Broken 32-3 shaft

[Scrub]

Actro 32-3 shaft broke in mid-flight. I've got probably around 60 flights on it. Gear mesh was right on. Running TP 8000's with 100-100-100 on my throttle curve. Is this a weak link or did I do something to cause it?


http://www.helifreak.com/album_mod/upload/0d3b606d3629b6e5689813b277cbc36e.jpg

[hjscm]

did this break today? bad luck with this heli this month.
chris

[Scrub]

did this break today? bad luck with this heli this month.
chris

hey Chris, it broke earlier this week. Tuesday I think.

Too bad this isn't a single piece.

[misskimo]

hey , I thought you said it was the heli version motor, he you could ream out the coupling to 6mm and have ChrisS produce a shaft with a 6mm end

Tony

[misskimo]

and buy a steal coupling for it and do away with the aluminum hub

[Russ McC]

Scrub,

Is that the 5mm or 6mm shaft? If it is the 5mm then do what Tony said if it is the 6mm then damn!

[BobbySmith]

From the looks of it that is a 6mm shaft already!!.I run one of each a Heli version and a airplane version and i yank on both pretty hard. The only differance iam seeing is i run the Extreme upper bearing block so the pinion can set in it nice and flat. Also i run 100,95,90,95,100 for curves
I havent broke a shaft since my converted predator max
:smokin:
Bobby

[MinAirChris]

Hi Scrub

Sorry to see that, call me today and I'll get another shaft out to you. Those are made from steel that is hardened to a Rockwell 60...hard to believe a little motor could twist it off... :roll:

Do not ream out the Actro coupler as this will leave very little wall thickness for the set screw. I would recommend the steel adaptor though as yours is the aluminum and I have seen a couple that were sloppy or got that way after running.

Chris

[Scrub]

Scrub,

Is that the 5mm or 6mm shaft? If it is the 5mm then do what Tony said if it is the 6mm then damn!
It's a 6mm on the top but steps down to 5mm to fit into the actro adapter. It broke at the point where it steps down to 5mm.

[Russ McC]

Chris,
Sounds like you changed your thinking on reaming the adapter, when I tried this motor 6 months ago you said to ream the adapter to 6mm. I have the steel adapter and reaming it worked good and still left enough threads to leave the set screws flush with the outer surface. I’m no mechanical engineer but 5mm isn’t going to work for long the way some of these are being flown, especially a 6mm shaft stepped down, this is very bad and will break every time. The twisting load wont do it by it’s self but adding the lateral (bending) load caused by the gears trying to move apart and it is just a manner of time tell it fatigues and breaks. I hate to question you Chris and mean no offence, please don’t take any. These are the main issues why I did not stick with this motor; no manner how you set it up it seems like a compromised situation. The Heli version and the shaft system you came up with for it is slick and far better then any thing that can be done with the aero version.

Scrub
I still have my adapter, steel reamed to 6mm, I will send/give it to you if you want to try it.

[Scrub]

We need a 6mm version of this with a longer shaft:
http://www.helifreak.com/album_mod/upload/c55cf5475da4f77c94a09210fb7d790a.jpg

Doesn't seem too hard to make but I guess demand wouldn't be high enough to produce these for the ION :(

Hey Russ, thanks for the offer. Chris is going to send me a new shaft. I just give that a try.

[misskimo]

hey , Scrub . that shaft you got there , I ended up getting 2 of those before I recieved 2 of the right ones , 6mm is a good idea , why cant we use that ? Chris
hey have any of yall ever had a hacker go wide open with just cracking the throttle , like to 1/8 th throttle , Bobs heli with the hacker motor went nuts on him this morning , went to a headspeed from hell , (damage) , frames, landing gear, batteries ,

Tony

[Scrub]

hey , Scrub . that shaft you got there , I ended up getting 2 of those before I recieved 2 of the right ones , 6mm is a good idea , why cant we use that ?

The one pictured is actro part number 261. The shaft is only 5mm thick and only 40mm long. Need 6mm thickness and long enough to go through the upper bearing block.

[Russ McC]

Hi Tony,

Yes I have had them go to the head speed from hell!!! Like 2500 I bet!! The rotor in the motor has slipped timing probably, had this happen a couple of times.

Always start the motor from a stop by engaging idle-up, this guarantees you a soft start. Moving the stick to 25% will often bypass the soft start then if you not careful it can come up in a hurry and scare the hell out of you :arggg:

[lucky]

My snapped also but cris has worked it out for me and I believe this new one is the ticket. Heres a pic of the moter case after we got the sheared bolt out

[BobbySmith]

Lucky which upper block do you have?

Bobby

[MinAirChris]

Bobby, these should all have the double upper bearing block.

I agree Russ, as long as the adaptor is steel. Reaming the aluminum one will leave too little material though.

I have run those myself for a long while in 6/5mm step form and never had one twist. Bobby is still running one that way. I think as long as there is a double upper bearing block to support the shaft it should be O.K. And everything runs true.

Chris

[Russ McC]

Soundes good Chris :glasses:

[lucky]

Double upper bearing block sounds good I dont think I had one when it snapped. Cris The one you sent me today , does it have the double block? Thanks (Lucky)

[lucky]

would a small tac weld and strength to this area?

[ChrisS]

Hi Lucky

Yes, the one I sent out to you today had a double block, I will never allow a single bearing block to pass through my hands again. I don't think a weld is neccessary, making sure of good alignment is. When you re-assemble the motor, make sure everything runs true. I'm sure you did the first time around, probably just a fluke that it broke.

Chris

[BobbySmith]

Good deal Chris i wasnt sure if some guys were using the single block

Lucky what i do is put the pinion up in the bearing and make sure it is square also i make sure it is square wiht the main gear and i tighten the block and then i go down and tighten the motor mounts last

Bobby

[Scrub]

Chris, I was using the single block.

Not sure if this is relevant or not but, the bottom CF plate seems too thin to mount the outrunner on. It allows fore/aft flex with minimal effort.

[lucky]

Thanks guys . Oh getting off suject here is a canopy my daughter just painted for me.

[misskimo]

damn , well the fury has a single bearing block , time to find my double , thats probably the reason why mine wollered out the shaft adaptor frange , thanks for the tip and a a posible crash in the future , sure hate to replace all the titanium in the fury , the motor shaft is 5mm , so I hope it dont twist that off ,