Open Tail Box Tail Gears

[wattybotts]

Hey y'all

I am planning on converting from a Rappy 90 SE to a real machine. lol

Fury Extreme baby! :thumbup:

The kit I am interested in does not come with the open tail box (buying it from a friend). Is it worth the extra $150 or so to get the open tail box?

I also hear, from different sources, that the gears are a bit weak and are breaking in flight. Does this have any truth to it? Also, whats this about the tail shafts as well? I hope these are not true, it looks like a great design.

Thanks
Bobby

[Dr.Ben]

Gears: Black ones had isolated failures. The new grey gears have been trouble free. MA will replace them out FOC on any box has the black gears.

Tail shafts: Problematic in the gas models. The shafts have been OK on glow models. MA will replace the shafts FOC on boxes that came in Spectra kits.

I think the box is worth the cost, esp since you'll be able to soon get one with the new parts. It's great to not have any mesh worries or lubrication schedules, plus the gears are SO smooth and quiet.

A reasonable option is for you to run the box that comes with the model you're buying, then get the open box when the time comes to redo the tail gears.

Ben Minor

[wattybotts]

Thanks Ben for the help.

I am getting a great deal on the Fury so it might be a good idea to get the box right from the beginning.

Any assembly tips you all recommend when putting the new box on?

Sorry if these are repeated questions

Thanks,
Bobby

[Joel Mann]

Is this a old kit?I thought all the knew kits came with open tail gear box..
Yes, its well worth the extra 150. if it doesnt come with it.As Ben said,the gears are very queit..

[EricLarson]

The box is very robust. Ben hit is all on the head. There where a couple gears that had MFG problems, so a change was made and the gears are now gray in color to ID them. It is very nice to be able to see the gears before flight. I have over 300 flights on the open gearboxes with absolutely no issues. I am happy with the design and improvements.

[wattybotts]

Hey Joel and Eric

Yes, this is an older kit. My buddy has had this sittin on his shelf on his "to do" list for awhile now.

I know it is a few months old, so its relatively new. I think I might cough up the $ and get the open tail box. It sounds like its worth it.

Now what to do about the clutch!? :dontknow

[Russ McC]

Now what to do about the clutch!?

I read the hole thred you never said any thing about the clutch. What's the question :?:

[WillJames]

One thing not mentioned in this thread about the open box is that I have heard multiple people who just installed the open boxes and made their first flights say they could tell a difference in auto performance and overall engine/heli performance(power) due to the open box being so free with less drag than greased gears/closed box. Some of the people I can remember saying that when they first got prototypes boxes from Tim are HC, Matt Botos and Clint.(Expert Pilots) Your flying is to the level of you could probably tell the difference as well Bobby. You ROCK man!

The open box also simplifies construction and maintenance. Not that the metal closed box is hard to use, but there is a method to setting the mesh correctly and you have to keep it greased with synthetic hydrogen grease periodically. The open box is factory built, so all you do is bolt it on and go at build time, with no further mesh maintenance required, just inspections.

[wattybotts]

Thanks Will! I appreciate all the help. The open tail box is the way to go.

Russ... sorry for the confusion.

This Fury comes with the older style clutch, not the bigger one. Is it worth it to send back the older clutch and get the bigger one?

[WillJames]

I have no idea about the clutch, but to help people who do, Bobby is an up and coming young Hard 3D pilot. :shock: His video from B-Ham is at the link below.

http://www.helifreak.com/about5674.html

Rock on Bobby, you are going to LOVE the Extreme!!

[Russ McC]

No you don’t need the newest clutch, the one in your kit will work very well for a long time :glasses2:

[wattybotts]

Thanks Russ and everyone else for the help. Damn... this site is SOOOO much better than the dark side's over there on RR. :lol:

Hmmm.... I'll consider the clutch upgrade. So I take it that the bigger clutch isnt necessary?

Bob

[3DME]

Hello

The clutch issue depends on your flying style. Conrod had a clutch issue with his extreme. If you flew smooth it was fine, but when you started banging and using abrupt collective movements the clutch would slip. With the governer on we noticed a wah wah wah sound when banging and Conrad thought it was the clutch. We checked this by flying the heli smooth and checked the temp of the clutch bell with an infrared gun, it was around 95 degrees after 3-4 min. Did the same after 3-4 min of banging and the clutch read 135 or so. With the big clutch the temp is about 90 degrees no matter what you do. Hope this helps. you can contact Conrod for more info.

Mike

[Russ McC]

So I take it that the bigger clutch isnt necessary?

Hi Bob,

I have had very good luck with the Fury Extreme clutch arrangement. But I have no problem with getting the newest bestest components either. What ever you choose will work very well :glasses2:

[wattybotts]

Aight.

Considering all this gives me a headache!

3dME, I met Conrad at Birmingham this year and talked to him about that a bit. Thanks for bringing that point up again, forgot about that.

Russ,
Since it is NIB, I might as well send it back and get the new clutch. It might save me from some headaches in the future. :arggg:

[Dr.Ben]

The tough thing about the smaller clutches is that some wil run a LONG time with few issues, and some will slip or spin out a liner in much less time. It is critical that the clutch to bell gap be kept quite close. 0.006" per side is about the most you want to have. I was setting mine at 0.005" and letting the head drag a fuz at idle. While 3D guys work on the clutches with heavy pitch pumping and so forth, I was pushing mine very hard because of the taller gear ratios we use for F3C. 7.75 puts a wicked load on the clutch. As described, my clutch bell would be really hot at the end of a flight, even if the gap was held close. The other variable that is a bit harder to evaluate is the exact clutch shoe spacing such that both shoes engage equally and spread the work. You can surely tell when this point isn't as it should be because one shoe will often be more blued than the other.

I see no problem with your using your smaller clutch parts for now, but you might save yourself a lost day of flying on what Murphy would predict will be the nicest day of the season if you go ahead and put the HD clutch in from the start.

Ben Minor

[wattybotts]

Yea.... Im getting the kit tomorrow and ordering the new clutch tomorrow as well. Anyone want an old clutch? :mrgreen:

Thanks everyone for the much appreciated help.

Bobby