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Old Sep 06, 2012, 06:38 AM
John
Australia, QLD, Brisbane
Joined Aug 2012
542 Posts
Think you said you used the EH200, Markkona - hard to get now, but Rexless says he's found some. Hoping he'll tell us where .

Yep - your post, page 58
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Old Sep 06, 2012, 11:24 AM
Fly Fast, Fly Hard, Fly Fun
rexless's Avatar
Canada, BC
Joined Apr 2012
1,535 Posts
Until I receive my initial order and have a chance to test and make sure the items fit and work as expected, I think it's premature to announce that I've found a source. I would really hate to direct people to a site and found out the parts are totally wrong or it's a scam etc. I'm optimistic though. When I was on hobby king last night I think all the parts I would need are into the - numbers now so it could be a long time until we get a kit from them.

What I don't have yet is a source for batteries that has any stock. The ones BThirsk has on his blog are both out of stock.
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Old Sep 06, 2012, 12:42 PM
Different fly 4 different guy
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Joined Jan 2011
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Quote:
Originally Posted by OldOz View Post
You guys got me into this – special mention to Gordonzo and Markkona! – and a few hundred flights (and many, many crashes) later I feel I’m at least a fair F45 pilot. And, imho I’ve found that this is a cheap, easy to fly, NEAR indestructible, 300ish size FP with some wind capability out of the box.
So I guess others reading our posts will ultimately take the plunge into FP and the MJX F45.
As in all helis, there are useful mods. These I have found particularly beneficial, and are mostly from previous contributors - but now collated in one place.

FWIW, my own ‘must do’ new F45 checklist (after initial hover test):
1) Install flybar bumper on main boom
2) ‘Paperclip and epoxy glue’ reinforcement of buckle (dogbone) loop guides on rotor head (see p184) – Or Hinnerk’s full rebuild mod when they fail (same page). Done both, on different F45s.
3) Check insulation around the main motor terminals – add heatshrink (or tape) if faulty. The canopy pushes hard on these wires, and a short here will total the FET on the main PCB instantly. Others have reported – and I’ve noted one of mine - coming OoTB with damaged insulation.
4) Anchor the PCB to support struts with glue gun. Similarly anchor other subassemblies to main PCB.
5) Remove at least 3 of the 5 tailrotor motor cover supports for improved airflow.
6) (nice, but not essential) Solid rod replacement for tube landing gear skids (the stock tube cracks very easily in front of the forward skid support).

And for better fff, at the expense of a little stability –
7) Shim both blades (3-4 plastic binder reinforcement rings on each blade work well). The blades should be (only just) able to turn the rotor without shifting.
8) Remove horizontal stabiliser and support tubes from the boom. Add an equivalent weight (about 10g) of Bostik blu-tack (or hot glue) inside the nose tip of the canopy - OR fit a longer LiPo as suggested in previous posts, which equally effectively shifts the CoG forward.

Finally, and more contentious here!
9) If free flights are going to be consistently over 6 mins, or hovers over 3-4min, fit heatsinks to both motors. Within these limitations, however, I have noticed no difference in motor MTBF between one of my F45s with heatsink, and another without. You get around 8-10h runtime, either way (but of course, YMMV).
However, I do agree that with long flight durations in high ambient temperature, it may be possible to destroy one of the brush support arms before the brush wears out, leading to very premature failure. Heatsinks here may tip the balance, unless they occlude the motor ventilation holes.
TL, DR? An awesome <$100 heli, but get spare motors. Or go brushless.

