The EQ6 Belt mod replaces the brass gears with a timing belt to reduce errors and remove backlash.
The EQ6 has standard brass gears on the stepper motor and worm gear, with a ‘transfer’ gear to translate the stepper motion to the worm gear.
These gears introduce errors and backlash, the belt drive mod is designed to replace these gears with a timing belt
The old and new parts
Replacement of the gears for a belt drive is straightforward but will take a day to do properly. Instructions are provided with the kit from Rowan Astronomy and another useful resource is the hyper-tune instructions from astro-baby.com
There are a couple of tricky steps
- Removing the adapter at the bottom of the polar scope shaft – you will need a steal belt, oil filter wrench (from Halfords)
- Removing the worm gear caps and the worm gear retaining ring, these can be removed using pointed pose plyers, but you risk damaging the caps if you slip, a better approach is to use the specially designed tool (available from Rowan Astronomy)
- The bolts holding the mount together are steel bolts with M6 threads tapped into the aluminium body – it is very easy to strip the threads be vary careful – if you do strip them you can repair them easily with a Helicoil thread repair kit.
Some of the tricky steps
Threading the belts through the guides can also be tricky, locking tweezers help a lot!
Fitting the belts is easier if you have locking tweezers, but it can be done with your fingers – if you are nimble – there is not much room to manoeuvre inside the mount.
The disassembly required to fit the belt mod.