RCGroups member and contibutor, glen, brought us a dramatic slowing of the ParkZone SU-26 micro plane with this thread:

https://www.rcgroups.com/forums/show....php?t=1092145

Having perused his work, and admiring what he did, I decided to take his approach to new heights, so to speak.

When I first tried to fly my newly purchased PZ Sukhoi in our small gym (approx 90 ft. x 45 ft with a scant 21 foot ceiling), I found that I was merely bouncing the plane off one wall onto another and flying much too fast for comfort! Clearly, there was a need for slowing the beast. Although retired, but still feeling the career engineer in me, I decided to look at the situation from a wing loading aspect. The wing area of the "out-of-the box" Su-26 is a mere 46.4 square inches. With a stock weight of about 33 grams, that calculates out to 3.46 ounces per sq. ft. Not good for a small plane in a small gym. We needed a way to reduce the weight and/or add wing area.

That's when I found glen's thread. But merely adding thick depron will add area, it also adds weight. So the engineer's mind went to work and came up with Durobatics!! Yes, .025 Durobatics will save the world!

The net result is what you see below.

I made patterns for the leading and trailing edges of the wing to develop a larger wing area and added an additional 2 inches to the span. The result is an increase in the wing area to 73 sq. ins. This now yields a 2.3 oz/sq. ft. wing loading. This will do nicely in this small gym.

The first two photos were made by placing the plane, with extensions, close to a sunlit window to highlight the addition of the Durobatics against a contrasting view that shows the original wing surface. The latter 2 photos show the enlargements for the elevator and rudder.

In a later post. I will offer the patterns for the foam that I added to my plane, as well as a couple of videos of the flying today. Enjoy!

Here's a link to the videos my friend and indoor flying host for our twice weekly sessions, Randy Hayden, took today while I manned the sticks. I have an old digital camera, so don't expect HD quality.

https://www.rcgroups.com/forums/show...4#post13025141

Also, here's the patterns for the Durobatics overlay pieces. Somehow the text that I added to identify the parts didn't get saved, so here's what goes where:
On the upper left is the elevator piece (make 2, duh!); in the middle is the wing trailing edge (again, make 2): on the right is the leading edge of the wing (of course, make 2). The rudder extension came after the previos pieces, so use the photos to determine the shape and size. After cutting the LE extensions, roll them over a bamboo skewer to form the leading edge, then tape the parts using Blenderm or packaging tape. Scotch Magic Mending tape doesn't want to stick to the Durobatics or the PZ foam, either.

If anybody cares, I made the patterns "ad hoc", as I fit the foam pieces in place. I cut and trimmed to fit, then opened the pieces and traced them. To make the patterns you see, I put the originals onto a piece of yellow tissue and scanned them into Photoshop. Using the Filters command ----> Stylize ----> Edge Detect, Photoshop defined the outlines of the patterns. Neat!!

Omit unnecessary info

Very nice.

Thanks for sharing this.

Thanks 356Jim for sharing your project with us!

I added on to my Sukhoi with some 3 mm EPP on just the leading edge, all the way to the nose, delta-like. I am generally pleased with my results. I still have some work to do to get the CG where I like it. I've run out of nose to put the battery as far forward as I need to. I may have to add material to the ailerons also!

What I'd like someone to come up with is a total replacement wing and tail made entirely of Durabatics. That should be somewhat stronger, yet lighter than adding on to the existing foam parts. Unfortunately the price will possibly be prohibitive.

And of course, the next step on that evolution path is a replacement fuselage of Durabatics. So why not just make a whole new plane and move the Sukhoi guts over to it!? I'm sure we'll get there, but so far it's close, but no cigar!

Bring 'em on and bring 'em indoors!

Jim

Originally Posted by Jim_Marconnet

Thanks 356Jim for sharing your project with us!

I added on to my Sukhoi with some 3 mm EPP on just the leading edge, all the way to the nose, delta-like. I am generally pleased with my results. I still have some work to do to get the CG where I like it. I've run out of nose to put the battery as far forward as I need to. I may have to add material to the ailerons also!

What I'd like someone to come up with is a total replacement wing and tail made entirely of Durabatics. That should be somewhat stronger, yet lighter than adding on to the existing foam parts. Unfortunately the price will possibly be prohibitive.

And of course, the next step on that evolution path is a replacement fuselage of Durabatics. So why not just make a whole new plane and move the Sukhoi guts over to it!? I'm sure we'll get there, but so far it's close, but no cigar!

