Roban AH-1W Cobra 700 Size Scale Helicopter

[sfcfury]

I actually cut an inch off of my skids... going into the frame and the actually 'skids' lol. I've been looking at the 800 size AH6 (and there's a white navy OH6)... they just look so tall to me... like the skids seem dis-proportionally sized. Yea I saw that you had flown yours as well! I swear these roban kits should be labeled as 'you will need to purchase a dremel tool'!

[DCORSAIR]

DC I was tinkering with you AH-6 lil cousin/old ancestor lol... I have a 500 size I have been doing up as an OH-6... I put speakers in the bottom etc lol.... I did okay with the tail... I'm satisfied lol. I see some of the guys take banana peels and a piece of Styrofoam and make an exact duplicate of a cockpit!! I just don't have those kinda skills


Not too bad considering it was a Magnum PI kit lol.

Love it, looks awesome, I kind of do wish Roban would have done the big 800 AH-6 with the short skids like yours, but I don't have the skills to shorten them and I actually do like the tall skids on the regular Hughes 500, there are some AH-6 with the taller skids, I guess I have the rare version, flew it today actually.

[DCORSAIR]

I'm using the the heavy nylon ones that came with my servo's... I can't fathom stripping those big nylon ones in scale flying... never ever gave it a second thought to be honest... but again I'm very far away from being a subject matter expert. I use the AR7210 Beastx myself... I have it on 3 heli's thus far and it does what I need it to do.

Great, glad you like your Ar7210, I have heard nothing but great things about it, I use Futaba so it won't work for me, I'm no expert either and was having a hard time getting rid of my flybared scale helis but now that I went to the FBL 800 size helis and started with the Microbeast, I really like them, once I get more experience I will try another unit, the Microbeast turned out to be easier than I thought setting it up.

Can't wait to see your Cobra in the air...

[sfcfury]

DC I was tinkering with you AH-6 lil cousin/old ancestor lol... I have a 500 size I have been doing up as an OH-6... I put speakers in the bottom etc lol.... I did okay with the tail... I'm satisfied lol. I see some of the guys take banana peels and a piece of Styrofoam and make an exact duplicate of a cockpit!! I just don't have those kinda skills


Not too bad considering it was a Magnum PI kit lol.

[sfcfury]

I'm using the the heavy nylon ones that came with my servo's... I can't fathom stripping those big nylon ones in scale flying... never ever gave it a second thought to be honest... but again I'm very far away from being a subject matter expert. I use the AR7210 Beastx myself... I have it on 3 heli's thus far and it does what I need it to do.

[DCORSAIR]

Thanks, DCORSAIR! In 40+ yrs of ac flying I’ve never had an inflight servo arm failure, but have stripped servo gears in crashes. I’m pretty new to helis but my take on the necessity for metal servo arms must be focused on high control forces, or the concern for slop developing in the ball link shaft hole in the plastic arm. I’m inclined to stick with my nylon arms most especially since I’ve installed ‘em already.

Had to change my electronics checkout plans today due to the fact my Demon 3X FBL requires a PC connection before startup, and I don’t own a PC. 🙄

Yeah, I now have five flights on my big bird with the nylon servo horns, have to say though, I think they will be just fine really, this thing flies so scale, big and slow and even though I know there is force on the controls horns, they only move just a little, very little movement is all I have to fly scale, I don't plan on flying 3D with it but I would maybe feel a little better if I had the metal horns, so I might order some or just keep flying it the way it is. I'm using the Microbeast 5.0 in my AH-6, works great, tail holds solid and you don't need a computer or anything to set it up, only thing is, it helps to have it mounted in a place where you can get to it if you need to program it, mine is actualy hidden once I put the cockpit back in but I have it all dialed in, so no need for adjustment so far and if I need to make any adjustment, 3 screws and I can get to the Microbeast. I like the Microbeast so much I put one in my 800 Magnum PI version that I am building now.

[PawPaw]

Thanks, DCORSAIR! In 40+ yrs of ac flying I’ve never had an inflight servo arm failure, but have stripped servo gears in crashes. I’m pretty new to helis but my take on the necessity for metal servo arms must be focused on high control forces, or the concern for slop developing in the ball link shaft hole in the plastic arm. I’m inclined to stick with my nylon arms most especially since I’ve installed ‘em already.

Had to change my electronics checkout plans today due to the fact my Demon 3X FBL requires a PC connection before startup, and I don’t own a PC. 🙄

[DCORSAIR]

Guess I better change out my servo arms if that is the case, I bought my 800 Roban AH-6 already built and flown with everything installed and the guy had the plastic servo horns all hooked up so I just used them not really thinking about a failure, guess I better order some metal ones soon.

Now get on that Cobra build.

[PawPaw]

Sfcfury, what’s your opinion on metal servo arms? I have them on my 3D Extra but only because of the length required. My Cobra arrived today & I read Roban specs metal arms. My servos are all metal gear digital HV, so I certainly will order the metal arms if nylon ones are the “kiss of death” to a 700 heli.
My thoughts (prob incorrect) are that a nylon arm could fail before the servo gears in a rotor strike, thereby providing some level of servo protection. Whatcha think?

