MA Stratus 'Bobby Watts Special' build videos

[jared_of_atlanta]

Sub trim is never a good idea but a little won't kill ya. You can mix out the interaction caused by them with pmixes but I don't know how to do that and it is aparently a little bit difficult to do.

[Mercuriell]

The new head dampers are a PIA to put in but I found using the grips and spindle M4 bold to screw down on them worked OK. Bob and I agree small amounts of subtrim NO big deal and both use it regularly - it's only if you use large amounts and push the servos operating range over its endpoints that you could run into trouble - I don't believe it contributes to mixing.

[WayneBrown]

You didn't use the MA drill guides?
Just drill your own holes in the wheels with the swash tool on, and the drill guide. Zero subtrim, the only trim you'd end up with is CG related.
Haven't watched the vids yet, so I'm reaching..

[Mercuriell]

TUrned out to be a simple cause of the 'mixing' (elevator lag on collective pumping) - while changing the servo arms to Mikado horns found the elevator bellcrank was binding on the head of the M3 bolt (red arrow) holding the left rear canopy mount - the solution was to put an M3 washer umder the left bellcrank spacer and grind off 0.8mm off the right brass spacer - Voila! - fixed :)

[Mercuriell]

You didn't use the MA drill guides?
Just drill your own holes in the wheels with the swash tool on, and the drill guide. Zero subtrim, the only trim you'd end up with is CG related.
Haven't watched the vids yet, so I'm reaching..

Good thinking Wayne for Futaba wheels - problem is JR wheels ain't big enough to get to 20mm :(

[WayneBrown]

Ah, I used some aftermarket alloy wheels... Dont remember who made them though. :arggg:

[EASYKILL]

Hi John, I found these http://www.horizonhobby.com/Products/Default.aspx?ProdID=JRPA236 They would be plenty long enough, but chances are the supplied holes would not be right at 20mm. Also they are pretty pricey, but hey we are building Stratuss so we must be rich!:woohoo I should complete the tail tonight and receive my receiver and throttle servo tommorrow. I am using the new AR7100R, looks like it wil be the ticket. Not sure about fitting the sensor on the back plate along with the pump unit and MA's mounting plate, might get crowded. To work!!
Tony

[gr8t1dini]

Shouldn't the balls on the servo arms go on the outside? My BW Stratus came with alum. bell cranks(a week later they would've been C/F). The bellcranks came with a note saying to install the balls on the outside to prevent the linkages going to the swash from hitting the linkages from the servo arms. I would like to see a video of the radio set-up when you get the chance.

[Mercuriell]

Shouldn't the balls on the servo arms go on the outside? My BW Stratus came with alum. bell cranks(a week later they would've been C/F). The bellcranks came with a note saying to install the balls on the outside to prevent the linkages going to the swash from hitting the linkages from the servo arms. I would like to see a video of the radio set-up when you get the chance.

I don't think you can be too dogmatic about ball position as it depends on your servos, how much packing you use beneath them and also the height of the output arms - on finish up I put ball links on the outside of the cyclic and rudder servos and inside on the elevator - to square up the pushrods and prevent them from fouling at extreme cyclic positions - gotta be a bit of trial and error involved - I'll video the servo & pushrods in my final assembly video which hopefully will get posted tomorrow then maiden over the w/e :shock:

[gr8t1dini]

Sweet. Looking forward to that video. I got motivated the other day and finished it up. All I need to do it the radio set-up and some final tweaking. then she goes airborne!

[Mercuriell]

Finished the build :woot and just posted the final video (http://video.helifreak.com/?subpath=mercuriell&filename=Stratusfinal.wmv) covering boom struts and tail pushrod with an overview and some final thoughts. I have really enjoyed this build - I can't speak highly enough for the quality of the design and engineering (no I'm not MA or anyone else sponsored :nanabobo) - for those who followed the build series THANK YOU :Bliss and hope you found them of interest - might get a maiden flight in tomorrow :wow2: and will video that but don't expect any Massive 3D :fly
PS Thanks to Nora for company while building and final inspection

http://www.helifreak.com/attachment.php?attachmentid=53844&d=1215253471

[gr8t1dini]

Nice final video. One thing I noticed was your throttle servo looked like it was over driving at high and low stick. I could be wrong though.

