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bstanley72 · 01-31-2012, 07:20 PM

You may have mentioned this and I missed it, but what about the motor? Have you switched out the motor? I have three of the 500MX motors and I can tell you if you sneeze near them the lower bearing race will mess it's pants and start vibrating. At times my tail has shown some vibes similar to what you guys describe. When I have the motor vibes down (using the Skookum vibe analyzer) then everything else is kosher too.

I know I'm grasping, but I think we're at that point.

duytang · 01-31-2012, 07:24 PM

Ya, we tried swapping motors too! I'm so confused. My BL mcpx takes less then 5 minutes to fix lol

bstanley72 · 01-31-2012, 07:26 PM

The only other thing I can think of would be a crack in the frame? Transmitting vibes to the boom block and on down. Of course I would think a crack large enough to do so would be pretty noticeable. Not what you want to hear but if you had a vBar or Skookum you could track the vibe down pretty easily.

el guapo · 01-31-2012, 11:15 PM

bummer!!!

I have that same heli. guess I was lucky. I did put one of those fusuno tail fins on it and that fin vibrated, they are way too flimsy. it was like a blurr. but it still flew good. although I went straight to a quark gyro and mounted it to the RX tray.

DKS_ONE · 02-01-2012, 09:32 AM

OK!! This is going beyond ridiculous and getting down right painful... So the esc isn't it, we were so stoked to see a smooth tail that we just jumped all over it and laid blame. But now I'm starting to wonder if the tail is being over-sped? Is that possible? As in we're checking with no head on and the tail hub with blades in place. Is it possible that with no load from the head that the tail is just givin'er and reaching (dare I say it) hull breach velocity?? I'm starting to wonder if it's a matter of getting the hubs PERFECTLY balanced, and if that IS the case, how would we go about getting them there? This is one thing I want to nail down because it seems this vibe is contagious... yes, now MY heli has the exact same vibe where it didn't before.

As if this weren't a pain enough. And to top it off, put the head on Duy's with blades, spun it up and up to 80% throttle it hovers nice with NO tail wag. We put it up to 100% and it seemed a little sketchy but still, wasn't howling and bouncing around the way mine is now. Any and all input welcome, I'm starting all over from ground zero and first thing's first, please give me an idea as to how to balance these hubs.

DKS_ONE · 02-02-2012, 09:30 AM

Alright, I'm pretty sure this whole situation is sorted out. This is my take on it, I would appreciate if someone with more experience would concur with me on it just to settle my brain. Duy's heli and mine now both appear to be flying great, some tweaks required to gyro gains possibly with Duy's, but vibes all settled on both machines. I took the tail assembly on mine apart and found all bearings toast, so I changed them all. Kind of surprises me cuz I'm nearly certain that I had inspected them not too long ago and they were good, but I may have them confused with another bird or area. In any event, last night I replaced all the bearings and test hovered in my garage, solid. Duy hovered his at a field nearby, no vibes. My impression is that perhaps there was a minor out of balance issue with the tail in Duy's ship that caused the initial vibe he experienced. Could have been the way he was attempting to ground the heli or just a bad bearing. So my biggest interest is to know that it seems that if we would have made a correction and put the head and all blades on and spooled up that we likely wouldn't have been chasing anything. Is it possible that once we changed one thing that made a minor improvement and then spun up without the head with just tail hub and blades on that the tail would have over-sped and caused it to hop/howl/vibe the way it did? I'm afraid to spin up the tail without the head on for fear it overspeeding is what took out bearings and caused it to howl the way it did. Literally, my bird was good on second, spun without head only to find same vibe as Duy's and when I put the head and mains back on, the tail was hopping/howling/vibing HORRIBLY. That's when I found the bearings... I dunno, maybe this is all a terrible string of coincidences running into each other that only happens once every 2379 years when all the rex 500's are aligned (pun intended) perfectly

I just find it unsettling that it seems we chased a ghost everywhere, never caught it and now both birds are essentially fine

. I'm just looking for some peace of mind in all this, to know I'm not insane and that our vibe diagnostic procedure isn't out to lunch.

kenkadish · 02-02-2012, 04:54 PM

I'm clearly no mechanical engineer (have to ask my son who is a ME Phd.), but it seems to me that the tail should behave the same with or without the head on the heli. the motor and tail are mechically connected, and while the heli may spin up FASTER without the head, the speed, once terminal velocity is attained, should be the same with or without the head on.

I think you guys encountered a perfect storm of coincidences.

Lesson learned MAY be...add tail bearings to the list of first things to check if there is a vibration...main shaft, feathering shaft, main gear, main bearings, tail bearings.

I know that with my Blade SR, the first thing to bend is the main shaft. Looks straight, rolls straight on the mirror, change it out after a crash, and the vibes are gone.