Additions or corrections welcomed from anyone!
- John
Very good summary. Maybe add the elev servo arm mod.

regards . . . g
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Old Sep 06, 2012, 01:09 PM
Fly Fast, Fly Hard, Fly Fun
rexless's Avatar
Canada, BC
Joined Apr 2012
1,535 Posts
Since this battery is out of stock for some time: http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html

I'm trying to find an alternative suitable 11.1v battery:
http://www.hobbyking.com/hobbyking/s...y_Battery.html

http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html

http://www.dealextreme.com/p/11-1v-1...b-35767?item=6

http://www.ebay.ca/itm/RC-Battery-25...item3cb9849bb0

http://www.ebay.ca/itm/GENUINE-DLGPO...item3cb9833f23

Anyone out there tried these "Battery Tree" LI-POs?
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Old Sep 06, 2012, 01:14 PM
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Joined Jul 2012
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Hey guys. I have use this chopper for a month and i have noticed that he fly forward very bad. Some times it just don't fly forward anyway even if i get my stick to the end. Is there any way to fix this. And i broken my main shaft so is there any good replace?
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Old Sep 06, 2012, 01:27 PM
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rexless's Avatar
Canada, BC
Joined Apr 2012
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You can get a lot of parts at http://www.banggood.com/buy/f45/inde...0-0_page1.html

This is where I have ordered many of my parts.

I too have had problems in forward flight. I've adjusted the swash plate so the connectors are in the outermost holes in the servo arms, upgraded my battery, removed the tail supports and fins, and shifted the weight slightly forward. It has helped a bit. Some of the more experienced flyers on here have upgraded to brushless main motor with different blades and batteries. I'm just starting down that path myself.
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Old Sep 06, 2012, 05:03 PM
Brent 黑雁
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Canada, AB, Ponoka
Joined Jan 2012
1,780 Posts
Maybe this one will fit. It's 2200mah. You have to check the 21mm height. I can't remember how much room we have.
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Old Sep 06, 2012, 05:56 PM
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rexless's Avatar
Canada, BC
Joined Apr 2012
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damn, that's a monster! 2200mah @ 11.1v I'm guessing that's damn near a rocket pack? hehe. At that height I think the max width that would fit in the stock tray is 18, maybe 19mm. Anything above that and we'd have to do some serious cutting and move the PCB. I think there's a good chance that 21mm would be thick enough to touch the tip of the drive shaft - at least with the stock motor. I haven't seen the length of the EH200 so if it's shorter then maybe that's not a concern.

Otherwise the weight is significantly more. I wouldn't want to add much weight unless there's really just that much more power to make it insignificant.

Totally off-topic but imagine if we could use quantum levitation?
Quantum Levitation (1 min 56 sec)
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Old Sep 06, 2012, 06:33 PM
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Malaysia, Federal Territory of Kuala Lumpur, Kuala Lumpur
Joined Jul 2012
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Quote:
Originally Posted by rexless View Post
damn, that's a monster! 2200mah @ 11.1v I'm guessing that's damn near a rocket pack? hehe. At that height I think the max width that would fit in the stock tray is 18, maybe 19mm. Anything above that and we'd have to do some serious cutting and move the PCB. I think there's a good chance that 21mm would be thick enough to touch the tip of the drive shaft - at least with the stock motor. I haven't seen the length of the EH200 so if it's shorter then maybe that's not a concern.

Otherwise the weight is significantly more. I wouldn't want to add much weight unless there's really just that much more power to make it insignificant.

Totally off-topic but imagine if we could use quantum levitation?
http://www.youtube.com/watch?v=Ws6AAhTw7RA
We'll surely miss the traditional way of flying a heli...
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Old Sep 06, 2012, 06:42 PM
Brent 黑雁
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Canada, AB, Ponoka
Joined Jan 2012
1,780 Posts
Quote:
Originally Posted by rexless View Post
damn, that's a monster! 2200mah @ 11.1v I'm guessing that's damn near a rocket pack? hehe. At that height I think the max width that would fit in the stock tray is 18, maybe 19mm. Anything above that and we'd have to do some serious cutting and move the PCB. I think there's a good chance that 21mm would be thick enough to touch the tip of the drive shaft - at least with the stock motor. I haven't seen the length of the EH200 so if it's shorter then maybe that's not a concern.

