Helm model M10 for Skywatcher EQ6, NEQ6, Orion Atlas/Atlas EQG (polar axis adjustment screw for EQ6 equatorial mounts)
most serious flaw of the popular german equatorial
mounts made by the chinese producer Synta, is the difficulty, which
often becomes impossibility, to adjust with the required precision
the inclination of the polar axis. This operation is necessary to get
the polar alignment of the mount. Who has used a SkyWatcher EQ6/Orion
Atlas EQ-G knows this problem very well, and knows that the latitude
adjustment is actually impossible to perform when the mount is loaded
with the telescope and counterweights. This is because all the weight
of the sistem is loaded on that screw, and then it becomes impossible
to turn. If you try to turn it, two things can happen: the screw
(made of soft steel) bends under the weight of the system, and the
thread which runs the screw will be damaged.
is a very serious limitation, that our company has solved with the
SOLUTION: THE POLAR HELM
Polar Helm (patented) replaces
the original latitude screw,
and offers the following features:
mechanical effort required to turn the adjustment screw;
the time of
2 of them are slower than the one of the
to the properties
and of the
ergonomics solution, the
the latitude adjustments:
the Polar Helm surface finish is reflective, making it visible
the Polar Helm
is made of a special Bronze alloy, carbon steel and stainless steel,
all high quality stainless
Bronze bar has
hardness values 100%, checked
signing the sticker
Control Passed” phase (Total Assurance Quality Procedure).
copy of the
Polar Helm includes the certificate
a guide for installation and use of the Polar Helm, a
makes installation understandable for everybody.
The latitude adjustment range of the polar axis of the german mounts equipped with the Polar Helm is from 0° to 60°.
Outer dimensions of the Polar Helm don't interfere with the polar scope protection cap and make possible to replace the cap after the adjustment of the polar axis.
The Polar Helm main screw threads-in smoothly inside the mount; in case the threaded hole of the mount would be damaged by the standard screw, the Polar Helm will restore the damaged thread because the material of its main screw is much harder of aluminum of the mount body. The socket extension (supplied as standard equipment) will help in turning the Polar Helm to restore the damaged thread.
HIGH PRECISION ADJUSTMENT
Extensive tests showed that, using the slower speed of the Polar Helm, it's easy to get an high precision in positioning of the polar axis, even under full load conditions (example: 20 Kg OTA plus 20 Kg counterweights)- The typical precision we measured is of about +/- 1 arcminute in EQ5 and EQ6 mounts.
What is really amazing when you use the Polar Helm on a full loaded EQ6 german equatorial mount is the smoothness of the motion and low force required. The strength of a child is enough to turn the extra-fine ratio Wheel Helm using the socket extension.
If you adjust the latitude of the mount using “fine” ratio you have only to turn the smaller Helm Wheel and you don’t need to use the socket extension.
The adjustment is easy, quick and hand-made; besides it allows to save the internal thread of the mount as the movement takes place inside the bronze sleeve rather than in contact with standard thread.
It should be noted that if you turn the Polar Helm with 1:1 ratio (turning both knobs you will get a goodpolar alignment. This means that when you use the “Fine” speed knob (the smaller one) you'll get an improvement in precision of angular positioning of the polar axis.
With the Polar Helm is then possible to align the polar axis with the highest accuracy, using the differential screw properties. The differential motion is obtained by turning the Helm wheel with the help of the socket extension (made with holes reinforced by stainless steel bushings, which generates the lever arm for a more precise and soft movement) and keeping the “Fine” knob (the smallest one).
Notes: to reach the better possible pointing precision you should always turn the wheels in clockwise direction to "lift" the Polar Axis. Therefore, to get the best results, it is recommended to start lowering the latitude angle and then lifting the mount until it reaches the angle suggested by the polar scope.
Otherwise, if you instead use the star drift polar alignment methods, please note that the polar axis is in a state of equilibrium between the brake exerted by the friction of the joint and the force of gravity exerted by the weight of the counterweights. Therefore, when you will turn the Polar Helm in counter clockwise direction, probably the polar axis will stay still, and then you will need to force the polar axis to reduce its inclination using the standard counter-screw (which is located on the opposite side of the mount).
The counter-screw must always be removed during the lifting of the polar axis with the Polar Helm, to prevent the deformation of the counter-screw. The counter-screw can be returned in touch (not too tight!) with the polar axis once the alignment has been completed, but should always be removed in case of further adjustment, even minimal.
IMPORTANT: we suggest to remove telescope and counterweights during the installation of the Polar Helm to avoid unbalancing of the mount.
Compatible with: SkyWatcher EQ6/NEQ6, Orion US Atlas EQ-G
Latitude Range: 0°-60° (*)
Security payload of main screw: 200 pounds (90 Kg) (**)
Materials: Bronze, Carbon Steel, Stainless Steel
1 --> pitch 1,5mm (standard screw pitch);
2 --> pitch 1mm (fine adjustment);
3 --> differential pitch 0,5 mm (extra-fine adjustment).
Pointing Precision: ± 1 arcminute
Dimensions: diameter 2.8” X 5” length
Weight: 10.6 oz (300 g)
for higher latitude range, please ask us. We can make a special
version for latitudes up to 68 degrees.
the Security payload of the screw exceed by 1.5-2 times the maximum
payload of the mount.
Installation Guide (PDF)
User Guide (PDF)