Enco 12x36 Lathe Rebuild (Picture Heavy!)

[macardoso]

OK, so spindle measured 2.2633 over .0717 wires so its right on the money if not a touch small. Took the backplate back to Small Tools and they offered to exchange it. They didn't have another in stock so they said they would re-tap the hole and gauge it. Again, it is nice shop run by very helpful people. I'll be going to them again if I need anything!

 

[macardoso]

Quick update again. The 8" backplate ended up having the pilot diameter bored 10 thou' undersized. I bored it correctly to size and now everything looks great! Once again, a million thanks to Small Tools Inc. for helping me figure out the issue!

The electrical panel has been completed for a while and works great. A pair of contactors control the FWD/REV control. I ended up swapping out all the switches for AB hardware.

I started a new project of machining servo motor mounts for my CNC mill. The stock was 4"x4"x18" weighing 40-50lbs. I parted off several chunks (effectively parting a 5.5" diameter bar, what a pain!) and squared them using the 4 jaw on the lathe. I have 8 pounds of chips laying on the floor. This lathe is a workhorse, and I can remove probably 5 times the amount of material compared to my mill.


This guy was a 2.25x8tpi thread lap. I thought the threads were slightly undersized on my backplate so I was getting ready to lap it. It will be saved for the future if needed. Good practice for threading.

Big chunk of aluminum!


(There are the fully installed leveling feet)




Until next time, Cheers!

 

[tweinke]

Good to hear you have the bugs worked out.

 

[familyguy]

Looks like you've put a lot of effort into that lathe - good work - I'm sure you will do well with it.
I have exactly the same lathe right down to the colour, sold in Australia as a Heerless mine I think was purchased around 1983, for me it has been great (hobby work only), I have though fitted a 3 ph motor and VFD. I mounted the mains on/off, jog button, fwd/rev switch and speed control on the small sub panel near the gear change levers, the original stop start is still works as stop start only. In setting up the VFD and 3 ph motor I did away with the 2 step motor pulley and fitted a link type belt from the counter shaft to headstock, mostly I use the vfd speed control rather than shift the belt.

There is another mod that I found useful you may want to do - the lead screw half-nut lever mounted on the apron has a spring loaded pivoting lockout bar that prevents power feed from being applied when screw cutting, if you have looked at the rear of the apron you will know what I mean, older lathes made in the 70's and earlier did not have this lockout mechanism and I thought why do you need it - who would engage power feed while screw cutting anyway ?

The issue here is that the spring is working against the half-nut lever trying to return to its rest position, I noticed on a few occasions while screw cutting that the half-nut lever seemed to be working its way back up, so I always had my hand on it. On removing the apron to investigate the cause of this and seeing the lockout mechanism my immediate thought was to remove it altogether as it did really look like a crudely made after thought and in any case who would engage power feed while screw cutting anyway ? On looking at it more closely I realised the same could be done with out the spring by redesigning the pivoting metal bar, it did take me 2 goes as on the first attempt I was a but too eager with the file but the second one worked a treat. I don't have any photos unfortunately - but if I'm sure if you have a look you'll see how it can be done.

 

[macardoso]

I contacted Grizzly and was able to purchase the three missing metric change gears which should arrive in mid-June.

As an update, I ordered the spare change gears at the end of March, I still have not gotten them. I call every month and get the same answer that the shipment is delayed.

 

[macardoso]

The issue here is that the spring is working against the half-nut lever trying to return to its rest position, I noticed on a few occasions while screw cutting that the half-nut lever seemed to be working its way back up, so I always had my hand on it.

Mine does the same thing. I think it may be less about the lockout and more about the nut riding up the 55 degree wall of the screw thread. I was taught to always keep light pressure on the halfnut lever while threading (probably more to keep you from taking your hand off of it). Maybe the detent can be adjusted to be tighter?

 

[Downwindtracker2]

On my '92 BusyBee version the spindle nose is 60mm x 8tpi. That's right 60mm. There is a European 60mm standard spindle, so the 8tpi is odd part.

 

[familyguy]

Mine does the same thing. I think it may be less about the lockout and more about the nut riding up the 55 degree wall of the screw thread. I was taught to always keep light pressure on the halfnut lever while threading (probably more to keep you from taking your hand off of it). Maybe the detent can be adjusted to be tighter?

I initially thought that my half nuts had worn from not being fully engaged while screw cutting, on pulling the apron off I was pleasantly surprised to find them in excellent condition, I also found that as you suspect the detent was not very deep so I gave it a few extra thou, if you do ever remove the apron you will see what I mean about the spring being set up to pull the half nut lever out of engagment

 

[macardoso]

I had some content I wanted to share about this lathe and I figured that I might as well resurrect one of my first ever posts on HM. I've had this lathe about 2 years now and I just use it a ton. I've gotten very comfortable with it and have made some extremely accurate parts, sometimes down to tenths on the diameter.

