smithcreek

My Feedback: (25)

How old is your super glue? I've got half a bottle of thin and half a bottle of medium that lost ability to kick as fast as they should. The thin should kick in a few seconds, medium ten to fifteen max. They can go bad pretty fast with the right/wrong conditions.

tailskid

My Feedback: (34)

I keep all my UNused CA in the refrigerator and that extends their life until I get around to using it. Don't put an OPENED CA in the refrig....it will go bad right away.

ChinookRC

The thin Mercury is probably from August 2011 (first opened) and really doesn't seem to work very well. Could it go bad that quickly?

The medium is brand new and no complaints.

ChinookRC

Hey Airraptor in the end I decided to trust the designer and didn't adjust the tail former spacing to reduce the length. But my suspicion is that it was simply fashionable at the time to make a warbird look like a pattern ship (the T-28B being a perfect candidate for that) and that it would fly just fine with about 1.5 inches removed. Then again, Ihave no way to confirm that so you could be the one to try! Too bad Dave didn't answer the question when I asked him.

ChinookRC

I'm in a bind with the battery hatch. If the hatch is the length of the space between the firewall F1 and the next former F2, there is enough space to slide a 6S lipo down onto the hardwood motor mounts. It's a very tight fit. Since the best lipo position for balance isn't known yet I'll leave holes in both F1 and F2 so the battery can slide in either direction quite a bit.

The problem is that the canopy is in two parts, with the front windshield piece sitting on top of what would be the top of the battery hatch (F1 to F2). At this moment I'm not confident that the gap between the windshield and the canopy could be held tight during flight, but it's possible that some well placed magnets along F21 and F20 could do the job. Any gap at all could force air under the canopy and will eventually rip it away in flight.

The other option, similar to what I see at the field on foamies and Extra/Edge designs is to have the entire windshield and canopy pull off leaving a huge access hole at the top of the fuse. But this canopy isn't like the the Corsair or Bearcat where it's just a bubble sitting on top of the fuse the T-28 canopy plastic extends well down the fuse sides all the way to the first stringer above the center crutch. It connects to a 1/8" sq canopy support that is glued to this 1/4" sq stringer. I could upsize the canopy support and use magnets between it and the stringer, probably with some cross spars to hold the shape width-wise between those canopy supports. At the front the hatch would separate just behind the firewall, and at the back behind the angled F19 piece that rests against shaped balsa blocks that form the transition between canopy and tail.

The second is becoming my preferred option, but this is where it's unfortunate that the canopy is somewhat warped and will likely need a wire support glued inside beneath the painted center canopy frame. Not too bad. I wouldn't build the C1/2/3/4 instrument panel box, nor do any other cockpit detailing, which I wasn't planning to do anyway, this being a flying machine for me and not a true scale model.

TexasAirBoss

My Feedback: (22)

One word of warning, the canopies tend to come out looking long and low. Combine that with the exagerated length of the fuselage and it really looks bad. Try to keep the canopy as high as you can. The Black Horse T28's canopy is actually slightly taller and might be preferable.

airraptor

My Feedback: (66)

i would put a hatch on the bottom of the fuselage right in front of the wing if you can make it fit.


Even better yet is i just looked over the plans and i think a box built around the battery inside the fuselage where its show in your pictures are. The battery will be installed from the front. Just have the cowl help on with magnets and alignment pins. take off prop, remove cowl install battery, hook up to speed control install cowl and prop. with this set up you can use one of those electric safety switches. everything is hidden this way and no holes or anything in the fuselage to distract from the scale look.

ChinookRC

Itook a break to stew over a few things that have been bothering me and of course to get in a lot more hours of flying time.

-1- long fuselage
Using either the 3-view included on the DP plan, or the Squadron/Signal 3-view, I figure i need to cut 12.5cm (~5") off the fuselage to get a match. But then the wingspan becomes a problem. the T-28B has measurements length 32'11", wingspan 40'7" for a ratio of 0.811. Measuring directly off the DP plans, the ratio is 0.808 for a difference of 0.003 which is negligible. So the model has the correct length/wingspan ratio which indicates that the wingspan is as much out of scale as the fuse is. I'm not sure that makes sense, but it seems that shortening the fuselage wouldn't solve the scale problem. It doesn't help that every photo of a full-scale T-28 seems to have slightly different fuse/canopy/cowl proportions from then next photo. Same with photos of the DP model sometimes they look fine, sometimes strange. I attached some pics of someone's DP model that look pretty good.

