T-Rex700 E-Conversion (with Video)

[Chachin]

Hello guys, time for a new project!

After seeing Bobby's T-Rex700E in action at the Jax R/C heli funfly I thought I needed to try one for myself. It turns out he is carrying an E-conversion kit (http://www.rremodels.com/t-rex700nitrotoelectriccarbonfiberconversionkit.aspx ) specifically made for the new Align T-Rex700 Nitro. So now e-flight with Align's .90 size ship is within easy reach :D. He has been successfully flying his 700E on some powerful 10S setups (see here (http://www.rremodels.com/helisetups.aspx)).

This thread will consist of a photo log sharing my experience while building and flying this ship. I don't expect to have it built quickly, but it will be built at a steady pace. Feel free to share your comments, questions or suggestions as I go along.

I've been wanting to try out a Scorpion motor for some time now so I figured this would be the perfect opportunity. I went with a 4035-500 which is to be powered on TP 12S 3850's Extreme V2. A good old PowerJazz will be used to govern it all. For cyclic power Bobby suggested I try out the Futaba S9452's on 6v instead of the S9252's on 5.1v I normally run. The servo specs sure show that you can get more performance for the same price. So anyways, this should all add up to a very lively setup.

Pictured below is everything I have to get this thing running. A special thanks goes to Bobby Smith at RREmodels (http://www.rremodels.com/) for his support with the components needed and technical knowledge.

Chachin..

Edit: Video (Flight-1) available in Youtube here:

http://www.youtube.com/watch?v=hsA1RWIex1w

Video (Flight-2):

http://www.youtube.com/watch?v=CpM5xN5BHDE

[Dogwoodtheone]

Nice Chachin, looks like it should be a nice project.

[Chachin]

Hey Doug, yeah I'm sure looking forward to this.

Pictured below is everything that comes out of the 700N box. I see that most of the kit is made of metal and CF bits. Some of the things that stood out from this kit was the very clean looking and nicely painted canopy, two CF booms (nice!), a blade holder, an align towel, T/R blades and a torque tube all comes standard. The last pic shows some items that I cannot recognize though... ;).

Chachin..

[SMITHB]

Carlos you will enjoy this machine

Here is a few pics of what it looks like completed

[Chachin]

Thanks Bobby, just what I needed. Those pics will come in real handy once I get to the frame.

The build starts off at the rotor head. It was a nice touch to include the "IN" and "OUT" markings to avoid mistakes during assembly of the thrust bearings. One of the outer rings of the thrust bearings had too small of an ID. I sanded it until a snug fit was achieved, which took care of the problem.

Blade grips installed.

Chachin..

[Dogwoodtheone]

The last pic shows some items that I cannot recognize though... ;).

Chachin..


LOL, looks like very nice kit, can't wait to hear your flight reports :)

[Chachin]

Hehe, thanks Doug.

Flybar seesaw and mixing arms installed. Everything pivots smoothly with no slop. More to come as I continue the build.

Chachin..

[litespeed]

Would it be taboo to ask what the total was for all parts in the first picture pre construction?

My e710 is a great flyer but I keep thinking about another one......

Tom

[Chachin]

Hello Tom, there is roughly 2.7K worth of heli gear in that first pic. I'm still missing an AR700 rx which RREmodels will be shipping out to me this coming week. Like you I was also looking to get another 3D flying .90 size electric to accompany my Ion and JokerCX to the funflies. Good parts support here in the US was an important factor. The T-Rex700 met the requirements but it was still Nitro. The E-conversion RRE sells made it possible. I will report back how I like it once I get some flights in.

Got the flybar, control cage, metal washout base, control arms, swashplate and mainshaft installed. The rotor head is coming along nicely. Notice the flybar rod has two flat spots for the control cage set screws. This not only mechanically locks the flybar to the cage, but it also speeds up the centering of the flybar. Nice touch from Align.

So far I am seeing better kit quality than I had expected.

Chachin..

[Blackrat]

sweet project ...

bobby , any chance of a pic with lipo's in place

[Chachin]

RH linkages, head button and flybar paddles have been installed. This completes the assembly of the rotor head. Up next is the frame.

Chachin..

[SMITHB]

Hi Blackrat

yes i wil post a few pics with lipos installed

[Chachin]

Hello, I was kinda busy last week selling some R/C gear and preparing for the Mulberry heli funfly this weekend. I got to see plenty of T-Rex700N's in action and man they look sweet! Bobby upgraded his T-Rex700E to 12S power and boy was it HOT :D.

