Dynam C-188

[Loneflier]

Hey Guys,

I have a simple question here. I have built the Dynam C-188 and I noticed several threads that said the CG as posted in the instructions was off, (90-100mm), and instead recommended a CG of 65mm from the leading edge. Now I know that generally, you take the leading edge at the fuselage, and measure back from there. Well, the C-188 has a pretty sharp triangular sweep starting at the fuselage and tapering back to what I will call the main leading edge of the wing. If I measure 65mm from the fuselage, the CG is only about an inch from the main leading edge. This looks kind of forward to me, but I would certainly rather have it nose heavy than tail heavy. The instruction have a picture showing CG about in line with where the Flap and Aileron wires come down the wing.

Have any of you guys run into this, and can you let me know where you balanced your plane?

Thanks!

[Loneflier]

RE: Dynam C-188

Well, after doing some more research on line, it appears that the instructions and the other sources I was using are both correct. I know that most CG measurements are taken where the wing meets the fuselage (wing root), but the instructions with the plane show a start point on line with the center of the landing gear. Curious.. However, if I take 90mm from the wing root at the fuse, the CG would go back approximately to where the servo wire channel is cut into the wing. If I use the 65mm as show on the MRC website, again from the wing root area, I come to a spot about 25mm back from what I was calling the "main leading edge" of the wing. The answer is that as long as the plane balances within that range, it should be fine, and using a 2600mAH 4 cell battery, that is exactly what I have, closer to the 65mm measurement than the 90mm measurement, which should be good for the maiden flight.

Now, if only I could figure how to get the flaps to work correctly, without using a servo reverser. I plugged one lead into the Aux port on my 6 channel receiver, the other flap lead is plugged into the port marked for gear. (Specktrum rx). I have tried reversing the channel to make the one servo work with the other, but so far no luck. I will obviously have to read further in my DX9 manual to figure this out. Or, I could just cheat and use the servo reverser I have.  I just wanted to try this separate channel method to see if I could do it. I did set up the programming for the wing as 1 aileron, and 2 flaps, so it should work.

[Loneflier]

Maiden Flight of Dynam C-188

Hello all,

The weather this morning here was overcast and chilly, but no wind at all! So I loaded up my new Dynam C-188 and my trusty Parkzone T-28 and went flying. I warmed up first with the T-28. I've had this plane for over 2 years now, and was one of the first low wing planes I flew when I was teaching myself how to fly. It is a testament to the stability and good design of this one that it has never been crashed, and still looks great. Everything functions perfectly still, even after too many flights to count.

Anyway, once warmed up on the T-28, I loaded the 2600mAH 4 cell into the C-188, and again checked all systems for proper operation and orientation. With the usual flutters, and brief prayer, I advanced the throttle and was only up to about half when she took off easily and started climbing. It took very little trim to get her flying perfectly. I was just a bit nose heavy, took about 7 or 8 clicks up before she flew level, but only a click or two on rudder and she was flying straight and level. Mine is the Blue and white version, and was very easy to see in even the overcast sky. I was very pleasantly surprised how stable and easy to fly this one is once trimmed. Most of the time I was flying at only 1/2 throttle or less, and she just really flew nicely. I tried a couple of passes with flaps on the low position, and she would slow down even more, and just kind of hang there. Very nice! I pulled up the flaps and tried some aerobatics, rolls, loops, Cuban Eights, inverted, hammer head stalls, if I knew how to do it, she would do it too! Full speed was plenty fast, I was easily outpacing the cars along the road, and the speed limit there is 50mph. Again, no bad habits at high speed either.

Then I tried some low, slow passes, both with and without flaps, and again, she just kind of puttered along floating in the air. By now, I was at the end of my 5 minute timer, and brought her in for a landing with low flaps. Just a touch of throttle as she flared in for the landing , and she touched down gently rolling to a stop in the grass. I am a happy camper! I bought this to handle grass fields, and to have a larger, heavier plane for windy days, and she is everything I hoped for. Of course, I haven't tried it in the wind, but I am sure with the extra power and weight, she will handle winds well.

The second flight went even better. Now with some confidence, and first flight jitters over, I was really putting her through the paces. Landing this time without flaps was just as uneventful, and even pretty easy. The only possible negative was that the tail wheel was not centered, causing the plane to want to go slightly left when taxiing. This will be easily corrected before the next flight.

If you are on the fence about this one, don't be! Very gentle flyer, easy to land, and looks great in the air.

Happy Flying!

[Rocketeer]

RE: Dynam C-188

Greetings Loneflier,

Thank you for the awesome flight report on the C-188!!

I am happy that you were able to pin down the CG characteristics and get it into a stable flight path.

A very happy ending for an outstanding little plane and pilot!!

Happy Holiday's!!!

Bill L.
in Okla.

[Loneflier]

RE: Dynam C-188

Thanks Rocketeer!

Always good to hear from you. Yes, to say the least, I was amped this morning after flying. So much so, that I went out again this afternoon and flew my Flyzone FW-190, the MIG-15 again, and also a flying wing called the Neptune that has a 70mm EDF on it. All flew very well, no mishaps at all. I even hand launched the MIG successfully and somehow it seemed to have picked up some speed. Same batteries, but maybe it is getting broken in better because it was really moving around in the sky today. Much faster than I remembered on the first 4 flights.

