JR 285's and a DS3400G on a PRO: Oh Finless?

[dizzy]

I fly my T-Rex 450 v1 with Hitec HS-65MGs and a Futaba S9257. So, now I'm building a PRO and got talked into the JRs. Like an idiot I bought a 4 servo package for $180.00 and got home to find out the tail servo isn't even made anymore. Everybody talks up JR but I'm down right disappointed and I haven't even got my heli in the air for the first time!

To add insult to injury, when installing them they are too small requiring me to do some mods just to hang them in the heli. Their leads are too short, making me angrier by the moment. Now as I put on the links to the swash the stupid rods are pointing outwards from the servos towards the swash like they're pigeon toed. I'm starting to think these JR support'n pilots are full on you know what! Even the damn package is ticking me off with its silly claim to give you ".90 Heli Feel"... whatever!

Now I'm reading the packages comparing them and the Hitecs are stronger, faster and have metal gears. Beside being digital, what have I bought? Where do these folk get off on JR?

Maybe Finless can shed some light on this... I feel ripped off!!!

[dizzy]

I've decided to toss the JR crap! Going to the Hitec HS-5065MG (the digital ones) and a Futaba S9257 driven by a Futaba GY520. I would advise AGAINST JR on the T-Rex PRO!

[stg099]

I think it's a stretch to advise people against servos you have never even flown IMO. The length of the wires and the specs on paper can easily be made up for in precision feel and centering ability when testing a servo "by the sticks"

While I"m not partial to any servo manufacturer ( I fly all of 'em in different birds) I don't think it's fair to call something crap that you've never even gotten in the air.

[wmartin38]

I have flown with both the HS-65MG and the 285MG.. the 285MG are way more precise and don't chatter. I have had dozens of crashes with the 285MG's and never have had to replace a servo on 3 different heli's. Yes they are smaller but I didn't have any issues installing the 285MG on my Trex 450 V2. and it is Really smooth. the HS-65MG is not a digital servo but both are good servo's and should serve you well. I know you are talking about a PRO and maybe the spacing is different on that, I don't know. There are lots of people around here who fly with the JR's and don't have any issues.. a shorter cable just means maybe you need an extension.

just my 2 cents and it probably doesn't amount to even that.

[huskynox]

285's and 3400G....? Those are old.

Try 287's and a 3500G! Awesome combo! I think the 287's are the fastest mini out there at .07 @ 6v and the 3500G is just plain awesome! The 3400G doesn't even compare to the 3500G.

As far as fitting the JR's to the Pro...in my opinion this is Aligns fault. They built the Pro to run Align servos which is complete BS!

I had to modify the Pro quite a bit to get the front 2 287's to fit properly. I machined down the main bearing blocks 1.5mm, made a spanwise carbon doubler to cover that stupid gap (half moon) between the 2 servos, then made some small carbon hold downs for each servo bolt. Quite a lot of work, but the thing is awesome! I've never flown a 450 with servo's this fast.... one word "awesome"

As far as the short wires... I got mine to work no problem with an AR6100 reciever. The servo leads are the exact same length from a 285 to a 287.

Clean wiring:





Modified Main Blocks:





287 mounted to the outside of the main bearing block. Cut unnecessary carbon from frame to do this. Nice straight shot from servo horn to swash



Internal wiring. AR6100 is sitting on a small 3/8" balsa wood spacer I made, with foam tape on top and bottom. I also machined away a small amount of the motor mount where the servo wires cross over the top....basically taking away the sharp edges.

Also, where ever servo wires cross carbon, I chamfered the carbon to be sure of no wire chafing.

[xf100t]

Whoa whoa whoa. First of all, the DS285MG's may be older and a bit slower. However, they have more torque than the 287MG's, so it's not a total downer to have 285's. The 287's were designed somewhat for the Blade 400 in mind as a drag and drop upgrade meaning they're a bit smaller. The servo slots in the blade 400 require filing for HS-65MG size servos. Also, the difference in speed between the 3400G and the 3500G are what, .02 of a second? Yeah it's a little better, but not much.

Plus, don't take out your anger on other people just because you are ignorant. JR servos are great, I've used them in my Blade 400 and they completely transformed that machine (though I still sold it). You just didn't know what you were buying when you bought it. Don't blame a manufacturer just because you can't read.

[huskynox]

Actually the 285's and 287's share the exact same case. The gear ratios are different, this is what gives the 287's speed and takes away torque. The 287's are rated at 16oz each which is plenty for a 450. 3 servo's on the swash equals 3lbs total torque. The speed of the 285's is .14 @ 6v, the 287's are .07 @ 6v. The 287's are twice as fast! If you're doing any kind of 3D manuvers you can definitely tell the difference. I've flown both and I can tell you I personally would never go back to 285's for 3D flying....... It all depends on what you want and how you fly.

Now, with the 3400g and 3500g, I'm running 6v, which JR reps have said is fine as long as you're regulated. So, I'm guessing the 3500g is more like .06 vs .09 of the 3400g. That's a 50% increase which is HUGE. Believe me, I've flown both on the exact same models and the difference is night and day. I've had 3 450's and 2 500's with 3400g's, once I flew the 3500g I swapped them all over to the new 3500g and sold the 3400g's.

You have to look at percentages, not total transit times. .02 seems minor, but if the orginal transit time was .04. that's a 100% increase.

[caotri]

Hi, Do we readly need to mod the frame for putting the 285 servo on?

[xf100t]

Yeah, but the difference is between .09 and .07. I don't know what the 3500G is rated at 6V, I assumed that the ratings I was looking at were at 6V. Also, I used the 287MG in my testing, and I would acknowledge that the difference in speed between the 285 and the 287 is a lot. I would be interested to see the difference between the 3400G and the 3500G though, the speed difference just isn't that much, though percentage wise it has maybe 25% improvement in speed.

[xf100t]

Originally Posted by caotri

Hi, Do we readly need to mod the frame for putting the 285 servo on?

Yeah, you do, there's another post on this sub-forum showing how huskynox did it.

[fflier9]

Well I put JR 285's on with no mods...?

I think JR servos are excellent by the way, they are extremely accurate and the precision is great.

There is almost no noticeable interaction on the swashplate compared to the align servos, when you pumped the collective the swash rippled like a wave.

[dizzy]

Originally Posted by xf100t

Plus, don't take out your anger on other people just because you are ignorant.

Such a strong statement, sir, especially since you don't know me or my flight experience.

I think huskynox answered the question and the frustration with a solution. I am still very disappointed with the JRs but now squarely on their price point. After matching the photos of huskynox's mods I'm happier with the setup but since I mounted the ESC on the side and radio under the battery I'm still trying to find a better placement for the wire from the elevator servo.

As to the actual flight attitude with the JRs compared to the Hitecs, well, simply put; In high speed turns (full left or right bank at 90 and hard up or down on elevator) and extreme pitch reversals the Hitecs win hands down. I suspect its due to the torque and nothing to do with speed or accuracy of the servo. My 450 v1 w/Hitecs performs almost as good as the 450 PRO with JR in these situations. Other that that I just think the 450 PRO rocks with whatever you put in it

[xf100t]

Originally Posted by dizzy

Such a strong statement, sir, especially since you don't know me or my flight experience.

Well let me apologize then, maybe I jumped on you a little too hard. It's just that almost every post in this forum from you seems to be attached with a sentence meant to be... controversial. Maybe if you'd proof read your sentences before you post you'd realize some of your posts make you sound like a jerk.