Closed loop stepper motors are also a choice. Not as accurate as servo's but if they lose steps in a movement they make them up at the end of that movement. This means if you are moving only on one axis all is well it will remain accurate. If you are moving on two or more axis then if only one stepper looses steps then it will make it up at the end but the result will not be exactly what you wanted.... So machining angles may be a concern, machining curves not so much - as they are made up of small straight movements so the amount of error only occurs on that one small movement. I haven't actually used any of these but that is the idea. If you can use servos, if you can't then closed loop steppers at least stop issues from compounding over the whole job. To see more also look at clough42 videos He did a great in depth look at all 3 types a while back. He also chose Clearpath servos. In fact on his surface grinder build went into the two types of the clearpath servos, so that he could overcome a dynamic issue he had.
Thanks for the info. I recently came upon some very nice linear axes that i'd like to make into a mill or maybe a printer. I've got some homework to do for sure
That was wher I got to as well on the price - but I know the size of such a project can be a bit daunting to people - hopefully my experiences will encourage a few more people to give it a go. Other people quite sanely want to just get on mill stuff, so if they have money but not much time I guess they will purchase instead. I really like that I have a much depper understanding after building a machine rather than just using one.
a guess it really depends what you consider a cnc. because i manage to remake exactly same mill to cnc for much less than 200$. no feedback steppers controlled by old lpt port, original lead screws with software based backlash compensation. everything else saved from trash bin...
@@eclecticbuilds1424 You are 100% correct. And the cost of manufacturing high precision parts doesn't stop with the machine tool. You need a controlled environment, plus allowances for the time for the parts to cool to room temperature before inspections and making the finishing cuts.
