Logan Model 200 Servo Threading

TomKro

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I was wondering how you planned to put a stepper motor in there and still be able to close the door. Great job packaging all the hardware.

Please let us know how the NEMA 23 motor works out for moving the carriage under cutting loads.
 

rwm

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Beautiful install! I would love to install this on the tailstock end of my SB 10K.
R
 
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Hukshawn

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so what would you estimate the cost/difficulties of getting a set up like that for a person that doesn't know an arduino from an ar$ehole
Lol, my dad used to say arse. That made me laugh.
 

Briney Eye

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so what would you estimate the cost/difficulties of getting a set up like that for a person that doesn't know an arduino from an ar$ehole
Quick estimate, about $350 in parts (motor/controller/encoder/microcontroller, miscellaneous electronic bits, pulleys and belts, enclosures etc.). Some things you have to buy in multiples, and I'm probably forgetting something, so make it $400 for materials. Of course I've spent a lot more than that in development costs. I've got a pile of spare electronics, a number of encoders, and quite an assortment of timing belts and pulleys at this point.

I've got a fair number of hours into programming the microcontroller and display. I've been working on it evenings and weekends since late November. It's been a significant effort. Lots of fun, but I've made a career doing this kind of R&D for nearly 40 years now. It's impossible for me to estimate the degree of difficulty for a novice.

I'm considering putting this together as a kit, but there is a lot to consider. I could shave some cost. It might make sense to contract out some fabrication. There is packaging and shipping. I would have to support it. And then there's the big one --- liability.

I did a respiratory monitor for a retired anesthesiologist years ago. He had the patents on half the ventilators in North America and Europe, and his liability insurance was costing him $250k a year. Lord knows what it would be now. He told me that his rule of thumb was that the "retail" cost had to be a minimum of 5X the build cost. I haven't consulted a lawyer on the limits of my liability, even if all I offered was a download. I assume that I would have to set up an LLC.

I still have to get it properly installed and a considerable amount of due diligence to make sure it's rock-solid. Bottom line, I might have to charge $1500 for a kit. Maybe I could do the download for $200, maybe I could kit the hardware for $500, maybe I could offer all three options. I would still have to support it, and there would still be liability. Even if I post it to GitHub and give it away there's liability.

All that, and I don't know how big the market is. I can't imagine selling more than 100 kits to Logan owners. Shoot, I probably couldn't sell 100 downloads! I might be able to broaden the appeal by doing versions for other lathes, but I don't know enough about what's out there. The Model 200 happens to be the perfect candidate for this. Anybody have suggestions for other non-gearbox machines? Or maybe there would be interest in an outboard version that would drive the other end of the leadscrew with the QCGB disengaged. Still have to get an encoder on the spindle, though.

Sorry, I thought that this was going to be a short post. Back to the shop!

-Jon
 

rambin

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well the 700 that I have is very similar to the 200...not even sure what the difference is other then mine was made for wards... I cant see why there would be big liability....with a respirator your talking someones life with this your talking a piece of steel with messed up threads. if your looking to market this and become a millionare theres prbly not enough interested logan people out there...if your wanting to help out fellow logan owners and make a slight profit then maybe.. at 1500 I wouldn't even think of it.. and im sure moston here are with me on that!
 

Briney Eye

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Yep, this is the "Hobby" Machinist site, after all. I'm doing this mostly for my own entertainment, with the reward being my own satisfaction, some validation from like-minded folks, and a lathe that is really nice to use. If money changes hands I incur liability and expectations of support.

The anesthesiologist was dealing with a lawsuit while I was working for him. A hospital technician had replaced the air fitting on a ventilator with an oxygen fitting, resulting in a rather intense fire in the operating room, and they went after the staff in the OR, the hospital administration, the manufacturer, and the designer. Everyone, in fact, except the technician responsible. Observing what he had to go through made me paranoid.
 

rwm

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Totally awesome! How does it work for regular feed for cutting?
Robert
 

rwm

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Can you give us some follow up on this awesome project!?
Robert
 

Briney Eye

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Can you give us some follow up on this awesome project!?
Robert
Had some family health issues to deal with, but I’ll be getting back on it soon. Last thing I did was switch to a “spare” controller from a different source to see how it worked. I expected it to be compatible, but it wasn’t working very well. Lots of noise and resonance, so I’ll have to hook up to the RS232 port and tune it, I guess. I’m hoping a download from Leadshine will provide the utility and guidance, but the documentation is a little sparse on these things. I’ve verified most of the feed rates against a dial indicator and the DRO and everything has checked out so far.
 

jh1990

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Are you using a thread dial for threading?

Or are you able to run the motor in reverse and have the stepper turn the opposite direction?

I'm sure you could have the arduino keep track of the steps and return to a "zero" point without having to run the motor in reverse especially if you add limits.
 

Briney Eye

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Are you using a thread dial for threading?

Or are you able to run the motor in reverse and have the stepper turn the opposite direction?

I'm sure you could have the arduino keep track of the steps and return to a "zero" point without having to run the motor in reverse especially if you add limits.
I've set it up so everything works pretty much "normally," thread dial included. The microcontroller just takes the place of the change gears, and adds the ability to do metric, diametral and module pitches. It does allow switching the lead screw direction on the fly, which is useful for facing.

I've been planning all along to add the ability to set limits, but I've started having second thoughts. It works so well as it is, and I'm not sure the added complexity would really be worthwhile. I plan to give it a try and see how it feels, though.
 

