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Old Dec 01, 2010, 11:54 AM
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Dynam SR Trainer ARF

Welcome to the Dynam SR thread! This thread is for all discussions regarding this plane including building, flying, modifying, and fixing this plane. See post #2 for links to useful information within and outside of this thread.

Here are the vitals on the kit:

The Dynam SR-22 is a 1:12 scale of the SR-22, 4 seat, single-engine composite airplane. It is constructed of EPO foam that is crash resistant and easy to repair. The model is equipped with a powerful brushless motor and ESC. The high aspect-ratio wings makes the airplane very stable with a good glide-ratio. All servos, receiver, brushless motor, and ESC are preinstalled from the factory. All you need is to add a receiver and fly your model. The model is suitable for pilots who wants their first low-wing trainer to advanced pilots. The building-time is approximately 45 minutes to an hour.

Note: The ARF version requires a LIPO Charger, 4 Channel TX Transmitter, 2200mah Lipo Battery, and Receiver

Specifications:

- Length 965mm
- Wingspan 1400mm
- Weight ~880g

Features:

- Power System #1 Consists of an 1100Kv Brushless Outrunner Motor and a 40A Electronic Speed Controller
- Power System #2 Consists of a 950Kv Brushless Motor and a 30A Electronic Speed Controller
- 9x6x3 Prop with Spinner
- 4 x 9g Servos with Nylon Gears
- Optional Flaps can be installed with the addition of servos, wiring, and miscellaneous hardware pieces.

4+ Channel Plane; Working Ailerons, Elevator, Rudder, Throttle and nose wheel. Includes fixed landing gear.

Performance: (posts from users using the stock motor, ESC and 3 bladed prop)

- 1100kv Motor

- http://www.rcgroups.com/forums/showp...48&postcount=8

- 950kv Motor

- http://www.rcgroups.com/forums/showp...&postcount=156

KMan
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Last edited by kman24; Oct 23, 2013 at 07:26 PM. Reason: added info
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Old Dec 03, 2010, 07:15 PM
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Dynam SR Trainer Information Links

This post is reserved for posting links to useful information, such as the Dynam website, build tips and tricks, mods, and build logs. Please send me a PM if you would like me to add something to the list KMan

Dynam Website Links

Dynam's Main Page (distributor/dealer links at bottom) - http://dynam-rc.cn/

SR Product Page - http://www.dynam-rc.cn/Products_view_24.html

Owner Manual #1 - http://dynam-rc.cn/uploadfiles/dlm/DY8936-manual-01.pdf

Owner Manual #2 - http://dynam-rc.cn/uploadfiles/dlm/DY8936-manual-02.pdf

Stock Prop - http://dynam-rc.cn/Products_view.asp?id=98

Build Tips and Tricks

Build Videos (thanks jim12) - http://www.rcgroups.com/forums/showp...&postcount=231



Modifications

Dubro 1.75" Low Bounce Wheels/Tires - http://shop.dubro.com/products/produ...7.0.0.0?pp=12&

APC 9x6E 2 Blade Prop - http://www.apcprop.com/ProductDetail...tCode=LP09060E

APC 9x7.5E 2 Blade Prop - http://www.apcprop.com/ProductDetail...tCode=LP09075E

APC 10x4.7SF 2 Blade Prop - http://www.apcprop.com/ProductDetail...Code=LP10047SF

User Build Logs (make a buld log of your SR and send me the link so that I can post it)
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Last edited by kman24; May 30, 2014 at 06:49 AM. Reason: added info
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Old Dec 03, 2010, 08:18 PM
dbc
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United States, FL, Brooksville
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Mine arrived today also. Typical Dynam packing - which is to say not very good. The parts are just loose in several internal boxes with no wrapping whatsoever. Mine arrived in generally good shape but bubble wrap would have avoided the little nicks and scrapes in the foam. I knew to expect this, however, as the other two Dynam planes I have were packed exactly the same.

The foam is the same high quality, very smooth, material used in other Dynam planes. It's probably the nicest foam I've seen.

The motor and esc look to be the same as used in the Cessna 310 (Grand Cruiser) and DC 3 (Skybus). They have performed well in these other planes but they are twins and consequently have a lot more power than a single engine plane. I'll run some power and calculated thrust measurments when I get the plane built.

The white version I got appears to have the decal set from the silver plane and the spinner, as mentioned above, is matte grey, not the chrome plastic as seen in the 310. The 3 blade prop is the same as used in the 310.

The wings have a very high aspect ratio which limits the wing area and could result in higher wing loading than desirable, especially for a "trainer". Others have reported in the Grand Cruiser forum, however, that this plane flys very nicely and can be landed slowly.

First impressions are very positive and I'm really looking forward to getting it together for a maiden in the next day or two.
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Old Dec 04, 2010, 12:11 AM
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Heys,

Ditto on mine. A few minor scrapes from packing/shipping and the same silver/grey spinner. Mine has the silver version of the decals.

I'd really like to get the white version of the decals. I like the look of the black decals on the the wings and horizontal stab.

Also if anyone locates the same version of the spinner in white, please post....
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Old Dec 04, 2010, 11:39 AM
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Put mine together and noticed my tail was bent and the rudder was detached towards the top of the tail. I took a hair dryer and heated it up to get it straightened out and taped the hinge where it separated.

I am getting ready to put on the decals and noticed that they are the same stickers that are on the silver model. I wish they were like the ones advertised on the Nitroplanes website, too.

