Carljw

If it is the stock servo it says in the book not to have the gyro in digital mode.
I forget why but it could burn out the servo. The stock servo is digital but not
designed to accept a pulse rate of 275hz. Page 26 on the owners book.
Clames it will burn out the servo within a few minutes. I put on a Spektrum DSP75
so I could run it in digital plus I got the DSP programer to set it to heli and tail
and reverse it.

johnniesav

just got the DSP75 servo for my B400 and just wanted to kmow if there is anything i should know before flying.

leadtongue

some tips....if you change out or replace any servos or your gyro they will in most cases be reversed from what came out... you will need to check your controls and reverse their settings in the tx. if you are replacing your gyro with a different brand....some newer gyros require the tail to be setup mechanically to hover without drift in rate mode before switching to hh mode....no subtrim can be used! from experience your tail slider would be almost all the way over to the one side...you end up with poor resoultion to one side and smooth resolution to the other...ideal setup would have tail slider centered on shaft with aprox 8 degrees of pitch on the tail rotors... i emailed horizon hobby about this as i believe this is a flaw in their design of the blade400....i gave them a few suggestions but anyway they now have a speed up pulley drive for sale...it has an extra tooth on it that speeds up the tail rotor. im going to order one and try it... maybe i can get the tail slider somewhere near the center of the shaft on the mechanical setup...im using the hitec hg5000 gyro and tail servo combo but this setup is being used by many newer gyros also.

johnniesav

Thanks for the tips, i heard that when you are using HH that you are not supposed to use any rudder trim, is that true? My B400 drifts to the left even after setting everything just right, but after adding just a little trim adjustment, it's just fine. Now for that spin-up gear, what needs to be done to install that. I have looked over my heli and from what i can see is that it needs to be stripped down to repalce that little part. Is that so? Is there any vids, instructions on how to do that? Even though i am in the Air Force and i am a acft mech, I still need to see how its done ever once in a while. Just done want to mess anything up.

Thanks,
Johnnie

jp473

I have a B400. Had it for almost a year. Got a metal head for it at Christmas. Took some doing but eventually got everything to work. On the original head assembly when the swash plate moved down the main rotors increased in pitch and when up a decrease in pitch. The new head assembly looks like it is of a trex design. The only real noticeable major deference being the actual swash plate servo link ball locations. Hard to explain with out pictures and arrows and a paragraph on the back explaining what each one was… (Sorry for that flash back. LOL) Any way, the first few flights went so well I thought I was flying a trex. No more slop in the head. So steady and responsive. I was very impressed! Until yesterday. I was fine tuning the main rotor tracking and making a very minor tail servo linkage adjustment. Now, no matter what I do or how I readjust things the tail has a right/left horizontal wag. Increasing the gyro gain speeds this wag up and decreasing the gain slows it down but no amount of adjustment seems to eliminate it. It happens in rate mode as well as heading hold settings. Any ideas on this?

Evan T.

so did you get the eflite head or the copter x head and maybe its your servo

jp473

Replaced tail servo with a new HS 65. The head is fine. Its the tail I cant stop from waging no mater how I set the gain.

DeUglyOne

Have you tried mounting the ball in one hole on the servo arm? Sounds as if the gyro is over compensating with the faster servo and the shorter rod travel may fix that.

jp473

Bought a new gyro and you know what? Still had the same problem. [sm=48_48.gif] Now I’m pissed and 64+$ lighter. Started checking everything again starting with the tail. Can you spell D a a a a?[sm=bananahead.gif] Found the answer to the 64 dollar question. Had a slightly out of line tail rotor feathering coupling causing the pitch to osculate ever so slightly. Throw in a gyro trying its best to keep things at a given point and you get a waging tail not related to a gain setting.[sm=49_49.gif]

Guess you could say the tail was waging the dog.[sm=spinnyeyes.gif]

r/cheliman

Well one good thing is u have a back up gyro. that sure does suck when you replace things and dont get any closer to a solution to your problem. I've done it ALOT. Glad to hear the problems solved at least.

jp473

And a backup servo. . . . getting closer and closer to having that next helli.

Diizii

I m wanting to upgrade my gyro what would be the best choice. I have heard good things about the futuba 401 is that the best bet or is there something better. Thanks

monradon

My Feedback: (1)

Bump just need to find this again