HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jan 15, 2012, 11:15 AM
Ascended Master
Sparky Paul's Avatar
Palmdale, CA
Joined Oct 2000
13,381 Posts
What the 9100 and 9104 really need is two more servoes, to become a real heli, with collective pitch.
Making the mechanisms from odd parts would be neat, but probably fruitless at the end.
Easier to get one of the many CP choppers around.
Maybe Double Horse might make one?
Sparky Paul is offline Find More Posts by Sparky Paul
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 15, 2012, 12:13 PM
LearningFast
United States, LA, Denham Springs
Joined Jan 2012
410 Posts
Dialing In the 9104 more

Got out this morning and flew a little. The antenna wire came of the PCB and had to solder. Got it to hover, once the wind was down. Got rid of the drift left as I cut some a little more off the rear rotor. It fought the little bit of breeze pretty well once I trimmed it out. going more forward. Battery started to die and would not respond well to input, so, back in now. Here are a few pictures of the mods. I made a little clamp keep the rod from shifting any. So far, the link ends are holding up. I had to wrap a little bit of paper clip around the one on the servo/swashplate connection just to firm it up and no problems. Still may order another original servo link and drill out to size on the new rod. No really big crashes, but it did get to far way and high, thus not responding to input very well so I killed the power and let it drop in the soft field. I am luck as I do have a field behind my flying area(150x200ft, orso). Enough for now.
Ken59 is offline Find More Posts by Ken59
Reply With Quote
Old Jan 15, 2012, 02:36 PM
Crash and learn
United States, PA
Joined Dec 2011
1,605 Posts
Does the new connection on the servo arm keep the pushrod straight or was the idea to gain more adjustment?

Also noticed you may have a servo wire chaffing foreward of the paperclip link.

I'm working to make the DH9104 radio link better. Will try an idea to double transmitter power output. Another to bond the helicopter metal parts with each other. A snub diode across the motor instead of radio noise going back to the snub diode on the Electronic Speed Control. Maybe try a separate receiver battery to see if it is a RF noise problem or low voltage. An electrolytic capacitor across the JST battery connector power socket to smooth power bumps from the pulsing motors.
---

Poking around inside the transmitter with an RF probe, turns out the antenna connector wasn't soldered too well to the copper, with no connection to L1 next to it. L1 was pegging my RF probe. The antenna connecter barely registered.

Soldered copper side and jumpered top and now range may be farther than I can see the helicopter.
Ribble is offline Find More Posts by Ribble
Last edited by Ribble; Jan 15, 2012 at 04:14 PM.
Reply With Quote
Old Jan 15, 2012, 06:52 PM
LearningFast
United States, LA, Denham Springs
Joined Jan 2012
410 Posts
That is the original servo link I used up front. It works pretty well. Tried the paper clip, but too hard to adjust. Now I can just go 1/2 turn if needed. Got it to hover quite nicely today before the wind kicked up. I broke a ball on the swashplate, had a spare on order, but will order another tonight. I want to create a plate for under the swashplate so I can attach a couple of balls to have a center pivot. We will see. I will wire the chassis for connections this week while I wait for parts. Rather interesting stuff! I am back to the 9074 flying around the living room for a bit!
Ken59 is offline Find More Posts by Ken59
Reply With Quote
Old Jan 15, 2012, 09:02 PM
Heli Mania
Hayabusa Heli's Avatar
PNW
Joined Dec 2010
2,604 Posts
Quote:
Originally Posted by Sparky Paul View Post
What the 9100 and 9104 really need is two more servoes, to become a real heli, with collective pitch.
Making the mechanisms from odd parts would be neat, but probably fruitless at the end.
Easier to get one of the many CP choppers around.
Maybe Double Horse might make one?
Double Horse does make a 4-channel version of the 9100 ... it's the 9116. Read all about it:

http://www.rcgroups.com/forums/showthread.php?t=1498575
Hayabusa Heli is offline Find More Posts by Hayabusa Heli
Reply With Quote
Old Jan 15, 2012, 09:33 PM
LearningFast
United States, LA, Denham Springs
Joined Jan 2012
410 Posts
been looking at the 9116, but not yet.

