ELS on Mini-Lathe?

devils4ever

devils4ever

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I have a Micro Mark MicroLux 7X16 lathe and I'm trying to determine if it's worth putting on ELS. I want it because I seem to be doing a lot of threading and I'm getting tired of changing gears. But, it's a small lathe and adding ELS could be challenging. I really don't have the room for a larger lathe at the moment, but is it worth it?

Opinions?
 
I don';t think an ELS would be particularly challenging on a 7 x 16 lathe. The largest component would be the stepper/servo motor. A NEMA 23 motor frame would be appropriate. The other mechanical components would be the encoder, pulleys, and belts. All the change gears would be removed.

Is it worth it is another question. Does an ELS give you any additional capability? e.g., reference, the Clough42 ELS It will give you forward and reverse on the lead screw, possibly a greater range of threads and feeds, Imperial and metric threads at the touch of a button, and a spindle rpm display.

As to cost, I converted my lathe for $225, using some components on hand. A more likely cost would be $350 to $500. There will be a moderate amount of work required including some milling; it's not plug and play. Your call as to is it a good value.
 
I have a working system (Clough42) on my work table. I am waiting on a 60 tooth gear and I still need to design and CNC the 2 brackets. I know for me, adjusting seen on the fly (VFD) was worth it and the ELS will even be a better improvement. For threading it is priceless (for someone that does a lot) for me, getting the right, fine tuned, rate is going to be so nice. I say do it!
 
I guess there's two aspects to this potential project. The first is whether it's worth putting on an ELS onto such a small lathe. So far, I haven't run into any problems with the size. I've been able to turn everything I need to. I would LOVE to be able to take bigger cuts. That's where this lathe is lacking. I see youtube videos where they are taking deep cuts on a full size lathe without issue that I could only dream of on my lathe. I would need to take 3, 4, 5 or more times as many cuts to achieve the same thing. A little more rigidity would be nice as well.

The second aspect is actually attaching this to the lathe. See pic below with a 12" rule for reference. I think mounting the stepper might be fairly straightforward, but the encoder on the main spindle looks challenging. It seems a little tight in there. I have no problems dealing with the electronics and wiring since I just finished converting my PM25 to CNC. Mounting the encoder and stepper looks more challenging. Also, I've never dealt with stepped pulleys and belts. Where to get? What size? etc.

IMG_5597.jpg
 
I'm sure you're already aware that the thing limiting your cutting is the mass of cast iron you are missing. No matter what attachments or how big a spindle motor you add, you'll never take a cut like a larger lathe will.

So here is a thought... Take the $500 you'd spend on the ELS and put it towards a larger lathe with a quick change gearbox. Yes, you'll still need to change gears to do metric threads, but whatever. I found a used 12x36" lathe (1000lbs) for $1200. That was a decent deal, but there are lots of options out there. The lathe you have is great to learn on, but will never be a production machine.
 
It's not so much the $$$. It's the space and access. I barely have enough room for this mini-lathe. It mounted on a plywood base with wheels which I'm constantly moving around. Plus, getting a larger lathe into my basement is tough. No outside access and stairs with a 90 degree bend halfway down.

My PM25 mill was tough to get into my basement.
 
100% agree then. I brought my 12x36 down the basement and it sucked! had to bring it down in pieces!
 
If you are committed to sticking to the little lathe, I expect you could install an ELS on there. As for if it's worth it, it depends on how much you find yourself messing with the gears and how annoying you find that. I like the ability to thread without changes, but the biggest reason for me was easily variable feed speed.

I went with replacing one of the gears on a stack with a GT2 pulley. So the spindle drives a normal gear, stacked with the pulley. That drives the encoder. I kept the ratios the same, so the encoder ends up 1:1 with the spindle. That's not strictly necessary, but I would suggest doing it if you can or at least using a whole number ratio. There is almost no power needed to spin the encoder, so it doesn't have to be really strong or anything.

The servo you could mount to the bench if you had to.

The GT2 belts and pulleys are available on Amazon. They are super common on 3D printers, so they are everywhere. They also have some of the larger ones, but I ended up ordering them direct from China on ebay. The encoder came that way as well. I think everything else had US sellers.

One thing I would want if it were me, is power cross feed. I'm not aware of any minis with that. The smallest I've seen with that is the PM1022. But if you're really tight for space, it might not work for you. There are a few mods that might help with rigidity, like replacing with compound with a solid block. But overall, your limit for cut depth is mostly down to the size of the machine. I have a PM1127 and have a similar issue there. I just figure it's a hobby, so I don't mind a few extra passes. I can't make a 4" deep cut like Abom, but I don't really need to either. :)
 
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devils4ever said:
I guess there's two aspects to this potential project. The first is whether it's worth putting on an ELS onto such a small lathe. So far, I haven't run into any problems with the size. I've been able to turn everything I need to. I would LOVE to be able to take bigger cuts. That's where this lathe is lacking. I see youtube videos where they are taking deep cuts on a full size lathe without issue that I could only dream of on my lathe. I would need to take 3, 4, 5 or more times as many cuts to achieve the same thing. A little more rigidity would be nice as well.

The second aspect is actually attaching this to the lathe. See pic below with a 12" rule for reference. I think mounting the stepper might be fairly straightforward, but the encoder on the main spindle looks challenging. It seems a little tight in there. I have no problems dealing with the electronics and wiring since I just finished converting my PM25 to CNC. Mounting the encoder and stepper looks more challenging. Also, I've never dealt with stepped pulleys and belts. Where to get? What size? etc.

View attachment 331605
Click to expand...

If I were converting your lathe to an ELS, I would remove all the gears and the reversing banjo mechanism. Ideally, I would replace the spindle gear with a gear belt pulley driving another gearbelt pulley on the encoder shaft, located toward the front of or below the spindle. The stepper motor would be either have a gearbelt pulley driving a second pulley mounted on the lead screw shaft. This arrangement wold be oriented horizontaslly at the bottom of the lathe.
 
Yeah, this is a tough decision. Having more space and basement access would have me sell this lathe and go for a bigger one. If nothing else, I'd get more rigidity and mass.

I'm not familiar with GT2 belts and pulleys. Are there any that would fit the main spindle gear? The pulley's ID would have to be matched to the spindle's OD. It looks like a set of special wrenches are needed to remove the current setup. I'm not as concerned with the lead screw shaft since it's a lot smaller.
 
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