Helix Conversion

[jharkin]

Originally Posted by LoveToFly1

now I see a 24T one too! https://www.helidirect.com/align-m1-...0e-p-29558.hdx

I am confused. lol

Notice that this one is straight cut. The pair that I posted above are both helical and appear to be the set we need.

Originally Posted by LoveToFly1

as far as tail grips go, I have several helioption tails laying around I will use one of them. and the KDE pitch slider is the key for no slop there man. the v2 grips work great too, I have them on my 600e. but I cant buy another set of them being I have the others laying around...lol. keep in mind with them they use a different hub/shaft too. not the shaft with the gear on it (drive shaft) the shaft the grips bolt to.

Yes the KDE looks interesting, seems like its a real improvement not just a bling upgrade, and I'm also in a discussion on this topic with Ansy and he is pointing me toward using all the newest align v3 tail parts. All this part hunting is frustrating but also fun at the same time because its like a puzzle and between us we could build 10 of these helix's and no two would be the same.

Originally Posted by LoveToFly1

from what I hear they are about to release a unit with an internal gov, I doubt they are going anywhere....

I hope they do any prompt a bunch of guys to sell off the current model so I can pickup another used one cheap

Originally Posted by rbort

If they all go out of business there will be other things out there to find and try. Its a hobby. Think of it this way, all the airplanes I have in my closet are "out of business" so to speak. Many companies make an airplane and then they discontinue it, so no parts. The normal thing for airplanes is if you crash it you take your motor and all your electronics out and buy a new airframe to move the stuff into.

I know that feeling, describes most of my airplane collection. I had this exact same discussion in the MA going out of business thread.. The ARF phenomenon and GP/Hobbico buying up all the little companies put most kit builders out of business.

One difference though, when I build an airplane kit I just keep the plans and trace the ribs/formers. Working in balsa and plywood its not that hard to repair or even scratch build a replacement wing panel if I have to. If only it where that easy to make heli parts.....

[LoveToFly1]

yea, i got ya man. yes, the kde pitch slider is amazing. i have hundreds of flights on one of mine and it is still just as tight today as when i installed it. the other one isn't quite as old yet so i cant brag on it just yet...lol

yea, its fun, but frustrating at the same time.

[jharkin]

Ok, Ive been doing a lot of research and talking to a guy here locally who flew the Rex 700 for a long time. These are the parts I think will work:


For the head:

• Use the DFC if you like it (v3)
• Else use the full V2 head (I am) - the V2 block has the swash followers and the v2 grips have the detachable pitch arms. The grips with the long balls are v1

For the main gear -
Use the Align 115T M1 ($16) or the KDE 115T M1 ($32)

For the trail drive:
104T M1 auto gear H70G007XX
21T Front drive gear set H7NG001AX
rear drive gear set H70G005XX

For that rear drive we need the latest metal grips that fit on the full thickness 700 output shaft. Looks like either the v2 metal grips HN6103B or the DFC grips H70T001XX will work? Im not sure which is better.

For the tail pitch control looks like the DFC metal unit H70097 or the KDE performance tail unit are good.


Its also been strongly suggested to me to throw out every align bearing and get a Boca bearing kit.

And Ive been warned that the TRex 700 torque tube is known for failures in flight (metal ends come loose) I'm researching if there are fixes.

Looks like the align plastic end boom supports fail a lot as well. fix is to drill and pin the ends, or substitute. Supposedly Rave ENV 90 supports fit, as do the KDE 90 size and probably even Whip supports if you have spares.

[fastflyer20]

Originally Posted by jharkin

Its also been strongly suggested to me to throw out every align bearing and get a Boca bearing kit.

This has not been my experience,but spend if you wish. Boca is just reseller and WAY overpriced for what you get.

I have had just as good "luck" with Avid bearings as any and for $1 each, hard to beat.

Do watch anywhere a 6800zz bearing is used. Not sure why heli mfg like them, it is weak almost no matter where it is used.

[jharkin]

Another thing I noticed. If you look up the same part number in AlignTrexStore.com and helidirect, for some parts you see different photos. Im going by the info on Trexstore as definitive and cross referencing the Align Parts locator.

[jharkin]

Originally Posted by fastflyer20

This has not been my experience,but spend if you wish. Boca is just reseller and WAY overpriced for what you get.

I have had just as good "luck" with Avid bearings as any and for $1 each, hard to beat.

Do watch anywhere a 6800zz bearing is used. Not sure why heli mfg like them, it is weak almost no matter where it is used.

i know they are a reseller.. Ive usually used RCBearings stuff over the years and had good luck at better prices but it looks like Boca has come down alot on price?

The recommendation I got is just that - a recocmendation from a guy I know who flew one for years. I have no first hand experience (other than my T450, those bearings fail if you look at them funny). He said that his 700 mainshaft bearings only lasted 50-70 flights till he switched to Boca. But he does fly a lot harder than I do.

In my case the used donor I got has some obviously shot bearings, so Ill probabyl get a set someplace and replace all the bad ones and hold onto the rest. looks like an entire airframe set runs in the 60-80 range depending on source.

[Azalin]

I used to use BOCA bearings in the past but tired spending. For long time I just use cheaper ones. Realized that bearings are all the same. More or less.

[jharkin]

OK thanks Tom and Suat Im researching and looking at the Avid now and will check that out.

[LoveToFly1]

Originally Posted by fastflyer20

This has not been my experience,but spend if you wish. Boca is just reseller and WAY overpriced for what you get.

I have had just as good "luck" with Avid bearings as any and for $1 each, hard to beat.

