OV-1 Mohawk by Blackhorse..

[AWM]

Hello 'leccy forum!!

 

Well, I am building a OV-1 as you will see from the title. I have ordered some Turnigy motors and servo's... a whopping big 3s 5000mah Li-po and a charger. I am looking forward to building this! Just wondering, has anyone else built one of these? Seen one?

 

So I have 2 Turnigy aerodrive motors.. C3536 - 1450

A 5000mah 3s 20C Li-po.

2 otter bs40A ESC with BEC 5V / 4A

 

Thats the kit I have bought for it. I will keep you all posted with the build, flying etc.. But please feel free to comment on the stuff I have. Electric is new to me... so I will prob be asking lots of questions! 

[Tim Mackey]

Dont know the model AWM - and without knowing things like AUW etc its hard to comment.

Couple of things....

1) How many servos are you likely to use - as a single 4A BEC unit on the ESC is not much - especially as the 4A is possibly only a peak value rather than constant.

2) Those ESCs have not had good reviews, and yu may want to think about going up to 50A ESCs anyway.

OK just done a quick google and found it - looks nice !

My only concern is whether those motors will possibly slightly too high a Kv - on a 10 X 6 prop ( recommended for the model )  you may find them drinking more Amps than they can safely handle....may be best to drop down to a 9 X 6 and see what the meter tells you.

You do have a wattmeter dont you 

Edited By Timbo - Administrator on 13/02/2010 09:16:25

[AWM]

A what meter?  lol..  Thats next on my shopping list. I have seen a few, can you recommend any particular one? I anticipate the build will take most of this week, I will order one for next weekend.

 

So, the Kv - I take it lower is better?  The esc's to be honest didn't cost very much, so if they are no use I will order up some better ones. As this is my first foray into leccy' it was a bit of a shot in the dark!

 

Do the amps then provide the torque and the Kv the rpm? Something like that?

[Tim Mackey]

I like the Astro flight "Whattmeter" - Others I am sure will be fine too

Lower Kv will swing a larger prop with a bit more torque.

Its the BEC on the ESC that worries me - I suggest a separate UBEC for more than 4 servos. Giant Cod do several - 5A or so is plenty.

Sort of yes..... you just need to ensure that whichever prop you intend to use does not ask the motor to pull motre current than its happy with  - hence the meter.

[winchweight]

AWM, I am away from home until next weekend but I have this model. Although it's a bit cartoon like, the performance is superb.It climbs like a home sick angel. I have a seperate rx battery in the nose to help with trim, I also replaced the hatch locking mech as the plastic bolts are very fiddly espec with cold hands.

 

 I have also added an airdrop option to mine and I am in the process of modifying it to make it a bit more scale, starting with the pilots.

 

Drop me a line next weekend and I'll let you know what motors etc I have in mine.

[winchweight]

 

Edited By Shaun Chant on 13/02/2010 19:55:09

Edited By Shaun Chant on 13/02/2010 19:58:37

[Matt Halton]

Looks great Sean, it's fun adding detail to models isn't it? I was tempted to buy one of these ages ago, but couldn't really justify more expense, but it looks nice though.

 

Matt

[winchweight]

It is nice but there are quite a few things to change. I am debating scrapping the u/c and dolly launching. I am going to fit the rudders, external stores and drop tanks ( to protect the props on belly landings) and finally repaint and badge it.

 

I love the unusual shape when its on approach!

[AWM]

Excellent Shaun and thankyou..  defo look forward to that - compare notes!  I bought this fairly cheap off eBay- as a new and unopened kit - my first dabble into leccy flight. I agree it is quite cartoon like... but it did look like great fun! I see some of the yanks have these models repainted and badged etc to look more authentic. Some nice ones on their sites.

[winchweight]

Glad you like it. I bought mine off eBay for £100 fully built with motors, esc and batteries (2 x 2500mah 3S lipos used together in parallel) so didn't get the chance to repaint it. I would strongly recommend repainting and modifying it before you assemble it. You can get someone like Pyramid to make up whatever decals you desire.

 

The pilots are from Pete's Pilots on ebay and I modified one so they weren't identical.

 

I would also strongly recommend using a UBEC for the rx or better yet a seperate rx battery which is what I do.

 

You will very quickly get bored of the little screws that hold on the battery access hatch, which whilst inventive, are a real pain. I went with a simple spring loaded canopy latch instead.

 

I broke one of the lateral fuselage formers that sits across the top fuselage just inside the battery bay. Doesn't seem to have made a jot of difference though.

