Open Tailbox v Closed

[Zilly]

I know the open tailbox was done to death a few months ago and I decided to stick with the closed box on my Stratus conversion until I was confident that the wrinkles had been ironed out. I have not seen any threads recently to suggest the open box is still having problems so I am now considering changing over.

The reasons I believe the open tailbox may be an improvement are as follows:

1 - Runs Quieter ?
2 - Weight (open weighs less) ?
3 - easier to work on ?
4 - cheaper to repair ?
5 - lower parts count ?

Can anyone confirm if I am correct in the above assumptions.
Weight is of real interest mainly cause a few grams on the tail can translate to a few ounes up front and I am on a mission to lower the weight of my Stratus as it needs a diet!

I do find my Stratus to be quite noisy when compared to other 90's and I reckon the plastic tail gears will run more quietly is this the case?

Any feedback would be gratefully received

z

[X]

Not agree with you on #4.
x

[wingtip]

we use the open box'es on our scalers running 4, 120mm blades and have had absolutely zero failures... i havent ran one on a 3d'r though..... just giving you some feedback in our situation... the open box fits in a more narrow spot than the closed box which is why we use it mainly....

[ChrisLaFollette]

The output shaft, and both gears run about $35 from MA. They usually get destroyed in a crash on the tail whereas metal gears would probably stand up (never crashed a closed box).

All in all id say go with the Open box with the latest output shaft with DIMPLES/SETSCREWS not HOLES/PINS through the gears/shaft. I wouldnt hesitate to run the latest shaft/gears on even a gasser. Ive had NO problems with my open box with the latest gears/shaft. It does run quieter and autos better and turns way smoother. Set the gears so you have barely any mesh, fly it for a few tanks, set em again after they break in so you have hardly to no lash at all again and fly the darn thing and not worry about a thing. I love the open box and I wouldnt change to the closed one for anything as mine has been working flawlessly. :glasses2:

Good Job MA! Two thumbs up! :thumbsup2:

[DavidH]

#1. Seems to be a little quieter.

#2. The open box actually weighs more than the closed gear box.

#3. Still has to be taken apart like the closed box.

#4. Metal gears and the plastic gears are about same cost.

#5. Same parts in both. Couple of gears and bearings. Also spacers and collars.

David

[ClayK]

What was the issue with the open tail box on the Spectra?

[DavidH]

Some of the open boxes on the Spectra were breaking the output shafts at the bearing. There is still some of the Spectra's also still running the original output shafts in the open tail box.

The original output shaft had a hole thru it where the pin for the gear went thru it.
Now all the out put shafts are dimpled and the out put gear is held in place by set screws.

David

[Gary O]

MA has it written on the package for the open tail boxes to run them on nitro and elec only. At least on the ones I have. All 3 of my Spectras have the closed box and haven't had any problems.

This past Sunday I was flying one of my Tempest FAI's and noticed a vibration in the tail that had not been there before. After checking everything I could think of I took the tail shaft out and it had some runout in it that was causing the vibration. This heli hasn't been down or even landed hard so I'm not sure what caused the shaft to do that but I replaced it and it's back to being silky smooth again.