Back to the build. As far as I can tell the main gear unit comes preassembled. I checked some of the screws and sure enough they were loctited in place. The main gear has 164 teeth in case you are interested.

Up next is the frame.

Chachin..

[Chachin]

Here is how the frame is looking so far. Up next is the installation of the E-conversion kit. Will try to work on it some more tomorrow.

Chachin..

[Dogwoodtheone]

hey Chachin, how about throwing something in with the picture of the frame so we can get a sense of scale? :)

[RC Man]

Trex 700 EP kit now available http://www.grandrc.com/inc/sdetail/147011



:) :cool:

[SMITHB]

Carlos i see you went home and did some work :)

We put a ton of flights on my 700E yesterday @ the Mulberry funfly

I think Carlos shot some video as well of one of us flying it
More info HERE (http://www.rremodels.com/helisetups.aspx)

[cgbole]

So Bobby, are you running gov mode on the CC controller? after reading a little on your site it sounds like you are...

Looking good there Chachin...
your gonna like it.

chuck

[SMITHB]

Chuck yes i always use the CC gov

[Chachin]

Hey Bobby, I sure got it on video. Check it out in this thread:

http://www.rcgroups.com/forums/showthread.php?t=951530#post10914581

Now I'm really looking forward to finshing mine :D.

BTW, yesterday I went out to see the BlueAngels in action. This was the first time I get to see these jets flying up close. Man it was quite a show! Those jets sure know how to make a presence. The best part was right after the jets did one of their high speed fly-by's the announcer said, "That my friends is the sound of freedom" ... priceless :D

Anyways, just thought I'd share some pics. More build pics are coming up.

Chachin..

[SMITHB]

Hey the Blue Angels flew over us yesterday @ the field

That is to cool

Seen the Video NICE WORK!!

[Chachin]

Thanks Bobby, glad you liked the Vid, it was quite a flight! All right, time to install the E-Conversion kit. The first pic shows the conversion kit contents.

I started off by installing the side plates. I had to start by slightly enlarging the fwd and aft cut-outs on the T-Rex frames to allow the langing gear mounts to fit properly (3rd pic - left). I also had to enlarge the 2 shown bolt holes from the conversion side plates for the stock T-Rex screws to fully seat (3rd pic - right).

E-Conversion side plates installed. From what I see, these side plates are there to re-inforce the fwd to mid section of the frame along the bottom. The stock T-Rex frame re-inforces this lower mid section through the engine mounting.

Chachin..

[Chachin]

The conversion kit installation continues with the motor mount.

The kit brings a guide (first pic) used to drill out the 4 (2 each side) motor mount installation holes on the frame. The guide is bolted onto the frames to show the appropriate hole locations.

Motor mount installed. Doug, attached is a picture next to my Eco-8 for scale. It's going to be a pretty big ship for sure :D.

Chachin..

Important NOTE: This post shows motor mount installed in low position to add a 3rd bearing support mod on top of motor pinion. I ended up flipping the motor mount over to high position (with bend towards the rear - as originally designed) to allow the motor to sit higher with more battery clearance. See Post #63 and #142.

[Chachin]

The last part to install, from the conversion kit, is the bottom plate. This bottom plate has no voids to fully support the rear battery pack. The landing gear must be installed along with the plate.

Bottom plate and LG installed. This completes the installation of the E-conversion kit. The conversion has been very straight forward so far. I'll try and get some more work done this week. Will report back.

Chachin..

[Dogwoodtheone]

LOL Thanks Carlos, that really does put in perspective :eek:

[Philpops]

hey mate,

the motor mount was designed to go the other way around to get the motor as high as posible. This is important because most motor shafts are not that long, and the bending moment of the shaft is smaller.

[Chachin]

Thanks for the info Phil, what you say makes sense. However, I'm going to keep mine this way since it should allow me to run a 3rd bearing support at the top of the motor pinion, like Bobby is doing. He may post some pics of his later on.

Chachin..

[Philpops]

ok fair enough, guess that just means less room for the packs. Lots of guys are using the 4035 on 12s, works just fine without a third bearing.

[Chachin]

That's good to hear Phil since I've read about issues with the Scorpion motor bearings. With the ThunderPower 12S 3850 V2 packs I don't foresee space being a problem. If for some reason it doesn't work out, then I'll flip the motor mount and do without the 3rd bearing. We'll see how that goes.

