rv7driver

My Feedback: (105)

Tim my F1 looks the same, I'll take pic tomorrow and post, the formers were already cut along with the foam wing and stab. the 4S is the long version

Timthetoolman1

My Feedback: (6)

Pete, you were right about the size. The 4 is a big plane. I have foam blocks in a generic size and I can get a full set of wings out of one block for the Dirty Birdy, Atlas, Vertigo and probably most others but the TT4 took so much foam I wasted the rest (actually there's just enough for a Dirty Birdy wing out of the scraps).

Thanks for your help.

It's sad that Ron's wife passed and we don't hear from him much. I didn't want to bother him with all my questions right now.

Tim

doxilia

My Feedback: (3)

Tim,

in what way does the Hyde mount not fit - width, height? Is it the bolt holes that are not landing on ply? Isn't the mount radial?

As we saw, there are some details on the plans which weren't clear. It's possible the lower hatched section might be referring to a balsa cap that mates with the back of the firewall.

With retracts, this cap would mostly be missing if not entirely leaving a rectangular opening in the bottom. With a fixed nose gear, the bearing would be mounted higher up on the ply section so only a hole for the strut would show on the underside.

Timthetoolman1

My Feedback: (6)

It's too wide. To move the mount off the center line so the prop washer ends up in the center of the cowl with 2 degrees right thrust you must move the engine mount off center line.

The lower part is actually balsa. We took Ron's Tiger Tail, that was sold to my friend here, and poked it with a needle and it is balsa. My other buddy realized he made a mistake.

doxilia

My Feedback: (3)

I see. Ron's plans do show a pretty slim fuse. The engine mount he's drawn is also pretty narrow which allows it to fit. I guess you have two options: 1) make the FW slightly wider (I'd adjust the entire fuse so that the top contour doesn't change, only the width), or 2) use a rectangular adjustable engine mount such as the GP or CG mounts.

I was playing with the plans just now and the material at the bottom of the FW depends on what type of nose gear one uses. His plans actually show a fixed gear and one can see the bearings attached to the lower part of the FW. If I were to use fixed gear, it might make sense to lower the ply to leave only about 3/8" thickness balance for the balsa cap. With retracts, the ply at the bottom is not needed as the unit is likely mounted higher up on to the FW or on a ply "tank bottom" plate. Ron shows a 1/8" balsa floor for the tank as he likely built these without retracts for SPA. To make the design flexible, it might make sense to lower the FW for fixed gear mounting. It has the side benefit of providing a "torque plate" for the belly mount retract plate. I like to integrate this last into the rear half of the FW 2-ply laminate - it just gives it that little extra rigidity.

David

rv7driver

My Feedback: (105)

Tim, what hyde mount do you have and what engine are you using, the hyde I have is made for the OS 91 4 stroke and it fits just fine, I'll post pic shortly been gone all day.by the way I built the TT4 for SPA only, so it has fixed gear and the 4stroke. the nose gear bearing is mounted to the back of F1 with no problem Pete

rv7driver

My Feedback: (105)

doxilia

My Feedback: (3)

Pete,

nicely built TT!

Thanks for the pictures - I was thinking about the front end. It seems like a wood cowl would be just as serviceable as a glass one. Except..., I'm just mulling over how this could be turned into an electric model.

David

rv7driver

My Feedback: (105)

David, I just looked @ my plans and f8 is correct. I did get the planes from Ron along with formers, foam wing and stab. I just need to do the wing fillet, and it will be ready to fiberglass, the tt4 is in the finish corner along with XLT .

doxilia

My Feedback: (3)

Pete,

right, thanks. On second revision last night, I removed my comment as I had forgotten about F9 - the former just forward of the stab. I was looking at F9 thinking it should look like F8...

Was the glass cowl an option from Ron or were the plans and sides he sent you designed/cut for a built up wood cowl? What's the purpose of the U-shaped cutout for the nose gear on the underside? Do I see a ply plate for a tuned pipe mount on the right side above the saddle?

David

PS Sounds like Spring will break out the spray gun!

rv7driver

My Feedback: (105)

No option David, plans showed all wood, the TT 4S is four 4 stroke engines, front end a little longer to except larger 4 stroke engines , without the regular TT 4 plans a think formers F1 and F2 are larger with the 4 S

rv7driver

My Feedback: (105)

David, the cut out by the nose gear is for access in case I need to remove or replace it. as for as the ply I think you are looking were I'm using an MK dual elevator horn so I have 2 push rods all off 1 servo mounted in the fuselage. Pete

Timthetoolman1

My Feedback: (6)

That's looking nice Pete.
I think David is referring to the square plate under the canopy as the pipe mounting block.

