The following is a review of the MicroHeli Precision Tail Pitch Slider
The first part of this review will center around the build quality of the
Precision Tail Pitch Slider.
Initially some good close up photos of the slider with some comparison
shots to give you a feel for the CNC quality and differences in build to
the stock unit.
As usual with MicroHeli upgrade parts the unit is very nicely engineered
and has a feeling of quality about it. Things of note are that the overall
bearing is larger on the MicroHeli unit, however, the units overall width
is exactly the same such that no length of throw is lost in the control
system. The blue plastic mounting plate is thinner than the Align stock
unit, which I'll come onto later. The whole thing is solidly built and
a perfect fit on the tail rotor shaft.
Assembly of the unit requires just screwing on the ball links that connect
to the tail grips. The screws are the standard Align supplied screws which
go through the blue plastic and into the short length ball link. The ball
links should be tightened down to get rid of any unwanted movement but
not so tight that they cannot rotate freely.
At this point I hit a minor problem. Due to the blue plastic mounting plate
being thinner it allows more of the screw thread to go into the hub of
the ball link. In screwing the ball links down to the correct length the
screw comes through the ball link and protrudes into the space where the
ball would normally sit. Either the blue plastic mounting plate needs to
be thicker, preventing the problem, or smaller screws should be supplied
and used. As neither of those options was available I chose to grind the
screws down by a couple of mm using a Dremel sanding disc. This done I
could screw down the ball links without fear of damaging them.
Once this has been done the whole unit can be installed.
Some pictures of the finished install ....
I noticed some minor stiffness in the pitch slider movement at around zero
degrees pitch on the tail blades. Loosening the ball link screws very slightly
resolved this issue.
In flight the unit performs as expected. I couldn't feel any noticeable
difference in tail control from installing this upgrade. This is not the
point I believe for this upgrade. The stock unit can crack and is not as
good a fit on the tail shaft. The bushing cracking on the stock unit could
lead to a tail rotor failure, this unit suffers no such metal fatigue issues
(although to be fair it needs a long term test to prove this) and is far
more solidly built than the stock unit. I believe this part adds some longevity
to the tail control system as well as peace of mind over tail control failure.
In use the unit is slop free and very precise with little or no twisting
of the unit on its bushing, the stock unit does suffer from some twisting
and this may be contributory factor to the aforementioned cracking in the
bushing bushing.
Overall Conclusion
As usual a very nice piece of quality engineering and less likely to suffer
(if at all) from the cracking of the bushing seen on the stock unit. This
should add longevity to the tail control system as well as being a bit
more robust and offering peace of mind that a failure won't imminently
occur. Performance of the tail unit feels relatively unchanged by the upgrade
and similar control movement throws to the stock setup are achievable.
The only negative aspect being the need to modify (shorten slightly) the
tail pitch slider ball link screws to stop them protruding into the ball
link space normally occupied by the ball.