StellarDrive 5 Mount

HEQ5 StellarDrive 5 - from £459 (with Rowan Belt Kit already fitted)
HEQ5 StellarDrive 5 - £579 (to have Rowan Belt Kit fitted)
(Stated prices are for upgrade/tune to customers own mount)


Please order via the website or drop it off to us (please call to confirm drop off date 
023 9257 0283 - dave@darkframe.co.uk)

We are proud to announce that we now offer a 2 year limited warranty on all 
Sub-Arcsecond StellarDrive™ tuned HEQ5, NEQ6 and AZEQ6GT EQ Mounts, 
re-engineered to our enhanced Bonneville Build Type.

Why tune your HEQ5 Mount?


Equatorial mounts by nature are precision made products. However, due to mass production and to keep the prices lower, they are often not adjusted to the best of their ability due to the variances in each mount. Various improvements can be made to transform the performance of your mount from what is a median production build, which may save you the need to upgrade to a more expensive mount if you are happy with the payload you have.

Check out how your mount compares in our performance charts.

EQ mounts are subject to being outside and often in the damp, so renewing the grease is often a first port of call with a better type more suited to our climate. It will also help reduce friction which means the motors can drive the mount more accurately, both unguided and guided.

Also, with more care in adjusting the worm-gears and motor drive train, they can often be made to run smoother and quieter, which also benefits better tracking and periodic error reduction. Mounts do need servicing and can be tuned, like any mechanical device. No-one as yet has designed a maintenance free mount!

This is also available as a NEW mount with full two year warranty for £1599 (See our BTO StellarDrive Catagory)

Single 900s test guided frame tuned standard hypertuned HEQ5 Reference Mount.

StellarDrive 5 Notes:

The HEQ5/Sirius EQ-G mount typically runs at 20-30 arcsecs from new unguided in independent tests and is said to be sweeter than the NEQ6 for astro-imaging. Once tuned our mounts run circa 4-6 arcsecs, and less than 1.0 arcsecs guided is often reported by our customers in independent tests. Also the mount will run smoother and much quieter.

This mount responds well to belt drive installation and wipes 10-15 decibels off the slewing noise. The Rowan Belt drive kit is an easier installation than the EQ6, but still needs setting up properly. It runs near silently and transforms the mount. We have an increasing number of customer fitted kits that have not followed the careful installation instructions. It's an easier upgrade than the NEQ6 kit, but still has to be fitted properly. Our installs provide at least twice the performance of a DIY kit, because of the extra work we do and the processes we employ. A StellarDrive upgrade virtually trebles it.

The worm-gear shaft just spins when upgraded with our new Hybrid Ceramic bearings. These reduce the end-float, and provide a very solid feel to the mount, which in turn virtually eliminates the well known rocking motion in both RA/DEC.

We measure and calibrate the end-float to an accuracy of 0.01mm, to ensure a consistent dial-out of backlash and minimised play in the gear-train. Cleanup and de-burring of the castings is often needed as they are quite rough in places, and the mating surfaces contribute to better engagement of the worm-gear. We don't often change the main axis bearings, but we test them and replace if not smooth. These only move 180º over the course of an evening, so replacing them with ones tested to 20,000rpm is largely academic! :)

Once tuned, consistent 15-60min subs are more than possible with this mount, with very few if any lost frames when guided and 5-10 mins unguided at circa 500mm focal length, 6-7 minutes at 700mm, and 3-5mins with an 8" f5 Newtonian (1000mm). All unguided.


Here is our own HEQ5 Reference Mount with 60 minute single frame star test and PHD Graphs from the session taken 13th Sept 2016 in the UK with a Megrez 72FD and a modded EOS450D. This mount as you see guided extremely well with just two 70mm f6 class APO refractors, plus a guidescope for a lightweight and versatile imaging rig.

This HEQ5  in 2016 was running a solid 0.9 Arcsec over a three hour session as part of our reference testing using standard bearings and took 3x60min drift free images. Our StellarDrive mounts can take this lower to circa 0.42 ArcCec or lower, and our Zero Drop Frame tuning methodology ensures that all our mounts are rebuilt to perform a similar level of performance. The sweet-spot payload for this mount is 11-13kg but can run up to 18kg. This translates into superior unguided performance too, up to 10 minutes with an ED80 refractor, 7-8 mins with an 102ED, and 5 mins with a 200P Newtonian!


Work includes:

Every Mount is examined externally for any damage and owner notified for any extra-parts (replacement Sky-Watcher EQ bolts for example).

The Mount is stripped back in both axis to component level, inspected for damage or wear, and degreased and ultrasonically cleaned where applicable. Bearings are then replaced with low friction and super smooth Hybrid-Ceramic worm-gear bearings, that really do improve the responsiveness of this mount. All bearings are checked and spun before fitting. Over and above our standard rebuild extra work includes:

• Re-engineered StellarDrive-SPX™ High Precision worm-gears for RA and DEC axis.
• Brass crown rings are super-finished as are cone axis bearing cups, and quality checked using a Specular Reflectometer.
• More surface work on internal castings.
• WaveFormR™ axis testing based on our build data to ensure correct backlash adjustment.

Owners are notified for any extra parts and time, if required, if there is a need of repair as other costs may be incurred.

Mount is reassembled using upgraded dampening greases and oils which operate in all temperatures from -30ºC to +125ºC (we use them in our Export Service and our own products so have been tested at these temperatures for over three years!).

We fit the Rowan Astronomy Belt kit that allows you to use the existing handset, which also is a major contribution to the mounts performance by eliminating backlash in the standard brass drive gears. It also removes the noisy meshing noises when going into and out of fast slewing.