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View Full Version : Lost another 9650 servo on Rotorworkz HFE frame.

heartnspirit
03-11-2007, 05:25 PM
Sorry Debiandog... couldn't let you be the only one this weekend!

I stripped another 9650 on the Rotorworkz HFE frame but this time I wasn't so lucky on getting it down I had just lifted off and did a quick roll at about 12 ft and at least one servo stripped during the roll. For a few seconds I had my choice of rolling left at full blade deflection or right with nothing in between. I got on the throttle hold as it came in on the nose and right front skid at about 2200 rpm.

At first glance it looks like the main and tail blades, flybar, CF boom, torque tube driveshaft, main drive gear, skids and a pretty bad crack in the canopy. The good thing is that my TP500SX, the Rotorworkz frame and both the front and rear torque tube drive gears all look perfect!

I WON'T be flying with the 9650's anymore! I'll have to see what else will fit in the HFE frame.
Tim Tompkins
03-11-2007, 09:01 PM
We had two of them today and the Hitec 5245 seems to be a good choice. I saw some pretty impesive flying by both Charlie and Steven Fox. Fox's was on the first day and not one issue! Good job by his dad Clyde setting it up. They tried a couple of sets of blades and burnt in a couple of new batteries. The quickness and pop of the tic tocs was very good. The 5245's have metal gears and more torque too. I'll keep my eye on these for any slop but none on either so far. TimT
Cryofix
03-11-2007, 09:32 PM
not good this makes me nervous.
Rotorworkz
03-11-2007, 10:37 PM
heartnspirit,

Just curious is this the same heli that tipped over prior due to bad auto / landing or something fluke and strip a servo can't remember what it was. I wondering, Maybe it may have damaged one also and you not notice it.
heartnspirit
03-12-2007, 02:59 AM
No tipovers on this one. I did hit the tail blades a few weeks ago during an auto and caused a tail grip bearing to fail a few flights afterwards. This is the second time this has happened but the first time I was lucky and got it down ok. When that happened I took all three servos apart and checked them just to make sure the others were ok and there were no extra teeth or pieces of nylon left over. I'm guessing I have about 50-55 flights on it ith the 9650's. I've been hittting it really hard lately and have also made some mods to my flybar seesaw and mixing arms to increase the cyclic response which has probably put more load on the servos. I think I'll try the HS-5245 MG's. Wonder if the Rotorworkz servo plates will be availible for them soon?
SteveL
03-12-2007, 02:31 PM
Charley has had the plates for the 5245s for a while now. Shoot him a PM.
MrMel
03-12-2007, 04:04 PM
Any chance that you run too much cyclic so the swash hit the main shaft perhaps (bind)?

Why I wonder is that ive run 300+ flights on my L14 with 600 blades and 9650, over 100 of them with VStabi system which puts alot more stress on the servo then a regular setup.
Plus another 50-80 flights on my T600.
(im running max cyclic without binding on my T600, +- 12.5 degrees pitch)

Not a single servo strip (except when making a hole in the ground with the heli :arggg: )
Ticidytoc
03-12-2007, 04:09 PM
That was exactly what I was thinking. Are you binding your servos Dan ? We beat the hell out of this setup and had 0 failures. I'm starting to think it might be something in your setup thats causing this.
Finless
03-12-2007, 11:31 PM
I gotta agree... Matt has had this setup the longest of anyone and even though he is running 550's I havent heard of a stripped servo... Matt you still running 550's?

Bob
heartnspirit
03-13-2007, 02:32 AM
Any chance that you run too much cyclic so the swash hit the main shaft perhaps (bind)?


Well that's a thought. I know there wasn't any binding on the last few flights because I had just reduced my cyclic pitch from 9 degrees to 7 and I know it wasn't binding at 9. I can't say for sure that the swash has never hit the main shaft. I've been doing a lot of playing with swash settings in my tx trying to get the cyclic rates up on the 600mm blades. I certainly could have raised them to where it hit at one time without knowing it. Just once would do it. When I pull the main shaft out I'll look for any signs of where the swash might have been hitting it.

I'm also wondering if any of the mods I've made to the mixing arms might have increased the loads to the servos. In an effort to reduce the length of the servo arms and to improve linkage alignment I decreased the ratio of the upper mixing arms so I could get the same amount of pitch with less swash travel. However, if my thinking is right... two short arms have the same load as two long arms so it shouldn't matter?

