This may be a feeble attempt at making a silk purse out of a sows ear, but I am a tinkerer and can't leave anything alone. This time it is my lathe.
I bought a small, used Delta 46-701 12" lathe off Ebay a few years back. Since I'm not much of a turner it meets my needs. One thing I didn't like was the Reeves drive type speed control. Awkward and noisy. So my initial tinkering was to remove the Reeves drive, change out the pulleys, add a Power Twist link belt, put on a bigger motor (replaced a 3/4 hp 1725 rpm, Emerson with a 1.5 hp, 3450 rpm, Baldor (Ebay :-D), add a better switch (Delta) (the original switch was just a toggle switch mounted to the motor connection box), and add a variable frequency drive (Ebay again) to control the speed. Since my last shop was tiny, I made a set of bench feet for the lathe. I mounted the VFD and new switch to a plate attached to the headstock.
In addition to the items mentioned above, this closeup of the headstock shows my latest addition- the small black box below the VFD that contains the tach circuit and digital readout:
In addition to the problems with the Reeves drive mentioned above, I never liked the gross rpm scale that you matched with the lever position, and of course I had none with the VFD, though I could have made a frequency to rpm table. I finally found a reasonably priced, nice little tach from MKC Tools (they sell tach kits and parts to restore Shopsmiths). At my request they sent it to me without the readout mounted so I could make my own lower profile custom installation or even remote mount the display. In the pic below a second display is mounted on a piece of circuit board material from Radio Shack and will be part of the future VFD and tach installation on my drill press. The tach unit comes with a small (2" X 3" X 3/4") circuit board and an illuminator/pick-up which is aimed at a target (sample provided) which you attach to a pulley, shaft, etc. I couldn't find a project box the right size so I made one out of thin ply and painted it black. The tach runs on 9-12 VDC. I have it hard wired through a small toggle switch to a 9V battery. It is very accurate. There are two versions of the tach- one just displays rpm, the other you can select rpm or sfpm. Other users are adding these units to metal lathes, mills, etc. etc.
Here is the unit powered up at a low VFD setting (10 Hz = 337 rpm- it will go down to zero)
Mid range (60 Hz = 2040 rpm):
An upper speed (88 Hz = 3000 rpm)
The lower and upper VFD limits can be programmed wherever I want. And before all you electro-mechanical whizzes out there jump all over me, I know there are disadvantages to this setup- torque and motor heating problems at low rpms, bearing wear at high motor rpms. Anyway, time will tell if any of these issues cause me problems.
The last upgrade for the lathe will to make a new, substantial, floor stand.
I bought a small, used Delta 46-701 12" lathe off Ebay a few years back. Since I'm not much of a turner it meets my needs. One thing I didn't like was the Reeves drive type speed control. Awkward and noisy. So my initial tinkering was to remove the Reeves drive, change out the pulleys, add a Power Twist link belt, put on a bigger motor (replaced a 3/4 hp 1725 rpm, Emerson with a 1.5 hp, 3450 rpm, Baldor (Ebay :-D), add a better switch (Delta) (the original switch was just a toggle switch mounted to the motor connection box), and add a variable frequency drive (Ebay again) to control the speed. Since my last shop was tiny, I made a set of bench feet for the lathe. I mounted the VFD and new switch to a plate attached to the headstock.
In addition to the items mentioned above, this closeup of the headstock shows my latest addition- the small black box below the VFD that contains the tach circuit and digital readout:
In addition to the problems with the Reeves drive mentioned above, I never liked the gross rpm scale that you matched with the lever position, and of course I had none with the VFD, though I could have made a frequency to rpm table. I finally found a reasonably priced, nice little tach from MKC Tools (they sell tach kits and parts to restore Shopsmiths). At my request they sent it to me without the readout mounted so I could make my own lower profile custom installation or even remote mount the display. In the pic below a second display is mounted on a piece of circuit board material from Radio Shack and will be part of the future VFD and tach installation on my drill press. The tach unit comes with a small (2" X 3" X 3/4") circuit board and an illuminator/pick-up which is aimed at a target (sample provided) which you attach to a pulley, shaft, etc. I couldn't find a project box the right size so I made one out of thin ply and painted it black. The tach runs on 9-12 VDC. I have it hard wired through a small toggle switch to a 9V battery. It is very accurate. There are two versions of the tach- one just displays rpm, the other you can select rpm or sfpm. Other users are adding these units to metal lathes, mills, etc. etc.
Here is the unit powered up at a low VFD setting (10 Hz = 337 rpm- it will go down to zero)
Mid range (60 Hz = 2040 rpm):
An upper speed (88 Hz = 3000 rpm)
The lower and upper VFD limits can be programmed wherever I want. And before all you electro-mechanical whizzes out there jump all over me, I know there are disadvantages to this setup- torque and motor heating problems at low rpms, bearing wear at high motor rpms. Anyway, time will tell if any of these issues cause me problems.
The last upgrade for the lathe will to make a new, substantial, floor stand.
