First Lathe - 12" Craftsman Lathe - Attempting Restoration

Hey guys, I have some slop or backlash in one of the gear to shaft interfaces. It's on the carriage apron transverse gear case assembly. If I hold the shaft, I can rotate the gear about 8 degrees. I measured this by drawing a straight line across the shaft/gear with the gear rotated to one side and then rotating the gear to the other end of the slop. I assume the soft shaft/gear material has kind of "egged out" over time but I just wanted to make sure this wasn't built in adjustability.

If it needs repaired, what approach would you recommend? I've considered epoxying it or soldering it? Maybe drill a hole along the length of the shaft, between the gear and the shaft, and leave a drill bit inserted (to act as a kind of key)? I'm worried about drilling the zamac gear.

Also, do I need to somehow try to ensure the front large gear is aligned to the rear small gear at the other end of the shaft?

Gear2.jpg
Gear1.jpg
Gear3.jpg
 
The factory probably intended the gear to be expendable and would recommend replacement if the fit becomes too loose.
You could of course use epoxy or some other method to improve the fit but you don't want to lose the ability to disassemble it later.
No, you don't need to align the two gears- the orientation is completely random AFAIK
-M
 
markba633csi said:
Pretty sure the motor shown in your first post won't work with that VFD unless it happens to be a 3-phase motor.
With a compatible 3-phase motor you could in fact do without a countershaft at least initially.
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@markba633csi Could you please elaborate on what you mean by "...at least initially"? I'm trying to get as much done at once while I'm in restoration mode and if this needs to be addressed, I suppose I'd rather do it now.

I did manage to pick up a 3 phase 2 hp motor. Do you think this will be too much hp considering the original motor is only 1/2 hp?
 
Because the VFD gives you variable speed you probably could do a lot of lathe work (maybe all) without the additional speed reduction of a countershaft
Back in the day with fixed speed motors a countershaft was essential to reduce the spindle speed to a usable range and multiply the torque.
Having a 2HP motor would be an advantage since 3-phase motors tend to lose torque at lower speeds with VFDs
-M
 
Well it's been a while but the lathe is 90% repaired and functional, and has been working very well. I took every bit apart and cleaned/painted anything that needed it. Machined surfaces were cleaned, stoned, and oiled. If anyone reading this is thinking about getting a lathe but not sure, I'd highly recommend. I'm super happy with the hammered blue finish; may be my all time favorite paint for tools.
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I ended up measuring the ways with a micrometer as recommended by Richard King (is he here, last active in April '23?) in post #5. Max delta on front way was 0.0007", back was 0.0004" and front to back was 0.0005" so all less than 1 thousandth; should be more than accurate for me.

The leadscrew is heavily worn in the middle. I haven't used it too much but if I end up needing to do more threading, I'll need to sort this out.

VFD seems to be working fine. If I run for too long, it doesn't seem to like it (a lot of blinking). I do have an auxiliary fan on it. I bought the 2.2 kw 3hp 10A version but possibly I needed to go up in the amp rating.

I had to run 220V to the garage, this was actually one of the biggest efforts and expenses of the whole project. Yes I could've used the original motor, but I wanted 220 anyway for other tools (compressor), and having the variable speed from a VFD is nice too.

The bench I built for it is super solid with 2x4 stringers topped with 2 layers of 3/4" plywood and a stainless top. The 2x4 are framed into the wall and the legs anchored into the concrete slab.

I spent a lot of time learning HSS tool sharpening and once I got decent results, I also bought a few carbide brazed tools (these need to be sharpened before use). The carbide does have better longevity.

The surface finish I'm getting when cutting steel isn't super great though, but easily cleans up with a file and some emery. The lathe is bolted to the bench. The next thing I plan to do is reverse the bolts so I can use them to level the lathe more precisely and easily.

Other things I'd like to do: Add method to more easily see RPMs, mount QCTP, fix gear change information plate, add display to tailstock, make depth stop for carriage, fix hand wheels (floppy crank on carriage and missing on tailstock), tailstock lock handle, make half center, make spindle thread cover, and several other small projects.
 
Clausing still sells the leadscrew, although at last check they weren’t cheap.

I’d recommend taking the top compound off and making a solid plinth if you go qctp. I did that on my 10” atlas and the difference in rigidity is striking. It will part now without any fuss, whereas the top compound would introduce just a little too much movement and let it chatter and catch. It works so well I leave it on all the time and only install the top compound when I need to cut a taper/bevel or similar top compound type work.

I went with a Baldor dc motor and Danfoss speed controller on mine, so I have no advice on the vfd issues.

For spindle rpm I just went with a cheap ebay guage that takes a magnetic pickup input. A small bracket mounts the pickup and rare earth magnet stuck to the spindle drives it:

IMG_0210.jpeg

Works great and I’ve got maybe ten bucks in it. Been that way for years now, so reliability is good enough.

Heres a pic of mine post “resto”:

IMG_0202.jpeg

i went with a “metallic teal”. Shows off the shapes and curves nicely, its easy on the eyes and is unique. Seems to fit it imho.

and with the plinth and qctp:

IMG_3585.jpeg

two best improvements were the dc motor and the qctp.

check ebay for a replacement threading chart. They show up in good shape from time to time.
 
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Just FYI, that large countershaft pulley is available new from Atlas / Clausing. The new pulley is a machined steel affair - very nice. I purchased one last year for around $100. All the original old Zamak pulleys wobble. The new one is better.
 
Wow @great white, that is a piece of ART! That color is stunning, and what a nice clean organized setup! I have a lot to learn still. Also, those are some great tips/pointers, thank you very much for those. I definitely will incorporate the plinth.

@JPMacG, ah thanks that's good to know. I should probably get one while they're still there...
 
I recently restored an Atlas 110 in lathe and had very good luck cleaning the Gears using Greased Lightning cleaner. I sprayed the gears, let it set a few minutes, and then used a nylon brush to scrub, washing off with water. A couple of applications did the trick. I found several 40oz spray bottles at Lowes for $3.50, but I suspect that was old stock.

Good luck with the restoration!
 
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