Saw the bird after ordering the 9104. I will fiddle with until I get it down and then order the next step up of the 9116. Or, just order the parts and modify the 9104 with the parts from the 9116. Who knows as I am a tinkerer. Getting a little fly time with the 9104 still dialing it, though, with spare parts on the way. A couple of slow controlled oops today and the swashplate lost a ball link.
Ken59 is offline Find More Posts by Ken59
Reply With Quote
Old Jan 16, 2012, 05:23 PM
Steve
Chester1's Avatar
United Kingdom, Staffordshire
Joined Jan 2012
156 Posts
Hi all, I am a newbie in the UK who has just bought a 9104. Quite disappointed in it really. Couple of problems I immediately had were;

Loss of control when heli is about 10 meters away - motor just cuts and it drops out of the sky. Sometimes it will recover before it hits the ground other times it bounces off the grass.

Lack of power/lift - I get it into the air but it slowly descends even on full throttle. I think this could be the stock Li-ion battery so have ordered a new 1800Mah Lipo.

Lack of forward flight - I have screwed out the servo pushrod about 10 turns now and the swashplate is tilted forward but it has about as much energy as an asthmatic sucking a straw...!!!

Was thinking of upgrading to the 9116 but they are not available in the UK unless you buy from Hong Kong or China on ebay but if this is the standard of Double Horse helis I may not bother. Suppose I have been spoiled really with my previous flying experience being with Eflite CX2, MSR and 120 SR, all of which flew beautifully and rock solid.

I will persevere with the 9104 but would be grateful for any suggestions for improvement that my limited mechanical skills could cope with
Chester1 is offline Find More Posts by Chester1
Reply With Quote
Old Jan 16, 2012, 05:41 PM
Crash and learn
United States, PA
Joined Dec 2011
1,605 Posts
"Loss of control when heli is about 10 meters away - motor just cuts and it drops out of the sky."

Do a range check by walking away from the helicopter and trying the controls. Do the same with transmitter antenna collapsed, and again with transmitter antenna removed.

Then try again after battery is fully charged.

At least you will have a distance to compare against.
Ribble is offline Find More Posts by Ribble
Reply With Quote
Old Jan 16, 2012, 05:46 PM
Steve
Chester1's Avatar
United Kingdom, Staffordshire
Joined Jan 2012
156 Posts
Quote:
Originally Posted by Ribble View Post
"Loss of control when heli is about 10 meters away - motor just cuts and it drops out of the sky."

Do a range check by walking away from the helicopter and trying the controls. Do the same with transmitter antenna collapsed, and again with transmitter antenna removed.

Then try again after battery is fully charged.

At least you will have a distance to compare against.
OK, will try it tomorrow if the weather is good, last couple of days its been around freezing but dead calm.
Chester1 is offline Find More Posts by Chester1
Reply With Quote
Old Jan 16, 2012, 06:18 PM
Crash and learn
United States, PA
Joined Dec 2011
1,605 Posts
I just took my 49MHz DH9104 outside (in the dark).

With helicopter sideways (on the ground) I get roughly 10 meters (30 feet) with the transmitter antenna removed before the helicopter red LED goes out. A foot closer LED comes back on. Solid with antenna back on the transmitter and collapsed. That is as far as I can go in my back yard.

Transmitter antenna removed:
Originally, with helicopter antenna tied to tail, I got 2 meters.
After refolding antenna on skid (as out of box), I got 3 meters.
After tied to tail again and tuning receiver, I got at least 5 meters, but was behind an inside wall and ran out of room.

Then I soldered the bad connection in the transmitter at the antenna connection. Now (outside) I get 10 meters line of sight, no transmitter antenna.

When tuning the receiver, I let the helicopter battery hang down and used a small jewelers flathead screwdriver to turn the slug inside the antenna coil (up through battery holder). But I used too much force and the slug and top wax popped out the top and fell in the receiver board - the slug is so small that it would have been hard to find otherwise. Slug back in and kept walking away from antennaless transmitter and tuning for best distance, watching helicopter red LED.

So, tuning the receiver worked, but it is very easy to lose the tuning slug or do other damage, and I don't recomment it.
Ribble is offline Find More Posts by Ribble
Last edited by Ribble; Jan 16, 2012 at 07:09 PM.
Reply With Quote
Old Jan 16, 2012, 09:19 PM
LearningFast
United States, LA, Denham Springs
Joined Jan 2012
410 Posts
Chester, check than antenna connection at the PCB. Mine actually fell off on a hard landing. I just had to soldered again and all is well. I had the problem of about 30 feet away and it would drop out. I checked it and fixed it. Now, I have 100 plus. I did a ranged check and satisfied for now. I was able to get my 9104 up and flying the first day, after the mods of course. I did not even try it stock. Since I broke the swashplate (more on the way), I tinkered some more today. I will have pics of the mod later.
Ken59 is offline Find More Posts by Ken59
Reply With Quote
Old Jan 16, 2012, 11:21 PM
LearningFast
United States, LA, Denham Springs
Joined Jan 2012
410 Posts
Dialing in the 9104 More, again