Do watch anywhere a 6800zz bearing is used. Not sure why heli mfg like them, it is weak almost no matter where it is used.

thank you for this tip Tom! now, are the ceramic bearings any better or longer lasting than the normal bearings in your experience?

[jharkin]

Ive used ceramic bearings in engines - I have a set in an old OS 2 stroke(modified with ceramic liner and tuned muffler) that I use on a Q-500 pylon plane. That thing spins at 18,000 in the air and giong on 5 or 6 years they are still like new.

I also tried them in a Saito once, but couldn't tell any diff from plain steel.

I think, but dont quote me, they are actually more fragile in a crash then steel so probably not worth for low RPM applications in a helicopter?

[LoveToFly1]

that makes sense though....

I do feel kinda dumb paying so much for bearings in the past now that I see that site....lol they don't have the main blade thrust bearings or the owb for the 700, but they have everything else!

[fastflyer20]

RC-bearings is my back up, the selection is better. However, they are 3x more expensive.
MA actually carried a little better quality bearings, so for critical applications I would pay the extra

I suspect Align is the best source for the OWB, buying in volume helps a lot on specialty bearings.

[LoveToFly1]

yes sir, it absolutely does. im excited about this build. I will for sure be buying most of my bearings there though. I like to keep several main shaft bearings, clutch/pinion bearings, and tail box bearings in my box at all times. I learned first hand how much trouble a bad tail bearing and bad main shaft bearing can affect the entire performance of a heli.

I think I will be toying with a few different motors on this heli as well, just so I can have something to fall back on if something happens to the others.

[cbrkhan]

Originally Posted by jharkin

And Ive been warned that the TRex 700 torque tube is known for failures in flight (metal ends come loose) I'm researching if there are fixes.

Looks like the align plastic end boom supports fail a lot as well. fix is to drill and pin the ends, or substitute. Supposedly Rave ENV 90 supports fit, as do the KDE 90 size and probably even Whip supports if you have spares.

What is the source of this information? I mean, is it only true for align gasser conversions because of weight and vibration and high torque from the motor? Could the failure be from older align kits and not the new ones?

I have the latest 700E and 700N with no problems at all what so ever with TT and boom supports. So I am wondering if I need to watch out for this in a gasser conversion.

BTW I will also be building a Helix soon, I already have the conversion kit. Your research regarding parts is helping me a lot so, thanks !

few things though, you would need two sets of main bearing blocks, one from older trex Nitro (HN7031) and one from older trex 700 electric (H70045 ). The second set acts as a pinion mount. Frame spacers you need are also from older 700E. Order extra as the helix frame flexes in certain places. You can use these spaces to stiffen up the frame as you please. part number is (HN7048). Go with the KDE gear as its a lot tougher the Align.... although I have not herd any reports of align gear stripping under normal loads. Gears stripped in electric models using very strong setups. This is what my research suggests so far. Since I have not started with the build yet, I could be wrong
but I figured I should share

[LoveToFly1]

I have had countless boom supports fail....the plastic ones. Buy aftermarket ones for the gasser man......

Where did you get yout info for the frame spacers being from the elect 700? That wasn't mentioned in the extra parts description, and I ordered additional nitro frame spacers to use. If the elect bearing blocks fit for the pinion, and the nitro bearing blocks fit for the mainshaft, then the nitro frame spacers should work.....right?

[jharkin]

Originally Posted by cbrkhan

What is the source of this information? I mean, is it only true for align gasser conversions because of weight and vibration and high torque from the motor? Could the failure be from

If we are in front of a judge, the answer is "hearsay"

That is to say, I heard it from one guy I fly with locally. I trust him, but do understand its just one guys opinion, nothing more.

Im still researching, and if Im lucky maybe learning something

[jharkin]

Another question I have for those who have built the G700.


Using V2 head, what blades fit with what booms?


The boom I have if the original nitro boom @ 785mm. Will Radix 710s clear? How about Rail 716?

Or would the longer 800mm DFC boom be better?


I know there are umpteen combinations of head and boom so there is no one answer,,, Ill measure the clearance once If got frames but figured Id ask if anyone has thoughts....

[Azalin]

Jeremy,
What you said about the TT ends is true. I had a failure, that the TT end came loose but that was long time ago. Haven't heard or seen this since.

The Radix 710's will fit perfect with the stock 700 boom but I'm not sure for 716's.

[FastRunner]

I've only used 690/105mm blades combo.

I read elsewhere that you'll need to go 115mm on tail to counter forces from the 710mm blades and it's easier to strip gears with those; but I don't have personal experience so others who did used 710mm blades might want to chime in here.

[jharkin]

Originally Posted by FastRunner

I've only used 690/105mm blades combo.

I read elsewhere that you'll need to go 115mm on tail to counter forces from the 710mm blades and it's easier to strip gears with those; but I don't have personal experience so others who did used 710mm blades might want to chime in here.

Hmm. I dont havea lot of experience, but at least for my mild flying I do fine with 710s and 105s on the whip and that has a 4.59 tail ratio.

If we use the 104 and 21 helical tail drive combo on the TRex its giving us a faster 4.95 ratio, so it seems to me like unless its got pitch range issues the tail should be stronger? (what am i missing, i am a noob school me ) I could also swap for the longer DFC boom and get even a little more leverage on that tail.

Actually, now that I look at it, in my lot of used parts the TT I got is not perfectly straight. Its a v1 also. Maybe I should just swap the TT, boom and pushrod for the longer DFC parts.

My "cheap" donor is getting less and less cheap. I see now why people just spend the $$$ to buy all new parts piecemeal