ALERT :exi aluminum tail upgrade
03-13-2012, 04:37 AM
#1
Senior Member
Thread Starter
My Feedback: (2)
Join Date: Apr 2011
Location: elmira,
NY
Posts: 775
Likes: 0
Received 0 Likes
on
0 Posts
ALERT :exi aluminum tail upgrade
heres a alert for any and all who have purchased the exi aluminumtail upgrade. you find these at hobbypartz, xheli for 29 bucks you cant beat the prices. so here goes a while back i purchased like 5 units and i recently had bearings go out in the tail section so i replaced the whole tail unit. i took it out for a test and about 1 minute into hover checking blade track the heli started to vibrate bad and lost tail control . i set it down no probs inspected and found that back on the tail shaft where the blade grips go onto the end of the shaft with the grub screw they turned down the shaft but never put in a flat spot where the grub screw can set into and not slip. i inspected other tail unit and it had the flat. so if anyone has these do pull off your tail blade grip assembly and put a flat (if it doesnt have one) and go about your biz.
03-13-2012, 04:57 AM
#2
Senior Member
Join Date: Dec 2009
Location: athens, GREECE
Posts: 1,764
Likes: 0
Received 0 Likes
on
0 Posts
RE: ALERT :exi aluminum tail upgrade
Hmm, sure a flat spot would help better not to slip.
But even without there should not slip at all.
The problem is the threadlock if the material is copper.
It hardens too quickly that makes the tightening hard. You think that it has tightened too much but in fact the screw is loose and it may has not even get to the end and only the threadlock makes this feeling.
If there was old threadlock in it and was not cleaned off then it would make this feeling even worse.
Else a grub screw makes so hard contact that it would not slip at all.
You can see the marks a grub screw makes to a shaft.
But even without there should not slip at all.
The problem is the threadlock if the material is copper.
It hardens too quickly that makes the tightening hard. You think that it has tightened too much but in fact the screw is loose and it may has not even get to the end and only the threadlock makes this feeling.
If there was old threadlock in it and was not cleaned off then it would make this feeling even worse.
Else a grub screw makes so hard contact that it would not slip at all.
You can see the marks a grub screw makes to a shaft.
03-13-2012, 05:02 AM
#3
Senior Member
Thread Starter
My Feedback: (2)
Join Date: Apr 2011
Location: elmira,
NY
Posts: 775
Likes: 0
Received 0 Likes
on
0 Posts
RE: ALERT :exi aluminum tail upgrade
well i think they thought the grub screw would dig in enough but it doesnt esp when the tail gets up to speed. even a small flat will help ensure it doesnt slip around the shaft.
03-13-2012, 05:16 AM
#4
Senior Member
Join Date: Dec 2009
Location: athens, GREECE
Posts: 1,764
Likes: 0
Received 0 Likes
on
0 Posts
RE: ALERT :exi aluminum tail upgrade
yes, I agree with you.
A flat spot would make it impossible to slip even if the grub screw was not too tightened.
On the other hand have in mind what I told about the threadlock effect.
Imagine that in my motors which do not have a flat spot the pinion does not slip, even if they have been stressed on some tail boom strikes.
And a motor`s shaft is thinner which is even harder job for the grub screw.
It should not slip even if there was not a flat spot so.
But again, as I said I agree with you. It would need less attention and it would make things better.
A flat spot would make it impossible to slip even if the grub screw was not too tightened.
On the other hand have in mind what I told about the threadlock effect.
Imagine that in my motors which do not have a flat spot the pinion does not slip, even if they have been stressed on some tail boom strikes.
And a motor`s shaft is thinner which is even harder job for the grub screw.
It should not slip even if there was not a flat spot so.
But again, as I said I agree with you. It would need less attention and it would make things better.
