HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jan 17, 2013, 09:32 PM
Registered User
Prof100's Avatar
Canton, Michigan USA
Joined Jul 2007
16,279 Posts
Quote:
Originally Posted by paulsmnz View Post
I like the model a lot. This is my 1st EDF jet.

Its disappointing the stock location of ESC and limited movement options for the standard recommend battery (3300 4S) position. With retracts the cg is way off without mods to component locations and foam removal to move the battery (adding weight is a quick fix , but should not be required) . Parkzone should have got this right out of the box and the user really should not have to do these mods for what is really a standard setup.

I expect this sort of thing from Hobby King,(and thats cool, get what you pay) and don't expect it from quality name brand products (in this price range).

4 stars out of 5 as a result.
You don't have to mod anything for CG adjustment. Add retracts and put some lead in the tail. Bingo, you are done.
Prof100 is offline Find More Posts by Prof100
RCG Plus Member
Sign up now
to remove ads between posts
Old Jan 17, 2013, 09:59 PM
Night_Crawler
paulsmnz's Avatar
Australia, QLD, Brisbane
Joined Mar 2012
115 Posts
Quote:
Originally Posted by Prof100 View Post
You don't have to mod anything for CG adjustment. Add retracts and put some lead in the tail. Bingo, you are done.
Yep , noted, Thanks and I have acknowledged that.

The point is this could have been done by manufacture with proper component location and battery movement options to not make this a requirement to get cg correct. As it is, we the consumer and doing this., and at this price point we should not have to do this.
paulsmnz is offline Find More Posts by paulsmnz
Reply With Quote
Old Jan 17, 2013, 10:31 PM
Registered User
Mugen4Lfe's Avatar
Joined Sep 2011
668 Posts
Quote:
Originally Posted by Prof100 View Post
Never fly to cutoff because when you do you shorten the lipo's life tremendously. Strive for 20% left in the pack.
The question is not regarding whether or not to fly to cutoff. We all know it's a bad idea. The question was about hard vs. soft cutoff and which is better when programming an EDF's esc....
Mugen4Lfe is offline Find More Posts by Mugen4Lfe
Reply With Quote
Old Jan 17, 2013, 10:34 PM
Registered User
Prof100's Avatar
Canton, Michigan USA
Joined Jul 2007
16,279 Posts
Quote:
Originally Posted by Mugen4Lfe View Post
The question is not regarding whether or not to fly to cutoff. We all know it's a bad idea. The question was about hard vs. soft cutoff and which is better when programming an EDF's esc....
To me it is a conversation not worth having. In either case your plane is going to land with little or no power.
Prof100 is offline Find More Posts by Prof100
RCG Plus Member
Old Jan 17, 2013, 10:55 PM
Registered User
Prof100's Avatar
Canton, Michigan USA
Joined Jul 2007
16,279 Posts
Quote:
Originally Posted by paulsmnz View Post
Yep , noted, Thanks and I have acknowledged that.

The point is this could have been done by manufacture with proper component location and battery movement options to not make this a requirement to get cg correct. As it is, we the consumer and doing this., and at this price point we should not have to do this.
First, the Habu is an entry level EDF and Horizon / Parkzone designed it to be nose heavy. The battery area is fixed since it drives the final CG. Fixing the battery location was to protect for newbie errors on battery placement. The design concept is called error proofing. Remember, a nose heavy plane flies and lands fast, but it lives to fly again. A tail heavy plane usually flies once.

By the way, the HABU 32 is nose heavy to many pilots and they move it back as well

Yes, adding retracts does require shifting the weight rearward and like I stated before, a few grams of lead in the tail does the job. Simple and effective solution to adjust the CG. Removing foam to slide the battery back is another simple solution.

The take rate for retracts is probably less than 10% so adding retracts takes adjusting the CG. To me it's no big deal.
Prof100 is offline Find More Posts by Prof100
RCG Plus Member
Last edited by Prof100; Jan 18, 2013 at 02:22 PM.
Reply With Quote
Old Jan 17, 2013, 11:16 PM
Night_Crawler
paulsmnz's Avatar
Australia, QLD, Brisbane
Joined Mar 2012
115 Posts
Quote:
Originally Posted by Prof100 View Post
First, the Habu is an entry level EDF and Horizon / Parkzone designed it to be nose heavy. The battery area is fixed since it drives the final CG. Fixing the battery location was to protect for newbie errors on battery placement. The design concept it called error proofing. Remember, a nose heavy plane flies and lands fast, but it lives to fly again. A tail heavy plane usually flies once.
Ok fair enough, I'll accept that as a valid reason. I don't fully agree , but its a valid reason. Thanks for your input