-2- canopy height
Texas correctly pointed out that the model's canopy has a lower profile than both the original T-28A canopy and the low profile canopy that was introduced later in the A-version production (ref. Squadron book). I've sent an email to Black Horse asking if they stock canopies for the .61 (65") ARF that they no longer appear to produce. Not holding my breath.

-3- battery access
I appreciate airraptor's ideas on battery access but when I'm flying I don't want to take the plane apart (either the wing or the prop/cowl/motor) just to change a battery. The BH ARF design has the entire canopy pull off - it looks ok and I'll go that route. The 65" one-piece wing is as large as I can transport and I don't want any more field assembly than that.

-4- prop size and motor selection
The BH T-28 ARF is the same wingspan but uses a 14" prop, whereas the DP model can accomodate a 12" max (13" would be asking for ground strikes or lawn mowing, even if the front wheel was brought from the 2" specified, to 2.5"). This was really frustrating as a 14" prop opens up a whole new world of motor/lipo choices (BH recommends a Rimfire .80). In the end I ordered the Scorpion S-4020-8. I have both 5S 5Ah and 6S 5Ah lipos and a CC 75A lite ESC available already. Switching to glow or gas just isn't in my plans now.

-5- finishing method
I spent the last few weeks watching the DP Bulding and Fiberglassing, and Detailing and Painting videos and have decided to take the plunge and try my first fiberglass job with Klass Kote paint. It's not hard to look at the TFCorsair and Bearcat I built and realize how much better they could look if they hadn't been done in Ultracote. If it flies well I might just redo the Bearcat - it's ready to test fly, I'm just working up the courage now. With the T-28 so much out of scale I'm leery of putting months of finishing work into it, but on the other hand, my first attemp isn't likely to impress anyone so... better sooner than later. Have been busy sourcing and ordering the K&B resin and KlassKote paints that are recommended - not as easy as it should be with few if any suppliers in Canada and chemical shipping restrictions from the States.

As far as color scheme goes, I think I'll stick with the red and white traditional T-28 colors. If I did it in yellow it would probably look like an old pattern flyer with Navy decals stuck on it! The grey and white looks good too but I think I'll go for markings that make it totally obvious what it is.

With that off my chest I'll get back to building! Just for the experience, I think I'm going to plank the fuse instead of sheeting it.

EF

I'm at the final stages of building the 1/5 79" span version of this model.

I too noticed the deviations from scale you mention, but after some thought decided not to worry too much.
After all it is a 'sport-scale' model and provided the color scheme is correct and some of the more important features are included, it will look like a T-28 and that's the whole point in sport-scale.

I did not shorten the fuselage or do much about the canopy for example, but certainly I did build the wing L.E. root extensions that are so typical of this aircraft (yet no hint of them is shown on the plan or in the manual).

BTW, mine is painted yellow, for good visibility, but then I discovered there's an ARF of nearly the same size and color scheme and so now everyone will think I did not actually build it myself [&o]

optech

My Feedback: (9)

Uhhhh.... you might want to rethink this. A few weeks ago I was doing a Top Flite P-51 maiden for a guy. I had seen the construction a couple times during its build and it wasn't perfect but not bad either. During the prefight I saw what I thought was ply plates added under the horns and they seemed solid so I didn't ask.

Wouldn't you know it... I lined up and rolled on the throttle. i was holding some right rudder but she was still torquing a bit to the left so I put in all the rudder it had. It straightened up just long enough for me to register it before she all of a sudden slammed over to the left and smacked the pilot netting about 2 feet from me. After I checked my britches to make sure I still had my dignity, I went over and checked it out. Not much damage as she hit nose and wing tip pretty square. A broken prop, and a dinged up wing tip and leading edge and a collapsed retract. What stood out though was the rudder pushrod dangling with the horn still attached. Turns out the plates were his idea of a balsa spacer to get a better pushrod geometry. He also had forgotten to add the play mounting plates so he just CA'ed the holes and epoxyed the screws. You could see the wood still attached to the screw where it pulled away from the rest of the balsa. I shudder to think what would have happened if it had got in the air with all the other horns attached the same way.