Elevator and aileron servos installed.

I had to dremel away some material from the elevator servo's case to minimize pressure on the servo's lead at the root (3rd Picture).

I also went ahead and removed the tabs from the Futaba J connectors so they will fit in the AR7000 Rx.

Chachin..

[Chachin]

Futaba S9256 tail servo installed.

This completes the servo installation in the frames. Still need to install the servo horns and linkages.

Chachin..

[DVS1]

Hey Carlos, Mike here, hurry up with your build, I like to see that thing fly. I was wondering why you chose a 4035 series motor instead of a 4025 like what Bobby6 uses. Anyway my builds are going slow...too much work with the real job which impedes on fun. I wonder if anybody has converted an aurora avant to E-power yet. Good build

[heli_addict]

I think the 4035 is the right size for this bird. You will be pulling a lot more watts on this vs. a 600 size heli, and the 4035 should handle it better.

[jamesppp]

I have the 4025 in my E-620 Raptor and it seems perfect for up to this size. My buddy has one in a .30 size Swift that is about ready to fly.

The 4035 will be much better in the .90 size IMO, even though another friend has the 4035 in his V-Bar Logo 600.

[laughingstill]

I have the 4025 in my E-620 Raptor and it seems perfect for up to this size. My buddy has one in a .30 size Swift that is about ready to fly.

The 4035 will be much better in the .90 size IMO, even though another friend has the 4035 in his V-Bar Logo 600.
I bet I know who that is ;) :D The 4035 is an absolute beast in my Logo 600 Vbar. I can't wait to hear flight reports from Robert and his Swift.......Ron

[Cloud Cruiser]

Yes, Someone tell Robert to hurry up and get off his lazy behind and finnish that thing up!!!!!!


Robert

[Chachin]

Hey Mike, good to see you here :D. Yeah I wish I could have it done quicker, but I've only been able to work on it a few steps at a time :rolleyes:. I'm hoping to get a lot done this weekend. Look up MrMel, he has done the "E-rora"... hehe. He posted some impressive videos too. BTW I think Bobby is running a 4035-560 right now with great results as we have witnessed. I went with the -500 so that I can use a slightly larger pinion. I may have to try one of these Scorpion motors in the Ion later on.

Got the cyclic levers installed. I had to shorten up the control shaft to eliminate lots of side to side play (1st pic). Everything rotates smoothly and with no slop.

Chachin..

[Chachin]

We now begin working on the whole tail section. It was a nice surprise to find all the components shown here to be pre-assembled. I checked most bolts to make sure they had been loctited in place.

Chachin..

[Chachin]

Slider, tail rotor hub and control arm installed. Again, everything moves smoothly with no slop.

Chachin..

[Gadget01]

Carlos, your build pics know no rival. Always impressive :)

[Chachin]

Thanks Gadget, I hope it turns out to be a nice build thread ... with good flight results too ;)

Got the torque tube, bearings/dampeners and guides installed. I had to run out to the LHS to get some medium CA for this step. The bearings are glued on the TT equally spaced. The one piece dampeners fit snugly over the bearings.

Chachin..

[Chachin]

Got the tail case and CF fins installed.

The quality and fit of the parts so far is excellent. Everything articulates silky smooth. I have a lot more done but will upload the pictures tomorrow.

Chachin..

[Dogwoodtheone]

... with good flight results too ;)
Chachin..

Well Carlos if it doesn't fly well it's not because of the builder :D

[Chachin]

Hehe.. thanks Doug. It helps when the build is straight forward, which it has been so far. Looks like it's going to be a solid 3D ship. It does have the Szabo and Krause signature on the box after all.

The tail boom is also mechanically locked at the fwd end (see 1st pic). Tail boom mount installed.

Chachin..

[Cloud Cruiser]

Chachin

Great build thread, and this bird is looking awesome!

Robert

[Chachin]

Glad you are enjoying it Robert :D. It's fun from my end too.. hehe.

I like how the tail boom mount snaps into the frame before bolting it down. This means the tail drive gear mesh is fixed.

Tail section installed.

Chachin..

[Chachin]

Got the boom supports, RH and main gear installed.

The kit includes a 0.5, 0.8, 1.0 and 1.2mm spacers to adjust for zero vertical play along the main shaft. I had to use the 0.5mm spacer for a proper fit.