KMan
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Old Dec 04, 2010, 11:42 AM
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Quote:
Originally Posted by BacknRC View Post
Also if anyone locates the same version of the spinner in white, please post....
I have been looking at spinners for another plane of mine and I noticed Dubro has a 2" white spinner for a 3 blade prop. Otherwise, you could always get one of their 2 blade spinners if you didn't mind changing it to a 2 blade prop.

KMan
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Old Dec 04, 2010, 01:04 PM
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Assembled!!!

Here is mine all put together. The silver/grey spinner doesn't look too bad. It goes with the decals (see pictures).
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Old Dec 04, 2010, 05:08 PM
dbc
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Assembled mine today after epoxying the wings and tail last night. Assembly was a breeze with no problems encountered. I elected to leave it "naked" as I really don't like the supplied decals but didn't want to spend a lot of time making custom trim until I had done the maiden flight.

I had to balance the prop/spinner assembly to get smooth running and then recorded the following power numbers with the stock setup: 307 watts, 25.5 amps, 11.86 volts. Prop rpm 9200. This was with a new 2200 20c battery. Calculated thrust is about 34.7 oz. AUW was 31.5 oz so this give a healthy 150 watts/lb.

I managed to get the maiden in just at sunset in spite of the breezy conditions. The plane flew nicely with more than adequate power and trimmed with only a couple of clicks. It was too windy to accurately assess it's flight characteristics but I think it's going to be a very nice flyer.

It flew well enough that I'm now considering what trim I'm going to make up.

Anyone else flown their's yet?
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Old Dec 04, 2010, 06:44 PM
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Quote:
Originally Posted by kman24 View Post
I have been looking at spinners for another plane of mine and I noticed Dubro has a 2" white spinner for a 3 blade prop. Otherwise, you could always get one of their 2 blade spinners if you didn't mind changing it to a 2 blade prop.

KMan
Thx for the info....

Your pics look great. Even those decals make it look good.
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Old Dec 04, 2010, 06:45 PM
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Quote:
Originally Posted by dbc View Post
Assembled mine today after epoxying the wings and tail last night. Assembly was a breeze with no problems encountered. I elected to leave it "naked" as I really don't like the supplied decals but didn't want to spend a lot of time making custom trim until I had done the maiden flight.

I had to balance the prop/spinner assembly to get smooth running and then recorded the following power numbers with the stock setup: 307 watts, 25.5 amps, 11.86 volts. Prop rpm 9200. This was with a new 2200 20c battery. Calculated thrust is about 34.7 oz. AUW was 31.5 oz so this give a healthy 150 watts/lb.

I managed to get the maiden in just at sunset in spite of the breezy conditions. The plane flew nicely with more than adequate power and trimmed with only a couple of clicks. It was too windy to accurately assess it's flight characteristics but I think it's going to be a very nice flyer.

It flew well enough that I'm now considering what trim I'm going to make up.

Anyone else flown their's yet?
Nope, not yet.

Any problems with CG?
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Old Dec 04, 2010, 07:04 PM
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Won't be able to fly mine till I get a new RX for the plane, which is enroute. I am going to try an Orange6 RX that I ordered a few weeks ago from Hobbyking.
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Old Dec 04, 2010, 07:30 PM
dbc
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It's hard to tell exactly where the recommended CG is located because the wings angle forward sharply at the root where joining the fuse. Where exactly do you measure 30-35 mm back from?
A 170g battery resulted in the CG being approximately 1/3 of the average wing chord back from the LE measured 50mm out from the fuse. The 1/3 rule has usually worked for me, this was where it fell without adding any weight, so I flew it there. I might try adjusting it later but it seemed satisfactory as is. At least as far as I could tell with the breezy conditions this evening.
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Old Dec 04, 2010, 08:04 PM
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dbc - I take it that the plane could handle the wind well? How responsive is the plane? Was it easy to fly?

KMan
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Old Dec 04, 2010, 08:51 PM
dbc
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Winds were very choppy and I really shouldn't have flown but I was anxious to do the maiden. It got tossed around a good deal but was generally very stable and responsive to input without being overly sensitive. Gusts caught it on the first two landing approaches and I had to abort them at the very end - there was plenty of power to get me out of these tight situations and I finally caught a break and got a really nice landing.

The plane had plenty of power for nice loops from level flight. Moderate roll rate and they were not very axial. I only did a few seconds of inverted but it was stable, requiring only moderate down elevator. Stalls were gentle with no tendancy to drop a wing or go into a spin.

I'm flying it with the cheapie 2.4G Dynam tx/rx that came with my Grand Cruiser. It's a very basic radio and the Cruiser did not fly very well with it. Cruiser needs a good deal of elevator expo and careful adjustment of the throws to get it to fly smoothly. The Dynam radio has no expo so I'm now using my Spectrum equipment with the Cruiser and it flys much nicer.

I was pleased at how well the SR flew with the basic radio equipment - much better than the Cruiser did with it. I'll know more after a flight or two under better conditions but I'm pretty confident in saying that it's going to be a real sweet flyer.
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Last edited by dbc; Dec 04, 2010 at 09:00 PM.
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Old Dec 04, 2010, 10:09 PM
dbc
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Here's my slightly different looking SR 22:


http://www.flickr.com/photos/54180698@N03/5233476290
http://www.flickr.com/photos/54180698@N03/5233474954
http://www.flickr.com/photos/54180698@N03/5233473772
http://www.flickr.com/photos/54180698@N03/5232951553/
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Last edited by dbc; Dec 04, 2010 at 10:24 PM.
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