What to do with 'ol rexy 700?

[shannimal]

Guys, I have a 700dfc pro perhaps V3? I have some pictures to help figure out which one I have. I never really fly it much. I think I have 23 flights on it. I was contemplating selling it but recently I shipped a small 9 pound box that cost me almost 40$ for ground. Last heli shipped a few years ago was 75$ so I'm thinking at current inflation that shipping may be over 100$. My current thoughts are just to upgrade mine and keep it.

1st area of concern. The tail ratio and the stupid hum. I don't fly at crazy smack HS. I like 1850 to 2000ish on a 700. I was wondering what is the best choice of gears so that I don't get soft tail authority? I know they have some new versions but I don't know if they are for the smack guys or the normal HS guys. Lastly are they compatible with my heli?

2nd area of concern. My dfc head (don't mind the rust on my linkages, I live by the beach lol). Never the less I would like the new version with followers. I do know that there are all sorts of main shafts of different lengths and what not..at least it seams that way. I would need a shaft that is compatible with the gears and head of course, but which one?

3rd area of concern. The tail boom, its too short. I thought back in the day people used nitro booms because they are longer? Not for sure on that one. Never the less it would be nice to run up to 720 although 710 at least blades, and longer tail blades without a problem. Longer tail blades would help with authority if the tail is spinning slower. Lastly if I get a longer boom wonder if it will still fit in my Align 700 bag? Seems tight already in there.

I've attached some pictures to identify my version. Align seems to unleash a new 700 bi-annually these days lol.

[Dennis Everett]

put the new Align tail blades on it ,if flying hard 3d , change out the head , if not, dfc is ok ,double side tape the boom support clamp to the boom,and fly it , great heli ...

where do you fly ? we fly on 7th st in rancho cucamonga ..

[Keyrigger]

The difference in the boom between the DFC Nitro and the E/DFC is 15mm. The nitro is only slightly longer. You loose the use of the bag if you go to the 800 boom but you would be able to run your choice of blades.

The main shaft will solely rest on the main shaft you end up using. There are a few different lengths that I have found and most can be made to work with a standard swash drive system. The really short DFC shaft might be a challenge to find a swash driver for that will allow the swash plate full travel but my own way would be to get the next length up shaft and then any swash driver for the older FL series will work. The only thing you will need to do is measure the distance from the swash ball to the grip ball in order to get the correct length turnbuckle. There is no point in going with standard links since turnbuckles have made tracking adjustments very easy to do. No popping off of links any more.

The tail ratio is something that you can either live with the lower gear ratio or look for the 4.5:1 parts. I only know the 550/600 parts but there is a similar issue especially when going to scale rpm ranges. A long time helicopter pilot suggested to me that the ideal range for a tail rotor is between 8000 and 9000 rpm. A 2000 rpm head with the 4.5:1 ratio gives you 9000, right at the top of the optimum speed range. 3.85:1 gives you 7700 rpm, just short of the ideal range but not far off. When you get a tail going more than 9000 rpm, it becomes very twitchy and is difficult to tame down with the gyro's sensitivity settings. If I could find a 5:1 ratio, I'd be all over it for my scale helicopters but in that absence, I use longer blades. It may not be much help but hope you can get it to work.

Don

[nynextel88]

You can lower the tail gear ratio to the new 4.43 ratio by utilizing the 102T auto gear and 23T drive gear. If you keep your standard boom with 115mm tail blades you will still probably have decent tail authority. However keep in mind it may even cut it close with Align 700mm blades. I would stick to 690s if you have them.

If you decide to swap over to the longer DFC boom, you would need the boom, torque tube and tail control rod to run up to 720mm blades however it would be close with 115mm tail blades, so you may want to keep the current ratio (4.73) with 105-106mm tail blades.

Parts for Nitro DFC boom:
http://www.aligntrexstore.com/700N-D...AX_p_4457.html
http://www.aligntrexstore.com/700N-D...XX_p_2188.html
http://www.aligntrexstore.com/700N-D...XX_p_2175.html

If you wanted to upgrade to a standard FBL head with swash drivers you can pick up just the kit H70H002XX and the only other additional item you would need would be the main shaft H70H003XX

So, http://www.aligntrexstore.com/700FL-...XX_p_2832.html

and http://www.aligntrexstore.com/700FL-...XX_p_2831.html

Your model is a 700E DFC. Most parts from any of the DFC lineup / 700L will fit your model. You already have the upgraded frame braces.

