Cold weekend - good lathe repair time!

COLD!

I got up to the farm late Friday evening.  Freaking COLD!  It hovered around 4F - never higher that 14F during the whole weekend!  Snow was coming down Friday evening for the trip and then Saturday the winds kicked up.  Here are some pictures from Saturday morning.

Logan Lathe threading/powerfeed gear train repair

I had purchased a number of items to help me attack the stuck key and gear issue that i left last weekend.  I used a small (5/64" diameter - 6 inches long!) "aircraft extension drill bit" that I got from Enco to drill out the old key from the between the shaft and the stuck gears.  Once the keystock was drilled through I was able to drive it out some.  Between that and twisting the gears by holding them with channel-lock pliers and holding the shaft with pliers, I was able to get the gears off.  Whew!  Then I needed to clean up the shaft, gears and new keystock so that everything fit together with a "slip" fit.  Lots of mini-file work.

The shaft, after gear removal, and some new under-sized keystock.

Filed and fitted!

The gears and keystock fitted fully and with a "slip" fit.

I had also purchased a adjustable reamer to clear out the gears - some of them were catching - I guess they got marred from being driven off the shaft.  They reamed out nicely.  Fit is superb.

Installing the gears into the casting is the tricky part!  I decided the only way that this was going to work was to remove the bushing from the keyed side of the casting.   I would have liked to press out the bushing using the arbor press, but there was no room.  I would have to "tap" them out using a mallet or hammer.  To keep from damaging the bushing I used the lathe to create a little tool that fit inside the bushing but with a lip to hold onto the bushing and provide a surface to hit the bushing evenly.  Its nice have a lathe!  I used an old bolt from the leftovers that were left in the garage when I bought the place.  It is a throw away tool so I didn't want to use anything nice...

Before and after...

The bushing removal tool made from an old tractor bolt

Bushing removal tool pushed in and ready to hit!

Bushing removed!!

Worked like a charm!  Even though I discovered that the bushing was thicker than I originally thought - it was just covered with dirt...

Only problem is... I removed the wrong bushing!  I needed to remove the bushing from the keyed side of the casting!

So, I reinstalled the bushing on the opposite side...

And then i took out the correct bushing!

Pushing the shaft in - no bushing on the right there

The end of the shaft as seen from the keyed side of the casting.  See that there is plenty of room there for the key between the shaft and the casting?

The free floating gears are installed on the left and the key is shown in the keyway here.  

Key is cut to correct length so that there is room for bushing to be reinserted but without room for the key to slip and allow the keyed gears to rotate on the shaft.

 

The gears are on the shaft and aligned so that I can slide the key in from the right...

Because I had cleaned up the gears, shaft, keyway, and key to ensure that they all had a nice "slip" fit - I was able to get the key in without too much trouble - no mallet required!

Key pushed in almost all the way here.  

Ready to put the bushing back in!

Bushing reinstalled!  

 

Everything back together!  Gears move nicely and selectors move and engage well.  Gearbox ready to install on the lathe!

Repaired and rebuilt thread gear - powerfeed assembly! TaDa!

VIDEO: Power feeds are working!

Backgears are next!

After reattaching the threading gear assembly onto the lathe I decided to check out the backgears.  The back gears are located in the headstock "crankcase" (essentially).  i was super worried that I would find some gear teeth missing when I opened it up, but nope!  All gears in good shape and even a decent amount of oil in the case!

The "bull-gear"

This shows the spindle handwheel and pulley assembly.  Somehow, the pulley-drive has to disconnect from the spindle so that the backgears can engage and drive the spindle.  If you engage the backgear and don't disengage the pulley drive, the spindle is LOCKED!  Locking the spindle this way is a convenient way to install things in the chuck or do whatever you need to do that requires the spindle to be still.  Hoewever, after watching many youtube videos on the subject, DO NOT EVER lock the spindle this way and HAMMER or aply great force to the spindle - this can destroy the bullgear!

I tried looking up how to disengage the pulley from the spindle by checking many youtube videos and even reading the manual.!  The manual (which I got direct from Logan)  shows several different headstock assemblies, the correct diagram for mine would need to be identified by the serial number of the lathe.  I found the number!  77770

Well, I found the diagram that Logan said was for my lathe, but my head stock does not look like that diagram!  My headstock looks more like the headstock in the series following mine.  But not quite!  So I was left just trying to disassemble my headstock to see what I could figure out!  And I did!  I was so frustrated that I couldn't find a description of how to do this that I made a youtube video of the process so that someone else may benefit from my frustration!

How to engage the backgears!

Backgears engaged and working! Yay!

Fully functional lathe!

Well, pretty darn close anyway!

I would like to get a collet system setup for the spindle and maybe a morse taper adapter for spindle as well.  A 4-jaw chuck seems to be a good idea too, since 3-jaw chucks aren't very precise.

All put back together!