Ron did offer the fiberglass cowl. Right now one of the guys in that area has the mold. He redesigned everything with plug in wings and stab with adjusters...nice work.
I wasn't aware that the cowl portion on even the wood version is a separate piece. It looks like most stop at the firewall and then add to the firewall for the cowl. So I guess it would be just as easy to use a fiberglass cowl and blend it in. I may look into that, or make a plug and build my own cowl.

The mount I ordered is for the Saito with, as David said, uses GP adjustable mounts.

I'll post pictures on the RCG page.

rv7driver

My Feedback: (105)

OK guys I see were you are talking about, what that is a mistake I made and cut the switch hole on the wrong side, I just plugged the hole and cut it out on the correct side. Tim I was not aware that Ron offered a fiberglass cowl for the TT4 and TT4S that sure would have made it easy for the front end. My hyde mount is not adjustable its the A type. Pete

crankpin

My Feedback: (14)

Hooks - Did you buy this TT-3 from me ? I had two, one with the pipe tunnel.

Crank

doxilia

My Feedback: (3)

Pete, Tim,

that's right, I was looking at the square "cutout" on the side.

I have the same issue Pete as I have to remember to flip servo trays all the time when cutting them as I draw as if seen from above but the installation is from the bottom.

In the re-draw of the plan, I decided to try working the cowl into the fuse design much along the lines of how your cowl is built up. I extended the narrowing sides (a good thing) to the front of the engine which will bond to a 1/4" balsa former. I'll use 2 x 3/8" balsa side bottoms under the sides and cut to the fuse side view. Both the cowl and "tank" area (now empty except for the battery - probably) will have 3/8" sheet caps on the underside to span the block sides. It should allow for a nice round shape. I also changed the planking region to only span from the wing CG (F3) forward since the slope of the fuse aft of this is linear and can all be treated like a turtle deck. It might have to be sheeted in two sections to account for the fuse side curvature so the wood doesn't deform but I feel it can actually be done in two half side passes. I like to mold over the stringer, mark the centerline on the skin, remove it and cut. I then repeat for the other side. I think I'll also deal with the belly pan in two sections; the front being solid balsa sheets cut to planform laminated and the rear with 3/16" or 1/4" sides with tristock and a 1/8" cap sheet. Things are still moving around but below is where I'm at with the drawing.

I moved the FW forward for long stroke 60 power but after thinking about Hyde mounts with the preceding conversation, I'm considering moving it back again and making my own Hyde mount. Apparently, all it takes is 2 balsa discs, 2 ply discs and some good inner tube, thread and CA. The only question is, how thick are the mounts for a 60-90 size engine? I was thinking of using 1/8" ply discs and 1/4" balsa discs which would result in a mount standoff of a little over 3/4". I would then use a radial Dave Brown mount on the front.

I also changed the incidences of the wing and stab back to zero per Ron' earlier TT's and will add down-thrust to the engine. It would be easy to convert the design to plug-in surfaces but the removable fuse top is not quite as simple. I'd be interested in hearing/seeing how your friend did it Tim.

The RE OPS shown at the moment is just for spacing as this is a long engine. I was thinking of using either a YS 61-S or an OS 61-SF-P allowing a regular tank to be put back over the CG. With the SF-P however, the Hyde mount wouldn't work too well as the rear of the mount is ideally hollow to allow the lines to pass through the FW. I also noticed that if one were to use a pipe, the location would be a little high on the fuse side. One could fix this by simply mounting the engine 30 degrees CCW from vertical which would lower the header output and put the pipe along the fuse side top datum. If it can be put just over the wing, better yet as the pipe would mount to the vertical side rather than the curved deck portion.

Any thoughts or suggestions would be welcome and appreciated.

David

PS Tim, I like how Ron sets up his blocks for wing cutting. He places the top of the root and tip airfoils an equal distance from the top of the block. This basically cuts in the dihedral and allows one to join the panels in the shucks as the roots are flush and perpendicular. Of course, for this to work, one has to flip the templates for the other core so one winds up with a left and right core. I've received cores which were cut with the templates off from the block centerline (just a fraction) and cut as if they were identical. Of course, once the core is flipped, the roots didn't match. In addition, the airfoil wasn't symmetric where it should have been. I couldn't build that wing...