The airframe is now mostly assembled. Up next is receiver, gyro and linkage installation.

Chachin..

[Chachin]

Well since the tail boom is locked at both ends this means there is no room for tail rotor alignment adjustments. The alignment is pre-set, unless I'm missing something.

As seen from the 1st picture, the tail rotor shaft is not perfectly perpendicular to the main shaft. I may have to either enlarge the tail boom hole (2nd pic) or shorten up the stub from the plastic piece to achieve proper alignment. A possible fix could be for Align to offer the plastic piece with the stub offset a few degrees to fine tune.

Did any of you guys with T-Rex700's run into a similar problem? Did you just leave it or adjust it?

Chachin..

[TomC]

Chachin,

Very nice build pics and commentary Mate. Good find on the t/r mis-alignment. I would not fly it like that myself. Personally, I would just dremel off the plastic stub (that goes through the boom hole) so you can rotate the rear tail case properly.

The split rear metal tail case should clamp down plenty tight enough. It's pretty similar to the metal TT one I have on my 600e and it's tight as. If you were worried about it, you could just drill and insert a 2-3mm setscrew through the case/boom.

I'll be interested to see how you think this thing fly's compared to your Ion's.

Best cheers,
TomC

[SMITHB]

Is that the carbon boom?

[Chachin]

Thanks Tom, cutting off the stub all together probably would work fine too. I may try reducing its diameter first.

Hey Bobby, yes this is the CF boom. It brings the fwd slot and aft hole pre-drilled. I will continue building it for now until I decide on something.

Chachin..

[Gadget01]

Thanks Tom, cutting off the stub all together probably would work fine too. I may try reducing its diameter first.

Hey Bobby, yes this is the CF boom. It brings the fwd slot and aft hole pre-drilled. I will continue building it for now until I decide on something.

Chachin.. I believe they key the Swift 550/620 this way on both ends, and this same thing sometimes happens. I would do the same as you suggest- trim the plastic stub just enough allowing you to rotate the tailcase to exactly 90 degrees. It would fly just fine off axis but you wouldn't like the cyclic interaction- tail inputs would give you a slight pitching motion.

[cgbole]

Yep found the same thing on mine. one guy here just took the dremel to the hole in the rear of the boom... I put the metal boom on mine and it lines up fine...
chuck

[SMITHB]

Yea it is there is a lot of talk about the carbon boom not being right

Carlo's what happen to you Saturday??

[Chachin]

Thanks for the info/help guys. I think I will simply remove the stub as suggested. I will report back on how that goes later on. Yeah Bobby, with the launch Friday night and some other things, it worked out better for me to stay working on this machine on Saturday. It's coming along well so I should have it flying soon. Hope you guys got some footage to share :D. BTW guys I uploaded a video of last Friday's spectacular night launch! Check it out here:

http://www.youtube.com/watch?v=U-i_ubpuPoQ

You can see the clouds moving out of the way @ approx the 1:35 mark. It looks more clearly in high quality.

Got the cyclic linkages, rudder control rod and Gyro/amp box installed. I've also been messing around with the placement of the electronics trying to find a good layout.

Chachin..

[SMITHB]

Wow that Launch was incredible wasn't it Carlos

Man the clouds doing the ripple effect was Awesome

The video was good but real life it was Incredible

[litespeed]

Thanks for the info/help guys. I think I will simply remove the stub as suggested. I will report back on how that goes later on. Yeah Bobby, with the launch Friday night and some other things, it worked out better for me to stay working on this machine on Saturday. It's coming along well so I should have it flying soon. Hope you guys got some footage to share :D. BTW guys I uploaded a video of last Friday's spectacular night launch! Check it out here:

http://www.youtube.com/watch?v=U-i_ubpuPoQ

You can see the clouds moving out of the way @ approx the 1:35 mark. It looks more clearly in high quality.

Got the cyclic linkages, rudder control rod and Gyro/amp box installed. I've also been messing around with the placement of the electronics trying to find a good layout.

Chachin..

Is the main shaft 12mm? It looks large to the swash plate.

Tom

[jamesppp]

Nice video Chachin, kind of made me want to head on down to Crossroads for all u can eat Atlantic Brown Shrimp...it had been a few years since I ate there.

The heli is looking good. Its going to be a monster.

[Chachin]

Yeah Bobby, it sounds better in person too. These launches are slowly turning more and more rare.

