xmhobbies G401B Gyro

Written by Ashley Davis Wednesday, 02 September 2009 20:43

G401B

The G401B is a Futaba GY401 clone gyro aimed at the budget end of the market. As can be seen from the pictures above it makes no excuses about being a virtually exact copy of the GY401 with the same control layout and options as a GY401 as well as the same setup procedures and configuration.

The gyro comes supplied with a couple of foam gyro pads, I chose to use my own pads for securing to the heli but the supplied pads looked adequate enough for the job. The gyro was installed onto the rear of a T-Rex 450 as this is really the market it is aiming at, although there is no reason why you couldn't use this gyro on a 90 nitro. It's just to my mind if you are paying for an expensive heli then you probably want a high end gyro to go with it. This in mind the market really is 250/450 or possibly 500 sized electrics.

For the purposes of the review I wanted to use a typical budget helicopter and installed the gyro onto an old T-Rex 450S. The idea being that the gyro is going to have to cope with slightly sloppy cheap beginner helis rather than ultra high quality upmarket helis. This also presents the gyro with a bit more of a challenge as the mechanics aren't as accurate or slop free as the gyro might prefer and therefore it has to work a little harder to keep things in check. Configuration of the gyro centers around the switches and dials on the top of the gyro. There are switches for normal or reverse of the gyro, digital or analogue servo support. The two dials adjust the delay on the gyro (useful for reducing/eliminating tail bounce) and a pot to adjust the endpoint throws of the tail servo. You can't adjust the left and right servo throws separately. My inital flights I experienced some wag and bounce on the tail and after some investigation decided that I was running to high headspeed for the 450S plastic blade grips and it was enducing some vibration which manifested in tail wag. Some adjustments on the motor pinion and things smoothed out a little more and then finally I reduced the servo arm to be as short as possible and added a tiny bit of gyro delay. These actions left me with a wag free tail but still a little tail bounce on hard stops from a pirouette. Given this is a budget gyro and there really aren't any configuration options I decided to live with the slight tail bounce. You can see it in the test flight video below.

I also was expriencing a little tail drift as the pack ran down and headspeed dropped. Again I put this down to being expected given the cost/quality of the gyro. You can stop the drift with some tail trim but as the pack looses power and headspeed drops off the drift will start to creep back in again. In test flights I found the tail hold to be adequate for most 3D moves, although the pirouette was a bit whippy in pirouetting walls of death. Also I could get the tail to blow out easier than a high end gyro but overall hold was not bad at all.

Pros

Reasonable to good tail hold
Capable of most 3D moves without tail blow out
Extremely cheap
Easy to setup

Cons

Some very slow tail drift, minor bounce on piro stops
Some whip in pirouetting moves

Conclusion

This gyro has a few minor faults and really they are to be expected at this cost point, there is some tail drift, getting rid of tail bounce on stops I'm told may be solved by fitting a metal plate in the gyro mount (pad - metal plate - pad - gyro) this info came to me a bit late so I've not tried it yet. Lastly pirouette rate is not very consistent under heavy demand, but even some high end gyros are similar to the G401B in this area. Despite all of this I don't remember ever using a gyro this cheap that could actually do some reasonable 3D. As a beginner where crash damage and costs are at a premium there's a good argument for using very cheap electronics such as this, especially whilst getting past those initial crashing flights. Beyond this it has the ability to take the pilot on to full 3D providing you are prepared to forgive it some tail bounce etc. The most important element in 3D is tail hold and in that regard it does quite well.

Overall this is a cost effective gyro for the entry level market that has a reasonable capability. I'd prefer that it didn't drift as this can be difficult for beginners but overall it's a very attractive proposition for the newbie pilot on a budget.

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