doxilia

My Feedback: (3)

Tim,

I had to split the post as the previous one was too loooong...

Thanks for the high praise (or..., tongue in cheek) but unfortunately not a revolutionary concept. Many a pan I've come across is done that way if they are deep enough. I was thinking of a partial stringer pan (rear two thirds) since the wing front mount dowels are located below the centerline of the wing in order to have some ply material from F2W above the dowels. It helps to have some solid balsa behind that so the dowels traverse ply, balsa and then foam within the wing for a solid mount. Also, the bottom of F2 has a fair bit of curvature so having solid balsa (vertically laminated 3/8" sheet works for me) there insures no voids after carving to shape.

Yet, as I think about the plug-in wing/removable top approach, the belly of the fuse could be constructed by extending the front block and rear skinned bottom building design.

Saw those - nicely done!

David

doxilia

My Feedback: (3)

Whoa, nice TT! (note I didn't say pair of TT... sorry, couldn't help it )

If that's a TT3 and the white striping tape departing the center of the nose ring runs level down the side of the fuse, then, this version has a stab above the thrust line!

I assumed the TT3 & 4 were more alike than the 1 & 3 but maybe not so.

David

Timthetoolman1

My Feedback: (6)

The Hyde mount is 3.25" at the base. I assume the one my buddy bought is the same but his has fixed rails and mine are nylon adjustable. He cut probably 3/8" off the side of his to get it in the cowling.
I'm not sure what sizes they come in. I just asked for the adjustable mount that will fit a 42mm case.
I wish Central Hobbies would put some dimensions on the Hyde mounts. I don't know if it's because they think they might change since they are hand made, or maybe they think they'll only sell to F3A pattern guys...who knows?
Where are you getting those dimensions?

rv7driver

My Feedback: (105)

Tim, the Hyde mount I'm using for my TT is: HCMYS115A, it made for serval engineYS 110-115, OS 91 2or 4 stroke, thunder tiger 91, and Satio 100 to 125. Price is 59.95. On Central hobbies, go to mounts scroll down almost to the bottom and it tells you the engine the fix beam Hyde mounts will fit, even the engine mounting hole are already drilled for you perfect fit. Hope this helps. Pete PS: Ron told me about this mount @ one of the contest

doxilia

My Feedback: (3)

Yea, 3.25" is too large. When you consider that a Dave Brown 90FS mount is 2.75" in diameter, there is no need for the Hyde mount diameter to be much, if any, larger than that.

The adjustable mounts are nice if you plan to switch engines of different widths a few times. Otherwise, I'd just get the mount that fits the engine like Pete suggests. I suspect Pete's mount is somewhere between 2.75" and 2.90" in diameter.

I agree. There seems to be plenty of marketing and advertising but figuring out which mount to get is a bit of a mystery. Perhaps Merl is not providing that info but it wouldn't be rocket science for CH to take some measurements and post them. Like I just will below!

If you are referring to the engine mount dimensions, I'm getting them from Dave Brown's site. Fortunately his products are pretty well documented (see attachment).

David

Timthetoolman1

My Feedback: (6)

We did some research and I have as much or more adjustment to get the engine to the side as the solid mount but at an additional 3 oz penalty. There is the possibility of using different engines. I've heard the Saito will not stand up to the abuse but from what I've seen on the OS it isn't either. It could be brand preference but I've seen guys trash equipment and then tell someone that it is low quality when it was operator error.

Anyway, what I'll do is drill the beams and get rid of as much plastic on the GP mount as I can and bolt it back up to the Hyde ring.

Another intriguing option would be to get the fiberglass cowl and make some cheeks on it. I'll look into that.

Tim

doxilia

My Feedback: (3)

Fellas,

for what it's worth, I've forged ahead with the electric version. I have a beautiful Scorpion 4025-10 (515 KV) which I thought I'd use on a Saphir II but the TTIVe just seems to be begging for it. The process is turning out very nicely and I'm happy with how it will build. Originally I was trying to adapt the glow "full fuse" construction (like Pete's) to the electric but after a day or two of brain storming, I realized that the cowl approach would be much better. While Ron's cowl, if available, could be used, I've designed it around a simple 3/8" balsa sheet sides, bottom and top with 1/2" tristock in the corners to produce the closure between the firewall and nose ring. These rings will consist of a lite ply cowl back ring to mount it to the FW (along the lines of Ron's plans for the FG cowl), a lite ply nose ring and a 1/16" ply ring in front of that. The balsa sheets are framed between the two lite ply rings.

I've also gone with a full plug-in wing and stab. The motor will be mounted at 0 degrees down thrust and 2 degrees right thrust per Ron's plans and the wing & stab incidences can be altered from their 0 degree mount datum including a 1.5 degree positive on each per Ron's plans if desired and effective. Due to the adjustable incidences on both surfaces, there will be no fillets on the model as any departure from 0 degree incidence would result in offset fillets. I've also designed it around the use of e-tracts as they strike me as the ideal type on an electric model.

