Scale RC Helicopter/ Roban 600 size Hughes MD500 Death Wobble!
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- Опубликовано: 18 июл 2023
- In this video, we get to look at what we think is causing what we call a death wobble!
This has been a mysterious wobble that has been occurring during flights of the MD500, we not talking talk wage, full body shakes! They are not violent but definitely need looking into because it makes flying the model really nerve wracking!
Scale is the purest RC flying. You do well flying your craft scale.
Thank you sir
Interesting to watch this, I have a 450 Trex inside a Roban MD500 fuselage and it always what I call bobbles, it doesn't seem ti be an issue if I fly it slowly in an attempt to make it look scale!! But if I fly a little faster the bobble gets worse, I'm flying with the stock Trex 450 blades and have never really solved the issue, I thought maybe I had placed the mechanics in the fuselage slightly off center!! Or maybe the rotor disc was a bit small for the bulky MD500 fuselage!! I'm glad you got to the bottom of your issue of the blades flexing 😀👍
Check out my video I did on here with a Trex 450 mechanics in a Hughes 500 fuselage. I had no issues at all with mine and it flies awesome.
RC Scale MD500 450 size/ Fuselage refurb/ Trex 450 mechanics fitting and Maiden
ruclips.net/video/vNGsjv-Gfbk/видео.html
Lovely field
That thing is gorgeous!!!!!!!
Thank you
Hi Rob. I'd say 1600rpm sounds fast. In fact 1400 sounds a bit fast. I'd maybe consider reducing head speed and increasing your 7 degrees to 8 or 9. Also you might want to reduce the Agility and gain a little bit on the beastx which cuts down on the feedback loop that results in wobble. It would never be noticed on a podnboom but heavier models don't react as quick.
Thank you for the advice pal which I took well. I reduced the gain and agility and it’s leaps and bounds better. I found that if I went from 1400 up to 1500rpm in flight as the head speed increased it wobbled a lot, now nothing at all so thanks for the heads up.
@@TheRMRCchannel good news. I'd still look at reducing the head speed.. I'd say 1400 as max and 1200 might be more like it. If you are running @ 1400 for tail authority.. Reduce the headspeed and put bigger tail blades on it. 1400 is fine for 2 blades. 4 not so much.
I would suggest trying to increase or decrease your elevator and aileron p gains and than try it again if it gets better or worse
hi there 😮 i had spinblades on my helicopter. they're not 12mm at the root like they should have beause of the paint. same wobble! i'm flying with align blades now and there is no vibration anymore 👍🏻 @ 1530 rpm on hard surface.. 12% vibes
I`m using this blades myself, 4 on my A109A, 6 on my AH-6M Little Bird. I love them!
ruclips.net/video/GBhc0xB4-8M/видео.html
ruclips.net/video/MQjCUJDzelY/видео.html
I have not seen any discussion about the gyro head rate and which gyro it is. Blades can be well balanced and physicals all good, however the gyro itself might induce wobble if head rate is too high. Here looks like -5% on head rate might do the trick. Note changing head speed can "hide/resolve" the issue as swash plate révolutions at different speed.
I don’t have the heli anymore bud so it’s all irrelevant now
Noted. Will eventually help someone seeing this, as public. Cheers.
I think more gain. Is tha tail holding when u lift up fast?
Rear Horizontal Stabilizer off about 1/8th pitch clockwise Sir. That's my assessment based upon visual observation. All the best!
Nope wasn’t that. The models gone now anyway, it’s over in Italy now.
So your 230 is slightly lighter than the 500? I don't know of the only 2 rc heli pilots I knew over 15 yrs ago are still flying orbif they're alive that can help me with mine if decide to get it ready for flight?
Also had wobble problems, blade tension was the answer. Beast X 1600rpm.
Is there anyone on a forum perhaps specializing in Roban that you could compare your setup with? Lot’s of great suggestions coming in, but short of testing them all, I’d try some specifics if I could find them for that bird. It might even be some gain or feedback loop setting on the FBL unit, but I’m definitely not the expert on that!
I sorted it, it was the gain set too high on the fbl. It was set for 3D
I'm thinking play around with your gyro gains a little to see if it's any different. If not, reduce your head speed.
Yes it was the gyro gain, it was set too high and the issue is now resolved
Iam willing to bet the gyro gains are too high.
Something you might want to try is to weigh the blades ..... there should be a "heavy" pair and a "light" pair which have to be across from one another ..... so if you run out of things try maybe this will help .....
I always balance and weigh my blades especially on a multi rotor and always set the heavy blades opposite but thank you for your input
Hi i am new to helis so can't pitch in with any advice, but where did you get your over glasses from?
Amazon pal
Hi thanks for the reply@@TheRMRCchannel
When I had a trex 600 electric FBl and wanted to fly low head speed I had to use soft dampers cause the harder dampers would make the head wobble. I'm not sure if you use those dampers in a 4 bladed head so I could be barking up the wrong tree.
Thank you for your support and input , but we found the problem to be the scale Spin Blades on the model because they were flexing in flight causing the wobble. I tested the blades on my 550X and it did the same thing on that model but not as pronounced as only using two blades and not four.
@@TheRMRCchannel He was right. The felxible Spinblades at only 35mm chord need harder dampeners. And setting the gains according to the blades. They are awesome on my 4-blade and 6-blade scale models.
Thx Rob. Any issues fitting in the trex 500 x?
No none whatsoever it’s pretty straight forward to be honest
You need a little trailer to drag it by hand out to the field
Tell me about it!
head speed too high and ail gain too high ^^
You're running a 4 blade head so shouldnt need anything like 1400 rpm. You should be aiming for 1300-1350 rpm max. The fact you get 'wobble' when it's windy suggests a gyro gain issue, either too low or too high in relation to the head speed. BTW, despite what a lot of people think and fo rthis size heli and bigger, you shouldnt have the main or tail blades set so they move in the grips as this is a main cause of vibration. The grips should be tight and not allow the blades to move.
Turns out the wobble was caused by the Spin Blades flexing in fight. Carbon NHP Blades stopped it
Blade lag
No not blade lag, it was the gain and agility set too high
Track the blades!!!!!!!!!!!!!!!!!!!!!!!!!!
The blades were tracked!!!!!!!!!!! And balanced!!!!!!!!!!!! We found out what the issue was, the Spin Blades were flexing in flight causing the wobble. Changed them out for NHP carbon blades and it stopped
@@TheRMRCchannel Spinblades are very flexible because of the low (scale) chord. No need to replace them, but set the gains according to the blades.
"Promosm" ❣️
Blade tracking and balance is off. Nothing you mentioned is the problem.
Nope. Blade tracking and balancing was all done and spot on. Found the problem to be the actual Spin Blades flexing in flight to be the problem