Tom, yeap.. I just measured it at 12mm :eek:. Noticeably thicker than my Ion and JokerCX's main shafts which are 10mm.

Hey James, is that the one in Titusville? I need to try it out with my gf one day.

I found a spot for the rx and satellite rx. I bound the radio and now I'm in the process of programming the radio and sizing the dual linkages at just the right length.
One question, this is my first time running 6v (regulated). I'm running a Duralite voltage step down for the 611 gyro. I see I can either install it at the servo end or between the rx/gyro. Is there any preference/benefit as to going one way or the other?

Chachin..

[TomC]

Chachin,

I always put the stepdown on the tail servo, not before the gyro. The Fut gyros are fine on up to 6v regulated. Possibly a bit more efficient this way, but there's probably not a lot in it.

Cheers,
TomC

[SMITHB]

Same as Tom just on servo

[Chachin]

Thanks guys, I will also install the step down at the servo end.

Got the cyclic servo horns, dual linkages and tail linkage installed. I had to trim the lower end of the elevator's servo horn to eliminate some minor contact as shown in 3rd picture.

I powered up the servos and verified they are operating properly. Basic swashplate programming is complete.

Chachin..

[Chachin]

Up next is the installation of the Scorpion 4035-500. Here is how it comes out of the box. It includes male/female 4mm bullet connectors, heat shrink, four M3x8 bolts and two decals. Not bad at all. The motor comes with 6mm shaft.

Chachin..

[Chachin]

I ended up flipping the motor mount back to upright for the extra clearance in the battery compartment as Phil recommended initially. Looks like I won't be installing the 3rd bearing for now.

Got the motor installed and gear mesh set. The top view shows the motor screws a bit slanted, this helps minimize pressure on motor wires.

A trial fit of the 12S 3850mAh Extreme V2 packs shows that CG is spot on so far.

Up next is PowerJazz installation.

Chachin..

[missle]

Chachin, like others have mentioned, your doing a great job with this build log. I plan to do a conversion & build following yours (once you've got it tweaked out) in the next couple of weeks.
I was reading in one of the other forums how some folks are having issues with the main gear being too week (not thick enough) and that they're stripping frequently. Have you come across this, and if so how do you plan to fix? Thanks Eric

[SMITHB]

Hi Eric

As Chachin mentioned he flipped the motor mount back over

We have many flights on this machine with a 3rd bearing support with no gear stripping issues using 12s 4200 Outrage packs

I got some pictures of how it is done let me post them

[SMITHB]

This is the upper bearing block

That is a 8mm shaft collar that holds the bearings in place and it pushes up into the bearing block and the other goes in the pinion.

The shaft is made out a 6mm scorpion motor shaft and it works great

[missle]

Hi Eric

As Chachin mentioned he flipped the motor mount back over

We have many flights on this machine with a 3rd bearing support with no gear stripping issues using 12s 4200 Outrage packs

I got some pictures of how it is done let me post them

Okay. So the stripped gear is more an issue of main shaft flex/movement (as opposed to being to thin). Got it. Thanks

[Chachin]

Thanks missle, I'm glad the thread has been helpful. I've heard of the stripped gears as well. I will be keeping a close eye on mine to see how it holds up to my style of flying. Luckily I tend to smooth out the aerobatic maneuvers which should be easier on the gear. I'll report back once I get some flights in. I have to say, I think Align should have gone with at least mod 1.0 gears instead.

Thanks for the pics Bobby, looks like a simple installation. I figured this should work well for now since I don't have all the parts on hand. My goal is to have this thing flying this Thanksgiving weekend :D. Can't wait!

All right I soldered on the connectors to the PowerJazz and programmed it for governor mode and fixed stick positions. These settings have worked real well in my Ion and Razor's PJs, so I hope they work reliably here too.

Chachin..

[Chachin]

Before attaching the PJ to the frame, I went ahead and installed the velcro loop for the batteries while I still had the extra room to work with. The fuel tank guards (3rd pic) came in handy to cover the CF frames' sharp edges along the rear. This should help protect the battery to ESC wiring from damage.

PowerJazz installed. Getting close here :). Will finish it off this week.

Chachin..

[Philpops]

Eric, the stripping of gears is on the nitro version, which is a meshing and alignment problem on the nitro setup. The electric motor mount is quite solid and you can adjust the meshing correctly. I havent heared of any issues as of yet, and many guys are pulling 6kW peaks.
The 3rd bearing block is a good idea, however isnt a necessity.