Now both of you go fly and enjoy yourselves!

Ken

DKS_ONE · 02-02-2012, 08:53 PM

I hear ya Ken, I thought the same, I just don't understand why we should have had to check anything in a new kit. My best figuring leaves me with the idea that somewhere during the parts replacing the fault was fixed and we just had to put the head on to see the result. I just don't buy it that the vibe only shows up without the head on?? Makes no sense but it seems that's just what we have. I'm sure if we take the head off and spin up to 100% that we'll still see that vibe and that bugs me. Should I see it or not? Why does having the head on make a difference for the better? These are things I don't understand but want to and just don't know how to find the answers.

But we certainly will be flying (this week end hopefully

)

duytang · 02-02-2012, 10:14 PM

Just to clarify a couple of things. Both of those videos I posted were shot with the head on the helicopter but after that, for diagnosing, we took off the head because it was a little dangerous. We did spool it up with the head on a couple of times but without the main blades...

What really bothers me besides the fact that it vibrates with the head off is that the bearings that fixed Dan's tail vibrations, were the same ones that came out of my tail... Hopefully this weekend we can get the gains dialled in and ill be able to "fly" this thing.

el guapo · 02-03-2012, 12:39 AM

i flew my 500E at lunch today. 5 packs of inverted backwards figure eights. that little plastic tail is rock solid and its light. trust that tail, it is good.

when you are ready.... I highly recommend the RJX head and a beastx.

DKS_ONE · 02-03-2012, 09:26 AM

I would almost ask to see if someone with a 500e (or any 500 for that matter) would take the head off leaving just bare mainshaft and spool their heli up to 100% throttle with tail hub and blades still on just to see if they experience what we did.

duytang · 02-04-2012, 08:24 PM

Seems like nobody wants to try... I don't blame you guys haha.

It would be nice to get to the bottom of this though, for now in flying at 80% throttle and it flies great!

RC_Feen · 02-08-2012, 09:25 PM

I'm going to be starting the build of my 500E in the next few weeks so hopefully I can provide some feedback. During the build are there any parts that I should upgrade? I was thinking the metal bearing blocks. Thanks!

duytang · 02-09-2012, 12:41 AM

Quote:

Originally Posted by RC_Feen

I'm going to be starting the build of my 500E in the next few weeks so hopefully I can provide some feedback. During the build are there any parts that I should upgrade? I was thinking the metal bearing blocks. Thanks!

I did order a metal tail and bearing blocks to give a try, but I would definitely look into getting 600 skids. They are so much bigger then the 500 skids (you do need to drill new holes though), I didn't even bother using training gear.

nbells · 02-09-2012, 01:16 AM

Quote:

Originally Posted by DKS_ONE

I would almost ask to see if someone with a 500e (or any 500 for that matter) would take the head off leaving just bare mainshaft and spool their heli up to 100% throttle with tail hub and blades still on just to see if they experience what we did.

I did this last weekend on my 500e...... no probs with mine.... sweet as a nut

nbells

RC_Feen · 02-09-2012, 02:13 AM

Quote:

Originally Posted by duytang

I did order a metal tail and bearing blocks to give a try, but I would definitely look into getting 600 skids. They are so much bigger then the 500 skids (you do need to drill new holes though), I didn't even bother using training gear.

Thanks for the feedback duytang. This is my first T-Rex 500 but second 500 size heli. Had a Blade 400 and then a Protos 500. Parts support and help at the local field for the T-Rex 500 is more ready available. Thinking right now that the only upgrade I want to install during the build are the bearing blocks.

kenkadish · 02-09-2012, 07:19 AM

Quote:

Originally Posted by RC_Feen

I'm going to be starting the build of my 500E in the next few weeks so hopefully I can provide some feedback. During the build are there any parts that I should upgrade? I was thinking the metal bearing blocks. Thanks!

I just finished my 500e build, but no test flights yet...Went together just fine with the plastic...just be careful with how tight you tighten the screws in plastic and push hard when tapping threads in the plastic. Metal upgrades I will eventually make are metal mixer arms, main and tail grips, tail case, bearing blocks, and canopy pins.

Ken

UnionJack72 · 03-03-2012, 03:55 PM

Quote:

Originally Posted by duytang

I also did the backlit mod on my dx6i

Looks sweet... How did you do the BackLight mod, wired up LEDs youself, or buy a kit?

Seen several versions of mods (hacks), just wondering what you did?

duytang · 03-03-2012, 05:44 PM

Quote:

Originally Posted by UnionJack72

Looks sweet... How did you do the BackLight mod, wired up LEDs youself, or buy a kit?

Seen several versions of mods (hacks), just wondering what you did?