You would be all set with the above if this is the route you wanted to take. Good luck and yes definitely keep it, great flying heli!

[shannimal]

Originally Posted by Dennis Everett

put the new Align tail blades on it ,if flying hard 3d , change out the head , if not, dfc is ok ,double side tape the boom support clamp to the boom,and fly it , great heli ...

where do you fly ? we fly on 7th st in rancho cucamonga ..

I appreciate the boom clamp tip! Depends on what I'm flying. I was originally part of the Carson group with finless and everyone. Actually through this site before finless ever made a video I reached out to him because he lived in Stanton and I just bought a knight 50 nitro and didn't know crap about anything, saw he had one, and bam!! I'm still at it all these years later lol. Anyway it was there, then at Seal Beach with the guys from RC Depot. After the last Helifreak that was in Escondido or wherever when everyone partied a little too hard and got all crazy the scene just fell apart. I think that was actually the hay days for us in socal and since then its just not been the same.
Back to where I fly now. Well if its a 250 practically anywhere right? I have 250, 450l, 550 (the old school V2), and my 700 in flying condition. Depending of where I find the space I will choose appropriate sized models for the areas I can find to fly as they are scarce in OC. What has spawned this new interest in my 700 is actually the Traxxas xmaxx. A buddy and I got a set of them and they are just crazy dope trucks. We are going to be camping in Ocotillo Wells. We are going to be bashing our trucks and I want to fly my 700 when I go out there. I figured I'd show the old lady some love and spend some money on her lol.

[intelectual]

Originally Posted by Dennis Everett

put the new Align tail blades on it ,if flying hard 3d , change out the head , if not, dfc is ok ,double side tape the boom support clamp to the boom,and fly it , great heli ...

where do you fly ? we fly on 7th st in rancho cucamonga ..

why change the head if flying hard?

[shannimal]

Originally Posted by nynextel88

You can lower the tail gear ratio to the new 4.43 ratio by utilizing the 102T auto gear and 23T drive gear. If you keep your standard boom with 115mm tail blades you will still probably have decent tail authority. However keep in mind it may even cut it close with Align 700mm blades. I would stick to 690s if you have them.

If you decide to swap over to the longer DFC boom, you would need the boom, torque tube and tail control rod to run up to 720mm blades however it would be close with 115mm tail blades, so you may want to keep the current ratio (4.73) with 105-106mm tail blades.

Parts for Nitro DFC boom:
http://www.aligntrexstore.com/700N-D...AX_p_4457.html
http://www.aligntrexstore.com/700N-D...XX_p_2188.html
http://www.aligntrexstore.com/700N-D...XX_p_2175.html

If you wanted to upgrade to a standard FBL head with swash drivers you can pick up just the kit H70H002XX and the only other additional item you would need would be the main shaft H70H003XX

So, http://www.aligntrexstore.com/700FL-...XX_p_2832.html

and http://www.aligntrexstore.com/700FL-...XX_p_2831.html

Your model is a 700E DFC. Most parts from any of the DFC lineup / 700L will fit your model. You already have the upgraded frame braces.

You would be all set with the above if this is the route you wanted to take. Good luck and yes definitely keep it, great flying heli!

Great information and thanks for the links to the parts. Using your information above how does this sound? The new gear set, nitro boom, 115 tail, 710 mains, at 1850 to 2000 HS what should I expect from my tail? Oh and ps will get the angled gear so the tail blades aren't close to the ground.

[HeliLust]

Love my old trex helis. With a bit of creativity with newer parts and updated electronics they still rip the sky apart just the same as some of my newer helis. I still fly my sev2 a lot only now it has EFL FBL head, 360 stretch, pro canopy, 470 skids and modern electronics. It's still a favorite of mine.

It's more of the same story for my 250 se. Now it's very light though and lost 100g of weight. I also have an older 700n I've been getting back up to date. It's getting 700x skids and EFL head and the works.

