Hello Neil - another 'chipsweeper' has questions - please tell us more:
The model?
Hobby or commercial?
What is an AHHA conversion?
What/why Dolphin software?
What problems?
What costs?
How happy?
Some pictures (machine & typical products/parts)?
etc.
In my curiosity I just found this:
http://www.centroidcnc.com/lowcostm39.htm