[cgbole]

I did my conversion a little differently,don't know that i was the first one but
i didn't see anything else around at the time..
But i had a Actro 32-3 on mine with a 15T pinion. And i was stripping gears about every 3 or so flights.It was because of the Plastic Logo 600 mount i originally used (for experimenting only) was flexing and it allowed the motor to move slightly. i've since changed to a metal Logo 600 mount and no more gear problems.
chuck

[missle]

My next question is about the deans. Has anyone tested to see if the deans is reaching it's limits with power flowing at this level? I thought the deans were only rated for up to 70amps (not sure when/where I heard this) and I'm wondering if there's any increased resistance that we aren't aware of because we've always used them and don't know that we're missing that extra power.

[SMITHB]

No issues here

[Philpops]

Genuine Deans are fine, the cheap crappy deans can be quite average. If there was significant power loss, then you would feel the deans quite hot after a flight, yet they are stone cold. I have drawn 85amp average and 160 amp peaks fine with the real deans.

[Chachin]

Missle, I haven't had any issues either with the original Deans in my 12S ships. The most I've pulled/logged is 89 amps peak with my Ion-X2.

I got the tail case aligned properly. I went ahead and enlarged the bottom half of the tail boom hole (1st pic). It actually didn't take much to get the tail case to rotate to proper position. The tail shaft is now perpendicular to the main shaft :). No modifications were made to the plastic stub.

Chachin..

[Chachin]

I decided to go with the included 105mm Align tail blades instead of the 95mm V-blades I had purchased. The longer tail blades should provide stronger tail authority.

Since the tail case is now properly aligned, I went ahead and CA'd the pushrod guides into place.

I got all the electronics in place except for the 2S 1320mAh ProLite pack (on the way from ThunderPower), the 6.0v regulator and stepdown. For now I installed a 4-cell 2000mAh High Discharge NiMH pack to get it going for this weekend. I also got the wiring cleaned up a bit but it's not final yet.

Chachin..

[Chachin]

Got the ThunderPower 12S 3850mAh Extreme V2 pack installed in the frames. I still need to get some proper velcro straps for these.

Since I wasn't sure how much these S9452 servos would drain, I temporarily installed a "VoltWatch" on-board battery monitor to keep track of Rx pack performance in the air.

I took the heli out to field earlier today. I barely beat the sunset but I managed to get it up in the air. Up next is the maiden flight :D.

Chachin..

PS: Canopy still needs grommets installed.

[Chachin]

As seen from the pics I just barely beat the sunset... hehe, but I managed to get it in the air. I first did a 50% power spool up without the main blades to make sure everything was running properly and that nothing was "reversed". I also checked for flybar paddle "tracking" which will need some adjusting.

I bolted on the main blades, spooled it up to a conservative 60% governor and popped it into a hover. The heli needed a few clicks of trim for aileron and elevator and it was rock solid. Main blade tracking looked real good but it wasn't perfect. Since I was low on sunlight I went ahead and flew the machine without further tuning.

The flight lasted approximately 5.0 minutes at a low 60 and 70% governor. Although no vibes were noticed I did see the tail boom wobble up and down at times as if headspeed was a little on the low side, but everything was running smoothly. I landed a couple of times to check temps and all looked good. The flight consisted mostly of circuits and figure eights with some hovering in between. I was impressed with the smooth and straight tracking of the ship in forward flight. Felt just like a .90 should feel. The machine was also nimble (reminded me of the Razor) which hopefully translates to high maneuverability.

So the T-Rex700E has been officially maidened :D. No inverted flight yet since I have to fasten the battery packs more tightly. The 611 gyro also needs to be properly adjusted. I am looking to do 3 flights tomorrow. Will report back.

Chachin..

[pjpg]

when you get it dialed in get some video. I like your smooth flying.

[SMITHB]

Looking good Carlos!! Trex 700 conversion kits are back in stockhere (http://www.rremodels.com/t-rex700nitrotoelectriccarbonfiberconversionkit.aspx )

[Chachin]

Thanks pjpg, I'll make sure I get one posted once I'm more comfortable with the ship and have it dialed in. Below is a short and very conservative "test flight" to get started. Bobby good to hear the conversion kits are back in stock.