The wind was picking up some, especially a hundred feet up and more, but only around 5mph at the ground. All in all, a great way to end the weekend! I hope you guys all have good flying weather too over these Holidays!

Rich

[retiredflyer]

RE: Dynam C-188

Hi guys,
  Has anyone tried a 3 bladed prop on the duster?  Looks like most of the real ones have a 3 blade.  Just asking, might be a cool upgrade.

[Loneflier]

RE: Dynam C-188

Hi guys,
  Has anyone tried a 3 bladed prop on the duster?  Looks like most of the real ones have a 3 blade.  Just asking, might be a cool upgrade.

Hi Retiredflyer,

No, I have not tried a 3 blade prop on the C-188. The 2 blade is actually more efficient, and likely faster. Dynam does have 3 blade props, I have an extra that came with my Dynam ME-109 that would probably work fine, but right now, I think I will stick with the 2 blade prop. If I decide to try out the 3 blade prop, I will update the results here!

[retiredflyer]

RE: Dynam C-188

Hi guys,
  Has anyone tried a 3 bladed prop on the duster?  Looks like most of the real ones have a 3 blade.  Just asking, might be a cool upgrade.

Hi Retiredflyer,

No, I have not tried a 3 blade prop on the C-188. The 2 blade is actually more efficient, and likely faster. Dynam does have 3 blade props, I have an extra that came with my Dynam ME-109 that would probably work fine, but right now, I think I will stick with the 2 blade prop. If I decide to try out the 3 blade prop, I will update the results here!

Thanks Loneflier,
  I was just wondering. You're right, probably doesn't need it, but I thought it looked nicer. I will leave well enough alone!

[Flygirl]

RE: Dynam C-188

Well, after doing some more research on line, it appears that the instructions and the other sources I was using are both correct. I know that most CG measurements are taken where the wing meets the fuselage (wing root), but the instructions with the plane show a start point on line with the center of the landing gear. Curious.. However, if I take 90mm from the wing root at the fuse, the CG would go back approximately to where the servo wire channel is cut into the wing. If I use the 65mm as show on the MRC website, again from the wing root area, I come to a spot about 25mm back from what I was calling the "main leading edge" of the wing. The answer is that as long as the plane balances within that range, it should be fine, and using a 2600mAH 4 cell battery, that is exactly what I have, closer to the 65mm measurement than the 90mm measurement, which should be good for the maiden flight.

Now, if only I could figure how to get the flaps to work correctly, without using a servo reverser. I plugged one lead into the Aux port on my 6 channel receiver, the other flap lead is plugged into the port marked for gear. (Specktrum rx). I have tried reversing the channel to make the one servo work with the other, but so far no luck. I will obviously have to read further in my DX9 manual to figure this out. Or, I could just cheat and use the servo reverser I have.  I just wanted to try this separate channel method to see if I could do it. I did set up the programming for the wing as 1 aileron, and 2 flaps, so it should work.

Did you ever figure the flaps out Loneflier or did you just use the reverser?

[Loneflier]

RE: Dynam C-188

Well, after doing some more research on line, it appears that the instructions and the other sources I was using are both correct. I know that most CG measurements are taken where the wing meets the fuselage (wing root), but the instructions with the plane show a start point on line with the center of the landing gear. Curious.. However, if I take 90mm from the wing root at the fuse, the CG would go back approximately to where the servo wire channel is cut into the wing. If I use the 65mm as show on the MRC website, again from the wing root area, I come to a spot about 25mm back from what I was calling the "main leading edge" of the wing. The answer is that as long as the plane balances within that range, it should be fine, and using a 2600mAH 4 cell battery, that is exactly what I have, closer to the 65mm measurement than the 90mm measurement, which should be good for the maiden flight.

Now, if only I could figure how to get the flaps to work correctly, without using a servo reverser. I plugged one lead into the Aux port on my 6 channel receiver, the other flap lead is plugged into the port marked for gear. (Specktrum rx). I have tried reversing the channel to make the one servo work with the other, but so far no luck. I will obviously have to read further in my DX9 manual to figure this out. Or, I could just cheat and use the servo reverser I have.  I just wanted to try this separate channel method to see if I could do it. I did set up the programming for the wing as 1 aileron, and 2 flaps, so it should work.

Did you ever figure the flaps out Loneflier or did you just use the reverser?

Hi Flygirl- I ended up just going with a reverser. Actually, the plane really doesn't need flaps, I have flown it many times now and I think I used flaps maybe twice just to check them out. Most of the time I fly on a grass field, and it comes in slow enough that I just haven't used them.

[Flygirl]

RE: Dynam C-188

Thank you!!!