Timthetoolman1

My Feedback: (6)

Pete,
Do you use RCG? If not I'll post here too.

David,
Wing - in your last paragraph, are you saying you like the fact that Ron puts the wing root and tip airfoil on the page in correct relation to where they belong? I put the dihedral in the cores so there is no guessing.
Somehow I screwed up on the stab that Chuck got though. He said it was a half inch short. I have so many cores laying around here I thought I gave him the wrong one...and no, I won't send them up North.

Thrust line - one thing I was thinking of is that the way he designed it the plane will fly tail high like a P-40. If you put the angles back in the engine and take them out of the wing and stab you also change the location of the chord line in relation to the thrust line. I think they will deviate a bit (verify this as I'm not pouring a lot of thought into it right now). I thought about adjusting the the chord line and thrust line relationship which would be a 'legal' modification I suppose.

Removable canopy - he went about an inch away from the canopy and cut at around 30 degrees in front and back and flat across the bottom and caped it. F2 through F5 have a bottom and top. Just extend the bottom portion a bit, get rid of the top of F3 and F4 and put the top of F2 and F5 at angles like this \ / Make matching top parts for F2 and F5 and put a bottom on it like this \____/ then plank the top and put the canopy on it. I'm sure you would have gotten to that conclusion at some point. How does that saying go? It's hard to see the trees for/through the forest.

Firewall - If retracts are used I'd move F2 about 18 mm forward or cut into the wing for the wheel. I would like to see a TT with cheeks just to give more room for the mount (just for S and Gs) but with the adjustable mount like I have I think you can get there too.

Wing belly pan - I like your idea about the stringers on the belly pan and sheeting over it but do all of it that way...my gosh man, you're a genius! I'll have to look into that. When I saw that it was carved I thought, ya, right.

The canopy mold came out great. Pics later.

rv7driver

My Feedback: (105)

Tim not so much on RCG , I also like the stringers and balsa cover on the belly pan as David said. I did carve the belly pan but really don' care for it as they are heavy even after removing a lot from the inside. I think I will give it a try. Pete

Timthetoolman1

My Feedback: (6)

This may be sacrilege, but who has tried a tail dragger version of the Tiger Tail? And would you do it again?

RCDENT

My Feedback: (2)

My Tiger Tail III is a tail-dragger. Works very nice. Hardly ever break a prop.

Timthetoolman1

My Feedback: (6)

That's the one my buddy saw. I told him I would try to talk you into one of our events

rv7driver

My Feedback: (105)

I for one do not have a problem with nose gear or conventional gear, my XLT I'm building will a taildragger . One of the local guys is flying a tt4 S as a taildragger it looks good

308jockey

I actually converted my TT4 from a nosewheel to a taildragger and was much happier with it. Planning to start my new one in February if we don't all frezze to death first.

JeffH

My Feedback: (43)

The TT is one of the few classics that look ok as a tail dragger. It must be due to the WW2 Fighter-ish look that it has. The TTs always looked like they could be a full scale plane.

doxilia

My Feedback: (3)

Tim,

Ron drew the core airfoil templates in relation to a 3" foam block depicted by the rectangles around the foils. The root is placed on the block centerline (1.5" up or down). The tip centerline is placed so that the top of the root and tip foils match and are equidistant from the top of the block. In other words, the top of the cores is flat when joined just as they should. This is a nice way to cut dihedral into the cores as joining them is a simple matter of laying the cores in their lower shucks and mating the perpendicular roots. It's sort of akin to how a Kaos wing is built but upside down. The other more typical way of cutting them would be to place the root and tip centerlines on the 1.5" center mark of the block and then angle cutting the roots. This then requires the shucks to be "blocked up" until the roots mate for joining and is IMO a little more tedious. The only issue with cutting the cores as Ron depicts is that the carved wing tips end up having a slight asymmetry about their centerlines as the core tip is perpendicular to the horizontal rather than having the dihedral angle cut into them there. It would actually be a simple enough fix (if one really wanted to not that it matters) to then cut the dihedral angle into the block at the tips.

