hi BM, you havent stated what type of machine is in use now which can determine the type of mod you wish to do and which effects the price. geared machines will almost always need an upgrade of motor while a gearless machine can generally be used as is(otis machines are pretty robust). on the choice as whether it needs a mod, it basically comes down to parts and expertise which in the case of otis selectors is getting rather slim. at the end of the day machines are designed for a life span of around 30 years and these lifts have done their job. the modern lifts have a more precise levelling system than the old lifts and can limit law suits. i would recommend to go ahead with a mod but use a non propriety supplier then later down the track you can have a broader base of service options than locking in an otis for example. we have used MCE gear and it has been pretty good. 1 thing to remember is to do a proper mod and not a half hearted effort(as in only replace controller and leave to door operator as is) as it just doesnt work well.
