Low cost servo/gyro combo?

[scallybert]

There also seems to be a feature in the dx6i (spartan gyro site) that it sends the bound value to the gyro before establishing contact with the tx.

Yes. It has no choice, really.

Anyone know how to easily tell what you stored in the rx? Normally you just look at the servos and its obvious but with the HL400 it defines the values used by the gyro during initialisation.

The gyro uses that initial value as zero ?

You can find out what that zero value is by putting the gyro into HH mode with the heli stationary, and finding the rudder stick position that doesn't have the tail pitch increasing or decreasing (or stuck at +max or -max).

[SRH990]

Quite a few gyro's can boot up before the transmitter & receiver connect with Spektrum systems, the receiver starts up with the rudder at the value it was when the receiver was bound to the transmitter, if the stick centre is slightly different to this value the gyro will drift.

This was an issue they faced with the Spartan gyro and changed the firmware so it will only initialise when it see's stick centre, they recommend you bind the receiver with full rudder on so the gyro will only initialise after the receiver has connected. Wth other gyros it can help to re-bind the receiver occasionally.

[cjcj1949]

I'm new to gyros and I'm surprised how easily a new user can get unexpected results. The spektrum rx 6200 doesn't send an output to the esc until the tx-rx link is established. I've used escs for a long time and their use is intuitive. A reset button on the gyro would be useful or perhaps a fuller description of what can be expected. Perhaps "After moving model be sure to switch off and on". Also a warning that some servos have dead bands that may not correspond with all transmitters mid stick positions. Stick twiddling before take off is normally a safety feature to establish servo function. With the cheaper heading hold gyros it leaves the gyro with an unknown position that it decides it needs to attain.

My mcx seems to behave sensibly. I'd be quite happy to buy a gyro with the same predictability.

[cjcj1949]

On a DS760, NT400 or BuzzFlyer gyro (and possibly many others) switching into rate mode then back to HH 'zeroes' the heading to the current one.

I make sure I do this before taking off (generally before spooling up) in HH mode.

Yes, sounds a good thing to do. Perhaps someone designed them and even included it in the instructions. I thought I'd discovered that my HL400 did that. Further testing found it didn't. (It's in an earlier thread). A list of cheap gyros that do this would be useful as well as the ones that don't. Hard information is difficult to come by. I wonder how many cars would be sold whose initial direction was unrelated to the position of the steering wheel.

I'm looking at the Align RCE-600 at the moment. I know it has an adjustable dead band, but I haven't been able to find if it can reset demanded heading to current position.

[scallybert]

I thought I'd discovered that my HL400 did that. Further testing found it didn't. (It's in an earlier thread). A list of cheap gyros that do this would be useful as well as the ones that don't. Hard information is difficult to come by. I wonder how many cars would be sold whose initial direction was unrelated to the position of the steering wheel.

I'd have thought working like this would be a requirement if you're to switch modes in flight ?

Otherwise going from rate to HH mode is going to result in the heli rapidly yawing to some arbitrary or random orientation.

[cjcj1949]

Good point. Opinions seem divided on wether the HL400 is not very good or unpredictable or complete crap. My local experienced flyer uses it in rate mode most of the time but says hold mode is ok. Lots of his mates go for the gy401. I've just been flying in the drizzle and the gyro needed two clicks of right trim to stop turning. Some days it seems ok and as I said earlier I did think switching into rate mode was reseting it, then it didn't. Perhaps they took a reasonable rate gyro and added hold mode as a selling point. Not a reliable gyro for sure.

[Mojogoes]

Uumm.........i've noticed that turning it on and couple of times is necessary plus doing so in HH modes when turning it back on sets it the best for me........but it does seem to work quite well for so long and then for what ever reason drift..........though its only done so once when i was flying but when its been just turned on on the ground and i'm making adjustments it sometimes starts to creep so it of a back on again...........i don't know the % but +72 is about it as any more and it wags.