Local CL ad - broken lathe. Worth my time?

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MiteyF

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I've wanted a small metal lathe for years, but have always been able to use the machine at work, so it was never a top priority. Now I've moved and don't have access to a lathe/mill and it's killing me. Right now I don't have the money or the space for a large "proper" metal lathe, so doing it the "right way" is out. I keep an eye on CL for deals though (even a cheap Chinese something or other akin to the HF models if it's uber cheap), and found one of these for sale

https://www.ebay.com/itm/253921196417?ul_noapp=true

The seller however has said that the "control board is burned out", and needs replacing. He sent me a few links to Aliexpress brushless/stepper motor controllers running about $100, but I have no idea if that's what needs done. *IF* that's the problem, it shouldn't be hard to source a proper power supply for a small brushless motor, right? Maybe end up changing the pot switch etc? The pictures on his CL ad look like it's seen very little use.

Does anyone here happen to know more about these little guys than I do?

I've built a 3d printer mostly from scratch, have a few years experience with brushed/brushless RC systems, and know my way around a machine shop fairly well, so I think I could figure out a solution, I just don't know the final $ tally.

He's asking $400, and I figure if all of the feeds, gears etc feel fairly tight, I could knock him down another $100 and it might be a decent little project that I could get into cheap.

Any thoughts would be appreciated.
 
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dogcatcher

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Little Machine Shop should have any parts that are needed. It also might not be a control board, it might just be dust on the contacts keeping them from opening and closing. I have to tap the control unit area every time I start to use it, but then mine is about 17 years old.
 

MiteyF

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Skip, I'm the type of sucker who buys "expensive" stuff used most of the time. So long as you're a savvy buyer, you can generally get back what you paid for it. I've bought/sold at least a dozen or so motorcycles/cars in the last few years, and not once have I ever lost a penny. Try doing that with a new car! Not to say there aren't risks involved, but you know, "buyer beware" and what not. If I go buy a brand new lathe, I could put it up for sale the next day and be out at least the few hundred $ shipping cost me. There's no way to win in that situation.

Dog, I'll check LMS. That's the trick with buying stuff that's "broken", it's a crap shoot. I've bought plenty of motorcycles that didn't run, only to find a 15 minute fix that someone overlooked that made me $1000 or 2. But you get bitten once in a while too.

Good thing I like to tinker eh?
 

MiteyF

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Dog, just checked LMS's site, and they have the control box for their 7x14 lathe which looks nearly identical for about $180
 

dogcatcher

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Dog, just checked LMS's site, and they have the control box for their 7x14 lathe which looks nearly identical for about $180
I have been using the same screwdriver handle to tap the control box for over 5 years. Yes, too lazy to open up the box with the circuit board and blow the dust out, but also afraid if I do, my screwdriver tap will quit working. Then I would have to spend money...
 

MiteyF

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A guy down the road from my parents runs one of his homemade tools with a Honda 4 stroke from the 70's. He said he's never changed the oil because he's afraid it will quit working. He just tops it off instead. Runs like a champ after 40+ years.
 

randyrls

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Mitey; If you switch from forward to reverse while the motor is spinning, you WILL burn out the mosfets in the controller. Many lathes have an interlock to prevent this either with a mechanical (middle stop) switch, or electronic circuit that shunts the voltage around the drive transistors.

The link isn't the one you are looking at??
 

MiteyF

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It's the same model (probably where he bought it from), the one I'm looking at however is local (and busted). A bad mosfet would be a lovely surprise actually, fairly easy to replace if you can get to it. I'll ask to see if he's got the board out already and have a look to see if I can tell where the magic smoke escaped. I don't mind replacing a few resistors/diodes/mosfets just to try and bring it back to life, even if it doesn't work. All those things are so cheap now it might as well be free depending on how much you value your time.
 

Woodchipper

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Personally, I would pass. Things like that get out of hand and cost a lot of $$$. Was given a riding lawnmower- spent $400 on it and still wound up scrapping it.
 

frank123

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Blown MOSFET's on the controller is the most common reason for one of those boards to fail.

An easy job to replace if you are at all familiar with electonics soldering (the MOSFET's are the ones with the heat sinks, be sure to heat heat grease when you put new ones in or they will fail rapidly).

Stepping up to a somewhat higher amperage handling MOSFET when replacing will help prevent future failure.
 

magpens

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That's not a bad little lathe ... if you are not using for really precision work. . But I wouldn't pay even $300 if it is not presently in working condition. . Even a new one is not worth the $890 being asked in the ad you show. . Retails here for about $700 USD, less on sale. . And no shipping.

I have been using one, nearly everyday, for pen making for over 10 years and it is still working great with no problems other than a very little bit of wear.

BTW, I very much doubt there is a stepper motor in that machine.
 
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A guy down the road from my parents runs one of his homemade tools with a Honda 4 stroke from the 70's. He said he's never changed the oil because he's afraid it will quit working. He just tops it off instead. Runs like a champ after 40+ years.
He's changing the oil just a little bit at a time and since there's probably no filter on the unit he's probably okay. I wouldn't suggest doing this on something like your car, boat or any other piece of equipment you like or have a lot of money invested in. I change the oil in all my equipment annually. Car and truck every 4,000 miles with a full synthetic oil. Cheap insurance in my opinion.
 

MiteyF

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He shot down $250, said he'd go $300. I'm gonna let it simmer a few days and see if I can't get another $50 out of him.
 

More4dan

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He shot down $250, said he'd go $300. I'm gonna let it simmer a few days and see if I can't get another $50 out of him.


What tooling and accessories will he throw in? My experience has been I’ve spent about as much on those as the lathe. They alone might be worth the $300 he is asking.

Drill chuck, quick change tool post and bit holders, bits etc.

Sent from my iPad using Penturners.org mobile app
 
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MiteyF

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He says it only includes what comes with the lathe - chuck, center and a few bits and bobs. No tooling. If I pick it up I'll be doing some ebay-ing to try and find some basic, inexpensive tooling.
 

magpens

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A 4-inch four-jaw scroll chuck is VERY handy ... bought mine from LittleMachineShop (LMS) for a little over $100. Like it much better for pens than the 3-jaw. I do all my pen turning between centers ... no mandrel, no bushings.

The lathe you showed pictured on eBay retails here for $850 CDN on sale, which amounts to $640 USD. I bought mine 10 yrs ago for under $500 CDN.
 
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