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jayfrs · 04-22-2012, 11:44 AM

Hi Guys,

Got a tail wag with my protos i have changed FBL controller and tail servo and it hasn't gone away with either, nothing is bent i have checked and its running a great head speed so thats not an issue. i run it witht he blades of on the bench and there are no vibes on it.

I have noticed this with the tail assembly is this right??

Many thanks

scott s · 04-22-2012, 11:52 AM

disconnect the tail pushrod from the servo and move it back and forth by hand. If it is not smooth as butter or any binding at all find the source and fix it. You can't tighten the bolts in the links to the blade grips to much or you will get severe binding. Ball links not sized will cause binding. If you over tourqe the bolts in the tail case it will bind etc. etc.

I just realized that is a video you posted and no that is not normal at all. Are you sure you have 2 bearings in each tail grip and they are seated all the way in the grip. The main shaft works perfect to seat them in. Or you do not have the bolts tightened all the way in the grip to the hub. I have found that the bolts get harder to tighten as they go in on a few builds. Gotta be one of the above

scott s · 04-22-2012, 12:05 PM

ps. Or you used the wrong bolt in the grips to hub (to long) and it is not seating against the bearing on the open end of the grip!

jayfrs · 04-22-2012, 12:06 PM

Cheers for the reply, the bearing are seated! I bought Heli second hand and rebuilt it! But I didn't look at the tail before I stripped it maybe the them screw got tight but I need to drive them in more! I will give this a go!

CrashAddict · 10-17-2012, 09:21 AM

I am dragging up this old thread because I have the exact same issue. (not the wag but the fit) The OP didn't report back on his findings. Scott said it WAS NOT NORMAL refering to the video. After fussing with it for hours on Sunday, I thought I had it right but before I rip it all apart, perhaps I can explain what I think is going on.

The blade grips have two 3 x 6 x 2.5mm bearings in them. When stacked they are 5mm deep. The tail spindle (thin part) is longer than 5mm. Or, the thick part is smaller in diameter than the base of the grip. I don't have mine apart right now but I will order a couple of spares to confirm this. When you put the blade grip on and tighten down the screw, it is still possible to push the grip back down on the shaft farther. You can push it so far down that the pitch levers won't line up. So, it is in fact entirely normal unless I have tail spindles or tail grips that are not machined properly. Can anyone offer any further insight on this issue?

Chris Nifty · 10-17-2012, 02:48 PM

Yeah, don't push 'em. After the bolt into the spindle is tight, just make sure the grips are always pulled outwards against the bolt head and all is good - like the centrifugal force will do when it spins up.

Thalios · 10-17-2012, 03:19 PM

The tail wag might be governor related. Turn off governor, and see if the wag goes away.

CrashAddict · 10-17-2012, 03:50 PM

Hopefully the OP got the wag issue sorted out over the summer. I was more woried about the build issue.

CrashAddict · 10-17-2012, 03:59 PM

Thanks Chris.. I can't see how one could avoid the behaviour seen in the video. I noticed it first when you start to screw the grip to the pitch lever, it will actually pull it in to far and unseat the bearings. Not exactly expected cause there is nothing else on the heli that fits quite like that. I looked into getting a thrust bearing for in there but no luck.

CrashAddict · 10-17-2012, 05:07 PM

Long day today, Ok, got this apart. The tail grips have a 5mm hole in the back of them. The OD of the thick part of the shaft is 3.95mm. So, Yes, This is normal.

ziper_it · 10-17-2012, 06:30 PM

I'm with Chris here.

After bolting the grips pull out them, you should hear a snap when bearings seat.

Then make sure there's no play from servo up to the blades.

soniczen · 10-17-2012, 07:28 PM

I had a tail wag a few days ago. Ended up being the belt; I had about 10 grooves in the belt that were worn all the way down and I suspect that when that part of the belt wrapped around the tail gear it lost rpm. So check your belt thoroughly if you have tail wag.

pilot4fn · 10-17-2012, 10:25 PM

I found the tail wag to be caused by worn out tail blade grip bearings on one tail blade. That allowed some slack on one tail blade grip.
Changed both bearings on one grip and all is smooth. No wag and no play at grips.

04-22-2012, 11:44 AM	#1 (permalink)
jayfrs Registered Users Join Date: Jul 2010	Mini protos tail wag Please Help!! Hi Guys, Got a tail wag with my protos i have changed FBL controller and tail servo and it hasn't gone away with either, nothing is bent i have checked and its running a great head speed so thats not an issue. i run it witht he blades of on the bench and there are no vibes on it. I have noticed this with the tail assembly is this right?? Many thanks

10-17-2012, 02:48 PM	#6 (permalink)
Chris Nifty Registered Users Join Date: Dec 2011	Yeah, don't push 'em. After the bolt into the spindle is tight, just make sure the grips are always pulled outwards against the bolt head and all is good - like the centrifugal force will do when it spins up. __________________ Mini Protos, Voodoo 400, Protos 380, Protos Leggero 700 & 700X, Diabolo 700

10-17-2012, 03:50 PM	#8 (permalink)
CrashAddict Registered Users Join Date: Sep 2012	lol Hopefully the OP got the wag issue sorted out over the summer. I was more woried about the build issue.

