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Old Jan 28, 2013, 04:57 AM
peterreebok is offline
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U


Put my mentor into a tree 3 months ago, and the tree won.

Been on order for 3 months, and finally one came in on friday.
Stripped out the usable bits from the carnage, and started building today.
Now i have a new mentor!
Only made one mistake, I assumed the servos were ok, and didnt test them.
After finishing and binding a rx, discovered the rudder servo was dead. Glued it in well as well too didnt I!
Tried a different rx, same result.
Cut out the servo, rectified the foam, ( inserted additional pieces) and installed another servo.

But, all is good now, all surfaces true and operational,
Just have to sort out the prop selection, and I will be in the air again.
Using a himax 3528 1100kv motor. Was using a 11x 5.5, which returns 440 watts at wot, and will try some other combinations before launching it. Only at the learning stage, so unlimited power is not required. Believe that will be enough.
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Old Feb 05, 2013, 04:31 PM
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I just ordered a kit! I have a EMP 3548-KV900 and a 60amp esc laying around I thought would work. I also have a few 3300mah 4s and a 5000mah 5s I was thinking of using with a 13 x 6 prop. I just ordered a watt meter too to check it all out. Hopefully the batteries will fit. Im still a beginner so if any of you guys see a problem with the setup or have any tips please let me know I would really like to get some floats and put some leds on it. Will the strips on ebay, the 5 meter 600 led strips http://www.ebay.com/itm/160895522420...84.m1438.l2649 work? I love it when the whole plane lights up!

Oh yea, i forgot, I bought 4 hitec deluxe standard servo HS-322HD. Will these work out for me, or do I need 2 micro?
Last edited by Dr.JJ; Feb 05, 2013 at 05:49 PM.
Old Feb 06, 2013, 03:28 PM
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Quote:
Originally Posted by flieslikeabeagle View Post
Well, James, congratulations on your new addiction, sorry, hobby.

Maybe I can help clear things up a little as to the UBEC issue. There are two kinds of BEC - the old fashioned kind is called a linear (or analog) BEC, and this is what is built into most ESC's. Unfortunately, linear BEC's do not get along with high voltage - they get very hot and may shut down if you run them on anything higher than 3S voltage. As you say, this will kill power to the receiver and servos, which means the model is going to crash.

Fortunately, there is a newer technology that outperforms the old analog BEC's. This is the switching BEC, or UBEC (UBEC is really a specific trade name, like "Colgate", while "switching BEC" is the generic term, like "toothpaste"). Switching BEC's are much more efficient than linear BEC's when you use them with high voltage.

So: the advice you got to use a switching BEC when you use a 4S (or higher) pack was definitely good advice.

Here's the thing, though. While certain heavily marketed American ESC manufacturers stayed with the inefficient old analog BEC's on their overpriced ESC's, the inexpensive Chinese-made Hobby Wing/Turnigy ESC's moved to superior technology several years ago - the higher current Turnigy Plush ESC's all have a switching BEC already built into them. Not a linear BEC - a switching one, the good kind, the kind that will happily handle 4S lipo packs without breaking a sweat.

So, if you use a $140 Castle Creations Phoenix 60 ESC with a 4S lipo pack, you need to also use a separate switching BEC, because the Phoenix has a crappy old-tech linear BEC onboard. However, if you use a $35 Turnigy Plush 60 A ESC, it has the good switching BEC already onboard, and you can safely use it along with a 4S lipo pack - no need for a separate switching BEC. You not only spend $105 less on the ESC, you also spend another $10 less for the UBEC, AND you get a smoother-starting ESC as well.

To make doubly sure we're on the same page: The Turnigy Plush 60A ESC you're using WILL happily power four servos and a receiver off a 4S lipo pack with no danger of an overheating ESC. Some other lower quality ESC brands, however, will not - they are incapable of doing the same thing and require an external switching BEC to be safe for 4S use.

Castle Creations has belatedly woken up to this, by the way, and now offer the Phoenix ICE Lite 75 A (there's no 60 A version) for $120. This does have an onboard switching BEC, at only three and a half times the price of the Turnigy Plush.