At the moment I've got two mini servos (Spektrum 5000's) in the tail for elevators but I'll also design in an option for the use of a bellcrank (MK or CHS - Central Hobbies) as Pete did on his model.. The individual servos would mount further formward than the bellcrank so it can be built either way. It appears that the choice of dual servos is less expensive than the use of a bellcrank unless one uses the lower quality CHS unit.

Top of model will be entirely removable from the wing TE to the FW and will give full access to the power hardware and radio. A separate steering servo is being designed in as well since the rudder will be actuated from a centrally rearward located full size servo in P-P mode. I'm planning on a Castle 85A ESC, 5800 mAh 6s motor pack, LiFe 1300 mAh 2s radio pack, a 7-9 channel Rx and 5 or 6 servos (separate elevator servos or single servo and bellcrank).

The construction is entirely 1/8" lite ply (except for the FW and the nose gear mount), 1/8" balsa, 3/32" balsa (decks - top and bottom) and some 3/8" balsa front bottom blocks. There is virtually no ply in the model and I expect it to be extremely light for it's size.

All this brings me to the following question Pete: is the MK bellcrank adjustable allowing you to place the servo pushrod actuation on the top with the elevator horns facing down? TIA.

David

rv7driver

My Feedback: (105)

David , I see no reason you could not use it 180 degrees from the way I have it, I'll post pic's of the bell crank soon. Should be no problem. Pete

rv7driver

My Feedback: (105)

rv7driver

My Feedback: (105)

David left photo is linkage taken apart, 2nd photo would be the way you would want it set up for control horns on top of elevator's, the 3rd photo is the way I will have them set up with the horns on the bottom of the elevators the outside horns can be rotated 180 degrees and locked in. The kit comes with plywood to mount on both sides of the fuselage to mount the assembly. hope this helps. Pete

doxilia

My Feedback: (3)

Pete,

many thanks for the pictures and reply. Picture 2 is exactly how I would want it. The elevator pushrods under the stab but the bellcrank/servo main pushrod above the unit (probably inline with or above the centerline of the stab). I'm not sure how you plan to install your elevator servo but from what I can see, placing the servo in the fuse bottom flush with the TE area of the wing, the elevator servo output wheel sits in such a position that its pushrod would run horizontal and would ideally place the center bellcrank actuation arm above the unit. One could of course slope the main pushrod downward and have the actuation all on the same plane for all pushrods but in my drawings it would interfere with the F7 and F8 formers even when generously lightened.

In short, I'd have the main pushrod actuation in the center from the top and the elevator pushrods below under the stab at about 1" under the 0 degree stab centerline. If you mount the MK unit inline with the 0 degree stab centerline, does this put the outermost hole in the outer bellcrank horns about an inch below? I'm thinking about using MK horn hardware on the elevators and ailerons (with their fancy BB's on the clevis point) but then again, the old and trusted 4-40 hardenend bolt and 4-40 clevis eyelet works just fine. The only reason I can think of to use a ball link horn attachment point is for pushrods which aren't co-linear with the bellcrank arms. However, one 4-40 ball link at the bellcrank arms should be sufficient with 4-40 clevis' at the horn end - yes? How's yours setup?

I hope you are anxious to get primer on it! I'm anxious to have one in your state... and the itch begins...!!

Planforms are all 95% done (5% details remain post design). Formers here we come! And there are plenty of them - all lite ply!

David

doxilia

My Feedback: (3)

Pete, almost forgot. What's the MK plywood like? Is it just material to be cut or are there custom pieces cut to a specific shape (like the mounting oval shaped plastic pieces)?

I'm going to use 1/8" lite ply doublers in the tail fuse sides just like Ron has (followed by 1/16" vertical balsa at the F6 & F7 stations and a 1/32" lightened ply main doubler on the 1/8" sides) which would provide a mounting point for either the separate servos or the bellcrank. An opening would be made into the balsa fuse side depending on which method is used.

I like the bellcrank approach better than the dual servo approach but it would cost about twice as much if using the MK unit (given Central's price on the unit). Have you tried or bought one of the alternative CHS units? I suspect no BB's on it but if it's made of good plastic and has smooth rotation, it should also do the trick. Worth a try?

David

rv7driver

My Feedback: (105)

David pic of the linkage installed, servo will be mounted @ the trailing edge of the wing in the fuselage the push rod is 3/16 carbon fiber . I also cut a hatch out on the bottom of the fuselage above the linkage, also I did lay up carbon fiber cloth on the inside before covering the bottom of the fuselage. I have not used the linkage that Central hobby has but it should work fine, I just like the ball bearings setup. 3rd plane I have used this set up, no problems in 3 years works great! Pete

doxilia

My Feedback: (3)

Pete,

that does look like a nice system.