My suggestion at your point in the construction would be to drill and sink some hardwood dowls into your balsa blocks all the way through the surfaces, then screw the horns into them or something similar. Balsa threads might be fine for servo hatches but not for flight surfaces.

Mike

ChinookRC

Now that's a warning I won't soon forget... well told and well received! Great solution too - many thanks. I'll post pics when it's done.

ChinookRC

Would love to see some photos of your model. I've been leaning towards yellow because it looks nice (especially with some detail added I think) and my field has lots of red and white T-28 foamies. Know exactly how you must feel!

The instructions sheet of this kit cover doing the LE extensions with microballoons and even has a paper mold to cut out of the plans. I'm picking up some of the phenolic type of microballoons that DP recommends in his videos at a shop this afternoon - they were hard to find.

JRgraham

My Feedback: (1)

looks great so far!

Yellow is a great color, very visible in the air.. Ithink more than most any other color! My only issue with Yellow, is it attracts every darn bug in the area! I suppose a light fogged coat of bug spray might work, hahaha.

That yellow full scale is beautiful!

optech

My Feedback: (9)

Looking good. Can't wait to see your final product. I really enjoy your builds and threads. I'm kinda in a medical hold from doing too much so its fun reading what other people are doing and you document your builds well. I still need to go back and find your Bearcat build as I don't remember if you put any final product pics.

Mike

EF

Here are a few pics.
The wing is finished and ready for flight, the fuselage still needs some work.
Right now I’m engineering the various engine cooling air exit ducts (at scale positions) none of which are shown on the plan or in the manual. Then I’ll make a dummy engine and it’s on to finishing and preparation for flight.

The finish is Silkspan, sanding sealer, hand brushed polyurethane paint, and satin clear. Kit decals used everywhere. I wish I could spray the finish but have no suitable place or equipment for doing it.

BTW I made the L.E.Xs from a 1/32� ply base and then 1/4� and 1/8� soft sheets on top and bottom, for a light and easily shaped structure. I know there are other techniques but I usually seem to get better results with basic wood construction.

The gear is fixed.
At ~12 Lb. this 79� span model needs proper (i.e. mega-$$$) retracts that after shipping and Customs in my corner of the world simply bring them beyond my budget.
But, since I hate bare wire gear, I did attempt to cover them a bit and install all the doors around them.

It’s a nice traditional kit, not the most accurate to scale you can find, but I enjoy building it very much and see no reason it should not fly well.

ChinookRC

Hey Erez... seems like I didn't get an email when you posted (or for any of my other subscriptions for that matter) so I didn't notice your post. Your model is looking really good! I'd be really interested in seeing some detail shots of how your canopy looks - I'm still mulling over how to turn it into a battery hatch. Got some ideas but some pics of the real thing would be great.

+++++

I've done a bit of work, not much with summer and flying. There's many long winter months coming when I'll be glad to have something to work on so there's no rush.

I mentioned I was going to plank the fuse, but when I looked at the size and nice quality of the big side sheets I dropped that idea really quick. So I glued it on and only then realized that I'd forgotten to sand the stringers level with the formers. My build threads are a litany of mistakes - the purpose being to reinforce lessons learned I hope. Rather than pull the sheets off and redo them I added some thin 1/16 - 1/8 strips along the edge of the formers so that the upper and lower sheets have something to stick to when they're glued flush with the big center sheets. It puts the profile a little out but nobody is going to notice. I haven't finished the sheeting yet.

I also cut square holes for the battery in the firewall and the first bulkhead. The holes are plenty big enough to accommodate any size 5S or 6S lipo, but the motor box is going to be pretty big to fit around it. The plan is to have room to push the battery through the firewall if it's needed for balance. Also finished installing the servos in the fuse as well as the nose gear mount on the firewall.

I was pretty surprised when I was prepping the Bearcat to see the servos in the fuse rip the rails right off their connection to the formers, so I'll be adding some reinforcement on the Trojan servo rails. The Bearcat is now down with Lado retract issues - another month I guess for parts to arrive from France. Nothing but trouble with the Lados.

Back on the Trojan, I followed Mike's suggestion and drilled 1/4" holes through the balsa block I was using as the horn mount on the flaps and ailerons and made a bit of a mess of it. The drill chewed through the thin sheeting and in a couple cases, ripped up the ribs a bit. I should have gone with a smaller hole but I had 1/4" dowel sitting around. In the end I used globs of resin mixed with microballons pushed through with the dowel pieces to fill any big gaps and hold everything in place. It looks a sight but after sanding it down it's hard to feel even a bump where the repair was done. I won't be noticeable after it's finished. Worth the effort for some peace of mind!