I still need to adjust the tail stock alignment and check the run out on the spindle.

Not to mention, there is a nut on the end of the leadscrew inside of the gearbox that I can't get tightened to my satisfaction.  I need to work on that.

So anyway, I went to take off the 3-jaw chuck to see what kind of spindle I have to deal with

Back of the 3-jaw chuck, for reference

Well crap.  I can't get the faceplate off the spindle.  However, I see threads there!

I have a text file that I saved from somewhere that indicates that my lathe, Model T6560H, has a threaded spindle that is 2 1/4" with 8 TPI threads.  Through bore should be 1 3/8"   Now, I measured the inside bore from the front using calipers (as best I could) and found the through hole to be 1.626" or about 1 5/8" - but it was hard to get to the inside bore from the front since the faceplate obstructed access.  I should have measured from the rear of the lathe I guess.  I measured the threaded portion, again, as best I could, and found about 2.135" - far from the 2.25" they say - but then again - its hard to measure a threaded outside diameter considering I can't actually get to the outside... I figure 2 1/4" is probably reasonable.

The stuck faceplate is evidently a global issue for machinists.  Advice from the internet and youtube sees to indicate that I should put the 3-jaw chuck back on and get some hex-bar stock to place in the jaws.  Then I should use an impact wrench to try to loosen the screw.  Important that the back gears should NOT be engaged!  leave the spindle unlocked or brace it some other way.  Do not brace it with gear teeth!

Time to leave already

weather turning bad - more snow then freezing rain!  Just before I took off I took these neat pictures of some super fluffy snow that fell early this morning.  Look close and you can see the individual snow flakes!

Finally! I got back to the farm...

Big snowstorm recovery...

After last weeks big storm (over 30 inches at the farm!) it mostly melted away and I was able to get to the farm!  Yay!!

I spent almost all of my time in the shop working on getting the mill up and running and then the lathe "gearing" issues.  

The Mill

Before I connected up the power lines I had to put the mill on the floor!  It had been sitting on the black pipe that I use to put it in position.  I man-handled it into position and used a crow bar to ease it onto the floor off of the pipes.  I moved it away from the wall a little to give myself more room behind the machine.   

Yay!  Its on the floor now.  Hopefully never have to move this beast again!

Before I could do much more though, I decided to clean up a little...

The floor before...

The floor after!

I burned the scrap wood from the floor cleanup

Changing the milling machines oil

The mill has 3 different oil reservoirs that I wanted to change and freshen.  One "lube point" was for the spindle, which takes special oil and special grease (both of which I bought from enco).  Another lube location was the gear case for the power feed (only the "x" - left-right - feed has power feed on this mill).  The power feed gear box takes SAE 30 (non-detergent).  Finally, the main gear box also takes SAE 30.  I was easily able to change and lube the spindle because the spindle has a nice easy to access rain plug.  However, the power feed and main gearbox do NOT have a oil drain and require the used oil to be pumped out.  Pumping 30 weight oil in below freezing temps is NOT easy!  I did manage to get the power feed box pumped out - it wasn't too much but it still took over 30 mins!  I added oil to the fill line, BUT - I think I overfilled it because the oil was so thick Iit was har to gauge how much was really in there.

Spindle oil lever indicator.  Spindle uses oil for horizontal operation but manual says it must also be greased frequently when using it in vertical mode.

This is the oil level indicator for the main gear box - looks pretty dirty!  The manual indicates that the main box takes 2 quarts of oil!  I am going to wait until things warm up to pump this out - otherwise I could be pumping it out forever!

Access port to the main gear box - this is only way to get oil in or out!

The access cover to the powerfeed gear box. Again, this is the only way to get oil in or out of the gear box!

Wiring it all up

Well, I had been worrying that I was buying a lot of stuff for the mill but I had no idea if it worked!  I went to connect some power to it - I was originally planning to do the extension cord to power cord trick like I had for the lathe, but it would have required 2 cords and I didn't like that option.  So i went ahead and "hard wired" 2 boxes and one switch to connect up the lathe and the mill.  Once I connected the mills VFD (variable frequency drive) to the power it lit up its LED display but also started a cooling fan which is on whenever the VF has power, even if its not being used!  That's why I put the switch on the milling machines power line.  It needed a dual pole single throw switch.  Eventually, I will put all of the wiring inside of conduit to give it some protection.

VFD wired up.  I need to put conduit on this wire for sure - its too easy to trip on this wire!

Went back and rewired lathe too.   I will probably put this connect seen here inside a box in the near future.  Again, this wire needs to be in a conduit.

Box for splitting 220V line between lathe and mill.

Mill Motor inventory 

When looking at the VFD I noticed it was for 2.2KW, which seemed small to me.  For some reason I thought that the mill main drive motor was 5 hp - its not!  Below are the specification plates for the 3 motors on the mill.

Coolant pump motor Just 1 amp here.

