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Posted by aphex4000 | Jul 27, 2013 @ 10:23 PM | 1,791 Views
I finally stopped tinkering with the head and decided to install the larger main motor from a V912. Both sides of the upper frame needed to be cut, new mounting holes drilled for the motor, and swash plate guide on the upper shaft support heated to make way for the motor. The 9116 control board seems to be holding up just fine with the increased load, and I am now able to hold a steady hover at about 1/4 throttle with a fresh LiPo pack. Great success!

There is almost no clearance between the lower linkages and the swash guide, but a new swash guide/upper shaft support is off to the printer and should be back sometime late next week.





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Posted by aphex4000 | Mar 17, 2013 @ 02:53 PM | 2,184 Views
A new fly bar recently arrived in the mail so I decided to do some testing with a shorter, but heavier fly bar in an attempt to resolve the issue with canopy damage. Despite the increased weight, the results came out great and there is no chance of further strikes from the fly bar weights.





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Posted by aphex4000 | Mar 05, 2013 @ 10:18 AM | 2,117 Views
My links came in from HobbyKing so I was finally able to get rid of the slop in the servo horn z-bends. Wish I could have gotten caught up with this mod sooner! We were able to fly around confidently on a very gusty day last weekend. Neither of us can fly a decent circuit still, but we're getting closer with each improvement.

Upgraded control links:


Video of my friend flying his modded 9116:
Double Horse 9116 with full ball links and custom chassis (0 min 46 sec)

Posted by aphex4000 | Feb 25, 2013 @ 01:44 PM | 3,289 Views
With Chinese New Year having recently passed, several of my orders are still delayed so I decided to start working on another project. I do owe a couple forum members a 3D model of a revised 9116 chassis but several changes are required since an extrusion deposition printer will be used instead of one that utilizes granular material binding technology. The hinge on the previous design will need to be eliminated and a new battery holder designed to allow the PCB to be serviced easily. Procrastination ensues!

In the meantime I have been sidetracked by an effort to shoehorn a 5" gps receiver into an automotive dash console. The previous model is over 3 years old and I am very eager to have access to the features in the updated design as well as the larger screen.





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Posted by aphex4000 | Feb 21, 2013 @ 04:58 PM | 2,379 Views
The new chassis for my Double Horse 9116 finally arrived today. This is great since it will give me something to tinker with while waiting for the quad to arrive!

The improved hinge looks nice and sturdy and all of the chassis mounting holes line up correctly this time. Also, the weight penalty of adding the battery tray is only .01oz over the factory part! Unfortunately, while moving the battery connecter from one side of the chassis to the other, I introduced a new error so the socket now fits loosely. A small styrene shim fixed the problem easily. Another design flaw is the location of the PCB relative to the battery tray. The retainer for the battery strap directly interferes with the servo plugs. I resolved the issue by bending both sets of pins towards the center line of the chassis. This allows the battery tray to rest on the upper chassis plate instead of having the servo plugs bear the weight and impact from crashes. The mixing arms were not a total loss despite the oversized ball stud mounting holes. A bit of body filler, a fine drill bit, and some patience resulted in a usable finished product.

Overall, I am happy with results but sure wish I had the foresight to move the PCB slightly further to the rear to prevent clearance issues. This will probably be the last attempt at improving the 9116 as it's time to start learning how to fly a quad!


Detailed photos:




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Posted by aphex4000 | Feb 13, 2013 @ 12:09 AM | 2,255 Views
Today I put a z-bend in my flybar which resulted in improved response. However, the heli also feels more skittish overall and the pendulum effect from sudden pitch and roll changes seem to have been magnified. I also replaced the Honey Bee direct drive tail propeller with a trimmed 9116 tail propeller for a significant reduction in sound and even greater tail authority. Over time, this caused the tail motor to heat up excessively (~96 degrees F measured with IR thermometer).

The flybar has now been bent straight and the tail propeller replaced with the properly sized Honey Bee propeller. I still prefer the stability offered by the straight flybar and the lower tail motor operating temperature afforded by the smaller tail rotor.