[Flygirl]

RE: Dynam C-188

Well, after doing some more research on line, it appears that the instructions and the other sources I was using are both correct. I know that most CG measurements are taken where the wing meets the fuselage (wing root), but the instructions with the plane show a start point on line with the center of the landing gear. Curious.. However, if I take 90mm from the wing root at the fuse, the CG would go back approximately to where the servo wire channel is cut into the wing. If I use the 65mm as show on the MRC website, again from the wing root area, I come to a spot about 25mm back from what I was calling the "main leading edge" of the wing. The answer is that as long as the plane balances within that range, it should be fine, and using a 2600mAH 4 cell battery, that is exactly what I have, closer to the 65mm measurement than the 90mm measurement, which should be good for the maiden flight.

Now, if only I could figure how to get the flaps to work correctly, without using a servo reverser. I plugged one lead into the Aux port on my 6 channel receiver, the other flap lead is plugged into the port marked for gear. (Specktrum rx). I have tried reversing the channel to make the one servo work with the other, but so far no luck. I will obviously have to read further in my DX9 manual to figure this out. Or, I could just cheat and use the servo reverser I have.  I just wanted to try this separate channel method to see if I could do it. I did set up the programming for the wing as 1 aileron, and 2 flaps, so it should work.

Did you ever figure the flaps out Loneflier or did you just use the reverser?

Hi Flygirl- I ended up just going with a reverser. Actually, the plane really doesn't need flaps, I have flown it many times now and I think I used flaps maybe twice just to check them out. Most of the time I fly on a grass field, and it comes in slow enough that I just haven't used them.

Just an FYI to anybody who gets this plane, this must be a newer version I have as it now comes with a reversed servo for the flaps that works with a Y cable. It came, however, with only one Y cable in the kit (need two for ailerons + flaps) but luckily I had one sitting around so order one when you order the plane. Also get a couple of servo extensions. Four inchers will do. It makes it easier to put the wing on so you have some slack. I haven't flown mine yet (batteries on order) but the kit went together well. This was my first Dynam plane and it was off the scratch and dent pile here at Motion because of excess glue on the tail wheel mechanism. I was very impressed with the fit of the foam parts and for a wing that has no spar except for 4 small wing joiners the wing is super stiff. Can't wait to fly it!

[Hippie 64]

RE: Dynam C-188

Mine came with two but only one of them is made to put on the flaps . It wasn't marked I just tried both and the just one would work the flaps . Like Loneflyer said it doesn't need them . 

My CG worked perfect slide all the way up . It's a fun flyer you are going to enjoy it 



Bryan 

[Flygirl]

RE: Dynam C-188

If you like it then I'm sure I will! I think we have the same taste in planes. :-) That must mean it has a wide speed envelope which is just the kind of plane I love! Thanks Bry!

[Thosmosis]

RE: Dynam C-188

I love civilian planes. And I only do foamies right now... So, there are never enough to choose from... Plenty of warbirds.

I always go back to looking at the 188.

Unlike some, the similarity of the plane to the "Planes" movie keeps me from seriously thinking about it. I know, that's odd. As I have seen 188's in the air before the movie was out -- which I haven't seen. But was tainted by advertisements...

[Flygirl]

RE: Dynam C-188

No googly eyes on this one Thosmosis! LOL! Trying to make it a nice scale plane.... Like you did with your Freewing... :)

[coystride]

RE: Dynam C-188

:@ I have owned quite a few Dynam planes and have had good luck with them until I bought the C188 "Dusty" . When I maidened the first Dusty I gave it full throttle on take off and the plane went straight up rolled over and came down hard on the nose. I should mention I had installed a guartdian stabilizer in the plane. A gyro that I have had great success with in the past. Anyway the first Dusty was beyond repair so being a glutton for punishment I bought another one from Motion RC and the exact same thing happened on the maiden flight. This time I was able to repair it but it has been hanging on the wall in my basement for months as I am afraid to try it again. I transferred the guardian gyro to a freewing F86 jet and it worked fine. Anyone else ever have this problem with the c188? :@

[Loneflier]

RE: Dynam C-188

:@ I have owned quite a few Dynam planes and have had good luck with them until I bought the C188 "Dusty"  .  When I maidened the first Dusty I gave it full throttle on take off and the plane went straight up rolled over and came down hard on the nose.  I should mention I had installed a guartdian stabilizer in the plane.  A gyro that I have had great success with in the past.  Anyway the first Dusty was beyond repair so being a glutton for punishment I bought another one from Motion RC and the exact same thing happened on the maiden flight.  This time I was able to repair it but it has been hanging on the wall in my basement for months as I am afraid to try it again.  I transferred the guardian gyro to a freewing F86 jet and it worked fine.  Anyone else ever have this problem with the c188? :@

Sorry to hear about your misfortune with both C188s. It really sounds like you may be flying too tail heavy from what you described. I know that mine is a very easy flying plane and really hasn't shown any bad habits at all in the year that I have had it. I am flying with no gyro at all in it. Otherwise, I don't know what else to tell you. Try adding some weight to the nose and rechecking the CG on it.

[ryramZ]

RE: Dynam C-188

Check the thrust line and try backing off the throttle.

[coystride]

RE: Dynam C-188

thanks guys. When I get up enough courage to try the C188 again I will follow your suggestions. It is possible the thrust line could be incorrect now since the maiden crash of the 2nd airplane really hit the front of the plane hard. It appears to be alright but I don't know how to check it properly.