Having an HEQ5 & wanting to mod to a belt drive for a while. I've found three options so far. I wish to continue to use my Synscan hand controller, so that cancels out the 4:1 ratio option. I am very used to the Synscan unit & don't wish to spend time adapting to the EQMOD system for now. I am glad that the EQMOD is available, but I don't want my hand to be forced, & my portable controller to be redundant.
Of the remaining two options, the Rowan Astronomy looks the better of the two. The use of an idler wheel in place of the spur gear gives two obvious advantages.
1. It wraps the belt further around around the pulleys. This may not matter much for the 47 tooth pulley, but will provide surer engagement on the 9 tooth pulley.
2. The belts are identical length, which means that carrying a spare belt could be a good option, as it could replace the belt on either axis, in the unlikely event of a failure.
There is a new Yahoo group for HEQ5 owners. It is fully moderated, so it will not become a spam dump like the last one. At the moment there are only 4 members, so any HEQ5 owners are welcome to swell the ranks. It is not meant to supplant this excellent site, but provide a specific adjunct to it for HEQ5 owners.
http://groups.yahoo.com/neo/groups/H...rialMount/info
One more item, I came across a site for a machining mob that make high precision worm drives & ring gears among other things, including replacement units for some Skywatcher gear. I will contact them to see if they can make replacement worm & ring gears for the HEQ5. That would complete the drive train upgrade for this mount. I'll get back to you when I know, but if anyone else knows of these people, & what their work is like, that would help.
http://www.aeroquest-machining.com/pricing.php