Century E640 finally done and test flown

[MotorRotor]

Originally Posted by Dennis P

How is everyone's E640,s flying? I bought a crashed e640 to do a stretch build on.I have been wanting to do this for awhile. I will probably try a build thread on it as I think it helps everyone. I can honestly say that my. E640 has been the most trouble free heli I have ever owned. I plan on 690mm and 3300 12s at a lowerheadspeed for a nice light setup with I hope approx 6 minute flights. Take care

Is that the one from the fellow that claimed he did not have adequate T/R authority, which caused him to crash the bird?

If so, check the pins that secures the tail rotor gears (as per the instructions) and see if it was properly secured with the allen/grub screws that go into the end of the shaft. Let me know if it was properly secured.

I would bet it wasn't, and it had been coming out and causing them to inhibit proper rotation and meshing of these gears.

[Dennis P]

Hello MotorRotor yes this is the heli that the fellow never tightened the grub screw that holds the pin in the tail drive gear .The pin slid out into the gears and stripped them. Definently not a gear problem causing the stripped tail gears.Hay we have all done it before

[ngin]

Originally Posted by Dennis P

Hello MotorRotor yes this is the heli that the fellow never tightened the grub screw that holds the pin in the tail drive gear .The pin slid out into the gears and stripped them. Definently not a gear problem causing the stripped tail gears.Hay we have all done it before

Yep, So many seem to find it easier to blame the design, or the manufacturer then to look deeper and find that it was a building error of their own that caused an issue. We see it all the time, not just here but also in forums that concern other brands.

[Dennis P]

Well here are the pieces that I bought from the crashed E640 before I started the inspection and repairs.I have started the pull down and found a few unseen damaged items but all in all it seem's fine.I will start shooting some pics and explaining what I have done as I start assembling the alternative parts that will be used.I am going for a lower headspeed (by todays standards) as I want a nice smooth flying heli with good flight time and light loading.I will be using a Hacker A50-14L 400KV 4500 watt Turnado and a 10 tooth pinion with the helical gears and a Kontronics Jive esc since I have it sitting doing nothing or I would have used a Castle 120HV .The 400KV and the Jive will give me a rpm range of 1600 to 1953 and I am planning a idle up speed of around 1800 to 1850 and a hover speed of about 1650 , I feel that this will be about dead on for me.The Castle does about the exact same setup with a 12 tooth pinion or going to the 470kv Hacker. The heli will be spinning the Rotor tech 690mm FBL blades.I will start testing with a 12s 3300mah setup,Spyder 3300mah 6s packs.I shall be back when I have made some progress and fell free to chime in with question's or idea's as that is what a forum is about. Take care.

[Dennis P]

Well I got some work done on the stretch E690 .The tailboom part # is HW6062GG and the TT driveshaft # is HW6063D and these are the G20 TT parts I am using.I have been playing with 690RT fbl mains and RT 105mm tail blades and there is not allot of clearance but they do not touch! I was going to use Trex 700 boom supports but they are to long and it appears the stock ones may be best.A couple bad bearing where changed due to the crash I am assuming but otherwise all is going well.Hope to get some photos up shortly .
Take care

[Dennis P]

This is the cause of the tail gears stripping out on this crashed heli that I bought.Make sure you tighten and locktite the lock screws in the shaft.

[Dennis P]

As mentioned above you must make a longer tail pushrod for the E690 build.I was going to use a universal Century pushrod kit but being cheap I looked around through my stuff and found a piece of carbon and some central hobbies ends left out of a airplane pushrod kit but I had to open up the inside of the links some due to the threads being 4-40.I cut some small aluminum tube to sleeve over the end to prevent splitting and cleaned everything up with alcohol and then scuffed the surfaces before assembling with JB weld. Just remember to put the guides on before installing the second end! The pictures explain it better.

[MotorRotor]

So Dennis....any flight reports on the stretched E640.....or should we call it the E690?

What battery packs are you using that fit on the tray?

[Dennis P]

Hello MotorRotor no test flights yet.If it would ever get warmer than -20c I would be happy.I have totally pulled the store apart and redoing the walls with more peg board and some new shelving.The stock keeps growing with more product lines.Hope to get the heli back on the bench and some more pics for this thread soon and maybe some flying photos! Take care

[rotorsport]

Dennis did you make your store even bigger?

Are you ready for X-Mass?

I will be back in your area mid January.

Charles

[Dennis P]

I am finally back to working on the stretch E690 and will get some pics up soon.Charles I look forward to your visit in January.I can see a little off your quad sticking out of the snow A nice balmy -38c

[ngin]

Originally Posted by rotorsport

Dennis did you make your store even bigger?

Are you ready for X-Mass?

I will be back in your area mid January.

Charles

No offence intended here, but I think this should have been sent as a PM.

[rotorsport]

My Apologizes ngin, and anyone else I may have offended.

I'll do better next time

Charles

[ngin]

Originally Posted by rotorsport

My Apologizes ngin, and anyone else I may have offended.

I'll do better next time

Charles

Charles, no offence was taken. I just thought I would point out a better alternative for personal oriented posts.

[rotorsport]

Merry Christmas

Have Fun in the Hobby.

Charles

[Dennis P]

The E690 is ready for a test flight .Sorry for the big delay.It was basically all together when things just got real busy and I could not finish the radio setup and final little details.The stretch is very easy and the only thing to really build or alter is the tail pushrod.I just made up a new carbon one as I posted about previously in this thread.I used the factory TT from the G20TT tail and copied the boom as I had extra G20 belt drive booms around and it is slightly longer so it is easy to cut down and ream the locator holes ect..I used the stock tailboom supports. I am going for a smooth flying heli ,not a wild crack machine so I have installed a 400kv Hacker A50-14L with a Kontronics Jive HV all setup and geared for a moderate headspeed range of 1600-1800 areas.I am using my normal Airtronics 94774 servos on cyclic and a BLS251 on tail.I had a full size blue line VBar kicking around so I put it in otherwise it would have had a Skookum 540 .It is a very easy stretch to do and I will let you know what I think of it after I get some time on it compared to the stock E640 with 610 & 620mm blades as that is what I have flown on it.The E690 has the new RT 690 FBL blades on it with KBDD 104mm tail blades.My fingers are crossed just waiting for the wild wind to calm for the maiden.

[distructor]

Looking forward to hearing the report. Love my e640! The guys at the field can't believe how quiet it is with the slant cut gears. Sometimes it's nothing but blade noise.

[Dennis P]

Well the heli did a test hover and then another.It is all feeling nice so far but the blades where starting to ice up from the snow and with the visibility about 150 ft maybe it was back into the shop,but it does fly !!!!! Finally

I brought in some different Quick UK magnetic canopy mounts and have setups that work on the E640 canopys now.Very nice setup

[distructor]

Losing a sight of an airplane in the falling snow... been there, done that. Used to warm the engine under the car exhaust to get it started.

I'd be interested in the canopy mounts. Pictures on a 640?

[karl k]

Very sexy looking!