering whether ASM F7F Tigercats have gone extinct or still providing excitement for
their owners.
Mine is now 3 years old and was last flown at the July 2014 Plum Island Airport RC Fly-in. I
love the power provided by the OS 1.20AX engines as demonstrated during the 2nd takeoff at
the 4:40 time mark in the YouTube video.
This a link to the first video I have ever posted on the web http://youtu.be/jBdOQumQwLY . I
call it Grandfather's F7F Tigercat, hoping that my grandchildren who are scattered in six
States will click and watch.

drob

Hi Rocketman. You have inspired me to get back onto my Tiger Cat. My last post #533 way back in Feb 2012 shows what I was doing with the flaps. I have advanced from that point but have allowed other projects to get in the way. Will be using DLE 20 gas engines in this build. Hoping to finish by Christmas.

David

Brad330l

My Feedback: (1)

I'm still going strong. Took mine on a 500 km road trip out to the desert to fly off a soon to be air strip. Had five flights and brought it home once with a dead engine.

Cheers,

Brad

Staggerflyer

Mine has many flights under it's belt, however, it is in the hanger for an extended stay. At a big warbird meet a couple months ago, after three great flights, the last landing caught a wind shear gust just before touch down, resulting in a drop/hard touch down from about two feet high. Result was both main longerons broken right behind the wing saddle, and the tail dragging on the ground, because the skin split at the seam. During disassembly, the skin split completely. The only thing holding the tail to the main fuse is the four small pieces of carbon fiber rod in the bottom.

Haven't touched it since, because of work and other things in the way. It's a winter project. It will fly again.

Rocketman_

Hey Drob,

Three Tigercats? That's a lot. I'll admit that I would have bought another one had I destroyed mine but that’s sadly out of the question now that they are no longer in production. I see that you are into scale detail with your attention to the flaps. Isn't that kind of like Fowler flaps? I'm not an avid scale builder but I do admire the work of others and always like to watch scale models fly successfully.
Your 20cc engines won't leave you short on power and you will enjoy that. What engines did you use previously?