10-17-2012, 05:07 PM	#10 (permalink)
CrashAddict Registered Users Join Date: Sep 2012	Phew.. Long day today, Ok, got this apart. The tail grips have a 5mm hole in the back of them. The OD of the thick part of the shaft is 3.95mm. So, Yes, This is normal.

10-17-2012, 07:28 PM	#12 (permalink)
soniczen Registered Users My HF Map location Join Date: Jan 2012	I had a tail wag a few days ago. Ended up being the belt; I had about 10 grooves in the belt that were worn all the way down and I suspect that when that part of the belt wrapped around the tail gear it lost rpm. So check your belt thoroughly if you have tail wag. __________________ Protos Max 700, Logo 550SX, Goblin 570 MSH USA Flight Team, MSH Brain, Jeti Model, Cyclone

04-22-2012, 11:52 AM	#2 (permalink)
scott s Registered Users Join Date: Apr 2010	disconnect the tail pushrod from the servo and move it back and forth by hand. If it is not smooth as butter or any binding at all find the source and fix it. You can't tighten the bolts in the links to the blade grips to much or you will get severe binding. Ball links not sized will cause binding. If you over tourqe the bolts in the tail case it will bind etc. etc. I just realized that is a video you posted and no that is not normal at all. Are you sure you have 2 bearings in each tail grip and they are seated all the way in the grip. The main shaft works perfect to seat them in. Or you do not have the bolts tightened all the way in the grip to the hub. I have found that the bolts get harder to tighten as they go in on a few builds. Gotta be one of the above

04-22-2012, 12:05 PM	#3 (permalink)
scott s Registered Users Join Date: Apr 2010	ps. Or you used the wrong bolt in the grips to hub (to long) and it is not seating against the bearing on the open end of the grip!

04-22-2012, 12:06 PM	#4 (permalink)
jayfrs Registered Users Thread Starter Join Date: Jul 2010	Cheers for the reply, the bearing are seated! I bought Heli second hand and rebuilt it! But I didn't look at the tail before I stripped it maybe the them screw got tight but I need to drive them in more! I will give this a go!

10-17-2012, 09:21 AM	#5 (permalink)
CrashAddict Registered Users Join Date: Sep 2012	I am dragging up this old thread because I have the exact same issue. (not the wag but the fit) The OP didn't report back on his findings. Scott said it WAS NOT NORMAL refering to the video. After fussing with it for hours on Sunday, I thought I had it right but before I rip it all apart, perhaps I can explain what I think is going on. The blade grips have two 3 x 6 x 2.5mm bearings in them. When stacked they are 5mm deep. The tail spindle (thin part) is longer than 5mm. Or, the thick part is smaller in diameter than the base of the grip. I don't have mine apart right now but I will order a couple of spares to confirm this. When you put the blade grip on and tighten down the screw, it is still possible to push the grip back down on the shaft farther. You can push it so far down that the pitch levers won't line up. So, it is in fact entirely normal unless I have tail spindles or tail grips that are not machined properly. Can anyone offer any further insight on this issue?

10-17-2012, 03:19 PM	#7 (permalink)
Thalios My HF Map location Join Date: Jul 2011	The tail wag might be governor related. Turn off governor, and see if the wag goes away.

10-17-2012, 03:59 PM	#9 (permalink)
CrashAddict Registered Users Join Date: Sep 2012	Thanks Chris.. I can't see how one could avoid the behaviour seen in the video. I noticed it first when you start to screw the grip to the pitch lever, it will actually pull it in to far and unseat the bearings. Not exactly expected cause there is nothing else on the heli that fits quite like that. I looked into getting a thrust bearing for in there but no luck.

10-17-2012, 06:30 PM	#11 (permalink)
ziper_it Registered Users Join Date: Mar 2010	I'm with Chris here. After bolting the grips pull out them, you should hear a snap when bearings seat. Then make sure there's no play from servo up to the blades.

10-17-2012, 10:25 PM	#13 (permalink)
pilot4fn Registered Users Join Date: Dec 2011	I found the tail wag to be caused by worn out tail blade grip bearings on one tail blade. That allowed some slack on one tail blade grip. Changed both bearings on one grip and all is smooth. No wag and no play at grips. __________________ MiniProtos Carbon with Low FBL, MSH 2580kV, YGE 60A, Mini V-BAR Kyosho Concept 46VR with ASP46, GP750 Walkeras: Genius CP Brushless, V100D03, V120D02 Futaba T8FGS

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