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25 Flights: 3D Hobby Shop 47" Katana

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25 Flights: 3D Hobby Shop 47" Katana

Old 11-20-2007, 06:49 PM
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Default 25 Flights: 3D Hobby Shop 47" Katana



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25 Flights: 3D Hobby Shop 47" Katana

Wingspan[/B]: 47.5"
Wing Area:[/B] 439.3 sq. in. Length: 41.5"
]Ready-to-Fly Weight:[/B] (without spinner) 35-39 oz.
Wing Spar Tube:[/B] Carbon Fiber

TORQUE 2818T-900 Brushless Outrunner
18 Turn, 900 Kv
Weight: 104g
38 amps max sustained current
5mm shaft diameter.
Includes back mount and 2 prop adaptors.

Why the Katana?

Having had so much satisfaction from owning and flying a 3D Hobby Shop Aspera, I concluded the guys from Fredericksburg, Texas know what they are doing. Lately I've been wanting something a little different, but I wanted to stay within the 3DHS stable of planes for a lot of reasons. I can go on and on about those reasons, but just ask anyone who owns a 3DHS plane how they like it and how they like doing business with 3D Hobby shop.

The Extra looked nice, and I since have bought one. The Yak really looks cool, I have always wanted one, and will definitely have one in the future. What cinched the deal with the Katana is that Ben told me the Katana was more precise with it's longer tail movement. With my pattern background, this seemed the most logical way for me to go.

That, and there has never been a plane that has so screamed to have American flags plastered all over it...............so, it was an easy choice.

Power System
Since the standard power system on the Aspera performed so beautifully, I also went with the Katana's standard power supply, an Extreme Flight Torque 2818T-900 brushless outrunner and Airboss 45 ESC.

I like these motors. They run really smoothly and have their own distinct sound. At speed you can hear the air being drawn through the motor, so it sounds a lot like a little turbine. They are also visually very attractive little gems. Like I say, I like these motors.

We tortured a Torque 2814 on 5s power during the Super Ballistic Aspera experiments, and it never missed a beat. Neither did the Air Boss 80 ESC, so I also went with the standard 45 amp unit for the Katana. One of the things I find most attractive about the Airboss is that it can handle up to seven cells without the need for a separate BEC and all the associated rat's nest of extra wiring. This keeps things extremely simple. Plug it in and it works. If you want to run four cells or five cells or six, just drop them in and change your prop to keep the amp draw at around 38 or so. That keeps the motor happy and everything running within spec.

Also standard for the Katana is the 3D Hobby Shop 3S 2200mah 20C Lipoly Battery. We used 3DHS 5s 3400 packs in the Super Ballistic Aspera project and they were terrific. They ran cool and delivered absurd power right down to when they dumped at the end of the run. As soon as I recover financially I'm going to get some 3DHS 3s 2200 packs so I can grab more flights per outing with the Katana and Extra.


Right now all I have in 3s packs is Thunder Power Extreme series 3S 2200 Li Po, so that's what I'm using. I'll compare them to the 3DHS batteries down the road when I have some of each, but for now I have to use what I've got on hand.

But, here's the fabulous news....if you have a 3DHS 47" plane, they all use these size batteries in their standard power supply, so you don't have to buy a bunch of different batteries just so you can fly different planes. I use my 2200 packs in my Aspera and Katana, and lately, my 3D Hobby Shop 47" Extra SHP. 3DHS' upcoming Velox will also use the the 3s 2200 packs in it's standard power package, so you can see that you buy the batteries, servos, motor, and ESC, and all the stuff works with all the other 3D Hobby Shop 47" planes.

Servos and such
Again, going with the standard equipment, I choose the Hi Tech HS65 servos. Where I deviated from standard is that I went with the metal gears so they would hold up should I want to use them later in something like another Ballisitc Aspera, or maybe even a ballistic Katana.

Also, this way all my servos are the same for all my 47" 3DHS planes. The HS65s drop right into, with no modification, the 47" Katana, Yak, Extra, Aspera, EBT trainer and the upcoming Velox.

Why 47" Makes Sense

All of my 47" planes fit in the back seat of my Altima fully assembled, or with the back seat down, sit flat in the trunk. 47" is big for an electric plane, but it's just right for us old 40 sized nitro jockeys (especially those of us who are so old that we don't see so well).

At 2 pounds and change, a fully loaded 47" plane has enough weight and substance that the wind won't bother it nearly as much as smaller 3D foamies. I think at 47" we are now talking about a real radio controlled airplane. Certainly planes like the Mini Ultra Stick and others are real radio controlled airplanes, but there are still a lot of toys out there. At 47", and with this sort of quality and performance, these are very serious, and very real radio controlled airplanes.

