View Full Version : Another Lepton Flies
ArthurKnowles
08-17-2006, 06:44 PM
Had my first hover on the Lepron today. The sound of the head is insane. I am using a Jazz 80-6-18 ESC. The original configuration would hover it below mid-stick. Less than 5 degrees pitch, but a much higher headspeed than my later configurations.
I set the Jazz at 20 for idle up 1 and it tached out at 1700. I have it at 35 now for a headspeed of 2000. It sounds ... I don't know how to describe it, but it is a serious sound that means business. I can't believe some of you are running headspeeds 2800 and up.
mudbogger2
08-17-2006, 07:14 PM
Congrats on getting it in the air!
What motor, pinion and battery are you running?
I set the Jazz at 20 for idle up 1 and it tached out at 1700. I have it at 35 now for a headspeed of 2000
Are you saying you are running at 35% throttle? If so please raise it up before you fry your esc!
toyturbo
08-17-2006, 07:32 PM
The sounds reminds me of a pissed off turbine engine when spooling up, I love it!
ArthurKnowles
08-17-2006, 07:59 PM
4S 3700 mah pack with a 24 tooth pinion on a Hacker A30-10XL. But now I need new blades. :(
TMoore
08-17-2006, 09:08 PM
I'm running mine at 2400 in the hover and 2650 upstairs.
TM
ArthurKnowles
08-17-2006, 11:15 PM
Are you saying you are running at 35% throttle? If so please raise it up before you fry your esc!
Yep. The Jazz is rated for unlimited partial throttle so long as the maximum amp rating is not exceeded. It's why I am using it. It's also an 80 amp model with a serious amount of headroom. If it fries, then it is defective and I doubt that will occur.
As for raising the throttle/headspeed I will if/when I feel comfortable doing so. Right now, I sure wish I had a smaller pinion so I could lower the headspeed. I doubt if I will ever want to reach 2400/3000 rpm. I also have no real need to do so as I am not a 3D advocate. Basic flight. Basic areobatics. More scale like flying is what I prefer.
Finless
08-18-2006, 12:06 AM
Congrats Arthur! Very different than a TRex aint it :)
You still need to bring the head speed up a bit if your doing 3D or not. The heli will just be more stable and perform better and your electronics will like you more too. At least get it up to the 2400 area at the lowest.
Bob
ArthurKnowles
08-18-2006, 01:37 AM
Bob,
I have it programmed for 2000 in idle up 1 and about 2400in idle up 2 so when I get some new blades I'll try again.
The only issue I have now is spool up. When it occurs the heli spins to the left and I lose right tail rotor control (meaning the gyro has pegged it all the way, but it still spins). This only occured with 2000 rpm headspeed. It also only occurs on the ground. Once up, the problem goes away. I need to figure out why.
I'm using a 401 gyro in normal mode and in idle up it is avcs. All at 50% (norm or avcs). And a S9650. Any ideas?
PS: Much different thant a T-Rex. Much better too.
ArthurKnowles
08-18-2006, 02:11 AM
Ahh, never mind. It just occured to me that when I spooled up in idle up 1 I had about 10 degrees of negative pitch on the blades when I lost tail authority. I'll have to remember to use throttle hold and set the blade pitch to 0 before spooling up.
Normally I use normal mode to start and use fixed throttle settings. Castle Creations govenor settings haven't been quite good enough, or have had issues with the signal settings. This is my first govenor use with a Jazz controller.
Are you using the stock tail blades?
poerqwa
08-18-2006, 06:05 AM
I have the exact same config as you(but a 55Amp Jazz).
My Lepton is ready to fly (but due to time constraints did not have it's maiden flight yet).
It sounds your flying style equals mine. Do you already have an idea about flight times?
TMoore
08-18-2006, 09:09 AM
Ahh, never mind. It just occured to me that when I spooled up in idle up 1 I had about 10 degrees of negative pitch on the blades when I lost tail authority. I'll have to remember to use throttle hold and set the blade pitch to 0 before spooling up.
How does using TH let you spool up at 0 pitch?
TM
Gscott
08-18-2006, 09:17 AM
Using the Jazz you need to have 0 degrees at center stick in your Normal flight mode. You then move the throttle/collective stick to center and wait for the Jazz to spool up. It's important that you let the head speed stabilize at center before proceeding. Your throttle curve also need to be 0-50-50-50-50 in Normal. The 50 setting is arbitrary and will depend on your setup and the head speed you are looking for.
poerqwa
08-18-2006, 02:26 PM
Still beats the hell out of me how throttle hold is involved here.
I can imagine the following steps.
