Logan/mw 04tlc-701a Purchase

Excellent progress Jerry!
It looks to be coming along very well.
Congratulations.
-brino
 
Thanks brino. The encouragement is appreciated. Since my note a friend in the sheet metal business built a box for the controls. Much better Than I could have done. Gonna try to find some switches and indicator lights worthy of his effort .
 
Some advice please:
An update for the New Year on my Frankenlathe MW701A. I've about completed the wiring for the changeover to the DC motor and controller and have checked out the wiring and variable speed control and all works fine. I made provision for an inexpensive tachometer (photo) and have the board for that mounted (photo) but am now facing the quandry of where to mount the pickup and magnet to get true rpm readings. The likely location would be somewhere on the spindle shaft, preferably on the spindle or one of the unused (probably smallest) spindle shaft pulleys to mount the magnet. I need to be able to mount the pickup which is about 2 in. long within about 1/4 in. of the magnet. The other locations would be on the gear end of the spindle inside the gear cover door. I'm looking for suggestions. Downside of all of these is the oily environment that might hamper pickup of the signal.
Jerry
Sorry, can't seem to get rid of extra digital tach photo

digital tachometer.jpg kogan dc control box.JPG

digital tachometer.jpg
 
Your doing a really nice job there Jerry. Seems I've read something here recently on lathe tachometer setups and options. Might try a search on the topic. Mike
 
I appreciate the guidance and did read the links. I also thought about the hand held digital that counts on reflected light but since I had committed to the DC motor, I thought why not replicate what I did a year earlier on an old 17 in. Jet floor model drill press. I converted that to a DC motor for ease of variable speed and torque and used a digital tach. I didn't have to reinvent the wheel to do the same for the Logan Lathe. You can see the floor drill press in the background of one of the attached photos .

Earlier this evening I did some scouting around for a place to mount the magnet and pickup and think I can mount them on the braking wheel on the spindle and manage to stay out of the way of the countershaft to spindle belt. In the attached photo of the headstock its the drilled wheel to the backside. I also got a better photo of the control box mounted on the lathe table.
Jerry
ps, yes the really big 4 jaw chuck in the photo fits the 10 inch logan just barely and it has the 2x8 threading but it is so heavy I'd be afraid of damaging bearings if I ran it. It came with the lathe. One of those extras you take just in case.

Logan lathe not 701A 001.JPG logan with DC control box 002.JPG
 
Hi Jerry,

I'm glad you found a suitable spot for mounting the tach. sensor on the lathe.
Your control box mounting looks convenient and clean.
That 4-jaw looks to barely clear the ways....just don't wind the jaws out too far!
That 4-jaw chuck could still be a vise for the drill press or mill.
-brino
 
I'm continuing to make some progress on the old Logan Lathe and was able to put in a piece of cold rolled bar the other day and make a few cuts to see what the lathe would do and to try out my repair of the 3-jaw chuck and my addition of quick change tool post.

It is going to take some fine tuning as the surface of the areas I turned are kind of rough as you can see in the photos. A combination of the fact I didn't support the outboard end with a live center from the tail stock and probably didn't have the right speed plus cutting tool is well used.

I'm more than happy with my Chinese quick change tool post for $130 + the shipping. I'm thinking maybe a stronger DC motor may eventually be called for as the treadmill motor I used tends to bog down if I'm taking more than .010 -.015 cuts on mild steel at less than about 250 rpm on lathe spindle. I'm not sure what that amounts to in motor rpm but when I turn it up to say, 350 spindle rpm I'm not bogging so badly. I expect turning too slow also contributes to the rough finish on the cut. I was able to reduce run out on the work piece from about .004 to about .025 by turning the mounting plate of the 3-jaw chuck and by fiddling around with how I indicate the work piece in the jaws of the chuck. Even though its a scroll chuck it has three sockets to tighten the work piece. I found the one marked '2' gets the best results if I tighten it first and then go around to 1 and 3. I can reduce TIR from .004 to .025. I will make another test with live center hooked up and work piece re indicated to see if that improves surface finish of cut.

I've yet to explore some other options like using the back gears when turning. I know it builds torque but in addition to engaging the back gears I have to also change belt location from countershaft to spindle to get spindle rpm to recommended level. That's for another day.
Jerry
shop machines 002.JPG shop machines 003.JPG shop machines 004.JPG
 
I've yet to explore some other options like using the back gears when turning. I know it builds torque but in addition to engaging the back gears I have to also change belt location from countershaft to spindle to get spindle rpm to recommended level. That's for another day. Jerry [/QUOTE said:
Jerry,

With a given motor and motor RPM, torque delivered at the spindle is inversely proportional to spindle RPM. If you have the belt positions selected to give the desired spindle RPM in direct drive, then shift into back gear and change the belt position so as to get back to the exact same spindle RPM (assuming that this is possible with the available pulleys) you will actually be delivering slightly less torque to the spindle than you were in direct drive because of losses through the back gears.
 
Transformation is amazing to watch. I'm gonna nominate you for most determined and ambitious restoration of 2016!!

Your finish isn't all that bad. These light machines demand a really sharp cutting tool in addition to speed and feed issues. Keep trying different feeds and speeds till you get the result you can accept. Use the power feeds.

I wonder why the PO replaced the compound wheel with such a big wheel, but kept the itty bitty dial?
 
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