Assan GA250 Test

In my last post I pointed out the wag my Align GP780 developed. Two of them, actually. Using the same heli, I installed a Assan A250 MEMS gyro, a $10 gyro from Hobby King. Yup, $10. I am not sure it is much better than a piezo... Here's a short vid of the test (I flew several). It works fine, no wag. This also illustrates that the tail system is otherwise intact.



UPDATE 2/29/12: The seller of the second gyro has kindly responded to my refund request. They are interested in helping me solve the gyro problem if they can before refunding, and offered up another 780, or the new 790. What I know of the 790 is that its a step back, a budget 780 using SMM instead of MEMS. This might be a good idea, they work fine, but are "softer" than MEMS. Along with a hinted at software update, maybe it will be less sensitive than the 780?

How not to make a canopy...

I blogged last week about losing the canopy of my Sbach 342 in flight. I also wrote about how I was not optimistic about getting a replacement from Hobby King (still waiting as I write this). So, I made one. Despite my having absolutely no idea, it came out alright, and more importantly, I learned a few things so version 2 will be even better!

I made a paper mock-up of the base.

Transferred it to file folder cardboard.

I then cut out a styrofoam copy, and sanded it to shape.

Took a little work getting the angle. I have better ideas but at the time, this was my crappy method.

And then I completely ruined it when I found out Bondo melts styrofoam... 

I peeled off the Bondo and tried to save it with Hobbico filler. Didn't work either.

So, I made a wood frame. Got the angle right this time.

Covered it with sheet balse, trimmed it and sanded it.

Used the filler to, well, fill the rough spots.

Sanded it smooth.

Sanded out some spots to lighten it.

Then primed it.

Painted it with black gloss lacquer, several coats.

Applied Monokote points in red and white. Bolted the canopy on, taken from salvage of the Eflite PulseXT. I had to work it on, and found that window glue, nor CA worked well, and made a mess as the canopy didn't fit perfectly. I used felt to line the edge of the canopy to help it fit. 

Its hard to tell, but one of my failures was getting the back of the new wood canopy to segue into the back of the fuse. There's a large gap and the canopy comes out high. But it works! 

I plan to build another one using the lessons I've learned, and I think it will be perfect!

By the way, I ordered a canopy for a 1250cm Sbach sight unseen from Nitroplanes hoping it would be a complete one like the original. Its not... its a ginormous piece of clear plastic. It covers the whole plane...

Align GP780 Tail Wag

My 4 month old GP780 on a seasoned 450 heli started to wag. I tried decreasing the gain, and it slowed the wag, but did not abolish it. Increasing the gain sped up the wag. I changed everything that might cause a vibration, no joy. I tried it on another heli, still wagged. That gyro just left for Align USA for eval. It will turn out to be fine. Some on Helifreak say its just too sensitive to vibrations and many have had to abandon it for this reason. Well, a new GP780 arrived today and guess what... same wag! I doubt these are bad gyros, just too sensitive which makes them unusable. I am trying to return it to the eBay seller for a refund so I can buy a Spartan Quark from Helidirect. I love Align, and am looking forward to building my Align 600e FBL heli soon, but maybe without Align parts as I had planned?

Here's vid of the wag, even though its strapped down tight!



UPDATE (2/25/12): See the Assan GA250 MEMS test.

HDX 500se Main Gear Grind

I have been shearing teeth off the main gear of the HDX 500se pretty much every day I fly her, without explanation, usually when bringing her up to speed while the rotor was already turning. I had read that the main gear one way bearing can get gummed up and lock once in a while causing teeth to grind off. When I replaced the main gear this time, I took the one way bearing out and soaked it in acetone, shaking it and the bearing. I was amazed how much crap came out as I cycled through the washes. Then I dried it, and soaked it in silicone lubricant, and reinstalled it. It actually turns much cleaner. Looking forward to seeing if it solves the problem!

Squirrel!

CAUTION: Ground is closer than it appears. When you are flying aerobatics and coming close to the ground, its a good idea to know just where the ground is...

Spin, reversed, ran out of airspace, parked it hard against the ground and the only giant concrete pipe segment in the area. My ADD kicked in and I lost track of where the ground was. This is my second Eflite Pulse XT, the first died an ignoble death due to a bad transmitter battery, doing pretty much the same thing.

Crap.

Busy doin' a whole lot of nothin'

Bad weather these past couple of days... Haven't tackled the issues that came up with the A-10 Warthog the other day. Everything worked but the motors didn't make a peep... something between the receiver and the ESCs most likely. Not likely to be the motors. Taking a look at those later.

I think one of the reasons I keep stripping gears on the HDX 500se is that on some hard landings the tail blade strike the ground. This can stall the main gear and that can account for the stripped teeth. I decided to put a wheel on it, but I may make it a skid. I used a piece of control rod, put a Z-bend in it and ran it through a hole at the bottom of the tail skid, the rod running up the tail skid and secured to it with a couple of  wide plastic wire ties. Not sure I am fond of the wheel.

I broke out the Frankenheli. I had it set up with a longer boom and 365mm blades, a stretch 450. I flew her several times, but I just could not get the blades to track. I even took the head apart and redid the feathering shaft, still could not no matter what I did. I decided to drop back to standard 325mm blades, and she tracks well. Not sure what was up with that.

The $10 Assan MEMS gyro I trialed is a piece of crap. I had to crank the gain up to 100% (real 100%), and now she has a quick tail wag. If I drop the gain down the wag period drops, but is wider. I even tried down to 15% where she wouldn't hold her head, and the wag persisted. I rechecked all the programming and its correct. I will likely put a good gyro on her and if I bend the outrage boom I'll make her a regular 450. I will be keeping the regular 450 blades on her. Grounded until I get a new gyro.

Still no news from Hobby King on a new canopy... I suspect they will just wait until I go away. I will probably have to buy a replacement plane for parts... crap. No more planes that don't have replacement parts available.

Will they, won't they?

HobbyKing customer service put to the test. I have purchased hundreds of dollars of aircraft and parts from them, will they show me any love? Hobbyists have long lamented HobbyKing's low priced equipment, versus their notoriously unreliable customer service. Here's a chance for HobbyKing to prove their mettle. I reported the loss in flight of the canopy from my HobbyKing Sbach 342 1000mm V2 aircraft, a model that shows that HobbyKing makes good quality products. While still at the fligtline I sent HobbyKing a request for help finding a replacement canopy. Overnight here's their response, from Ian, quick, to the point, utterly unhelpful, with my challenge for them to step up their game. Let's see what happens...

UPDATE 3/2/12: Well, they won't. And why I have to go to a forum to make a suggestion instead of them taking what I am sure is a very freq request for parts to a meeting themselves is beyond me...

Quote:

Your request (#185173) has been deemed resolved.

Andrea, Mar 02 15:44 (HKT):

Hi Ken , Thanks for contacting the HobbyKing Support Team Sorry for late reply. We are sorry we do not have requested part for sale at this moment. You may consider logging in our forum and making suggestion. Our marketing and management team review customers’suggestions online. Thanks for emailing support. If you have any other questions, please let me know. Regards. Andrea