Even though you spend a lot of money trying to keep up with all the cool new planes 3DHS comes out with, you save in the long run because you don't have to buy all new equipment every time. From a financial standpoint, the standard equipment from any of the 3D Hobby Shop 47" planes (except the Aspera uses the slightly larger Torque 2814 motor) will work in any of their other 47" planes. I prefer that every plane has it's own equipment, but if you're on a budget, you can fly, for example, an Extra for awhile, then decommission it and put all the stuff in a Velox for awhile....or a Yak....or any of 3D's other 47" planes. You don't need to buy a motor, servos, ESC, and batteries every time you buy a new 3DHS 47" plane.

The interchangeability of parts is something that I've found lacking since I started flying electrics. It used to be that you knew what a 40 sized airplane was, and what servos it took and on and on, but with electrics, there are so many variables that you can easily make a major mistake putting a package together..........and I've done it more than once. Every manufacturer has their own system for rating their motors and such, and unless you do a lot of research, it can be a nightmare.

The way 3DHS packages their planes and equipment, there's no guesswork. Buy the 47" plane of your choice and the standard recommended equipment and then you're set. What's extra nice is that all your equipment from all your 47" planes is now interchangeable and you don't need a basket of different spare parts for each plane.

The Katana ARF

Shipping Rant
I wasn't surprised when I opened the box.....or more correctly, all three boxes. The Katana came just like the Aspera inside it's own kit box that's inside another box, that's then put inside an outer brown box. This assures that very few 3DHS planes get damaged in shipping, but it still happens. Still, it's nice to buy knowing that the odds are on your side.

The Katana comes all nicely, if not strikingly packaged. The boxes are plain white, and while this obviously doesn't cost as much money to make as a nice, shiny one with some superstar pictured on the lid hovering the plane, it does allow 3D to send us a better plane for less money. You can pay for the box or pay for the plane. I prefer to put the money into the plane.

Worth noting again is that, however plain, the boxing does it's job and gets the plane to you in good condition. My Katana came with holes punched through the two outer boxes, so the UPS guys must have used it for soccer practice during their lunch break or something. However, the plane was undamaged. Belaboring the point to tears, I'm tired of shipping companies tearing up my stuff, but at least it has a fighting chance when it comes from 3DHS.

Oh, but back to the ARF itself.......All the stuff was there. Outside of the radio equipment and power system, everything was included......everything. The carbon landing gears are beautiful and the wheel pants are almost foolproof to install. All the hardware is top notch stuff and I used all of it. The only exception here is that I used a bolt-on Goldberg control horn on the elevator because I hadn't yet learned to trust the kit horns that stick into the wood and epoxy on. I've since used them on my Extra SHP and even full throttle blenders and parachutes can't pull them loose. I'll use them from now on.

The Build

Like with all my reports, I prefer to let the individual look at the construction manual rather that blather on about gluing part A to part B. The manual covers it, so you don't need me hammering you with what you already know.


Jimmy D put the tail on mine. I always get Jim to put the tail on straight because I get all dyslexic with that sort of work. I measure it over and over and can still never get it right, so I just let him do all of my important projects. And, while he's got it anyway, he puts on the wheel pants and cowling, so I don't do too much except install the gear, which I enjoy. Outside of that, the rest of the assembly is extremely basic and most of it is very hard to get wrong.

Radio Layout
One of the things I like best about the Katana is that it's radio compartment makes for an extremely neat and clean radio installation. I am very obsessive about these sorts of things, but the Katana was easy and pleasing to put the gear into because it all fit together so well with very little extra thought having to be put into it. It was just engineered right to begin with.

Beefin' The Former
We only made one change worth noting on the whole build. I noticed the former that holds the radio receiver was flexing when I slid the wings on. It's a very thin piece of plywood, and I imagine it would be easy to break it if you were to use too much pressure plugging in (or removing) a servo lead and not supporting the former.

We glued a Popsicle stick across the front of that former and it considerably stiffened the whole fuselage in that area. It didn't take much time, it doesn't weigh anything and it stiffens everything up real good, so this was a righteous mod. It wasn't necessary, but I feel better about that former now that it's bulletproof. Gotta find something to complain about, right?

ESC Location
I wanted the ESC out of the radio/battery compartment as much as possible to avoid heat saturation. We simply velcroed the ESC to the outside of the motor box where it sits dead solid perfect right in the middle of the incoming airflow.

The ESC runs cool, and with the rest of the air passageways clear, so does the battery. Yesterday in 90 degree heat a friend used his heat gun to measure the Katana's engine compartment temperature at 108 degrees.

Switch installation
One item which threw me a little bit was the switch installation. On the Aspera there were switch mounting holes cut out on both sides of the fuse. You simply chose which side you wanted and then cut the covering back. On the Katana there was no such luxury. Because of short wiring on the switch, and the ESCs location, there really wasn't a good place to put the switch where it would be out of the way on the inside and yet easy to get to on the outside.

