I’d like a large snow grinder with some deck height which I could use for way grinding. I’d just make a vertical sub spindle for dovetail and way underside
OK so I have some enquiries out about a couple of machines, one of them is an Ajax AJT1 with 3 axis CNC controlled by an Anilam 1100. Anyone know much about the Anilam setup? Capacity wise the machine isn't much bigger than the bridgeport but it does look like a good condition machine.
Next question, what about Semco CNC machines? I've seen a Semco 800 bed mill for sale at reasonable money. Although I'm not too clued up on the CNC side of things it would sure be interesting to learn.
I think most of these makes/types of machines will be Taiwanese.
Nothing wrong with that, in fact probably good as Taiwanese stuff tends to be reasonable.
Regarding the CNC control, without knowing what it is hard to say but if fairly old then it may be expensive to sort if things go wrong.
Nothing stopping you retrofitting with a newer control whether that be something pc based like Mach3 or stand alone like the SZGH I have just fitted to the lathe.
Ok cool. The controller is a GSK 983Ma-H so I've no idea if that is good or bad. I figured most machines like that are from the same Taiwanese factory.
GSK controllers are similar to the SZGH controller and is a Chinese stand alone control. I am not sure how old that particular model is but I do know the earlier GSK controls could be problematic and were not very good compared to the newer breed of controls from China.
From a quick search that seems to be quite a recent GSK control, still available as well so I suspect someone has recently fitted it to the mill if the mill is fairly old.
Yes and no, well closed loop is definitely better than open loop but there are different kind of levels of closed loop.
My Chiron for example is similar to the GSK in that the servo drives are commanded with an analogue voltage (+/-10v) and the control makes sure the axes are where they are meant to be within the error that has been set in the control. With a well tuned and set up system that is good, with a very loose and poorly set up system it may not be so good. Also with this type of feedback the control always knows where the axes are so even if you E-Stop or disable the drives and turn by hand the control will still know the position of the axes.
On the lathe I have just fitted the SZGH control to it uses Step/Dir signals, the servo drives themselves close the loop to the motors and make sure they are where they are meant to be within the error allowance set in the drives, so basically the same except the control itself is not aware of whether they are where they are meant to be or not. The control however also has feedback and although it is not used for actual positioning it is used for position error monitoring and if the axes exceed the set error it will halt until they are within the error.
On the lathe previously it basically had the same setup but without feedback to the control so in theory something could go haywire in the servo drive and the control wouldn't know, in reality that is unlikely but....
On a fully open loop system like you may have with stepper motors then any positional errors will not be picked up and the control will continue to command moves which could cause collisions etc and certainly ruined parts. On a well designed and specified stepper system that however would not be very common.
Well I've committed to buying the Semco mill, hopefully it'll be a bit better a machine than the bridgeport, albeit slightly less versatile. Best get learning G code!