I do have a major complaint though. Features along the Z (length) of the part were coming out significantly out of location when I used the carriage handwheel markings. I think there could be something damaged or wrong with the rack and pinon drive, perhaps from me using the lathe as a light duty arbor press for broaching 5mm and 1/8" keyways.

I decided to invest in a DRO rather than tearing down the lathe since I would also get a lot of additional benefit from the DRO (and tearing down the apron is a real chore). I looked at DRO PROs but found their pricing to be a bit too high for my taste. At the recommendation of a few on this site, I ended up buying a DRO from AliExpress.

The seller was YGLILGEN Official Store and I bought the "NEW 3 Axis LCD Dro Set Digital Readout System Display and 3 PCS 5U Linear Optical Ruler Dimension 50-1000 for Lathe Mill Machine" (LINK HERE)

This was my first time buying from AliExpress and I was quite skeptical, however the DRO was 1/4 of the price of the equivalent product from DRO PROs. I spoke with the seller over many days (12 hour time difference) and was able to build a custom package of 2 scales (with the cross slide being a 1 micron slim profile scale) and a 3 axis display. I figured I'd buy the 3 axis unit in case I wanted to add a tailstock DRO, compound angle DRO, spindle angle DRO, or RPM display later on.

Total price was $230 including shipping and it arrived about 2.5 weeks after payment. It was well packaged and had no damage. It did include a fairly good English user manual. The display is moderately large and came with a bright LCD screen and large easy to read numbers. I liked this unit because the menus are graphical context menus rather than a million buttons like other DROs. It came with some basic hardware to mount it, as well as a heavy duty plastic film cover.



I opted to mount it to the back of the headstock (unfortunately right in the path of the chuck spray!). I broke 3 drills trying to drill and tap the casting. Not fun!



The scales arrived in a separate box about 3 days after the display. The read head rides on the glass strip using bearings and some kind of spring suspension system. There are rubber wipers to seal out chips and dust (the full size scale has two layers of wipers while the slim only has 1). The red plastic piece seems to support the read head and will be removed after installation. The scales came with some mounting hardware and thin extruded aluminum drip covers as well.





I started with the install of the carriage (Z) axis DRO. Unfortunately I had to remove the motor to make enough room to hand drill the casting.



The scale was lifted on some standoffs and indicated true within a tenth over the length.



Here is the aluminum guard over the top.



To be continued...

 

[macardoso]

It was important to be to be able to retain the use of the carriage and cross slide locks, so this added a ton of complexity and time to the installation. My lathe uses these wing screws for the axis locks. They take up too much room so I created my own low profile version.



This consisted of a 304 stainless "hub" which was tapped to accept an M5 screw. The screw was glued in place with some Loctite green. I then cut the length of the screw to a precision value to the screw head did not protrude beyond 0.25" from the surface. I cross drilled the entire assembly to add a handle, then filed it to clean it up.



Here is the new lock installed.



I then placed the entire cross slide onto my G0704 to drill some mounting holes for riser plates.



These plates lift the scale away from the cross slide so the lock can be used.



Here is a mockup of the final assembly with the lock sticking out.



I also added a plate on the carriage to mount the read head. Thanks to the casting being unfinished, I had to machine, file and sand this piece into a angled mess to get the exterior surface sitting flat.



Due to the proximity to the ways and the length from the end of the bed, I was forced to drill the tapped mounting holes with this aircraft extension drill (which had the rigidity of a wet noodle). Drilling the two holes, opening them to size by hand, and tapping them took 3 hours and a lot of swearing.



I also wanted to make sure I could use the carriage lock. On my lathe this is a stud which protrudes out of the top of the carriage and is pulled upwards by tightening a hex nut. I replaced the hex nut with a slim 0.2" "nut" made from 440 stainless.



To clear some of the mounting features on the cross slide, the nut was machined into a tear drop shape on my CNC.



And a cross hole drilled and tapped on the small lobe of the tear drop to accept a handle.



Here is the piece installed. The threaded handle will be replaced by something prettier when I can go to the store next.



The stud was hacksawed off in-situ.



And cleaned up with a file.



With the scale installed, you can see why I had to be so careful with the vertical height.



At this point the cross slide install is done. The locks don't let me get as much clamping force on the axes as they did before, however it is nice to be able to snug them up on heavier cuts.

To be continued...