[PawPaw]

Haha.....I ordered the heli yesterday morning (27th). Motion confirmed shipping in the afternoon. Just their regular free shipping. I ordered the Scorpion today.

[sfcfury]

You ordered it this morning and it will be delivered tomorrow? Holy crap batman! You must've gotten the super delivery service lol...

[PawPaw]

You were absolutely correct! I tried the numbers on ecalc & they were close to yours. I ordered a Scorpion HK-4035-560 instead. FedEx says my AH-1W will be delivered tomorrow, so I’ll just occupy my time detailing until components arrive. Looks like I’m out of luck on the CC Talon 120 as everybody seems OOS.

[sfcfury]

Well now, don't take my word as the gospel lol... I fired up the castle link software and this is what it says: 500kv motor set at 1250 is 86.3% on the ESC, 1300 is 89.8%,1350 is 93.2%, and 1400 is 96.8% . So 500kv will get the job done... just my personal preference to have a lil more room on the top end. Hey, I'm a copycat of Rcjetdude, I asked him what motor he was using on his 700 apache.... I went and checked them out, and just wanted to give this motor a try. I also have a scorpion motor. There's definitely more experienced guys on here that could throw their two cents worth in as well.

[PawPaw]

Thanks! I’ve started another cart at Motion this morning & was about to order the 500Kv along with a Talon 160 ESC w/cooling fan. They’re out of stock on my ideal choices & I’m a little concerned this COVID-19 will crimp their resupply efforts. I figured 1350-1400 HS about right for scale flying but have read some folks flying 700’s at 1250 about the same weight. I’ll go look at the TENGU’s.....ok to call me copycat!

[sfcfury]

IMO, I think the Kv should be in the 515 to 560 range... Especially if you are going to try to use the ESC to set RPM... it will give you some overhead, but you will in the 84-94% range of the ESC. I am using the talon 120 and a 515Kv motor, and set my head speed to 1400rpm, which puts me at 94% on the speed controller.

[PawPaw]

Motion recommended the Scorpion HK II 4235-630Kv but it’s OOS when I ordered. Roban manual says 450Kv - 600Kv. I’m looking at the Scorpion 4235-500Kv. Your input here is most appreciated!

[sfcfury]

Sure glad to find you! I ordered my AH-1W 700 this morning & will be my first heli build. Motion was out of stock on the recommended motor & ESC but did have the servos & gyro. I’ll be watching closely & hope to pick your brain!

Welcome aboard PawPaw! Definitely ask any question you have, b/c there are lots of knowledgeable people (not me!) on these forums. I would say look at any of the Roban build pages, especially the 700/800 ones, as the mechanics are very similar... and you will be surprised the tips/tricks you will find scattered throughout various discussions. This was my first 'big' build (it's big to me!) as well as first belt drive heli. Probably the best advice I can contribute on the build is to watch the belt tension when you set up it up. You can definitely over tighten and cause yourself other problems (ask me how I know lol). I found this video after the fact, and even though it's in German, you get the jist of what they are doing and saying.

https://www.youtube.com/watch?v=iEqE7KebqmY

What motor were you looking at?

[PawPaw]

Sure glad to find you! I ordered my AH-1W 700 this morning & will be my first heli build. Motion was out of stock on the recommended motor & ESC but did have the servos & gyro. I’ll be watching closely & hope to pick your brain!

[sfcfury]

sfcfury If you don't plan on moving the figures much, you may want to consider using Mod Podge to help stiffen and tighten the flight suit. In the past, I have used Mod Podge to stiffen fabric and get it to lay "flatter" onto large 1/6 scale pilot figures, such as the excellent ones made by www.Warbirdpilots.com. Mod Podge is brushed on with a brush and dries clear with a slight sheen. It's basically thinned white glue, that dries stiff but still somewhat flexible. The idea is that the hardened Mod Podge helps the flight suit conform more realistically to the body instead of looking "puffy".

Experiment with a doll from the Dollar Store or on a scrap piece of fabric, to learn how best to apply it and how to hold it in the shape you want while it dries.

'Just an idea.

I will have to try that... although the don't look to puffy, my pilots are actually too tall for the cockpit; both of their helmets are touching the canopy. The pilot was really bad, i trimmed his seat down and shaved a couple mm's out of the wood were his seat attaches. The gunner i didn't touch at all... if I would have shaved his seat down like the pilot's, it probably would have been perfect for him. What works in my favor is the fact in the real helicopter, the pilots take up a lot of the space/look big as well.

[Alpha]

sfcfury If you don't plan on moving the figures much, you may want to consider using Mod Podge to help stiffen and tighten the flight suit. In the past, I have used Mod Podge to stiffen fabric and get it to lay "flatter" onto large 1/6 scale pilot figures, such as the excellent ones made by www.Warbirdpilots.com. Mod Podge is brushed on with a brush and dries clear with a slight sheen. It's basically thinned white glue, that dries stiff but still somewhat flexible. The idea is that the hardened Mod Podge helps the flight suit conform more realistically to the body instead of looking "puffy".

Experiment with a doll from the Dollar Store or on a scrap piece of fabric, to learn how best to apply it and how to hold it in the shape you want while it dries.

'Just an idea.