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Old Oct 08, 2012, 12:35 AM
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I got the fans mounted and everything into place. For the first time I can really look and see if I can even get cg with my selected 6s packs.
9cm from leading edge is the recommended cg but I read some people thought it should be more like 11cm to fly right.

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I got it to balance nicely at 10.5cm with packs stuffed into the pocket between the intakes behind the battery tray which is now being used for the retract mounting plate and the electronics.

I will take it into a buddy's shop where I can access to a large scale in the next few days. Should be able to get a auw soon.
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Old Oct 08, 2012, 09:11 AM
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If I remember right the cg is 9cm!! I would start at 8 or 8.5 and then move back!

My first pro design F-18 was listed at 9, I flew it that way but got it a tiny bit to slow and the cg bit me. They have since changed the cg on that model to 8!

I would start at 8 or 8.5 to be safe, I think mine is at 9 with a slight nose drop.
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Old Oct 08, 2012, 01:19 PM
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I bought a digital kitchen scale today to get the official auw...

Plane weight without lipo 6lbs 6.5oz

With lipo packs the auw - 8lbs 4oz

Lipo options - 1lb 14oz (6s x 2 3000)
- 1lb 15oz (5s x 2 3300)
- 1lbs 6oz (5s x 2 2200)

*up to 8oz can be cut from battery options but this weight is needed for balancing..

If I were to use 9cm as the point of cg I would still need to add 2 oz of weight to the nose to balance out. So if any weight can be removed it would have to be from the rear end and the only thing there thats removable is the retracts... crap!

Maybe Gary's dolly idea could be the answer.


I need to shave a pound off this jet, any ideas guys?
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Old Oct 08, 2012, 06:09 PM
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This is a picture of Gary's dolly from one of his posts. (effluxrc)
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Old Oct 08, 2012, 06:18 PM
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You need to put one of the batteries in the nose.
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Old Oct 09, 2012, 11:28 AM
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The front retract, steering servo, rx, gyro, 20A bec, 2 sets of battery connections with leads and detailed canopy are all stuffed into the nose of this plane. Even if it was all removed my smallest 5s lipo still won't fit under the detailed canopy. I think I would need to replace the detailed canopy with just the window and trim as a means to open more cavity space.

Either that or I completely rebuild this entire plane and move or reduce weight from the rear. I am not really too keen on the latter option and think maybe I should just fly this plane as an 8.5lb bird. After all, that is the listed flying weight suggested for this item in the product description.
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Old Oct 15, 2012, 03:34 PM
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Oh yea, the Raptor is done and ready to maiden... unfortunately the season is mostly over and I have to drive into another country to use the only maac/ama sanctioned runway capable of a takeoff.
I have some guerrilla locations here where I live but this bird CAN actually do some damage so better use my Maac and be safe.
I will post the maiden when it happens.
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Old Oct 15, 2012, 04:04 PM
"Take Off" eh!
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Good luck on the maiden!

In your title it says this is your first build. Does that mean this is your first Comp EDF? If so..May i suggest that you have a professional EDF pilot maiden it for you. I would hate to see all your hard work go down in flames. You may feel as though your being robbed of the experience.. but it is one big hurdel removed. Once they plane has been trimmed up for you..Your first EDF experience will be much more enjoyable.

Im not trying to piss on your BBQ.. Just want the best possible outcome for you.

Good luck.
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Old Oct 15, 2012, 07:04 PM
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Quote:
Originally Posted by vettster View Post
Good luck on the maiden!

In your title it says this is your first build. Does that mean this is your first Comp EDF? If so..May i suggest that you have a professional EDF pilot maiden it for you. I would hate to see all your hard work go down in flames. You may feel as though your being robbed of the experience.. but it is one big hurdel removed. Once they plane has been trimmed up for you..Your first EDF experience will be much more enjoyable.

Im not trying to piss on your BBQ.. Just want the best possible outcome for you.

