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Thread: Help with Italian electric motor

  1. #16
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    Cut a dowel and it was heavily tapered, so I chased down that problem this evening. The taper was .020" and did not seem to have any effect on length, a short dowel was tapered as much as a long dowel...how strange.

    I checked the cutter to make sure it was set the same distance from each center....probably 10 times, all was well.

    Finally I noticed that when I tighten the tail center the tailstock would rock slightly and put the stock upward just slightly. The result was that it would cut smaller on that end. I fixed this by filing the tail stock seat until it sat perfectly flat and also matched centers exactly. It was not significantly off, but enough that it seemed an error worth removing.

    Now I'm down to a difference of .005" from end to end on a short dowel. I'm sure I can knock that tolerance down a bit.



    Spun it up to full speed and made a nice smooth pass on this stick of gumi. This will become a chisel handle.
    Bumbling forward into the unknown.

  2. #17
    Quote Originally Posted by Brian Holcombe View Post
    My background is almost entirely with hand fed tools or basic tools with manually set stops, so I'm interested to check out a bit more about that. ...
    ^^I am intrigued by the idea of automating a simple pattern following lathe...
    Perhaps a servo to generate the x-axis motion, with a spring loaded y-axis to keep the 'follower pin'/tool carriage engaged with the pattern, and an air cylinder to push the tool carriage out (negative y-axis)?? Or, go whole hog and put a servo on the y-axis to do coordinated x-y moves? The actuators are probably the easy part here. It is the controller, and most especially, the user interface (GUI) that will make or break you.

    My background is 99% process automation using PLCs (I can be a big help if you want to make 9 million pancakes every 2 weeks, 2 million bagels/day, or maybe a pair of car seats every 50 sec.??). I would differentiate motion control in process automation from the motion control that (I think) you are interested in here. In my world, a system is usually built to forever execute only 1 or 2 things based on a simple 'recipe' selection. The recipes (generally) aren't editable in any sort of user friendly way. ...And I suspect you don't want 9 million chisel handles!

    So, that probably bumps you into the CNC world, where small batches or one-offs rule the day. But I'm not much help there - - just really curious!

    Glad you got it working, and I suspect with a good alignment smack here and there, it will serve well. As I said earlier, the variable speed was a huge plus for my dad.
    ____
    Dust-
    The serious vortex-ers don't seem to be engaged on this thread, so I'll offer what dust collection tidbits I've gleaned from my shop (and Dad): He only turns small stuff now, and has tried vacuums, dust collectors (3/4hp), and numerous dust 'shoes' mounted to the lathe. The best shoes seem to be sized for 2.5" vacuum lines, but he hates the noise. If he connects the 4" DC to these shoes, it's stalled and does nearly nothing. The DC to 4" shoes seem to do very little as well, as the shoe ends up too far from his work. His current setup (tightly positioned 2.5" shoe & DC) gets maybe 30% of the chips and ~80-90% of the fines :: your POOR CARPET!!

    I'm getting close to pulling the trigger on a 5hp DC, so that may change everything - - I hope.

  3. #18
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    The cool thing about this lathe is that the y-axis is already doing everything it needs to. Heavy spring maintains the cutter but the max depth can be adjusted by the user. Basically it can follow a pattern without my manually engaging the cutter.

    To remove the endless winding of the x-axis I feel a servo motor and timing belt could replace the pulley and the rest would simply be done by controlling the rate of feed and setting some switches to open the circuit at the end of the run. Presumably they could be mounted on the ends of the pattern fixtures.

    Thanks for your insights on this and the dust collection. I have a 3hp Oneida cyclone, so I’ve got to plumb that into this shop. The vacuum does surprisingly well, I assume becuase I can mount it at the cutter where a 4 or 6” hose is really going to be in the way there. Maybe the best way is to have both.
    Bumbling forward into the unknown.

  4. #19
    Quote Originally Posted by Brian Holcombe View Post
    ...
    To remove the endless winding of the x-axis I feel a servo motor and timing belt could replace the pulley and the rest would simply be done by controlling the rate of feed and setting some switches to open the circuit at the end of the run. Presumably they could be mounted on the ends of the pattern fixtures.
    ...
    Probably no need for a servo if that is the case - it allows both speed and position control that you may not need?? And they are considerably more $$'s. The Bridgeport power feeds I've used aren't servos. Look at a small (1/4hp?), reversible gearmotor with output RPM close to your desired x-axis lead-screw speed. (Maybe even a mill axis feed motor?) You could direct couple it, use a belt drive (with multi-step sheave?), or even a VFD. The latter two allow you to 'tune' the speed for the job at hand.

    Set up switches (just like a mill) to stop the feed at the end of a given pattern.

    You could even use a DPDT switch* to stop feed and energize a solenoid to send air to a 'retract' cylinder, and so pull the cutter back = no burn marks, when you can't get to the lathe in time. (cuz' I know you'll let it run all night unattended - makin' 9M chisel handles.)

    * - motor on the NC switch; solenoid on the NO switch.

  5. #20
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    Thanks Malcolm, appreciate the insights. All seems fairly practical and something I think I can do with mainly used parts. I'll hunt for a mill axis feed motor and take a closer look at the one on my Bridgeport.

    I will probably build a belt sander for it prior to this, but I want to do this as well. Replacing the three armed handle with a single handle will be nice as well (I'll put a handle on a timing pulley) since it will stop me from whacking my forearm every time I move the cutter when I look closely at the work. I've used plenty of mills and have never seen one of these three armed devices, I can certainly understand why they're not popular.
    Bumbling forward into the unknown.

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