By the way, some of the smaller (lower current) Turnigy Plush ESC's do not have a switching BEC onboard - they have linear BEC's instead. So make sure you read that data sheet carefully before you decide whether or not you need an external UBEC. (My policy is to use a $8 Hobby King UBEC on just about every ESC that has a linear BEC - I don't trust linear BEC's as far as I can throw an elephant.)
Good info here
Old Feb 06, 2013, 04:03 PM
NCRealEstateGuy is online now
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I have been flying my Mentor with a 60 amp Turnigy Plush ESC for two years with no problems. I use a 4s 4500 battery.
Old Feb 06, 2013, 04:56 PM
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I use a castle ICE lite 50A ESC with no nonsense stand alone unit for 4s lipo. I follow this Voltage Regulator / BEC article.
Old Feb 06, 2013, 06:38 PM
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Quote:
Originally Posted by Dr.JJ View Post
I just ordered a kit! I have a EMP 3548-KV900 and a 60amp esc laying around I thought would work. I also have a few 3300mah 4s and a 5000mah 5s I was thinking of using with a 13 x 6 prop. I just ordered a watt meter too to check it all out. Hopefully the batteries will fit. Im still a beginner so if any of you guys see a problem with the setup or have any tips please let me know I would really like to get some floats and put some leds on it. Will the strips on ebay, the 5 meter 600 led strips http://www.ebay.com/itm/160895522420...84.m1438.l2649 work? I love it when the whole plane lights up!

Oh yea, i forgot, I bought 4 hitec deluxe standard servo HS-322HD. Will these work out for me, or do I need 2 micro?
IIRC the specs call for a 3S LiPo pack. Running a 4S-5S pack is really pushing things. If you are really a beginner, then you may be getting more speed and power than you bargained for. I find this plane has plenty of power with a 3S pack. And heed the advice about BECs and ESCs.

I have Hitec 85 (micro) servos in the wings and they fit perfectly. I think I have standard servos on the rudder/elevator, but I don't remember for sure.

Is this your first plane? I wouldn't get too carried away with lights and floats just yet, either. You'll have you're hands full just keeping this plane in one piece. The Mentor is supposedly a trainer, but it's not as stable and forgiving as the true trainers that I learned with.
Last edited by wjjones; Feb 06, 2013 at 06:45 PM.
Old Feb 07, 2013, 01:21 AM
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Thanks for the info, and its great to see the thread is still alive. I have some experience w planes and helis, just consider myself a beginner still. I have a epp hacker zoom zoom 35" and 1200mm flying wing, and I spend way too much time on RF6. Sold my cp heli. I put nav lights on the zoom and love it, but I really like the planes w led strips that light up the whole sky. We have a 2 acre pond, and this big plane on floats lit up like Christmas would look spectacular! Im thinking of adding flaps, but some say they aren't needed. Any thoughts about the flaps?
Old Feb 07, 2013, 03:48 AM
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Flaps? I think it can fly slower than my Apprentice!
Old Feb 07, 2013, 08:39 AM
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I think most here agree that flaps aren't really necessary with this plane. They can be fun to play with, especially if you like shooting touch and goes like a Super Cub tundra plane. If I didn't have a FunCub already (with flaps) I would consider putting flaps on my Mentor just for sh*ts and giggles.
Old Feb 07, 2013, 01:31 PM
NCRealEstateGuy is online now
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I installed flaps on mine and really like them. I do like doing touch and gos. I posted how I did mine a few pages back.
Old Feb 07, 2013, 04:13 PM
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Im currently on page 58 and taking some building notes along the way. The flaps would be just as easy to install after I build it right? Or if I plan on doing it, should I do it while building? The runway is pretty lumpy grass so im putting 4" wheels on it to start. I thought flaps would set it down nearly vertical.
Old Feb 07, 2013, 09:48 PM
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You can add the flaps at any time. If you go to "Thread Tools" and then "Show All Attachments" you can scroll through the entire thread of pics in no time.
Old Feb 08, 2013, 02:30 PM
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Thanks, I didnt know you could do that. Like most of us, Im a look at the pics knida guy, as opposed to reading instructions
Old Feb 11, 2013, 04:11 PM
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ready to go


mentor mk2 (for me) ready to go.

battery tray to make the battery stay put, all throws checked, and the C of G at 80 mm from leading edge.

made a cog checker, from scrap, cost $0. reckon the model is balanced?

used a watt meter, and even though the battery is at 60% capacity, managed over 450 watts, so dont believe power will be an issue for training duty.

unfortunately, wont be maidening this one for 2-3 weeks, as I am off to Vietnam for a brief bit of R and R. Really want to get it into the air.
Old Feb 11, 2013, 04:23 PM
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Quote:
Originally Posted by utrinque View Post
This is what Im planning on doing, I love how it lights up. Great Job!


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