Good luck.
Actually I appreciate the words of caution. This is my first comp edf but I have been flying foamies and arf's for a few years now. Actually I don't know anyone with the expertise that I could trust to shake out my plane for me. This Raptor will be fast and a bit wild to bring down gently and maybe finding a veteran would be a good idea.
This would actually be my 3rd edf but my first time putting together a composite model and designing and installing all the guts and electrical. I have had to learn how to solder and I have had one heck of an education in edf dynamics. I have had a tremendous amount of support and input from RcGroups and it is everyone else's blogs I had constantly reffered to for my own Raptor. (For this I am grateful)

The one thing I have not had which I really want is a veteran edf pilot/ builder to go through my plane and look over all my work. Everything is based upon blogs and forums so therefore no real face to face help. I have joined a few local clubs but unfortunately there really isn't much for support out here in terms of high powered composite edf's and I feel like I really am having to pioneer my way through all this. This is mostly because we don't have facilities to support comp edf's and one of the only clubs around here that could have helped was shutdown a couple years ago. Most of our sanctioned clubs either have cabbage patch grass runways or they are the paved ones but are surrounded by tall timbers. I can't blame them for sticking to arf foamies and tundra tire warbirds. But in a time where instant gratification can be found in relatively affordable rtf foamies a craft is being lost. Fiberglass, ecote and composite models are not what is lining the shelves in our hobby shops these days and nobody is really turning the newcomers on to the big boy stuff.
If someone knowledgeable is around the field the day I decide to take the Raptor out I will certainly ask for opinions.
In the meantime I continue to reach out locally and try and find some old pros. I don't mind waiting it out until I feel more qualified or have some assistance. I do alot of roadtrips down the coast line towards California sometimes. Maybe I could coordinate with one the big events?
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Old Oct 19, 2012, 02:24 PM
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Old Oct 19, 2012, 06:34 PM
"Take Off" eh!
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I hope those photos were taken AFTER the maiden
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Old Oct 19, 2012, 06:50 PM
A-4 nut!!
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I could look at it and fly it if you want.
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Old Oct 19, 2012, 06:56 PM
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Skyhawk, that would be nice if you looked it over. Where would you fly it?
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Old Oct 21, 2012, 01:50 PM
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I have mounted a small single channel head locking gyro in the nose and have it controlling the steering servo on the nose gear.

This proved most effective in my 90mm F18 when taking off and landing on the runway. What normally was pretty wild even with high expo is now bone straight rolling down the runway and reliable when landing. Unfortunatley there is no rudders on the F22 that can take advantage of the gyro action like my F18 did. It wouldn't stray off line on approach even in harsh crosswinds.

I hope to get the Raptor out into a large open space today to check the effectiveness of the gyro.
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Old Oct 21, 2012, 08:45 PM
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So I took it out today and it was a disaster!

I wanted to just try doing some taxiing exercises up and down the runway and to try out the steering gyro. The plane was tracking along pretty well and the gyro was doing it's thing but the problem came when the jet had to be turned abruptly or in a sharp radius. The raptor would completely oversteer in one direction or the other. On one account the plane did tip over and scuff one of the wings. Ouch, my first booboo.

I think I narrowed down the problem somewhat. I suspect the problem is because of the strut and the angle of the axle. The Eflite strut is offset to one side because of the coil they put in it at the base. I had also tweaked the strut a little to get it to tuck in nicely when retracted. I should replace it with something that has a bit of a castor to the axle so that the wheel drags instead of the leading the plane.

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I packed it all up and took home to the work bench. I went to discharge the packs back to storage voltage by running the fans for a bit but one the fans shutdown. The one esc was playing back the overcurrent error code and had shut the motor down. When I plug the pack in the motor begins to make a little clicking noise. The esc didn't power up right away with its usual tones and beeps. I wanted to record the noise so I can play it back to someone and figure out what the problem was, but at this point the esc had flashed and a little plume of smoke trailed out. Crap!! The was also a small plume coming out of the motor windings too. Now I am really confused about wth happened here. I did have it out running up and down the runway just moments prior to this and everything was fine. There is no chance of fod here, I looked all through the ducts and the fan. I had quickly unplugged the packs when all this happened and when I tested them with the cell analyzer I noticed one of packs suddenly has a bad cell and is now operating as a 5 cell. Even on the discharge plug I was getting 18.8V and not the expected 22.4V.
I pulled out the fan/ motor and esc unit and I am still in the process of looking at the CC data logs for any clues to what happened.
I imagine I am screwed again and will now have to send out the motor and esc for repairs or replacement, again. Oh yea this is the same motor and esc that was replaced in an earlier post, now getting ready to ship out again.
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