If I follow you, yes. If I remove the incidence from the wing and stab, it alters the draft of each of these in relation to the thrust line. I saw no reason to change the location of the thrust line so I just left that per plans. As far as locating the chord line of the wing and stab roots, I placed the wing at the draft of the CG location marked on the plan. It would be like rotating the wing downward about the CG (which incidentally would not be a bad location for a wing tube in a plug-in design). The stab in the original is placed such that the extension of the chord line grazes the top of the wing at its thickest point. Upon returning the stab incidence to zero, I left this relationship so the chord line still touches the top of the wing. This kind of wing/stab draft relationship is not uncommon in classics. It ends up putting the wing and stab chords at 2" and 0.8" South of the thrust line, respectively. I just checked Ron's earlier TTI which has a more pronounced upward angle to the lower rear fuse. Guess what? The stab is placed 0.8" North of the thrust line (the wing is at 2.15" from thrust)! A significant change in design approach between the I and III/IV (I haven't seen plans for the III but I suspect the relationship is similar if not identical to the IV).

Honestly though, as with any good adjustable pattern model, the ideal setup would be to have plug-in surfaces allowing one to alter the incidence as well as down/side thrust. Changing the incidence would allow one to experiment with decalage as well as thrust line angle of attack in flight. I plan to do all that with the Brushfire which I designed with plug-in surfaces. I also have a Dalotel which will have both wing and stab plug-in. I like the idea of "tail high" flight but we'll see how this works out. For now, I'm thinking along the lines of a simple no retract, low servo count (7 at most), long stroke YS ship with pipe above the wing along the thrust line. I'd like to try and keep an even mass distribution about the thrust line so the pipe will be on it and the thank will be above it while the wing is below. The fixed gear are the only thing that sort of bothers me but I may consider a conventional retract version.

I don't quite follow you here. What adjustment were you thinking of? Incidence related or draft related? Are you thinking of moving the stab up closer to the thrust? It's too bad Ron is somewhat less reachable nowadays. It would be interesting to hear why the stab came down below thrust from his original. I bet it has to do with rolling maneuvers what with the TT1 being essentially a flat top and a pronounced curved bottom (much more P-40 like) while the TT4 has a more fish-like fuse shape about the thrust line. He might have had no choice but to bring the stab down in such a fuse. Still, it could be flush with the fuse top datum or even higher on the thrust line with a an airfoil shape fin bottom...

Yup, I guess this all makes sense. I suppose I was thinking along the lines of a more extensive removable top (for electric setups) but was concerned with structural integrity in a glow engine setup. The planking makes for a stronger front end than a skinned former approach too and I have removed half of that planking as I don't love that type of building.

Looking at my plans now, I think if I made the wing and stab plug-in structures, the fuse would then be a fairly solid structure even in the absence of a top deck especially if I extend a 1/32" ply doubler into the 3/16" fuse side top extension shown on Ron's plans. I think I'm going to do that regardless and cut the extension from 1/8" balsa and then mate the three fuse sections (top, front and rear) with the doubler. The top would then remove entirely from firewall to F5 along the fuse side top with the deck portion of F5 canted back 30 degrees as typically done with removable tops (and as you were suggesting). The top would then have a 1/8" planked front half and a 3/32" skinned rear half (I decided to switch the skinning from 1/8" to 3/32"). The remainder of the fixed deck potion would also be skinned with 3/32" to match. The front portion of the removable top would also taper upward per the fuse side top extension. Last but not least, I'll use a 1/8" lite ply floor between F1 and F2 which will serve for both an optional nose gear base as well as a battery floor and steering servo mount. With a removable top, this would all be easily accessible including the tank and remainder of the radio which at the moment is all wanting to be mounted output wheels up. I'm thinking one P-P rudder servo in the fuse and two mini (Spektrum 5030) elevator servos in the rear (which will require that battery behind the FW).

Mmmm.... as I'm brain storming it here, the more I'm getting sold on this... Projects always seem to take on a life of their own. So much temptation when designing...

I didn't measure how much I moved the FW forward but I can now see that a nose gear and a 2" wheel would easily fit with a 60 without having to butcher the front of the wing (another building bug I seem to have). Of course, with plug-in wings, this is a non-issue... The retract location and strut length can pretty much be any length desired. Dang, did I just say that! More hard selling seems to be happening to me.

It sounds like the Hyde mount you have is a touch too big for the model. I placed a 2.75" ring (the size of a Dave Brown 90FS mount - 2.74" actually/beam width 1.69") centered 3/16" offset from the FW centerline and it fits without a problem with a little space to spare. In fact, it matches well with the cutout shown on the lite ply cowl ring depicted on Ron's plans near the spinner. The left side (from the front) is vertical as there is no mount there to interfere. It sounds like Pete also got a hold of a Hyde mount of that dimension. Even at 2.9" for the 120FS there doesn't seem to be a problem - it still fits. Is the Hyde mount diameter larger than 3"?

David