Bring 'em on and bring 'em indoors!

Jim

It's in the works. much lighter and stronger!!!!

Regarding my mods to the PZ Micro Sukhoi, I forgot to mention the radical change in the CG position.

Flying stock, most of us preferred a battery position slightly rearward of the existing battery tray, with some flyers carving away some of the under-fuse foam.

With my mods, the "sweet" spot for the new CG is with a battery located approximately halfway between the FORWARD end of the battery tray and the front of the cowl. I locate the end of the plastic tag (at the back of the battery) straight even with the front edge of the cowl.

I'll add a pic later today

Here's a pic of the "new" CG with my Sukhoi mods as described in this thread.

I apologize for the poor quality, but I was getting a "zoom error" on my camera for some reason. Anyway, note the battery position midway between the front end of the batt tray and the front edge of the cowl.

Interesting thread.

Originally Posted by Jim_Marconnet

...
I added on to my Sukhoi with some 3 mm EPP on just the leading edge, all the way to the nose, delta-like. I am generally pleased with my results. I still have some work to do to get the CG where I like it. I've run out of nose to put the battery as far forward as I need to. I may have to add material to the ailerons also!...

Perhaps to move the center of lift back a little (without adding to the ailerons),
one could add foam to the leading edge of the horizontal stabilizer,
or add a "wing/stab" inbetween the wing and horizontal stabilizer.

Originally Posted by Jim_Marconnet

*snip*

And of course, the next step on that evolution path is a replacement fuselage of Durabatics. So why not just make a whole new plane and move the Sukhoi guts over to it!? I'm sure we'll get there, but so far it's close, but no cigar!

Bring 'em on and bring 'em indoors!

Jim

Its easy!

Nice work, Jim

Nick

For now, I will continue to fly mine with the mods described at the top of this thread. It's so much fun. Wish the original, as purchased, flew this light!!

Meanwhile, my additional ar6400 and as2000 linears are being test flown in a 66% Arrow (see BudgetRC.com for Robert Youen's neat design). It has a 1.6 oz/sq. ft wingloading and as Cassius Clay used to say, "it floats like a bee".

Wait a minute!! Wasn't that "...stings like a bee...???

Well, it floats, all right!!

Originally Posted by 356Jim

...as Cassius Clay used to say, "it floats like a bee".

Wait a minute!! Wasn't that "...stings like a bee...???
...

As I vaguely remember, "floats like a butterfly, stings like a bee"???

I am hoping that the upcoming Parkzone micros are more floaty.
I have scratch-built and hacked, but not on a micro scale yet.
But threads like these give me ideas of what to try.

Ive just done this mod to my sukhoi as well as add a 240 mah battery!

Man!

What a blast!

I couldnt fly this plane indoor as im new to micro planes and without this mod i kept crashing!

Fantastic job!



Here a small video

Parkzone sukhoi indoor action! (1 min 29 sec)

Hi Guys, I also did the mod to slow flight but didnt get it completed before time to go to the Gym. I only had the leading edge done but decided to take the sukhoi anyway in case I destroyed my other planes. As it turned out I didnt destroy anything and Was there myself so I flew everything I took. I still had a half hour left after flying my regulars so I said I would One takeoff to see what the partial mod would do. Takeoff run 1/2 throttle straight as an arrow lifted off in 10 ft flew around low for a couple circuits then tried more power. This plane flys soooo good. I am not an engineer but if you do the mod only do part of it. Mine balances with the batt at the back of the slot. It came with the longer slot. It will turn around on itself with the rudder or with the ailerons. loops and rolls in the gym. I will try toget pics in a couple weeks when I know my son will be with me. I tried last week with camera on tripod and the other planes but I could only see the plane when flying close in front of the camera. I used hot wire sliced blue foam for the wing extensions and they didnt change the balance. If nonbelievers try it. It will fly around the free throw circle you dont even need half a Gym.I am going to the field to fly in a few minutes to try it outside. Thanks for the plan for the extensions.

JCS

Originally Posted by miatamama

Hi Guys, .... This plane flys soooo good. I am not an engineer but if you do the mod only do part of it. .... It will fly around the free throw circle you dont even need half a Gym.. Thanks for the plan for the extensions.
JCS

Glad you like it. I enjoyed mine so much, that I pretty well wore out the airframe. I exhumed the guts for my Dynex 2.4 (terrific plane!!!) and gave the airframe to a fellow flier who made a biplane out of it with vapor and Cessna guts!!