Otherwise the weight is significantly more. I wouldn't want to add much weight unless there's really just that much more power to make it insignificant.

Totally off-topic but imagine if we could use quantum levitation?
http://www.youtube.com/watch?v=Ws6AAhTw7RA
If it would fit, it would work. I actually have one of those coming for my V400.
I'm going to put magnets all over my yard and start freezing my helis. No more crashing for me.
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Old Sep 06, 2012, 06:53 PM
Fly Fast, Fly Hard, Fly Fun
rexless's Avatar
Canada, BC
Joined Apr 2012
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Quote:
Originally Posted by juang1430 View Post
We'll surely miss the traditional way of flying a heli...
Yeah. I bet a lot of people that became good flyers 10 & 20 years ago say that when they see how easy some of the new helicopters are to fly eh?

Quote:
Originally Posted by BThirsk View Post
If it would fit, it would work. I actually have one of those coming for my V400.
I'm going to put magnets all over my yard and start freezing my helis. No more crashing for me.
Battery - hmm... tempted but I'm going to try for something smaller first, unless I can easily step the voltage down to 7.4v for the PCB/tail. I know some guys say 11.1 should be ok but I'm not going there!

No doubt! I guess for now a big screen TV and a hacked simulator would be about as much fun.
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Old Sep 06, 2012, 07:31 PM
Head in the clouds
slothy89's Avatar
Australia, VIC, Sebastopol
Joined Apr 2012
775 Posts
Quote:
Originally Posted by BThirsk View Post
Maybe this one will fit. It's 2200mah. You have to check the 21mm height. I can't remember how much room we have.
Ignoring width, 21mm just won't fit. At absolute max you have 19mm clearance under the stock PCB mount. Some considerable modification would be needed to fit it.
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Old Sep 06, 2012, 10:27 PM
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rexless's Avatar
Canada, BC
Joined Apr 2012
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Quote:
Originally Posted by douglas2950 View Post
The tail takes max 1.2 amp under load, go ahead and order.
I will post a pic from an rc-buggy I used this on to bring voltage down from 16v to 12v.
During the test I went to 11.1 v as well, the increase in thrust was significant and the motor didnt fry.
This is why the DD tailmotors don't work, esky HB fp run on 3S 11.1 lipo's.
Some time ago there was a discussion about using diodes to reduce voltage. Instead of that, I was wondering if a UBEC like THIS, would be suitable. If the tail draws 1.2amp max, then having one battery at a higher mah and voltage could in theory replace 2 batteries and have sufficient power for both PCB/Tail/Servers and ESC-EH200

I'm still very new to all this so I could very well be out to lunch...
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Old Sep 06, 2012, 10:42 PM
Registered User
Malaysia, Federal Territory of Kuala Lumpur, Kuala Lumpur
Joined Jul 2012
90 Posts
Today my f45 main motor has died on its 63rd flight. But I am very pleased with this fantastic bird as I've never replaced anything other than a dead tail motor so far. Thus today after work, I'm planning to drop by at the LHS where I had bought the f45 a couple of months back (won't be too sure if they can remember me well..). They got lots of f45 parts there, and maybe this time I'll buy a complete bnf unit to fulfill my spare part needs..
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Old Sep 06, 2012, 11:02 PM
John
Australia, QLD, Brisbane
Joined Aug 2012
542 Posts
Rexless -
A good idea, but unfortunately the output voltage seems to be 6V max (not enough for tail rotor). A simple adjustable regulator would give the exact voltage, but isn't as efficient. A switching adjustable regulator would require a little familiarity with electronics. The diodes would definitely work, but suffer a disproportionate voltage drop as the 11.1V LiPo fades in use.
Got to be an ideal solution out there!

A simple regulator
http://www.ti.com/lit/ds/symlink/lm138.pdf

A switching adjustable regulator, 5A
http://www.alldatasheet.com/datashee...2678T-ADJ.html
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Last edited by OldOz; Sep 06, 2012 at 11:23 PM.
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