Possibly the best part of the older trex helis is they are so plentiful, cheap, spares are everywhere and with a bit of research easily upgraded. I see some listed in the classifieds cheaper than busted up blade micros.

[Atomic Skull]

Originally Posted by nynextel88

You can lower the tail gear ratio to the new 4.43 ratio by utilizing the 102T auto gear and 23T drive gear. If you keep your standard boom with 115mm tail blades you will still probably have decent tail authority. However keep in mind it may even cut it close with Align 700mm blades. I would stick to 690s if you have them.

If you decide to swap over to the longer DFC boom, you would need the boom, torque tube and tail control rod to run up to 720mm blades however it would be close with 115mm tail blades, so you may want to keep the current ratio (4.73) with 105-106mm tail blades.

Parts for Nitro DFC boom:
http://www.aligntrexstore.com/700N-D...AX_p_4457.html
http://www.aligntrexstore.com/700N-D...XX_p_2188.html
http://www.aligntrexstore.com/700N-D...XX_p_2175.html

If you wanted to upgrade to a standard FBL head with swash drivers you can pick up just the kit H70H002XX and the only other additional item you would need would be the main shaft H70H003XX

So, http://www.aligntrexstore.com/700FL-...XX_p_2832.html

and http://www.aligntrexstore.com/700FL-...XX_p_2831.html

Your model is a 700E DFC. Most parts from any of the DFC lineup / 700L will fit your model. You already have the upgraded frame braces.

You would be all set with the above if this is the route you wanted to take. Good luck and yes definitely keep it, great flying heli!

You could also use the 700X head, this is the head that they are shipping on the 700L V2 but the taller head might be better if you're more into F3C and big air type flying.

There are four FBL heads for the Trex 700, the names are unofficial and just something I use to distinguish them.

Original 700FL head with separate swash driver base.

700FL V2, basically same as V1 but with intigrated swash drivers.

Both of the above use plastic radius arms HN7016 and control arm set HN7124 and originally used mainshaft HN7010-1 on the Trex 700E and Trex 700N which is a bit taller than the "700FL" shaft for the 700L. (the overall lenght is 1mm shorter but remember that these helicopters lacked a third bearing block)

700FL V3, shorter hub, plastic radius arms are also 2mm shorter. This uses control arm set H70H007XX, the plastic radius arms are not available separately. Also the aluminum arms have a slight cosmetic difference (the edges are chamfered instead of sharp, you need a magnifying glass to see this) You can use HN7124 with this head if you lower the swashplate by 2mm.

All of the above use mainshaft AGNH70H003XX on the Trex 700L

700X head, even shorter than the V3, the upper two M4 screws are replaced by another through bolt and the lower bolt is rotated 90 degrees on the hub so it won't interfere with the swash driver links. The new swash driver arms are red and the plastic arms are much shorter (these are sold in a 4 pack separately now but for a while they were not sold separately). The mainshaft for this head has the same dimensions as the DFC shaft but has a through hole at the top instead of a threaded hole. It is still labeled as a "DFC" shaft but the part number is H70093A. Some dealers have gotten these mixed up, if it has three jesus bolts and no M4 screws it's the correct one.

The 700X head is the same height as the DFC head. the 700X head and the "V3" 700FL head ship with rock hard plastic dampers which will need to be replaced if you want a softer more traditional cyclic feel.

[Number]

Atomic, are these the arms you mentioned are not available?
http://www.aligntrexstore.com/700X-R...XX_p_4771.html

[Flyingzook]

Deleted

[nynextel88]

Originally Posted by Number

Atomic, are these the arms you mentioned are not available?
http://www.aligntrexstore.com/700X-R...XX_p_4771.html

2nd to last paragraph he did post that they are available

[Number]

Ah ok, didn't see that. Cool beans.

[Thestructured]

The new Align 106mm tail blades eliminate the hum problem. Do that instead of changing gears maybe.

I'm not sure why change the head or anything since the heli flies well as is. I don't think a new head will change anything really.

The 700 DFC frames are still sold currently as the 700L v2. I know that many of us are just bored with seeing this same heli everywhere, but it's a good, solid machine.

Put a speed fuselage on it or something to make it look new :]

That's what I did for mine.