I think I'll go ahead and try the HS-5245MG's. They're a little slower, .12 instead of .11, and a few grams heavier but they have more torque and the metal gears plus I have a programmer available for the Hitecs. The nylon gears in the 9650's always felt soft to me, especially with those long servo arms on them. Just pushing or pulling on the arms I could feel the give in the gears.

I don't mean to scare anybody here or imply the 9650's aren't any good. I'm just passing along my experiences. I could very easily be causing my own problems here. I really like the 9650's and the Rotorworkz frame setup. I only wish Futaba would made a stronger gearset for them.
MrMel
03-13-2007, 02:35 AM
I think I'll go ahead and try the HS-5245MG's


If you have a setup issue it will not matter overtime if you have metal gear or not, they, you need to check and double-check your setup first.
Else the metal gear will wear out pretty quick too.
heartnspirit
03-14-2007, 01:23 PM
I agree MrMel. I've been going back through everything. I know I've never had enough cyclic pitch to bind anything, but... I may have overextended my collective on one flight to where the washout base could have come up too far and hit the rotor housing. Right after I installed the XL motor I was experimenting with increasing my TX swash pitch setting during a flight just to see how far I could go with it. It was on the second flight after that the servo stripped. I'll bet that's what happened. Seems pretty stupid now to think back on it... making changes without checking for interference. :oops:
MrMel
03-14-2007, 01:27 PM
Glad you caught it!

Ps, you are not alone by forgetting to check things, I backflipped my Logo in the backyard when testing it after some electric modifications, I had reversed BOTH elevator and aileron controls.. It was my shortest flight ever..
BobbySmith
03-15-2007, 08:58 PM
Iwould have to agree the 5245's are a better servo i just built a HFE600and i went wiht the 5245's
Iflew the 9650'sin my L14 and didnt care for them i use to use the 5245's in my Roxxter55 and the servos are very strong

Bobby
Finless
03-16-2007, 12:33 AM
Got to agree Bobby... After seeing them in action and knowing some issues I have seen, the Hitech 5245's are a better servo!

Bob
MrMel
03-16-2007, 03:09 AM
Its 11oz-in difference in Torque, not a lot but still some, however, Hitec is slower.
heartnspirit
03-16-2007, 07:06 PM
Well, rather than to rebuild the 9650 servos I went ahead and installed the HS-5245's. I made 6 flights with it today and have to say... I think the difference is quite noticable over the 9650's. Even though the Hitecs are rated slower the overall cyclic rate seems to be a lot quicker! I even reduced my swash throws a little to slow it down some because my timing was off on some maneuvers. Makes me wonder if the extra 11 oz-in of torque of the Hitecs is making up for the speed of the 9650's? Maybe with a good load on them the 9650's are actually slower than the 5245's?
BobbySmith
03-16-2007, 07:45 PM
I went to 3421's Jr servos in all my Mikado machines as they have even more torque then the 5245's

I think it was discussed to make a frame plate to fit the 3421's JR's

Bobby
MrMel
03-17-2007, 02:06 AM
Well, rather than to rebuild the 9650 servos I went ahead and installed the HS-5245's. I made 6 flights with it today and have to say... I think the difference is quite noticable over the 9650's. Even though the Hitecs are rated slower the overall cyclic rate seems to be a lot quicker! I even reduced my swash throws a little to slow it down some because my timing was off on some maneuvers. Makes me wonder if the extra 11 oz-in of torque of the Hitecs is making up for the speed of the 9650's? Maybe with a good load on them the 9650's are actually slower than the 5245's?


Did you run 5 or 6v?

Strange that it shows that much, i vent from 5v to 6v on the 9650 (went up about 12 oz-in, and speed down to 0.11) with that, didnt notice that much, oh well, I need to order a few 5245's and try for my self.
Ticidytoc
03-17-2007, 03:19 AM
Who lists 6v numbers for the JR servos ? Hitec 5245's are faster at 4.8 and just about the same torque.
heartnspirit
03-17-2007, 03:42 AM
Hey Matt,

You're right, even at 6v the JR's are still about the same torque as the 5245's and still slower. I found the specs here.

http://www.jrradios.com/Products/TechnicalSpecs.aspx?ProdID=JRPSDS3421

BTW... The specs I saw for 6v on the 9650's stated 62.5 oz-in and 76 oz-in for the 5245's. That's about 20% more torque.

I've been running mine on a 6v Ubec directly off my TP5000SX's.
Ticidytoc
03-17-2007, 03:51 AM
Wow, Jr actually put 6v specs on their site. I never bother to look there because they only listed 4.8v in the past.

Thanks.