[bd2312]

Great builds john,

thank you so much for taking the time to do a great set of build vids.

thanks again and cant wait to see the maiden flgiht.

cheers

[Bignose13]

Nice final video. One thing I noticed was your throttle servo looked like it was over driving at high and low stick. I could be wrong though.

Yep I thought that John, you might want to check that out mate.
Great build series by the way, can't wait for the maiden vid.

Simon

[Mercuriell]

Yep I thought that John, you might want to check that out mate.
Great build series by the way, can't wait for the maiden vid.

Simon

Well spotted guys - yes the throttle servo was trying to pull itself out of the grommets. The final video was shot before tune up - found that changing the throttle subtrim affected the end points which I haven't noted before so had to go back and forth between endpoints and subtrim to get it all correct. Makes you wonder whether subtrim on cyclics has similar affect so there may be substance in the NO subtrim argument after all.

Anyway she was trimmed up and maidened this afternoon - no blade tracking adjustment necessary and could hover 'thumbs off'' with no trim adjustments for about 15 secs. I was thrilled - this is my first 90 (excluding a stretched T600) and so awestruck by the grace and majesty of the big bird. Put through 2 tanks of 80:20:20 fuel using red Glowpower oil. Crankcase barely warm at 13/4 main and 1/2 turn midrange - OS 91SZ started and purred away like a dream - thanks to Ben, Wes and Mat for moral support and help getting her airborne !

Final line up:

Bobby Watts Special MA Stratus with OS 91SZ and no8 OS plug
JR 8717 on cyclic at 5.8V from an Align 2in1
Spartan DS760 driving a 9256
Hitec 5965 on throttle - GV-1 at a later date
AUW less fuel 4.7kg

First a quick canopy off hover to check tracking then video of 1st maiden (http://video.helifreak.com/?subpath=mercuriell&filename=Stratusmaiden.wmv):clappp

http://www.helifreak.com/attachment.php?attachmentid=53940&stc=1&d=1215332260

[Caleb.R]

I bet your happy mate... you'll have to come down to Dakka sometime! We'll come up.

[gr8t1dini]

Get one of the newer governor/limiters.

[Mercuriell]

Get one of the newer governor/limiters.

Certainly intend to but as this is my first 90 motor and heli want to get a feel for the throttle curves first - what do you use on your big birds?

[mlucia]

Certainly intend to but as this is my first 90 motor and heli want to get a feel for the throttle curves first - what do you use on your big birds?


Hey John... Try a RevMax. Very simple, cheap and super effective.

Good work on the vids....... now flip that thing in idle up and beat it will ya ;-)

-mark

[Kinger]

Beautiful looking machine. Thanks a bunch for putting together the video of the build. Those of us who have always wondered what goes into an MA build are quite grateful :) I've said it once and I'll say it again, I will own an MA machine at some point in my time in this hobby.

[Laurens]

It isn't as hard as it looks from a distance, its just different.

I sold my raptor and got a fury, with some tlc it flies way better then my raptor. Maybe because I'm more cautious with it too.

[rotorhead58d]

really nice job on these build videos. that is an awesome flying field too. it would have been nice to see a few kangaroos frolicing about in the back ground. thanks so much. :thumbup::thumbup:

[jared_of_atlanta]

I would have liked to see Nora goin' for a ride.

[bd2312]

really nice job on these build videos. that is an awesome flying field too. it would have been nice to see a few kangaroos frolicing about in the back ground. thanks so much. :thumbup::thumbup:


I will make sure we show the kangaroos next time we film. Its always fun herding them up with our helis. Although they dont pay much attention to us anymore.

But john stratus is starting to come alive after a few more tanks yesterday. By the weekend i think it will be really on song.

Cheers

[gr8t1dini]

The revmax is a good governor. I have one in my N9 and Avant FX. I had to buy a tach to check/set the head speed though before MA(model avionics) came out with a calculator for it. I have the ATGv1 in my Aurora. I just got the ATGv3 for my BW Stratus. the Multi-gov is another choice, so is the CSM unit. I've never used the CSM unit. I know someone who has the MG and he swears by it. BW uses that one also.