Paul
paulsmnz is offline Find More Posts by paulsmnz
Reply With Quote
Old Jan 17, 2013, 11:50 PM
Registered User
Mugen4Lfe's Avatar
Joined Sep 2011
668 Posts
Quote:
Originally Posted by Prof100 View Post
To me it is a conversation not worth having. In either case your plane is going to land with little or no power.
Having a conversation about how to best program an esc for a particular application is not worth having? Ok. Now I know not to ask those types of questions in the future.
Mugen4Lfe is offline Find More Posts by Mugen4Lfe
Reply With Quote
Old Jan 18, 2013, 01:17 AM
C.E.R.N. field tester
supercollider's Avatar
United States, NE
Joined Sep 2012
901 Posts
Quote:
Originally Posted by Prof100 View Post
To me it is a conversation not worth having. In either case your plane is going to land with little or no power.
All conversations, regarding the flight of a plane are worth having, that is what these forums are for. Soft or hard cutoff could mean the difference between a safe landing or a crash for some pilots. There are all kinds of people flying, from new pilots to veterans, any info regarding esc settings can help. Different manufacturers have different settings, weather it be for prop or edfs, so its good to talk about the different settings.
Personally, hard cutoff makes me panic, I think there is something wrong like a smoked esc or motor. Soft cutoff tells me calmly that the lipo is running out , time to land. Usually I run a timer, and don't have this issue, but we are human after all and from time to time tend to make mistakes.

Cheers
supercollider is offline Find More Posts by supercollider
Reply With Quote
Old Jan 18, 2013, 07:47 AM
FireHawx
United States, FL, Jacksonville
Joined Oct 2011
1,042 Posts
+1...
FireHawx is offline Find More Posts by FireHawx
Reply With Quote
Old Jan 18, 2013, 07:56 AM
Registered User
Prof100's Avatar
Canton, Michigan USA
Joined Jul 2007
16,279 Posts
Manage your power and flight time so you don't land without power. Set the timer to allow you one go around and still land with 20% in the lipo. Deadsticking an electric should only happen if there is a catastrophic failure of the electronics. Deadsticking due to reaching LVC is simply a self inflicted wound and careless flight planning and execution. It's like building a plane to crash. It's silly IMHO. I will, however, enjoy reading the plusses and minuses of soft vs. hard cutoff.

The real conversation should be how to determine overall flight time with a target goal of 20% left in the lipo.
Prof100 is offline Find More Posts by Prof100
RCG Plus Member
Old Jan 18, 2013, 09:57 AM
Registered User
Joined Nov 2005
1,854 Posts
Prof, I agree about timing your flights. I never fly to the cut off. That is like creating an emergency every flight. I like to set a short flight time on my maiden (4 minutes). Land and charge the battery to see how much I put back. Then I use the 30% rule to determine my flight time. This gives me "go around" time if needed. The first few flights I go easy and make sure my flight times are good.

No way would I depend on the ESC for the proper cutoff. Also, I always program my Eflite ESC for the number of cells and I do not use the default setting of 70% of start up voltage because if you forget to charge a battery, it will not go well.
tclaridge is offline Find More Posts by tclaridge
Reply With Quote
Old Jan 18, 2013, 10:09 AM
Registered User
DamonH's Avatar
United States, NM, Clovis
Joined Oct 2011
2,974 Posts
I think the point is being missed here. I don't believe anyone purposely fly's to LVC but it does happen from time to time whether it is pilot error, bad battery, weather (forcing go arounds or whatever), etc. The question was asked "why is soft cutoff bad for EDF's" when obviously many people setup their esc's this way. Some how it was taken off course by someone stating the obvious "you should never fly to LVC" when what is really needed is useful information about the differences/pluses/minuses of soft cutout vs hard so people can make an informed decision on which is better to use in the event for whatever reason you do hit LVC.
DamonH is offline Find More Posts by DamonH
Reply With Quote
Old Jan 18, 2013, 11:09 AM
Registered User
Eric Henderson's Avatar
United States, NV, Las Vegas
Joined Dec 2005
1,308 Posts
Quote:
Originally Posted by DamonH View Post
I think the point is being missed here. I don't believe anyone purposely fly's to LVC but it does happen from time to time whether it is pilot error, bad battery, weather (forcing go arounds or whatever), etc. The question was asked "why is soft cutoff bad for EDF's" when obviously many people setup their esc's this way. Some how it was taken off course by someone stating the obvious "you should never fly to LVC" when what is really needed is useful information about the differences/pluses/minuses of soft cutout vs hard so people can make an informed decision on which is better to use in the event for whatever reason you do hit LVC.
It may not be a voltage thing, but more of an inflight information thing.

