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DX-7 Throttle question

Old 10-05-2009, 03:57 PM
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sweetrex
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Default DX-7 Throttle question

I'm setting up my Spektrum DX-7 Tx on an airplane. The ESC I'm using is a CC HV85. When I throttle up, at 3/4 throttle, the ESC is indicating full power. Can I adjust the tx to give full throttle when the stick is at 100%?
Old 10-05-2009, 04:01 PM
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Zeeb
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Default RE: DX-7 Throttle question

You need to get into the programming instructions for the Castle ESC.
Old 10-05-2009, 04:10 PM
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Default RE: DX-7 Throttle question

How are you setting the throttle - autocalibrate or fixed endpoint?
Old 10-05-2009, 04:55 PM
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Default RE: DX-7 Throttle question

Whatever is the default setting. Auto calibrate?

Zeeb- What am I looking for to change in the ESC settings? I have a Castle link so changes should be simple.
Old 10-05-2009, 05:04 PM
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Default RE: DX-7 Throttle question

I think the default is autocalibrate. If you have CastleLink, switch to fixed endpoints and try.
Old 10-05-2009, 05:34 PM
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Default RE: DX-7 Throttle question

Thanks, I'll give that a try. If it doesn't work I'll let you know.
Old 10-05-2009, 05:37 PM
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Default RE: DX-7 Throttle question

I generally use autocalibrate - but both of my twins needed the fixed end point.
Old 10-05-2009, 05:42 PM
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Default RE: DX-7 Throttle question

Will it correct itself automatically or will I have to play with the settings?
Old 10-05-2009, 05:51 PM
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Default RE: DX-7 Throttle question

It should correct itself automatically. I don't have the software on this PC (work), but when I get home i'll open it and check.
Old 10-05-2009, 11:11 PM
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Default RE: DX-7 Throttle question

Jeff, I changed the setting on my ESC. It was set to autocalibrate. Throttle response is at mid. It seems to have gotten better, however I'm still not quite at full when the light goes solid on the ESC. Now I have the problem of the motor sounding like it's running out of power and then when I back down the throttle, it ramps back up again. This isn't a new problem. It was doing this before. My watt meter reads 60A at the time when the motor does this so I don't think I'm juicing the ESC as it is rated for 85A. Sny ideas?
Old 10-06-2009, 12:22 AM
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Default RE: DX-7 Throttle question

I think I might have answered my own question when I read the CC Phoenix instructions. I think the current draw is too high. I'm going to change propellers and see if the problem goes away. Instead of propping down, can I change the pitch? Will a shallower pitch also aid with the high current draw? I hope this works b/c these batteries are getting expensive.
Old 10-06-2009, 08:45 AM
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Default RE: DX-7 Throttle question

Okay I'm not a 'lectric expert and I'm not familiar with that 85HV other than to say I've seen some folks having difficulties with that unit over on Castle's support forum at RC Groups, but I'll run what I can think of past you;

There's been some updates from Castle for the Castle Link specifically related to the 85HV along with updated software for that ESC, not sure but IIRC it has to do mostly with using the governor mode on the heli's which includes throttle operation. There have also been some issues with smoked ESC's and the new software on the 85HV's. You may wanna touch bases with Castle about it?

The other thing is that I went to the fixed endpoints on my CC 35 that's in my little electric heli after screwing around with the other possible setups, that just turned out to be the cleanest.

Yes going down in pitch will decrease the load on the prop and should drop the amount of current draw you're seeing. Props are funny critters and when you get to trying to match things up for electrics or getting the best prop for a GS gasser, you just have to experiment to find the best prop for your setup and flying style. This is because props of the same size/pitch from different manufacturers will not perform the same, so you can get advice from folks about what works for them but you just have to try 'em to zero in on what will work best for you.

Hope that helps.
Old 10-06-2009, 10:19 AM
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Default RE: DX-7 Throttle question

Thanks Zeeb. I kinda figured that would be the case with regards to the props. An answer from the battery forum on this question was that the batts are 20C packs and they can only handle a 65A draw. This is consistent with my findings two nights ago. I thought the meter said 60A but I was distracted when the motor cut out and it very well could've been closer to 65A.

I'll check the CC website. I did download the new software for it so hopefully that won't give me a problem.
Old 10-06-2009, 11:11 AM
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Default RE: DX-7 Throttle question

Can't speak from experience on the HV series - but all my other CC ESC's don't start to cut the throttle down until about 10% more than their rating. Is it possible that you don't have enough battery ahead of it? What I've done is to stick a huge source on it (like a pair of 5000mah) to eliminate that issue.
Old 10-06-2009, 11:22 AM
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Default RE: DX-7 Throttle question

That's what I'm going to have to do. I need more power!!!
Old 10-06-2009, 11:54 AM
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Default RE: DX-7 Throttle question

I try to make sure there's only one variable in any testing. Milady says it's the "anal electrical engineer mentality" - but then I remind her that she's an EE too

If you have the "inventory", put an ESC and battery into the "equation" that you know is overkill - run the motor/prop combination up and chack results. Then pick a smaller ESC and battery to work with the amps you recorded. May be hard as you're already at 85A, unless you have a 100A ESC in the parts box. I have a 80A ESC and a pair of 5000mah/3S I use for this type of testing.
Old 10-06-2009, 12:29 PM
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Default RE: DX-7 Throttle question

Yea, my inventory is mostly for smaller models. This is the first big model I've set up. I'll try changing the props around and seeing where that gets me. Unfortunately I've sold most of my sellable items. I'll get it straightened out. Thanks for the help.
Old 10-06-2009, 12:33 PM
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Default RE: DX-7 Throttle question

The only reason I even have an 80A around is from a Funjet project I never started. Most of my CC ESC's are 45A and smaller

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