Main drive motor - only 5.1 amps.  But look at that service factor! 2.2!!  so amperage could be up to 11.22 (I think).

This is the powerfeed motor - just 1.2 amp here/

So, all told, just 1.2+5.1+1=7.3 amp! (but COULD be as high as 13.42 amps because of main drive motor service factor).    I noticed that whoever programmed the VFD set the overamperage setting to 10 maps...  maybe I should change that setting to 13 amps?  The VFD indicator did show an "over current" error a couple times when I was playing with the machines switches.

Milling machine vise installed

I had to machine about 1/8" off of the heads of 2 bolts that I used to bolt the new vise to the table, but the lathe handled that real easy!

Vise under the milling head.

Bolted down

Facing off  about an eight of inch of the bolt heads so they would fit in mill table tee-slots

Using the mill to fix the lathes tee-bolt

First thing I milled was the tee-bolt for the quick change toolholder on the lathe.  It came too big to fit in the tee-slot of the compound on my lathe.  Easy enough to mill into shape...

Yeah - i used a piece of wood as a spacer.  I didn't have my set of parallels yet and besides, this tee-bolt is not needed to be that precise.  It just needs to fit!

Tada!  Beautiful!

And it works great!  I got rid of the spacer washer I ha been using on the top of the QC holder.  Much nicer fit that the original tee-nut too!

Broken end-mill bit...

BUT, I didn't learn from my many warnings for youtube machinists... ALWAYS put down a towel or something soft on the mill table when loosening the tool bit!!

Sigh.  After I put the mill bit in the collet I noticed it was not centered - so I loosened the collet to adjust and ... the bit fell out - bounced off the table and onto the concrete floor!  Upon examination I found that only one for the 4 flutes ha been chipped... or so I thought.  When I went to use it however, two more flutes broke and a chip came off of the 4th!  ARG!  I was still able to use the bit, but its not producing a nice cut on the side cuts.  I ordered more bits...

Lathe "gear" work

I brought up the new bushings for the 3 replacement gears for the lathe back-gears, machined them to size (they didn't need much machining!), and pushed them into the gears! Beautiful fit!  I did have to machine the inside of one of the bushings after insertion in the gear due to shrinkage of the ID, but it didn't need much.

I used my arbor press to press the bushings in

Excellent fit!  

Reassembly of the gear train...

Now to the hard part..  reassembly of the gear train!  As can be seen in the pictures below, there is not a lot of space to work!  All those gears on the right there are KEYED to the shaft - and the key runs the entire distance of those gears!

I devised a scheme that I hoped would work to get those gears on the shaft without having to remove the bushing on the right hand side.  The idea was to machine another shaft that I put the gears and key on and then run the actual shaft in from the left (it has to come in from the left - unless I also want to bore out the center bushing and replace that WHILE the shaft is in place - can't do it!).  The actual shaft, of course, would have to be driven into the gears AND the key!   This gave e  an excuse to use my lathe to make a dummy shaft and use my mill to make a flat for the key!  Fun! (it really was - lol)

Used my lathe to make a dummy shaft to help with gear train install.

Got to use many of my lathe tools!

And since I was turning a shaft, I got to use my live center! [BTW, I finally got a replacement nut for the tailstock handle so that's working nicely now]

I saw a neat idea on youtube about making my own 60 degree center for my 3-jaw chuck to hold so that I didn't need to remove the chuck just to turn between centers!  I milled an old bolt left over from previous owner.  Carbide tooling cuts even that hard stuff!

However, this "wonderful" dual-dummy shaft idea lead to my downfall.  I was using a wooden mallet to drive the actual shaft onto the key and gears, but the fit was very tight. I decided I would "help" the fit by milling off some of the key height and width as well as filing some of the shaft so that the gears fit easier (the shaft was quite worn and had some creases in it that obstructed the gears from sliding on.  I milled off so much of the key that it was able to fit inside of the center bushing/  This helped a lot because then I was able to have more room to fit the gears in place on the right hand side!  However, When I got all of the gears on and everything seemed to be good - I discovered that the key was not engaging the gears near the center of the shaft!  So I had to take it all apart again!  Oh, but here is where things get really messed up - all of the gears came off easily - EXCEPT the ones near the center!  The key got out of the key way (because it was so undersized) and WEDGED between the gears and the shaft.  WEDGED tight!  I tried using the mallet and even a hammer to remove them, but no go.  I decided to give up at that point and left the farm before I could break something expensive!

My plan at this point is to try to drill out the key stock that is stuck between the gear and shaft. Then, hopefully that will loosen things up enough that I will be able to use the mallet to rive off the gears.  Then I guess I will bite then bullet and bore out the bushing on the right side of the shaft and put the key in from that side (which I figure is how they assembled it to begin with).  Of course that means I will need to get another bushing an press that in!  UGH.  Might be another month of work here!