AWGB Woodturning Forum
General Category => Tool tips & reviews => Topic started by: jay on May 12, 2020, 10:16:47 PM
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I think that the mandrel pulleys and motor pulleys are not aligned very well on my Graduate lathe does any one have a simple way of checking/aligning them ? Usually one can use a straight edge but the lathe casting/body is so crowded inside this does not seem possible. Secondly i have tried moving the motor mount platform laterally to correct the line but it disconnects the tensioning lever. Any advice from Graduate users would really help Thank you
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Plumb bob hung between them?
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A plumb bob will do to check alignment, but if you are having to move the motor platform so far that the tension lever falls off then something else is causing the misalignment.
One of the pulleys may have moved or been incorrectly fitted during overhaul.
If the motor has been changed & is a different frame size,this could also be causing the problem.
As a quick fix, a washer or two fitted to the tensioning lever stub shaft between the handle & the frame should do the trick.
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I think that the top pulley can only go in one position. My first thought would be to remove the grub screw/screws which hold the pulley in position and see if the exposed hole is in line with the indent in the spindle. If not this could be part of the problem,
Roger.
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Thanks for the advice . I will have a close look. The bearings and motor were replaced some years ago and it has been idle for the last 5 yrs. This was done when the VFD/ 3 phase motor was fitted.
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When I fitted variable speed to my Graduate a few years ago, the motor was sold as a "direct replacement" This was not the case. I ended up slotting the motor feet to get the correct alignment. I could have sent the motor back at the time but it was less aggravation to just slot the feet.
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jay something you might want to try is to remove the grubscrews completely and just flash the lathe on and off, this may well move the pulleys into the correct alignment along the shaft. Mark the position and then rotate the top pulleys by hand to find the grubscrew hole. The otherv thing to make sure of, and that it you say the bearings were replaced so just make sure the shaft has been put back in the right position before doing any of this.
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The alignment problem seems to be solved. I used a plum bob. The problem was that the upper pully was too far to the inboard end of the mandrel . I looked at a manual and the drawing showed the outer bearing housing almost recessed into the pully cluster. On mine it was well clear . So I loosened the grub screw and with a block of wood and a dead bloew mallet tapped it across . Now it aligns with the motor pully . I think the 3 phase motor is a bit longer so it is a close fit inside the pedastel but nothing is touching even when the tension lever moves the motor up . Thank you all for your contribution in sorting this .
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If you can't fix it with a hammer , Use a bigger hammer ;D
Good result :)