Here we simply chopped up another faithful Popsicle stick and made some brackets to hold it. The framing on the inside of the canopy hatch needed to be trimmed back so it didn't rub on the switch, but a dremel make quick work out of that. I have to pull the hatch to work the switch, but at least it doesn't show on the outside and clutter up the plane's beautiful lines.

Old Glory
No plane I have ever seen has ever screamed out so loudly to have Old Glory slapped across her nose, and I am sure that is part of why I wanted this plane.

I encourage the rest of you to pay tribute to our brothers and sisters far from home protecting us from harm. Put an American flag on your plane. It isn't as cheesy as a yellow ribbon, and, IMHO, Old Glory should have always been there after 911 anyway.

However, so far, the biggest stumbling block to successfully learning 3D has been my own arrogance and thinking that I know everything. I set the Katana up the way the book calls for, but initially I didn't like it, and I went my own way with setup.

I mean, what the hell? I know what I'm doing................... right?

The danger of having flown these things for as along as I've been at it is that you do think that you know it all, but 3D is a different game and the technology has blasted right past me in the few years I took a break from the sport. Basically, since the airplanes are now doing things that only a few years ago they weren't supposed to be able to do, we now set up the planes up in a way that a few years ago would have been dead wrong. In one way it doesn't make sense to take everything you have learned in a lifetime of modeling and throw it out the window, but that's what you gotta do.

After a bit of head scratching I finally called Ben to see if he could help, and his answer was as simple as "Read the book." 3D Hobby Shop puts a lot of research into building and developing these planes, and these planes work with the setups 3DHS have come up with. I went back to the 3DHS setup, struggled for a bit, and after a few debriefs with Ben and a few chapters of Scott Stoop's "Mastering Radio Controlled Flight," it all started to make a little more sense.


Learning 3D
Here, as always, is where it gets interesting. The Katana is a really nice, smooth airplane, but with a 3D setup everything is completely different from the way I learned conventional flying.

Where I've been having trouble adapting is years of flying pattern and racing planes has demanded smooth flying. Some of those racing planes will bite you really hard if you yank the stick, so again, it's almost like sticking your hand in the fire: you bury that elevator and you are expecting it to burn.

In conventional flying yanking any stick looks sloppy at best, and disastrous at worst, but a 3D plane rotates so hard that it will dramatically slow and drop into whatever maneuver you are entering. I think this is the basic fundamental truth I've been living in denial of. So many years of trying to be smooth had me not believing anyone, even Ben, that you have to manhandle these planes. It doesn't make sense that it works until you understand what makes the maneuver happen, which Ben was kind enough to explain to me. None of these 3D things existed when I was flying before, so all of it is a culture shock for me. 3D is a different game that requires a different approach. What I think I know isn't going to apply very often. Things that used to be impossible are now routine.

In a lot of ways, you just have to believe. You have to trust the plane.....trust your thumbs.....use the force. Whatever it is, I'll find it and report back. Watching the way Ben flys these things, I'm starting to think it's black magic.

I was also afraid to just yank the crap out of the plane because in the past I have had a lot of planes bite me like that. I preach and I harp over and over to my students to be smooth. Even after they have soloed I will sit in the pits and watch, and I will say loudly enough for them to hear "smooth....be smooth...." When they screw up I ask them what they did wrong, and they already know the answer I am looking for is "I wasn't smooth enough." In pattern, smooth is points, and in racing, smooth is speed, so yanking the crap out of the plane just goes against my nature.

However, once I started burying the stick I discovered how much fun a wall is. One moment the plane is rocketing along and the next it's slammed to a stop with it's nose pointed up. But then, since I haven't figured out the hover just yet, I make a lame attempt, flop around with the tail hanging for a few seconds, and then I'm forced to punch out. This is easy enough because the standard power system rocks. Either that or, if I have enough altitude, I slam in full down and full power and she will rotate tail over nose, otherwise known as a waterfall.

The big fun comes with parachutes because of the surprise factor. You just dive the thing straight at the ground like you are trying to wreck it and yank in full up at the last possible second. This one pretty much sends everyone in the pits scattering for cover, at least in my club where no one has ever been this nuts before. She will slam to a stop and settle into a nice, nose high sink, otherwise known as an elevator, whereupon you just sort of apply a little power and fly off while everyone else is still collecting themselves.

Once I parachuted so low that I did a harrier right into the runway. I didn't mean to get it that low, but the plane rotated out and was sinking so nice that I just held it, and right before she touched the tail wheel down I gave her a bit of power, drug the tail wheel, and flew off. I'm not sure I can do it again like that, but everyone who saw it thinks I'm an aero-god now. I'm sure one day I will vaporize a plane trying to do this with the throttle pegged until the last possible second. Then, Ben will have a good laugh and take my money again.