Hey, check out this thread https://www.helifreak.com/showthread.php?t=339313

and here is a pic of the inside wire routing

UnionJack72 · 03-03-2012, 06:35 PM

Quote:

Originally Posted by duytang

Hey, check out this thread https://www.helifreak.com/showthread.php?t=339313

Awesome, just ordered my kit

01-31-2012, 07:20 PM	#141 (permalink)
bstanley72 Registered Users My HF Map location Join Date: Feb 2011	You may have mentioned this and I missed it, but what about the motor? Have you switched out the motor? I have three of the 500MX motors and I can tell you if you sneeze near them the lower bearing race will mess it's pants and start vibrating. At times my tail has shown some vibes similar to what you guys describe. When I have the motor vibes down (using the Skookum vibe analyzer) then everything else is kosher too. I know I'm grasping, but I think we're at that point. __________________ Bunch of Planks, DX18, over-inflated sense of self worth! Helis I've had: Trex 500, Compass 500, MCPX, Nano CPX

01-31-2012, 07:26 PM	#143 (permalink)
bstanley72 Registered Users My HF Map location Join Date: Feb 2011	The only other thing I can think of would be a crack in the frame? Transmitting vibes to the boom block and on down. Of course I would think a crack large enough to do so would be pretty noticeable. Not what you want to hear but if you had a vBar or Skookum you could track the vibe down pretty easily. __________________ Bunch of Planks, DX18, over-inflated sense of self worth! Helis I've had: Trex 500, Compass 500, MCPX, Nano CPX

01-31-2012, 11:15 PM	#144 (permalink)
el guapo Registered Users Join Date: Dec 2010	bummer!!! I have that same heli. guess I was lucky. I did put one of those fusuno tail fins on it and that fin vibrated, they are way too flimsy. it was like a blurr. but it still flew good. although I went straight to a quark gyro and mounted it to the RX tray. __________________ Greg MSH USA Heli Flight Team Mikado V Team Lynx

02-01-2012, 09:32 AM	#145 (permalink)
DKS_ONE Registered Users My HF Map location Join Date: Mar 2010	OK!! This is going beyond ridiculous and getting down right painful... So the esc isn't it, we were so stoked to see a smooth tail that we just jumped all over it and laid blame. But now I'm starting to wonder if the tail is being over-sped? Is that possible? As in we're checking with no head on and the tail hub with blades in place. Is it possible that with no load from the head that the tail is just givin'er and reaching (dare I say it) hull breach velocity?? I'm starting to wonder if it's a matter of getting the hubs PERFECTLY balanced, and if that IS the case, how would we go about getting them there? This is one thing I want to nail down because it seems this vibe is contagious... yes, now MY heli has the exact same vibe where it didn't before. As if this weren't a pain enough. And to top it off, put the head on Duy's with blades, spun it up and up to 80% throttle it hovers nice with NO tail wag. We put it up to 100% and it seemed a little sketchy but still, wasn't howling and bouncing around the way mine is now. Any and all input welcome, I'm starting all over from ground zero and first thing's first, please give me an idea as to how to balance these hubs. __________________ *Danno* Blade 500x, Trex 500xt, just back after some time off. You don't ever really QUIT helis do you??

02-02-2012, 09:30 AM	#146 (permalink)
DKS_ONE Registered Users My HF Map location Join Date: Mar 2010	Alright, I'm pretty sure this whole situation is sorted out. This is my take on it, I would appreciate if someone with more experience would concur with me on it just to settle my brain. Duy's heli and mine now both appear to be flying great, some tweaks required to gyro gains possibly with Duy's, but vibes all settled on both machines. I took the tail assembly on mine apart and found all bearings toast, so I changed them all. Kind of surprises me cuz I'm nearly certain that I had inspected them not too long ago and they were good, but I may have them confused with another bird or area. In any event, last night I replaced all the bearings and test hovered in my garage, solid. Duy hovered his at a field nearby, no vibes. My impression is that perhaps there was a minor out of balance issue with the tail in Duy's ship that caused the initial vibe he experienced. Could have been the way he was attempting to ground the heli or just a bad bearing. So my biggest interest is to know that it seems that if we would have made a correction and put the head and all blades on and spooled up that we likely wouldn't have been chasing anything. Is it possible that once we changed one thing that made a minor improvement and then spun up without the head with just tail hub and blades on that the tail would have over-sped and caused it to hop/howl/vibe the way it did? I'm afraid to spin up the tail without the head on for fear it overspeeding is what took out bearings and caused it to howl the way it did. Literally, my bird was good on second, spun without head only to find same vibe as Duy's and when I put the head and mains back on, the tail was hopping/howling/vibing HORRIBLY. That's when I found the bearings... I dunno, maybe this is all a terrible string of coincidences running into each other that only happens once every 2379 years when all the rex 500's are aligned (pun intended) perfectly I just find it unsettling that it seems we chased a ghost everywhere, never caught it and now both birds are essentially fine . I'm just looking for some peace of mind in all this, to know I'm not insane and that our vibe diagnostic procedure isn't out to lunch. __________________ *Danno* Blade 500x, Trex 500xt, just back after some time off. You don't ever really QUIT helis do you??