EF

Here are some pics of the canopy and cockpit area as you requested.

The canopy was not made removable since I’m not going to use electric power for this model.

The whole canopy issue was rather frustrating.
First, as already mentioned in this thread, it is not quite the correct scale size or shape. I did not want to invest in after-market replacements, so I did the best I could with it. Maybe after some paint it'll look better but still it seems not tall enough and not as "bubbly" as some photos of the real one show. Second, the supplied canopy was too short (by more than 1/2" ) in comparison with the canopy shown on the plans, so I had to add some material to the block just aft of the canopy to compensate, and then carved and sanded it all to more or less blend together.

If you can source a better canopy, I'd give it serious consideration.

The canopy installation was done per the plans and carefully sanded and blended with the fuselage sheeting.

Be very careful if you make your canopy removable since it means the cockpit floor will now not be fixed to the structure, leaving you with a rather large ‘hole’ that may weaken the whole fuselage, unless other changes are made to compensate for it.
Possibly, a ply frame all around the opening may help but watch the weight.
I’ve seen quite a few ARFs that have such a large opening in the middle of the fuselage, and was quite amazed in some cases to see how they fall apart after what I considered to be no more than rather heavy landings that should not have caused damage to a properly built model (or maybe it was the lack of glue?)

ChinookRC

I think you might have trimmed your canopy too much and that's why you had problems fitting it. If you look at some of the real T-28 photos above, you'll see how the bottom of the canopy extends down quite a bit - it's especially noticeably when the canopy is open, less so when it's closed because the painted metal bottom blends with the fuselage quite well. It's a lot different from the Bearcat and Corsair I built where the canopy is trimmed tight and rides the top of the fuse. It looks like you must have extended the fuse skin upwards an inch and a bit. But I think the painted result will look the same.

+++++++

I finished skinning the fuselage and gave it a rough sanding. Also rough shaped and hollowed the rear canopy block and played with the canopy position some more. Masking the the clear areas (I masked the inside, but on second thought I think it should mask the outside and paint the outside is that correct?) made the structure more visible, and is giving me confidence that a canopy battery hatch is going to work. The center crutch and upper longeron run the length of the fuse and I don't see that having the canopy removeable is going to change the structure much from the original design. I'll be fiberglassing the plane to that'll add a lot of strength too.

Next will be to trim the F6 canopy floor to fit in the higher position (upper longeron, vs the intended center crutch position), add canopy rails and start putting together the removeable canopy structure. I won't be doing much with the cockpit.

EF

Looking at the canopy in your pics, it is obvious to me now that the canopy in the 65" span kit is very different than the one in my 79" span kit.

My canopy did not extend downwards as does yours.
Actuall I trimmed it right at the point where the horizontal flnage all around begins.
The balsa sides are exactly as on the plan, no mods done here by me.

BTW, my kit came with a plastic underbelly pan, supposed to fit under the wing center, and that was more than 2 (two) inches too short (so I made it out of balsa).

But even though the 79" span kit has quite a few 'shortcommings' I'm past them now and on the way to soon start the finishng process on the fuselage.

ChinookRC

No wonder I was confused looking at your photos! I was wondering how that could be the same model. Should have read your earlier description more carefully, but regardless appreciate your help and am taking your advice on cockpit area strength seriously. I'm heartened to see that the support within the canopy bubble (pic below) looks good because I'm going to have to make one to provide support on mine.

mkoe

Subscribed! I loved my DP T28 years ago.Great flying plane.

ChinookRC

Here's a vid from YouTube.. looks like the same size.

EF

The ESM ARF version is ~80" span I think, like my Pica kit.
It looks very good if you're into ARFs, however the video demonstrates (yet again) why I dislike retracts...

optech

My Feedback: (9)

Retracts can be a pain but his "Almost-stall-to-a-No-Flare-nose gear-as-a-landing-spike" to the runway attempt sure didn't help.

Mike

[email protected]

Anyone out there have build manual (or a copy of one) for the Platt T-28B 65".  Got an old kit that had been stored in the attic for a long time and the manual is not there.  Thanks from a new subscriber!