Here is a video of the test flight:
Double Horse 9116 indoor flight (1 min 4 sec)


Modded:


Back to normal:

Posted by aphex4000 | Feb 12, 2013 @ 09:57 AM | 2,183 Views
The 3.8mm ball studs for my custom mixing arms arrived in the mail yesterday. The balls fit the mixing links perfectly, but I had overestimated the size of the threaded ends by over .5mm. Unfoturtunately, these ball studs will not stay in the mixing arms once they arrive. My lesson learned? Be patient and take actual measurements instead of approximating. The price of this lesson? $5 and a bit of disappointment.

I don't plan to re-print these mixing arms with the correct hole sizes as I would like to wait for the 3mm Honey Bee ball bearings to arrive and draw up new plans around those, with ACTUAL measurements. By then I should also have a few designs completed and ready to print for unrelated projects, to help offset the shipping cost.
Posted by aphex4000 | Feb 08, 2013 @ 05:02 PM | 1,975 Views
Eagle eyed Steve_ recently pointed out that the mixing arms on some of the more agile helicopters are biased while the mixing arms on the 9116's head are totally symmetric. The 9116 community has started researching possible mixing arm donors but in the meantime I am hoping to build a set tailored to this head. First, I ordered a few of 3.8mm ball studs for use with the original mixing arm links. Then I sent off some plans to have mixing arms printed. The ball stud mounting holes on one end of the first set are in their original position, while the others are moved 25%,50% and 75% further away from the axis of rotation so we can test with all three.

Again I find myself waiting for parts. Time for a few more practice flights!

Duratrax DTXC6263 ball studs:


Custom mixing arms:

Posted by aphex4000 | Feb 07, 2013 @ 10:38 AM | 2,195 Views
My 9116 recently took a hard nosedive while fighting a strong gust of wind. The crash resulted in a broken hinge on the first chassis I had printed for the 9116. I have had to glue the hinge back in place and am not happy about how fragile the joint is as it could easily break again on the next (inevitable) crash. I went ahead and redesigned the chassis to address the weak hinge, switch location (which turned out to be a bit of an inconvenience), and battery retension system. The v.2 chassis order has been place, and now the waiting begins. On a side note, as my 9116 ownership continues I find myself relating very well to this post from our friend, mikefromgermany.

9116 revised chassis v.1:
* extremely lightweight
* battery support reuqires velcro on each battery pack
* fragile battery support joint
* slightly mis-alignment rear-most side frame mouting holes


9116 revised chassis v.2:
* more robust overall design
* power switch moved to move convenient position
* plug moved to opposite side to improve balance
* revised battery support which utilizes a 1/2 inch velcro strap
* corrected alignment on rear-most side frame mouting holes

Posted by aphex4000 | Feb 07, 2013 @ 10:36 AM | 2,225 Views
I have finally learned how to fly the 9116 like a halfway decent pilot and have recently worn out my first two tail motors. After reading a really great direct drive conversion How-To post by mikefromgermany, I ordered the necessary parts and completed the conversion. WOW! What a difference this makes in tail holding and authority.

Here is how my 9116 sits with the completed conversion:


Posted by aphex4000 | Feb 07, 2013 @ 10:20 AM | 2,308 Views
My DH 9116 is my very first helicopter and was purchased several months ago. After reading many threads about how easy it is to master 2ch, 3ch, and 3.5ch helicopters, I decided to skip straight on to a 4ch with a proven design, strong user base, and cheap/readily available replacement parts. This is how the obsession began.

Two weeks into owning the 9116 and hovering indoors, I decide to take it outside for the first real flight. That ended in disaster with a broken top shaft and eventually a broken gyro. Fast forward another three weeks, and I had gone through 3 more receiver boards ($60+ worth of hardware, including the original) due to gyro failures. I had seen a lot of clever chassis mods associated with PCB relocation and wanted to try my own to avoid wasting any more money due to broken gyros.

Here are a few of the ingenious and inspiring mods that were carried out by a few of other 9116 owners:
* Steve_
* simz
* Pa flyer
* resago

Here is the first solution I came up with:


Two weeks later, it arrived in the mail!

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