That sounds like a cool solution! Using the adapter below and combining that with your welding idea would get you an awful lot of 1 stage gearing! This would also work with boring out and broaching a cluster gear for a 1/2"hex or finding an off the shelf output gear that matches your intent.
If you can use 2 stages and don't feel like modding anything another idea would be to buy one of these 8mm to 1/2 hex shaft adapters:
http://www.andymark.com/product-p/am-0588.htm
Depending on what you need for gearing you could then use a 50 or 56 gear on the CIM to a 14 tooth or any of the cluster gears. On the output stage keep everything as close to 1:1 as you can, 50:50 may be an ok option. Or adjust as you need, it doesn't really matter because it's modular.
Hope this helps get you going!
That sound you hear is of every programmer in the country cringing at the thought. - Billfred [more] 
Hybrid Mode