Per discussions in early post, I have created this center pivot for the swashplate. As stock, it is not very efficient. So, I took a broken swashplate apart and used the top half, mounted a ball link on either side, and just sandwhiched it between the frame and the body pegs (might score the underside of the body peg to make a small channel for the rod to set in). It may not hold up, but I have another mounting point in mind. Maybe attaching the rod directly to the center plastic section. There is not much space to work with, but we will see. When the new swashplate arrive, I will just epoxy the modified plate to the bottom and it should hold. As you can see, it is completely adjustable. I hope it works and it should increase the response with the servo not having to work to hard. I am already thinking of the 9116 parts upgrade for this thing. Man, I never should have bought that first 9074. It is addicting, but it keeps the mind working!
Ken59 is offline Find More Posts by Ken59
Reply With Quote
Old Jan 17, 2012, 07:39 AM
Steve
Chester1's Avatar
United Kingdom, Staffordshire
Joined Jan 2012
156 Posts
OK, did a bit of testing this morning. Fresh lipo installed, new batts in the Tx, antenna wire unwound and have checked the antenna wire to the pcb - all good.

With antenna unscrewed - 2 meters and the pcb red light goes off

With antenna attached but collapsed - 5 meters, light off

With antenna fully extended - 10 meters and there is a bit of flickering going on and at 15 meters light fully out.

Definitely seems to be losing the signal. When I tried it in flight it was dropping out again at about 10 meters, sometimes it can be hovering nicely and when I input rudder or fwd/rear movement it dies.
Chester1 is offline Find More Posts by Chester1
Reply With Quote
Old Jan 17, 2012, 08:19 AM
LearningFast
United States, LA, Denham Springs
Joined Jan 2012
410 Posts
Do you have a tester (ohm/volt)? I am sure you have tested all the batteries in the TX and you just put in a fresh lipo. What about a test of the antenna wire itself for breakage? You don't know until you put an ohm meter on it. I can't do anything right now as mine is out of commission due to swashplate. I guess I can just turn it on and check the lights, though. I had extended and managed to chop of about 4 inches on a crash. I have not tested it since. I want to find a good piece of copper wire (I think they use ali)for the antenna and then cut it to the freq. t may not help, but it can't hurt. Even at 1/8 wave it should about 28 inches, but I know it was not that long from the factory, so they just make an estimate. Can you take a picture if the swashplate position at the center trim position and post it. I would like to see the angle.
Ken59 is offline Find More Posts by Ken59
Reply With Quote
Old Jan 17, 2012, 11:00 AM
Crash and learn
United States, PA
Joined Dec 2011
1,605 Posts
Quote:
Originally Posted by Chester1 View Post
antenna wire unwound
Try range check again with antenna wound around skid. My DH9104 was better that way until I tuned the receiver.

Also check Li-Ion helicopter battery voltage with a digital voltmeter. Should be 7.4 volts to 8.4 volts, depending on charge. Same with LiPo if you are using extra batteries.

Understanding RC LiPo Batteries
http://www.rchelicopterfun.com/rc-lipo-batteries.html

Is it on 40MHz?

Always double check that the red JST battery connector is pushed all the way in on the helicopter.
Ribble is offline Find More Posts by Ribble
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Double Horse 9100 Series 3-channel Helis killbucket Mini Helis 1500 May 13, 2013 01:41 PM
Discussion New Double Horse 9100 3 Channel Co-Axial Helicopter w/ Built in Gyro chanerz Coaxial Helicopters 86 Apr 13, 2012 07:12 AM
New Product New Double Horse 9101 3 Channel Co-Axial Helicopter w/ Built in Gyro thercguy Coaxial Helicopters 40 Jan 11, 2012 05:24 PM
Sold 9089 Double Horse Shuttle Electric Heli w/Video DVR Senor Jack Aircraft - Electric - Helis (FS/W) 0 Apr 10, 2011 08:15 PM
Mini-Review Double Horse 9100 3-channel copter -Image Heavy! killbucket Electric Heli Talk 0 Jan 30, 2011 05:50 PM