Worth noting is that when you rotate the plane that violently, the wings will sometimes wiggle a bit, but it's nothing that you can't easily control. I'm sure some of it comes from not entering with the wings perfectly level, and some of it may be that I am still subconsciously holding back a bit on slamming the stick back. And I'm sure some of it is the plane because the Extra SHP doesn't do it at all.

And, oh, does this baby ever blender violently. I mean, she will do such a sick blender that you can't tell what the plane is doing. It was so much stupid fun that I started doing them faster and faster until I did one at full throttle and terminal velocity. I don't know why it didn't blow up. Everyone just sort of stood there with their mouths open and couldn't believe it. Like I say, there's never been anyone in my club before that's as nuts as I am, so they never know what to expect. The plane held up just fine, but I still like her too much to do any more suicidal stunts like that again. I also think when Ben sees this that I just voided any warranty I may have had on my Katana.

So, that's about all I can tell you about the Katana's 3D performance because I am not fully 3D proficient yet, but it's getting better.

Conventional Aerobatics
On low rates and flying conventionally the Katana is very nice and honest. For slow and point rolls, the Katana is a nice tool, and roll coupling is not very noticeable. It's not quite as good as the Extra SHP, but it's good enough that with my limited flying skills I can get around it.

The Katana grooves very well at high speed and generally sport flies very competently. She will slow down to just about nothing on landing, and that's without even harriering it in on high rates.

She stall turns very nice, and will almost flat spin on low rates. If I work on it a bit I can probably get her to do it, but I'm having so much fun on high rates that I haven't gotten to that yet. Actually. I haven't gotten to very much conventional aerobatics yet because learning the 3D stuff has been so much fun.

For now, the Katana will be running on 4s packs and low rates so I can use my 3S packs to concentrate on learning more 3D and getting a decent hover with my 3DHS Extra SHP. When propped for 4s, the Torque 2818 will sure haul the mail at high speed.....perfect for sport flying, but once I get my 3D skills polished up a bit, I can go back to her and she will be a more wild and violent performer than the Extra.

Final nail
In conclusion, I think the Extra would have probably been a better choice for a first 3D plane, but I am still extremely pleased with the Katana and I'm very glad I have it. I think a more experienced 3D pilot can get a lot more out of the Katana than he could the Extra, but the Extra is better for a guy who is looking for something that will lock really solid into a hover so he can learn more quickly. Right now I need to learn, but the Katana will definitely be a big part of that once I progress a little further with the Extra
Old 11-21-2007, 01:53 PM
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Default RE: 25 Flights: 3D Hobby Shop 47" Katana


I appreciate your article and wish it had come a few weeks ago, may have revised my thinking a little. In past experience, I see hype on something "wonderful" and buy the full package expecting the same results. In the past, I have had to replace the motors, esc. batteries to achieve "decent performance", so have many good Hacker, axi, castle etc. items in various drawers.

Recently purchased a Katana MD, and since I had a axi 2808 and castle 60 in the drawer and several 2s1p 3000mah max amps 20C packs, did not order their stuff. Quite happy with the finished airframe. First pre flight with apc 10 X 3.8, the the motor pulled 46 amps. Woa, the prop came of a axi 2208 with 10 amp esc, obviously too much prop, or not enough juce. Went to 3S 2200 pack, 28 amps, so go fly time. Airframe flys good, except not enough motor to high alpha or hover. So, order a axi 2814-10 good for up to 70 oz airframe, mine 35, no . While waiting for the brown truck, find a pa katana thread and find in actual performance the airframe needs a 11 or 12 length prop. The AXI is not going to like a 11 or 12", so its back to poop time. Seems all are happy with the PS thrust 30 stock motors, so going to bite the bullet and get one. At this point in time, I would like to pass a message on to the "Big boys" I am happy for you that you can grin at your year end bottom line profits. There seems to be a host of people out here that are finding as good cost effective motors, esc. batteries and related items through other suources. Thre are also some growing hobby shops that recognize the market gap and are taking the time to experiment with equipment and offer superior packages at reduced prices. Your buyers are learning, and will soon be going elsewhere regardless of how many models and claims you may offer. Toward this end, I offer up several shops that I find to be exceptional, and are truly working at overall quality and performance rather than add hype. IT IS INTERESTING THAT THE BIG BOYS ARE ALL UNNLISTED SO FAR. I HOPE THIS CHANGES FOR THE SAKE OF OUR HOBBY AND THEM

1. rcx planes.com
2 .Atlanta hobbies
3. 3D hobby shop/adchobbystore

Old 07-11-2023, 03:35 PM
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wondering if this 47" Katana will ever be released again, its a size you dont find anymore these days.

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