When the fan stops as in a hard cut-off, the pilot knows that it is time to land regardless. It can happen at full-medium-low throttle etc. either way you know it's time to dive :-)

With the fan still running, as in a soft cut-off, you may well be flying at that setting and be unaware of the voltage situation. Imagine that you then throttle-up to go around and you have "nothing!" and nowhere to go.....

My best guess.(SWAG)

Eric
Eric Henderson is offline Find More Posts by Eric Henderson
RCG Plus Member
Latest blog entry: Mental hang-nails
Reply With Quote
Old Jan 18, 2013, 11:42 AM
Registered User
DamonH's Avatar
United States, NM, Clovis
Joined Oct 2011
2,974 Posts
Quote:
Originally Posted by Eric Henderson View Post
It may not be a voltage thing, but more of an inflight information thing.

When the fan stops as in a hard cut-off, the pilot knows that it is time to land regardless. It can happen at full-medium-low throttle etc. either way you know it's time to dive :-)

With the fan still running, as in a soft cut-off, you may well be flying at that setting and be unaware of the voltage situation. Imagine that you then throttle-up to go around and you have "nothing!" and nowhere to go.....

My best guess.(SWAG)

Eric
Thanks Eric. I have always used soft cutoff so I guess my question for hard cutoff is that once it happens you can throttle down and reset esc so motor works again? I think my hesitance to use hard cutoff is that you have to hope that it happens at a good time and you have time to reset and save your plane. At least with soft cutoff you get a little heads up warning (if you are paying close attention and can pick it up). It may all just kind of boil down to pilot preference as it seems there are good/bad with both.
DamonH is offline Find More Posts by DamonH
Reply With Quote
Old Jan 18, 2013, 08:11 PM
Parkzone junkie
kalmon's Avatar
United States, MI, Grand Traverse
Joined Oct 2008
3,530 Posts
Soft cutoff saved my plane!

Here is my take on it. I still have my plane today due to soft cutoff. I had a pack drop a cell in flight. I was flying from my back field with has trees on 3 sides that I have to fly over. Normally this isn't a problem at all. However on one flight I plugged in the pack did my control test and everything was fine. I launched and flew for just over 1 min. I was flying probably 50 ft above the trees and almost directly away from my position. All of a sudden I noticed a loss in power and could hear a change in rpm. I knew something was wrong so quickly, to quickly, tried to turn around. I lost way to much energy in the tight turn and was now heading straight back at me with engine pulsing. I cleared the tree line by only about 5-10ft. If the esc did a hard cut and I had to cycle to reset I would not have had enough power to clear the trees. I was lucky, and landed in field although quite a bit downrange. (usually I approach from the side with no trees so I don't have to clear the 50ft ers.) I took the pack out and hooked it up to my tester: got 4.0 - 4.05 on cells 1,2, and 3 and 1.7 and falling on cell 4. To this day I haven't figured out what happened to the pack. It was never dropped or crashed and flew earlier that day just fine. It was only 4 months old too...

Anyways this is why unless there is very good reason not to I stick to soft cut on all my planes.

-Brian
kalmon is offline Find More Posts by kalmon
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sold 2 PNP Parkzone Habu's - willing to ship jgalexander Aircraft - Electric - Jets (FS/W) 16 Mar 29, 2012 09:44 PM
For Sale Brand New in pack ParkZone Habu EDF Jet Painted Wing PKZ7020 zsultan Aircraft - Electric - Airplanes (FS/W) 3 Nov 15, 2011 12:36 AM
For Sale Brand New in pack ParkZone Habu EDF Jet Painted Wing PKZ7020 zsultan Aircraft - Electric - Jets (FS/W) 0 Nov 13, 2011 02:40 PM
Sold Brand New Parkzone Habu EDF Jet BNF zsultan Aircraft - Electric - Airplanes (FS/W) 0 Nov 07, 2011 01:05 PM
Sold Brand New Parkzone Habu EDF Jet BNF. zsultan Aircraft - Fuel - Airplanes (FS/W) 4 Nov 07, 2011 01:04 PM