Logan/mw 04tlc-701a Purchase

I think I may be as far as I want to go for now. I want to make some chips!
1. Took out the Treadmill 'beer can' motor and control. Just not enough grunt unless running at really high (5,900) rpm. Sold the pair for $110 locally
2. Purchased a 1 hp servo motor (2000rpm) and matching control. Built a new enclosure and mounted controls and tach. Much improved torque and quieter.
3. Purchased an inexpensive 4-jaw Chinese-made chuck and modified the one-size-fits-all 6 in. mounting plate to fit including boring and inside threading to my 2 x 8 spindle. Got some help from more experienced guys in evening machineshop class doing that. Darn, with 4-jaw it takes a long time to indicate a workpiece down to .001 or less.
4. As a treat to lathe and myself I got a Logan Lathe logo from the Internet, copied a couple of them onto vinyl and put some 3M adhesive on the back and put them on the control enclosure and lathe head stock. (see photos). Since its a Frankenlathe but still mostly Logan I figured it would be OK. Not the metal plate the originals had but the same logo.

Future work to do: figure out why it takes so long for longitudinal feed to start up once half-nut is engaged and figure out a fex.
Jerry

Hi Jerry,

I really respect the effort and skill it takes to take something that most people would consider junk and turn it back into something of use and beauty.
It is almost hard to believe that last picture and the first picture are of the same lathe.
What a great job you did resurrecting it!

47convertible said:

Future work to do: figure out why it takes so long for longitudinal feed to start up once half-nut is engaged and figure out a fex.

Click to expand...

likely one (or both) of these:
1) the carriage does not fit tight to the ways; there is some slop to take up as it shifts directions. Try disengaging the half nuts and simply using the handwheel to move the carriage left and right. Look for a diagonal twist or slight rotation of the carriage as you change directions.
2) some slop between the lead-screw and half-nut. if either (or both) are sufficiently worn, there could be "backlash" which is really just slop in the threads.

Some people will disagree with me, but I believe as long as you know about and understand the problems, you can make allowances and work with or work around them.

You can do so much more with an imperfect lathe than you can without a lathe!

Now go make some chips.
-brino

Hi Brino, thanks for the encouragement. It has been a bit of a slog at times but also really rewarding to take a Lazarus lathe and bring it back to life. I always had a plan B which was to part it if it was too far gone. I think I can set that aside. I have a drill press project that will involve turning a .75 x 8 Acme thread about 14" long to make an electric actuator to move the DP table higher or lower. I will use an actuator from a treadmill but their range of motion is only about 5 to 6 in. I plan to make my own Acme 8 pitch forming tool from HSS and attempt making satisfactory threads on shorter practice pieces. Should be fun.

Re the hesitation in the take up when engaging the half nut: I've been doing a 'work around' when doing threading practice by just backing off the thread engagement point far enough that I'm sure it will be fully engaged when threading tool meets work piece. Seems to work OK. I also notice some slop in cross feed when backing out at the end of the threading run. The cross feed hand wheel dial will show about .020 or so of movement before any movement is seen by the eye. It makes it difficult to return to zero and then set a good depth of cut when getting ready for the next threading run. That small dial doesn't help. Maybe time to get on Ebay and find one of the new cross feed nuts I see there from time to time.
Jerry

There are 3 possible sources of so-called backlash in crossfeed. The first is end-float in the cross-feed screw. It should be possible to reduce this to about zero, and this should be done before checking the other two. On most machines with sleeve bushing type cross-feed screw bearings and plain thrust washers, you adjust it by first cranking the cross-feed nut off of the screw and then alternately loosening and tightening the two nuts that adjust the axial position of the crank or handwheel that drives the cross-feed screw. After doing that, re-engage the screw in the nut and back the cross slide up until two or three screw threads a sticking out of the nut. Then measure the nut backlash using the cross-feed dial. Then back the cross slide up some more until as far as you know the cross slide is in the area where most work has been done over the years. Repeat the backlash measurement. The difference between the two measurements is screw wear.

On most new machines, total backlash would be expected to be 0.003" to 0.005". 0.010" is still OK. 0.020" indicates wear that's getting to the point where you should think about replacing the nut. But... even with 0.100" backlash, there is no excuse for not being able to do good work. One of the basic machinist skills is learning how to get around backlash such that the technique becomes second nature.

Good information. I will print out your reply and have it beside me when I attack that problem. Thanks very much.

If the lathe has a 2.25 spindle you may be able to add a 5c collet set up . I used to run Logan lathes in the early 50"s and all the Logans in the shop had production cross slides .
jimsehr

Jimsehr, If I had a 2.25 spindle lots of things would be easier on this lathe. It is sort of a Frankenlathe and has a two inch spindle of unknown origin with 2-8 threading and four V-belt pulleys on spindle and counter shaft. I've checked all the sources I could find including Scott Logan and basically struck out. The headstock is custom made plate steel but all of the rest of it such as back gears and end gears appear to be Logan. Being a newbie I was fooled by the fact the Montgomery Ward / Logan tag showing 04tlc-701A had been affixed to the headstock (perhaps to give a clue as to its original form). Cross slide is also a one off as are some other pieces. Bed and tail stock are Logan. Ser. # indicates 1947 production. If you follow the thread back to its beginning there are photos of some of the different parts. 10 inch Logans had 1.5 -8 spindle/threading originally. I think the 11 inch and larger had the 2.25 spindle. I purchased it very inexpensively and though its not 100% Logan I'm happy after renovating it with what it will do. It is better than I am and I'm figuring out the work arounds.

I thought you said you checked spindle and found it to be 2.25 8 when you said it had a 4 v set up. Check the spindle bore, 5c spindle is 1 3/8 with a taper at front to take a collet adapter.
jimsehr

Now you see why I'm taking the evening machine shop classes at the local community college.
I didn't have so much as a caliper when I started so measurement was checked with tape--Bad Jerry. I'd read Logans were either 1.5 or 2.25 and even with a tape I could tell it was more than 1.5 and was at least 2". Knowing the tape was imprecise at best I made the assumption it had to be 2.25".
The bore of the spindle measures 1.016" with my caliper.