Briney Eye

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I've been neglecting this thread (and project). I thought that I ought to put up a couple of pictures of what I've got at this point. The electronics are enclosed. I extended the drum switch bracket and mounted the touch screen on a friction hinge. The main box will mount on the leg under the headstock:

IMG_1963.JPG

The "home" page. The touch screen and knob make for a very straightforward interface:

IMG_1970.JPG

There is a setup page for displaying the valid spindle RPM's for a given feed rate and adjusting the screen brightness, and a page for setting feed limits, but I don't have pictures. Right now I'm re-writing the jog code, but I'll have it all working any day now. I swear.
 

middle.road

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What a mod! It is, in my mind at least, still very cool. On an Ol' Logan Model 200 no less. :encourage:

Now all that is needed is a complete write up with diagrams, schematics, drawings, and a BOM. :grin: (I'll see myself to the door now...)

Wish I had the talent, not to mention the time, to take this on and do mine up.
 

Briney Eye

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I could stop right where I am and just have a programmable gearbox, jog, and instant feed reverse, but I think it would be cool to add a couple of "enhancements" while I'm at it. I was watching Robin Renzetti make a differential screw (look him up on YouTube and Instagram if you haven't already) and thinking how neat this would be for that. Want 0.001" per turn? Do one thread at 0.025" pitch and the other at 0.026" and there you are! Of course, that means that I have to add "custom" feed rates now in addition to the 79 fixed inch rates that I already have. It's only software, right?
 

middle.road

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Getting into "differential screws" now -eh? I caught that video of Robin's awhile back.
Soldering fumes are being ventilated properly aren't they? :grin:
Edgewood is only @6700' so lack of oxygen isn't a factor...

Talk about breathing new life into Old Iron.
 

Richard White (richardsrelics)

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I would love to be able to thread on a taper, using an older machine, with your setup... Now that would be epic!
 
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Briney Eye

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I would love to be able to thread on a taper, using an older machine, with your setup... Now that would be epic!
Too bad that Logan taper attachments are so rare, and expensive when they do surface. The way that I set up the digital scale on my cross slide would lend itself to adding a taper attachment if I ever have a need and decide to build one.
 

Richard White (richardsrelics)

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I currently have both original end pieces and an original cross slide cover for the correct Logan Taper attachment.. Only missing the bar, need the length to make my own and finally need, well not really... Only need the correct length of the bar as with my Bridgeport I can make the rest...
 

Briney Eye

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I currently have both original end pieces and an original cross slide cover for the correct Logan Taper attachment.. Only missing the bar, need the length to make my own and finally need, well not really... Only need the correct length of the bar as with my Bridgeport I can make the rest...
When I bought my 200 it had the cross slide extension for the taper attachment, but the attachment itself was long-since gone. I gave the extension to someone for the cost of shipping it to him. I had to make a sheet metal cover for the bracket and digital scale that I added and couldn't use it, anyway.
 

greenail

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When I bought my 200 it had the cross slide extension for the taper attachment, but the attachment itself was long-since gone. I gave the extension to someone for the cost of shipping it to him. I had to make a sheet metal cover for the bracket and digital scale that I added and couldn't use it, anyway.
are you planning on sharing the source code?
 

Briney Eye

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are you planning on sharing the source code?
I'm waffling, because I can't decide whether I want to turn it into an actual product. Of course, I kinda have to finish it first. Over the weekend I ripped out the jogging routines and completely re-wrote them. Much cleaner code, and a better acceleration profile. It tends to work that way, since on the first (or second) pass you don't really understand the problem. Then I worked on feeding/threading to a shoulder some more. It's going to take another pass or two to get that right. Then I have several other "enhancements" on my list. Software is never done.
 

jwmay

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Just wanted to drop a note to say there’s at least one more stranger on the internet that is highly impressed with your project. I’m an industrial electrician by trade, and have often tried to imagine how this could be done. Unfortunately,I’ll likely never be knowledgeable enough to pull it off. It’s easier to identify a broken one(me) than design and implement(you). Lol I read in a trade magazine that Monarch I think, has put a programmable leadscrew on their newest lathe.

As far as cost of a kit, I’d say you’ll have to come in under 500-600 dollars . Only because that’s the going rate it seems for a QCGB. Your kit though, after complete, looks to add additional,valuable functionality that a person wouldn’t get, even with a QCGB. Anyhow, I’m convinced you’re way ahead of me on that whole thing too, so I’ll stop now. Kudos to you. It’s a great project, and a fine testament to your ability.
 

markba633csi

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Electronic taper attachment! Now that would be awesome too, since the mechanical ones are so expensive and rare for some machines
Nice work Jon
Mark
 

Briney Eye

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Thank you for the kind words. Like I said, I have some "features" to finish. I've been working on this in fits and starts, but I've been pushing the last couple of weeks to finally get it done (for certain values of "done"). I'm probably going to retire next month and get a detached shop built this summer. That will give me some room to do things.

I know that there are Hardinge HLV clones now that have been computerized. I saw something about Monarch buying old 10ee's for the iron and rebuilding and retrofitting them with a modern drive system. In fact, a 10ee just came up locally, and I was going to try to get a look at this afternoon. If I buy it I'll have to rent storage for it until I have the shop built, but it would make a great project.

So, my plan is to finish the last bits of the leadscrew "soon" and do a lot of pictures and a video or two. Threading to a shoulder is really slick, but I'm missing something in the synchronization. I really want to get that working right and put out a video. I think that will impress people more than anything else.
 

Briney Eye

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Electronic taper attachment! Now that would be awesome too, since the mechanical ones are so expensive and rare for some machines
Nice work Jon
Mark
It would be interesting, but it's outside the scope of what I'm trying to accomplish. My goal is something that will bolt on to a stock Model 200 (and maybe some other QCGB-less lathes further on) and give the functionality of a Monarch 10ee with an ELSR. A full CNC lathe is another animal entirely.
 
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