LinkBack URL
About LinkBacksStepper motors can be spun while Manuel machining but servos can't. Also you want friction while Manuel machining with ballscrews because they backdrive. They wouldn't stay put when you let go off the handles.
Judleroy
Stepper motors can be spun while Manuel machining but servos can't. Also you want friction while Manuel machining with ballscrews because they backdrive. They wouldn't stay put when you let go off the handles.
Judleroy
Complete package, contact me me for a better price than what I have it on ebay for....
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices
Sorry if this is the wrong place, but, the G0704 did come up in the thread.
Ah ha! Now I get it. That is something that I had not considered. I was thinking of converting the machine to ball screws a while back so it would be ready for CNC sometime in the future and was wondering why they did not just build them will ball screws in the first place. Obviously price is a reason also, but would not have cost Bridgeport that much more over what the acme screws cost.
I guess you could get good results in manual as long as you always remembered to lock the tables or did not take your hands off the wheel.
My concern was back driving the motors in manual for two reasons. One was the extra friction and the other was that when unpowered steppers are turned they kind of ratchet from step to step which makes it hard to do precise slow turns and stop exactly where you want. Also kind of gives it a built in vibration as you crank the handle which can give a bad part finish.
The extra friction might negate the need for the brake if it is just the right amount.
The ratchety turning might not be as much a problem as I am expecting with the bigger hand wheels on the BP.
Thoughts?
Disconnect all leads on the steppers (make sure they are not touching each other) and see about that rachet feeling. Should be much smoother. You wouldnt feel it on a BP anyway if using them manually. I cant imagine why anyone would go manual after the refitting. Just use an MPG/Shuttle Pro and do anything you want quickly and smoothly.
Looked at the Shuttle and also the VistaCNC pendants and I see what you mean. Having something like that probably would end my hand cranking days. Thanks.
Yea you willl throw handwheels out the door when you find how easy & good pushing a button works.
Jess
GOD Bless, and prayers for all.
or using the MDI line for a smooth feedrate
Posting Permissions