 

I rarely use the flaps when flying it as they just make it go up really quickly, it climbs like the space shuttle with them deployed.

 

More over the weekend I hope.

Edited By Shaun Chant on 16/02/2010 09:16:33

[Djay]

i built one about 9 months ago, and still flying it.

It uses the Quantum 2814/06 motors, with 10x6 props. Power is from two 2500 3s battery packs, one to each motor.

I have a seperate 4.8v 1000mah battery for the receiver.

 

it flies very fast, but it turns horribly as it has 3 fins and no rudders.

I recently scrapped the fixed gear and fitted a set of lightweight pneumatic retracts. It looks so much nicer in the air then with a fixed gear hanging down.

 

Ensure you have plenty of speed on take off as it will tip stall .

Landings are a doddle with the flaps down.

 

Darryl

Edited By Djay on 16/02/2010 09:30:52

[winchweight]

Never had an issue with it on takeoff, but agree about the turns, hence I'm fitting rudders. Any chance of some pics and details about your u/c installation as I dismissed it because of the lightweight skinny wing?

[Djay]

No pics at the moment. I used lightweight plastic framed retracts, Robart sell some.

 

You do not have to cut open the wing, as the fixed gear mounting blocks are quite substantial, and I mounted the retracts straight to these. The nose I mounted in front of the fwd bulkhead, retracting rearwards, and just fitted 2 heavy duty hardwood mounting rails from the bulkhead to the front frame where the nose cone glues to.

No problems so far.

 

The tank is at the back of the fuse cutout , under the servos.

 

Will try and get some pics but my daughter has my camera so I doubt I will ever see it again.

 

Darryl

[winchweight]

What about the wing retracts? Did you cut themm into the engine cowlings?

[Djay]

the retracts are mounted inbd of the cowlings, using the original fixed gear hardwood mounting points.

The gear retracts inwards towards the fuselage, with the cut out for the wheels just outboard of the in board wing rib (the one that fits onto the fuse side).

 

the gear is very short with small wheels, but it is only aprox 1cm shorter then the original, and provides plenty of ground clearance.

 

Darryl

 

[AWM]

I have installed a 4.8V battery for the Rx.. Put it way up in the nose to help balance it. Looking forward to getting flying!

[winchweight]

Mines is a 6v in the nose as well. What else are you doing to it?

[Djay]

I put two 2500, 3s batteries in the nose either side of the centre battery compartment, and a 4.8v 1200mah square r/x pack just fwd of the wing spar, and it balances fine.

ESC's are in the nacelles.

 

Some quick pics of the retracts.

 

Areas around the gear have not been finished off yet to tidy them up.

 

 

[winchweight]

Have you flown it with the retracts yet? More importantly have you landed with them?

 

I ask because I really worry that the wing is not man enough for retracts, but I could be persuaded otherwise.

[Djay]

it has flown many times with the retracts.

they operate just fine, and are plenty strong enough for the tarmac runway I use.

Then again it depends how hard you land.

For a grass field I would suggest wire legs the same gage as the original fixed gear.

 

the original fixed gear mounting blocks are very heavy duty and take as much impact as a set of retracts. No mods at all to these mounts done.

I mounted the gear direct to these blocks.

 

It looks so much better in the air.

 

the retracts are made by Hoyle, and were from Hobby King.

 

[winchweight]

Good stuff. I fly from tarmac as well so I'll have a look for these retracts.

[AWM]

That looks really good!!  Mine is totally standard, for now. I have just finished building it and I am pondering the best way to install the power train. I have the motors on and deciding where to put the esc's. I was going to put them in behind the motors in the nacelles. I see you use 2 batt's. I have one, and a separate Rx battery - as many have suggested.

[winchweight]

I have installed the escs in the nacelle, just behind the motors. As I understand it, you can lengthen the wires from the esc to the battery, but the wires going to the motor should be kept as short as sensibly possible.

 

I do use two batteries, but I have linked them together in parallel using a home made Y lead, so in effect I doubled the capacity but made two batteries into one 3 cell 5000mah  lipo.

 

When I plug it in, I only connect one pair of leads as though they were one battery.

[AWM]

Ah I see... I have one 3s 5000mah LIpo and 9x6 props. What kind of wire did you use to lengthen the esc wires?

[Tim Mackey]

Its actually the opposite Shaun - long wires to the battery is a potential ESC killer.

Tut man have we taught you nothing