The Art Tech Discussion

celticveil · Extreme 3D Joined: 04 Mar 2010 Posts: 282

I know Art Tech isn't an incredibly popular brand, but at current time it is all I have, and have easy access to.

I rebuilt my MD500 'Little Bird' upon arrival back to the states. I also constructed custom training landing gear which after 4 successful flights has already paid for itself. Now I am looking at other mods I can do to this mid-range size coaxial heli.

I would like to upgrade motors, build my own battery packs and possibly add a stabilizing gyro to the inside, but since I' still wet behind the ears, don't know if that is possible as hh gyros require a tail rotor, which my coax lacks.

Any of you gear-heads out there have suggestions/methods/ideas/ramblings/mumblings/incoherent speech, give it to me! I need whatever info I can get.

solentlife · Posted: Sun Oct 16, 2011 11:57 am Post subject:

I would think that the Gyro question is a difficult one as generally Gyros on the single rotor jobs are there to control the heading / tail orientation by pitch control of tail rotor.

How you would integrate a HH gyro into your co-ax ?? It would have to intercede in the motor controls ... as Co-Ax's turn by virtue of differential rotor speed.
I would think that the limited turn control you have with a Co-Ax would be worsened by such addition ?

I know this is not what you want to hear ... but I would suggest that if you want to improve heli flight - then maybe it's time to think about moving on from Co-Ax ?
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If you don't crash - you ain't flying !
Fast learning to be 450 Heli Repair specialist !
Have : 2ch Bumblebee,
Co-Ax Syma S006 Alloy Shark
2x Clone 450 SE V2
+ fixed wing stuff ...
Returning to RC after 20 odd yrs away .. Ex Display flyer.

nick_onelove · Posted: Sun Oct 16, 2011 12:05 pm Post subject:

The Xtreme 180 Pro ball-bearing motors for the Blade CX/2/3 might work. I warn you though that they're a pain to get working right, even in the CX3, which they're designed for.

Regarding the gyro issue, the 3-in-1 in my CX3 has a HH gyro built in, so it's definitely possible to have one without a tail rotor.

I agree with solentlife though, I would save my money and put it towards a more advanced, non-coaxial heli.
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Align: Trex 250 3GX + Trex 450 Pro with Vbar
Blade: 450 X, mCP X, 120 SR, mSR X, CX3, mCX2
Esky: Belt-CP X and V2 - Futaba: Heli-Max Axe 400
Walkera: V500D01, M120D01, V100D08, DEVO 8
Spektrum: DX8 - AMA #967873 - IRCHA #4095

celticveil · Extreme 3D Joined: 04 Mar 2010 Posts: 282

I'll get around to getting a better model when I get time and better funding. Uncle Sam doesn't pay very well.

I'm looking at getting a better battery setup. I am having trouble identifying the connector on the charge cord. The connector to the heli electronics appears to be a typical red JST connector.

The charging connector almost looks like a JST-XH, but smaller in width and fewer notches that plug into charger.

Are there generic or after market LIPOS that fit the bill for my heli? The brand name ones cost over 25 bucks without shipping. Is there any way I could build my own LIPO?

nick_onelove · Posted: Sun Oct 16, 2011 12:55 pm Post subject:

There's these:

http://www.xheli.com/83p-950mah-2s1p-74-15c.html

Tombo242 is the man to talk to re: building your own batteries.
_________________
Align: Trex 250 3GX + Trex 450 Pro with Vbar
Blade: 450 X, mCP X, 120 SR, mSR X, CX3, mCX2
Esky: Belt-CP X and V2 - Futaba: Heli-Max Axe 400
Walkera: V500D01, M120D01, V100D08, DEVO 8
Spektrum: DX8 - AMA #967873 - IRCHA #4095

tombo242 · Posted: Sun Oct 16, 2011 4:34 pm Post subject:

Hi celticveil,

Your major problem in building your own li-pos will be finding the cells. As far as T know, they are not commercially available in that size. You would - most likely - have to buy two 3.7V batteries and make one 7.4V out of them. That would not be cost-effective.