I got 3 more flights in today. The machine is flying great so far. I got the blade tracking as well as paddle alignment corrected. Got the 611's neutral point set but it may still need a bit more tweaking. With the extra daylight I noticed the machine is shaking a bit during spool up/down. I still need to install another frame component that helps stiffen up the frame as Bobby recommended.

Below is a short "test flight" video of the 2nd flight. Just some gentle hovering/flying since I was worried about pushing the Rx pack too hard with these servos (2S TP pack on the way) plus the camera was on a tripod :rolleyes:. Hopefully the video conveys how rock solid the machine feels in the air:

http://www.rcgroups.com/forums/showatt.php?attachmentid=2197881

Will post more this coming week as I continue to tweak it and liven it up.

Chachin..

[sneu]

Here is another nice clean T700 conversion that was done by Ray Nemovi. There are few non stock parts used. No new side frames or major mods needed. Ray supplies a new motor plate. It even uses the stock pinion gear from the nitro version. Ray supplies it with the motor--1915H/1.5Y. There is more info on this forum: www.runryder.com/helicopter/t442413p5/

Steve Neu

[Cloud Cruiser]

Chachin ,

Very cool!!! You sure make it look easy.

Robert

[litespeed]

You just get smoother and smoother. You make it look easy.....but it's NOT!

Great build thread Chachin, just fantastic.

Tom

[SMITHB]

Nice Carlos i new you would love this machine

[skijones]

Great build thread, as usual.

Did you have any heat issues with the Scorpion motor?

Great video.

Don

[jamesppp]

I have watched the video 5 times. It looks so easy. just point the nose down a bit and fly off the screen and without even hearing it happen it comes sailing back into view inverted, I love to watch smooth flying.


Great pics, info and flying.

Jimmy

[misskimo]

hey Chin! YEH! you been busy huh? got all the big helis now, One thing about Chachin! He keeps his machines and never sells them, he he ! Now you should try the Joker 3DD! On spooling down it shakes, My trex 600 and when I converted it to a 700 kinda did the same thing, but when shutting it down , I just let it spool down alittle and then added full neg pitch and no shakes

[rcman]

Carlos

Dude it looks very very nice. As aways your the man.....

David

[Chachin]

Don, no motor overheating issues yet. My IR thermometer ran out of battery and I haven't been able to measure it. But after the 3 consecutive (with approx. 15min break periods) 4min flights I've been doing, I can keep my hand on it for a few seconds before it gets uncomfortable. Will report motor temps later on.

Thanks Jimmy, I'll try and get some better footage taken later this month. Also, just thought I'd point out that there is a scene change/transition right before the heli comes back into view inverted at the beginning.

You are right Tony, I tend to keep my helis for a while. I did sell my T-Rex450 in exchange for this 700... hehe. So there was a trade off... sort of :D. I need to sell one or two more helis though. I've actually thought about trying out the Joker3DD in 2009 sometime. Soon I will be upgrading my JokerCX to 12S as well. Then I may sell it to help fund the latest 3DD version. We'll see how that goes. From your videos the machine looks very impressive :eek:.

Thanks all for the nice comments. I'm really looking forward to more flights with this bird.

I received the 2S 1320 ProLite from TP. I cycled it once and went ahead and installed it along with the 6.0v regulator and step down. I got 3 more flights in yesterday and the machine is flying superbly. I guess the heli should be capable of crack moves now (not that I can do them). It's nice not having to re-peak the Rx pack every two to four flights. I should be able to get a couple more flights in today and have it ready for the Orlando heli funfly this coming weekend.

Chachin..

[missle]

Chachin, good to see all is going well and that the final assembly is coming to life. Can I plead for one favor when you're finished and completely satisfied with all the parts and how she flys; can you go back and edit one of your initial post with all the parts that worked (and even those that didn't) so that the lazy folks like me can cheat without having to spend several days reading all the post just to start buying the necessary parts (even though I have followed this one since the beginning).
Second, I see your using the Duralite regulator as opposed to the more common CC one. Have you used this particular regulator before (I'm guessing yes since it's leading the way in your $3K heli)? I am currently upgrading my 600E to the new Align 610 servos and I've been warned about the possibility of the CC BEC not being able to handle the servo/radio systems that are now available, WITHOUT running dual BEC's. I'm told this is because, allthough the CC's are rated for UP to 10A, they can only sustain 5A which could be surpassed with the 610's, 8717's, ect...