01-31-2012, 07:24 PM	#142 (permalink)
duytang Registered Users Thread Starter Join Date: Nov 2011	Ya, we tried swapping motors too! I'm so confused. My BL mcpx takes less then 5 minutes to fix lol

02-02-2012, 04:54 PM	#147 (permalink)
kenkadish Registered Users My HF Map location Join Date: Feb 2010	I'm clearly no mechanical engineer (have to ask my son who is a ME Phd.), but it seems to me that the tail should behave the same with or without the head on the heli. the motor and tail are mechically connected, and while the heli may spin up FASTER without the head, the speed, once terminal velocity is attained, should be the same with or without the head on. I think you guys encountered a perfect storm of coincidences. Lesson learned MAY be...add tail bearings to the list of first things to check if there is a vibration...main shaft, feathering shaft, main gear, main bearings, tail bearings. I know that with my Blade SR, the first thing to bend is the main shaft. Looks straight, rolls straight on the mirror, change it out after a crash, and the vibes are gone. Now both of you go fly and enjoy yourselves! Ken __________________ Blade SR - 870 flights; Blade MCPX - 963 flights Trex 450 Sport - 700 flights; Trex 450 Pro DFC - 200 flights; Trex 500e - 240 flights; Blade 300x - 366 flights - Trex 550 DFC - 70 flights; Blade 130x - 234 flights........Learning every day!

02-02-2012, 08:53 PM	#148 (permalink)
DKS_ONE Registered Users My HF Map location Join Date: Mar 2010	I hear ya Ken, I thought the same, I just don't understand why we should have had to check anything in a new kit. My best figuring leaves me with the idea that somewhere during the parts replacing the fault was fixed and we just had to put the head on to see the result. I just don't buy it that the vibe only shows up without the head on?? Makes no sense but it seems that's just what we have. I'm sure if we take the head off and spin up to 100% that we'll still see that vibe and that bugs me. Should I see it or not? Why does having the head on make a difference for the better? These are things I don't understand but want to and just don't know how to find the answers. But we certainly will be flying (this week end hopefully ) __________________ *Danno* Blade 500x, Trex 500xt, just back after some time off. You don't ever really QUIT helis do you??

02-02-2012, 10:14 PM	#149 (permalink)
duytang Registered Users Thread Starter Join Date: Nov 2011	Just to clarify a couple of things. Both of those videos I posted were shot with the head on the helicopter but after that, for diagnosing, we took off the head because it was a little dangerous. We did spool it up with the head on a couple of times but without the main blades... What really bothers me besides the fact that it vibrates with the head off is that the bearings that fixed Dan's tail vibrations, were the same ones that came out of my tail... Hopefully this weekend we can get the gains dialled in and ill be able to "fly" this thing.

02-03-2012, 12:39 AM	#150 (permalink)
el guapo Registered Users Join Date: Dec 2010	i flew my 500E at lunch today. 5 packs of inverted backwards figure eights. that little plastic tail is rock solid and its light. trust that tail, it is good. when you are ready.... I highly recommend the RJX head and a beastx. __________________ Greg MSH USA Heli Flight Team Mikado V Team Lynx

02-03-2012, 09:26 AM	#151 (permalink)
DKS_ONE Registered Users My HF Map location Join Date: Mar 2010	I would almost ask to see if someone with a 500e (or any 500 for that matter) would take the head off leaving just bare mainshaft and spool their heli up to 100% throttle with tail hub and blades still on just to see if they experience what we did. __________________ *Danno* Blade 500x, Trex 500xt, just back after some time off. You don't ever really QUIT helis do you??

02-04-2012, 08:24 PM	#152 (permalink)
duytang Registered Users Thread Starter Join Date: Nov 2011	Seems like nobody wants to try... I don't blame you guys haha. It would be nice to get to the bottom of this though, for now in flying at 80% throttle and it flies great! __________________ I'm getting out of the hobby so if you need to contact me, you can email me at my Paypal address if I don't reply on here. Thanks

02-08-2012, 09:25 PM	#153 (permalink)
RC_Feen Registered Users Join Date: Apr 2008	I'm going to be starting the build of my 500E in the next few weeks so hopefully I can provide some feedback. During the build are there any parts that I should upgrade? I was thinking the metal bearing blocks. Thanks!

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