First Crash

Well, I can finally say I had my first bad crash with the EXI450.
I just replaced the ESC with a Scorpion 35A ESC and was trying it out. I had set the thing for high cutoff and the motor started increasing and decreasing in throttle. I knew I was no where near the voltage level and just goosed the throttle a bit instead of just landing it and fixing the problem. Anyway, it got up a bit higher than what I wanted and I ended up stuffing it into the side of a hill. Guess that will teach me to stop when I notice a problem,,,,,,,LOL.
Bent main shaft, flybar, feathering shaft, snapped the jesus bolt holding the main gear to the main shaft in half, and killed the elevator servo.
I'm glad I ordered the cnc head & tail assy. a few weeks ago because I still have the original head assy. so I have spare parts to replace all the mechanical stuff I damaged.
I also have a Belt CP that I can use the servo's from. I use the Tower Pro 9G servo's for everything so I'm planing on taking the tail servo and put it in place of the elevator servo. That will give me 3 Tower Pro Servo's for the cyclic and than I'll take one of the Belt CP servo's which are digital and use that for the tail. I really like the Tower Pro servo's but doing it this way, I'll still be able to fly until I can get another one on order.
I also think I can use the jesus bolt on the spare head for the one on the main gear and if not, the one from the Belt CP should work.
So all in all, I got away lucky as it won't cost me anything to repair this.

Its always good to have spare parts in hand for your helis, the fun part about this is you will be able to know your heli well. Goodluck on your repairs and let us know how you progressed.

Some ESC give the warning of voltage cutoff by just what you decribed speed up then down... like a surge.. I think that is quite normal with the Scorp... but you need to be ready for it.. The Hobbywing's I use just cut the power and you WILL land when that happends!!! Since I started using the volt watch, I have not had that happen. I always know when its time to land way before anything happens!!! Best 5 bucks I've spent!!!

Sorry to hear that.....My first and only (so far) heli crash was with the EXI450.
I piled it into the ground. It looked like some one was golfing there.

But it was easy and cheap to fix. I love that thing...

FD,
I had a Hobby Wing Pentium 30A with the bec on it and the thing bit the dust after about 10 flights. That's why I had to get a new ESC. I'm using the HDX450 motor which is rated at 28amps, not that I would ever draw that much the way I fly but that is close to the 30A esc rating so who knows. The Scorpion was in stock at the LHS so I picked that up. I like the fact that it comes with a programming card and takes all of 2 seconds to program but I don't care for the low voltage cuttoff. The battery was only at 11.8 volts when it started acting up and it shouldn't have done anything until it was around 9.6 volts so I'm not sure what is going on. I'm going to reprogram it so the cuttoff is at 9 volts and see what happens. I'm not concerned with the esc cutoff set too low as I fly with a timer on the transmitter set to 5 minutes and that allows me plenty of head room in the lipo's. I usually put back about 1200mah in the packs and that is way less than 80% for a 1800mah pack. I just finished charging the pack that this happened on and only put 625mah back in so there is something going on that I don't know about.
Anyway, I'm back up again. I took it out real quick for a test and everything is smooth with no vibration so that's the good part. Bad part was when I brought the head speed up to get it lite on the skids the thing wanted to tilt forward and to the left big time.
Had to add alot of back and right trim just to get it up in a hover but it was stable once I got it up. I shut it down after a minute and brought it back in to set the servo's and head mechanics back up as I didn't bother doing it before I tested it.
Just finished setting everything back up but it's to dark to try it out so I'll have to check it out tomorrow morning.
Hopefully everything will be fine tomorrow when I check it out.

I haven't ever used the 30AHW. I've only used the 40A platinum's, even on my HBK2 I had a 40!! Always had good luck with it!! The one on my Screamer 480 does get pretty hot when I run a 4S but I suspose that due to lack of air flow, but is changing too! I will continue to fly like I stole them till I can't fly them no more!!!

What gizmo would that be?

Fatdaddy wrote:

Since I started using the volt watch, I have not had that happen. I always know when its time to land way before anything happens!!! Best 5 bucks I've spent!!!

Well it a gizzmo that plugs into the balance lead and monitors the voltage and beeps when voltage gets low, it also has lights that start out blue and turn to red and then flash. I think I paid bout 5 bucks from HeliDirect, called MAXPRO

Thank you. I found it. http://www.helidirect.com/iosc/product_info.php?products_id=8159

Are the light easy visible during the day?

I think these are better than using a watch timer.

Fatdaddy wrote:

Well it a gizzmo that plugs into the balance lead and monitors the voltage and beeps when voltage gets low, it also has lights that start out blue and turn to red and then flash. I think I paid bout 5 bucks from HeliDirect, called MAXPRO

Well, just went out and went thorugh 2 packs and everything is fine. Didn't have to add any trim at all.
What a difference setting up the head and servo's mechanically make.
Only thing left to do now is to adjust the rudder servo on the boom, but even without adjusting that I only needed to add in one click of right rudder and I was fine.
I'm a happy camper once again.

Well the lights are not very easy to see, unless the heli is directly over your head!!! However the beeper is easily heard from a good distance! It starts out beeping slowly and quickens as voltage drops... I have one on every one of my heli's. Even the "E"

on 2 of my 450 running 3500kv motors, im using 30a esc's, but i also run it with a ubec and the esc is not even warm after flying.

on other hc i run a 50a esc and ubec running a 3700kv motor with 12t pin, with that setup, esc/battery/motor just warn cool

if you are not going all out 3d flying, then you will be fine using a 30a esc, i fly fff on my hc's and its fine as long as you are not hot roding your bird


-pete

Now come on FlyBaby!!! You look like Justin Ci when your airborne!!! You ain't kiddin nobody!!!

MB,
I had not had any problems with the 30a esc at all and then all of a sudden it just took a hike and I also used a seperate bec as well. In fact the ecs was cool to the touch as well as the bec and motor. So I don't know why it crapped out all of a sudden but it did and the only thing I could think of is the motor can pull up to 28amps and that only allows a 2amp buffer in the esc. That buffer should have been way more that enough to handle the way I fly as I'm not taxing anything.
I don't do 3d because I'm not capable yet and I'm still lucky to hover out a few packs and bring it down in one piece.
This new Scorpion esc is great. I also decided to use the internal bec on it as it is rated for 5v @ 4amps. This is not something I would normally do as most ESC BEC's are linear and not switching but in this case it seems fine and also seems like it is drawing less as well. When I had the 30a on there I would time my flights a 5min and put about 1200mah back in the pack. With this Scorpion and a 5 min flight, I'm putting about 950mah back in, which is one heck of a big difference.
The motor is cool as well as the pack and the esc is warm but not real hot. If I do have a problem I can always put on a bec but I'd like to see what will happen when I increase my time to 6min and go from there.
It makes me wonder why the people that build ESC's put a linear BEC in them as well when most people will put in a switching BEC and bypass the one that is in the ESC. Seems to me if they just produce the ESC without an internal BEC, they could produce the product for less and make it smaller as well.