[TomC]

Missle,

I doubt that you have much to worry about since you are unlikely to pull a sustained 5A on any 600e setup imop. I've been using the Align 6A regs on my 600e and Ion-x's and they have worked great.

Chachin,

Great review, as usual!

My only concern is that your Rx battery capacity (2s 1350 mahr) seems a bit small. Probably only about the same 'usable' capacity as a 1700-2000 4.8v nicad pack.

I really think you need something like a 2s 2000-2500mahr (I use Evolite 2s2100's myself). I can easily get ~6-7 flights before I need to top off my Rx pack. I'd probably need to top off a 1350 pack after ~3-4 flights to stay on the safe side.

Cheers,
TomC

[missle]

TomC, I'm the same way in that so far I've not had problem running the CC's on my 600 (and others) but that was up till now. I'm concerned with the higher power servo's as well as the load the electric system will have to endure while running a 8S with a sustained HS of 22-2300 (and maybe higher but too early to know). I will definately do some measurement and I'll report back. I know CC has reported that 8717's are pulling more than 2 amps EACH.

[missle]

Well I got the new Align 610 servos in and installed and went to test everything out, and wouldn't you know it, the darn things draw too much current. I'm using a CC BEC with the voltage set at 6.0, the rudder channel empty, and I was testing in high rates. After about 4-6 sec of fast up/down on the pitch (11 deg +/-) the rec (AR7000) would reset and once it started doing this, it would continue to do it after only a couple of seconds from that point on. So I figured maybe that particular BEC had been jarred too hard, so I replaced it with a NEW CC BEC and the same thing occured again. I put a WattsUp meter in line to see if I could measure the readings of which it showed on 3 amps while doing the pitch pumping at 5.8-5.9V.
So, then I used TWO of the CC BEC's (both with most current firmware and settings), connected them in parrallel, and retested. Although it would drop the voltage much less frequently, it continued to do it.
Next I figured I'd better test everything outside of the BEC's, so I plugged my 2S 2100mah bat directly into the rec and there were no problems (other than the servo's reaching a temp of 105-110 deg after about 30 secs of continuous hard pitch pumping). This tells me that the limit is definately in the CC BEC's.
Lastly, I pulled out two of my orginal Align 3A BEC's and connected them in parallel. The good news is that they did absolutely great and after 1 minute of continous pitch pumping, there were no dropped voltage frames. I guess now I'll order one Align's 6A BEC's so that I can use a single BEC (instead of having 2 of the three Amp in parallel).

[Gadget01]

I put a WattsUp meter in line to see if I could measure the readings of which it showed on 3 amps while doing the pitch pumping at 5.8-5.9V. You might have better luck if you supply the BEC power from a 3s pack instead. 2s is closer to output voltage, yes, but they will run more efficiently from 3s and draw less amps to supply the 6v output. You lose some voltage in the switching process anyways- it's never 100% efficient. I used to run my CC bec from a little TP 3s 1320 pack for my Swift (all digi's, 401/9254) and it would last a LONG time- easily 5 or 6 flights with plenty to spare.

[RC Man]

I agree with the 3s comment. The CC BEC has been known to give problems with a 2s LiPo. Although I do think the best solution is a UBEC connected directly to the power battery.


:cool:

[missle]

You know, I never even thought about that (running 3S) but I was actually planning to just run her straight off the 6S main packs (eliminating the rec bat all together) but I when I started having the problems listed above, I threw that idea out the window. It's too late though as I've already order Align's 6A BEC.

[missle]

Holycow! I just tested the system with a single CC BEC and a 3S and IT WORKED! The funny thing is that now it totally makes since. I guess I'll re-wire with the plans of running the CC BEC off of the main bat pack. Thanks guys.

[SMITHB]

Holycow! I just tested the system with a single CC BEC and a 3S and IT WORKED! The funny thing is that now it totally makes since. I guess I'll re-wire with the plans of running the CC BEC off of the main bat pack. Thanks guys.


I would highly recommend not to do that

[Gadget01]

I would highly recommend not to do that You are going to have to elaborate on this recommendation.

Most BECs have an input voltage range of 2s to 6s. High amp draws should have a 3s input minimum. Toward 6s, BECs get less efficient. I'm running my CC BEC on 6s since my last Swift rebuild and it's doing just fine with an AR6200 receiver.

This thread is still on topic, right? :)