TX in TH
Walk to the field
Make sure you put your pitchstick at 0 degrees (thank you T14MZ :) )
Release TH
Wait till spool up and fly ;)
Greetz,
Marc
ArthurKnowles
08-18-2006, 03:30 PM
Are you using the stock tail blades?
Yes, but I have a set of 68 mm carbon replacements. I'm just surprised a bit by the behavior on the ground. As I said, it does not occur in the air.
My thinking at present is this is a tourque reaction, but I've never used a govenor before. I've always used fixed throttle curves and never experianced loss of tail rotor authority on the ground.
ArthurKnowles
08-18-2006, 03:31 PM
It sounds your flying style equals mine. Do you already have an idea about flight times?
Not yet, and I'll need new blades befor I can find out.
ArthurKnowles
08-18-2006, 03:33 PM
How does using TH let you spool up at 0 pitch?
TM
Turn TH on. Change to Idle Up 1. Move throttle to mid-stick (0 pitch). Turn TH off. Spool up and go fly.
ArthurKnowles
08-18-2006, 03:39 PM
Using the Jazz you need to have 0 degrees at center stick in your Normal flight mode. You then move the throttle/collective stick to center and wait for the Jazz to spool up. It's important that you let the head speed stabilize at center before proceeding. Your throttle curve also need to be 0-50-50-50-50 in Normal. The 50 setting is arbitrary and will depend on your setup and the head speed you are looking for.
I don't like 0 degree in normal flight mode. I prefer a standard arrangement of 5 degrees or so at mid-stick and hover the helicoptor at mid-stick. For myself, 0 degrees at mid-stick is strictly an idle up function.
If I can't get the Jazz to operate in the configuration I prefer, I'll just change it out for a CC 60 or 80 and set it up for fixed endpoints and go fly.
Truthfully, at this point I can say I don't like any of the electronic govenors that I have used to date. All of them have a harsh spool up (Jazz) or fail to hold the headspeed well (CC). But I haven't used them all.
When I get my new blades, I will play with it some more and see if I can deal with the spool up, ground behavior, etc. If not, I really don't mind switching controllers. If I can't use govenor mode on the Jazz I will have to switch as mode 1 (normal) really slams the gears starting up.
toyturbo
08-18-2006, 03:53 PM
fwiw: the Jazz ESC's have the best soft start in the business. Are you sure you have it programmed for mode 4?
Your heli just needs to spool up to a solid RPM for the tail to hold. What you're describing happens all the time with my 90's everytime I fly off concrete.
ArthurKnowles
08-18-2006, 05:48 PM
Oh yeah. Mode 4. I went through the programming and confirmed the selection. When it starts to spool up the helicoptor spins. Way too much. Some f that may because of the high negative pitch I had on it. I'll check it out after I get new blades. But the CC esc allows you to specify the spool up speed (current beta software revisions) and is much better than the Jazz. I just had a problem getting it to arm. Same problem on the Jazz and had to maximize the ATV setting to 120 top/bottom.
As for spooling on concrete. I have to say that I'm not about to let it do that constantly. I mean, it's out of control. Sure it is spinning in just one place, but I can't accept that. Way too dangerous in my opinion. If I can't fix it after I get new blades, I'll use a different esc and fixed endpoints so I can control the behavior.
I mean it is no big deal. Throttle curves and cyclic to throttle mixes do pretty much the same thing in keeping a constant headspeed.
The tail only moves 20 to 30 degrees when I spool on concrete. Yours sound much worse.
TMoore
08-18-2006, 06:21 PM
Y'all are making this way too hard. My heli just sits there in the grass while I spool up in normal mode and then flip to the appropriate flight mode. I've got Flight mode Normal, FM2, FM3 and Crack mode.
TM
ArthurKnowles
08-18-2006, 09:51 PM
I landed mine in the yard once, but the tail rotor started to dig up the ground as it spooled down. That's what caused me to not land it in the yard when I got close to the tree. I didn't want to damage the tail rotor. So, instead I'm down one set of main blades and both tailboom supports (bent).
I'm going to have to seriously think about a small portable helipad. I saw one a long time ago that I wish I had of bought. It was a three foot circle with a gelpad exterior (for weight). Put it anywhere and have safe place to tackoff and land.
TMoore
08-18-2006, 10:12 PM
I raised my Lepton up 8 mm with a set of risers. I installed an extended fin and the 68mm tail blades so now the machine copes with the grass. I'm going to install the 720 gyro this weekend as well.
A piece of commercial grade carpet used to be what I used for a take off pad but I tended to leave them at the field from time to time and so I was visiting the remnant shop a little too much replacing them.
TM