Say, the mount point seems to be quite low in the fuse. How much below the stab centerline is the center of the mount point? Also, how big a hole do you need to pass the system on either side of the fuse?

The fuse sides seem almost parallel in the picture rather than converging toward the tail post. Is that just an optical illusion?

David

rv7driver

My Feedback: (105)

Ya it just an illusion David , the ply sides that come with the linkage are pre drilled , perfect fit. Again I think your looking @ the linkage and think it low it's not, the center of the linkage is in line with the stab centerline.

doxilia

My Feedback: (3)

Pete,

excellent. Now that I know it's installed inline with the stab, did you add the supplied ply plates to the inside (or outside) of the lite-ply doublers or did you make a cutout in the doublers and replace with the supplied ply? Is it 1/8" birch ply or lite ply? just wondering whether it's needed given that ply is already there in the design with the lite ply doublers.

I think I won't pester you further with questions after this...

Edit: I just added a picture. Does this look about right. The hole in the rear inline with the stab chord would be the location of the MK unit. Make sense? The hole is 3/8". if it needs to be smaller, I have a problem, if larger, no problem. BTW, all the cutouts are obviously in the lite ply doubler on the inside. The outside 1/8" balsa sides are intact unless one installs servos as shown or one makes the required cutout for the MK unit.

Thanks again, David

rv7driver

My Feedback: (105)

David, your drawing is very close to what I have, the arm on the mk is a little longer, so you might have to compensate a little. I cut out the balsa, it's the same thickness or very close to the mk ply mounts, there is plenty of lite ply double to glue the mounts to. I then went in and put carbon fiber sheet on the inside to give it extra strength , just make sure you do this before sheeting the bottom or adding the bottom tail block. Pete

hook57

My Feedback: (21)

Howdy Vince!
Yep, I did buy a TT3 from you, I don't think it had the pipe floor though. I didn't really care as I planned a side exhaust anyhow. Unfortunately, I let it sit on the bench while the P-7 and the GPMA Dirty Birdy took over. But....!, I just finished glassing the ailerons, elevators, and rudder the other day, the rest is in primer so I plan to paint it in the spring. She's been refitted with an old school Rossi .65 (yep, a .65) and will be piped. Plan is to fly her sometime in late summer. I've always admired the Tiger Tails, they fly true, straight, and are very tame for the novice, simply can't go wrong with one. Keep the info flowing. Thanks again Crank for the opportunity to snatch that one from ya!
Mark

doxilia

My Feedback: (3)

Pete,

I've added a better drawing below clear of other elements.

There's no problem if the actuation arms are longer than the pushrod showed in my previous drawing. it just requires a slightly longer control horn or using the hole higher up in the arm. The key thing I want to get right is the mount point for the bellcrank both in draft (height on the fuse - it's inline with the stab per your advice now) and in distance from the horns. I'm sure it can go further forward but unless the space is needed for some reason (e.g., not enough spacing between the bellcrank and the F9 solid former), this keeps the pushrods short at the expense of a longer main servo pushrod which is fine - I think.

Makes sense to add the supplied ply mounts in place of the balsa side for a 1/4" ply thickness... after all, elevator we can't loose. Nice touch on the CF. Strikes me as though adding it when setting up the doublers and sides before frame up is the ideal time.

I might just have to bite the bullet and put 50 green ones toward Japanese tech... Maybe I'll add another 20 for the CHS unit to compare. Can always use it on a lesser model.

Looking forward to seeing all your TT's this Spring/Summer!

Hard to tell but isn't your avatar a TT?

David

rv7driver

My Feedback: (105)

No David it's a blue jay DB, the rear of the mk ply is approx. 5/8 inch in front of the leading edge of the stab or 3/16 in front of F9. The top of the mk ole is 7/8 inch from the top were the vertical stab mounts. Make sure if you get the mk purchase the small one @ that point of the fuselage is narrow , ask me how I know purchased one that was to wide! Pete

doxilia

My Feedback: (3)

Ah, got it. The TT3 with the side exhaust 2-stroke & pipe will be an interesting bird to fly alongside the TT4 4-stroke...eventually.

Thanks for the dimensions.

Yup! Caught that one already - cheers.

David

Joe_L

I know this is an old thread but for those researching the TT 4, the 70" wingspan version with built up wing and fuselage, internal pipe, retracks and wooden motor mount is available from the AMA plans service. Request plan #36103.

That is the exact version I built in the mid '80s.

..Joe L

flywilly

My Feedback: (121)

Great looking TT4! OPS power and Kraft wheels - definitely vintage '80s... ahhhh the good old days :-)

hook57

My Feedback: (21)

Might finally get my TT3 done this winter! Would still like to scratch out an original TT, anyone have the wing and stab rib profiles? Or know someone that can laser cut the wing and stab ribs? Thanks.
Mark

Joe_L

I still have that engine! It ran fantastic and was completely reliable.