The link that Nick gave you is a good one, you could try a search on Ebay or just Google for "2s1p 7.4v 800 900 li-po". I doubt that you will better Nicks' link by much.

The battery that you describe is a perfectly normal li-po. Just ensure that the size of any third-party replacement will fit into the heli, and that the C rating is the same as stock or better.

Tom.
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celticveil · Extreme 3D Joined: 04 Mar 2010 Posts: 282

Tombo242, how do I properly identify the C rating? Its not listed on the battery, just reads "QCPass No. 02". Is this a C 2 rating then?

tombo242 · Posted: Mon Oct 17, 2011 12:11 am Post subject:

celticveil · Extreme 3D Joined: 04 Mar 2010 Posts: 282

Oh wow, thats a pretty sweet deal. Thanks for the link!

What kind of battery would I use if I wanted longer life?

Also, are there other similar helis that I can order replacement blades from, that will fit the MD500?

tombo242 · Posted: Mon Oct 17, 2011 6:56 am Post subject:

Re: longer life.
That's not an easy one. Bigger battery = more weight = more power required to stay airbourne = shorter flight time. You have to match rotor blade to rpm & lift required. Very technical and complex. Your best solution is to stick to the stock weights and size and just get more batteries. That's why I said that I would get 4 of them. Give the motors time to cool between batteries and you have maybe 40 mins in total flying time. Do not run the batteries flat that WILL ruin them.

Re Blades:
I haven't researched this. I have a feeling that your heli is an odd-ball size. The Big Lama blades might work, but I can't be sure. You will have to check the blade dimensions and match to what is available. I have found these blades very good on the BL. You might find a U.S. supplier on an Ebay search.

Tom.
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celticveil · Extreme 3D Joined: 04 Mar 2010 Posts: 282

I found a multi set on ebay for almost the same cost as a single set from xheli. Thanks for the idea, ebay didn't occur to me for some odd reason, which is strange since it's the first place I go to to get nikon or canon equipment for my cameras.

What are some basic mods I can do to help stability and performance? I see a lot of things randomly around the forums but don't know how to decide what the right thing for me would be. I'm not afraid of DIY stuff, as I picked up a host of oddball skills on deployment, things I had no idea I would ever need to do. So I am confident that given the right instructions, tools, and patience, I can accomplish almost anything with this lil' bird.

One thing I would like to do is scrap the body shell that comes with it and construct a wire-frame exterior. I can't find any links on how to do this online, anyone have experience doing this on their heli? I was thinking about using thin carbon fiber rods or ultra thin aluminum rods. Just enough to make a vague outline for a nose/cockpit, cage for electronics and tail section.

solentlife · Posted: Mon Oct 17, 2011 7:45 am Post subject:

celticveil · Extreme 3D Joined: 04 Mar 2010 Posts: 282

Definitely good info to know.

I'm sketching out a wire-frame design for the electronics and body. Basically, I want to surround the electronics in a rectangular frame, maybe give it criss-cross brace support. Four rods would then extend forward to create a pyramid-shaped nose, while the tail section would resemble the MASH tv series helicopter. This would hopefully strengthen the tail section as the current body design in thin plastic with a styrofoam fill.

UPDATE

SO there will not likely be any upgrades or rebuilds...the tail was vibrating yesterday afternoon and snapped completely off the rear, unbalancing the heli and causing it to rotor into the ground, breaking the flybar and all blades. Its too much of a hassle to rebuild a mediocre heli in the first place. So this time the lil' bird may be laid to rest permanently. I'm probably gonna scrap the pieces and sell them to whoever needs them.

nick_onelove · Posted: Wed Nov 09, 2011 10:31 pm Post subject:

celticveil · Extreme 3D Joined: 04 Mar 2010 Posts: 282

My wife actually bought me an E-Razor 450...and its being repaired lol. But at least I'm getting the hang of it faster than the art-tech failure.

Never. Ever. Buy art tech. And I sold the remains of mine on ebay.
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