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Jet BD-920 lathe inquiry

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ARC-170

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QUESTIONS FOR THE BRAIN TRUST:
I have come across a Jet BD-920 9x20 lathe.

NEED PARTS
1. Change gears. Jettools.com has them, but the entire set costs about $700.
2. Steady and follower rests.
3. Tail stock hold down nut (currently has a bolt)
4. Drive belt. The one on there is too tight.

Are these readily available elsewhere?

REFURBISHMENT
How hard are these to take apart, clean and re-paint? Any special tools required?

TOOLING
Looks like LMS has most of what I need. Anywhere else have decent, inexpensive parts and accessories?

I've attached some images. The gearbox image is a bit dark. The gears for the leadscrew do not engage because they don't reach each other. I think the gears need to be switched out.
5.jpg 6.jpg 7.jpg 8.jpg
 

Bi11Hudson

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#2
I could write a book on the BD-920. I have, and occasionally use, a Grizzly G-1550. A defunct product, Grizzly now sells the G-4000. The only difference I have found is on the spindle nose. The 1550 uses 1-1/2X8, the 4000 uses metric M39X4. The difference only comes into play with another machine. I also have a Craftsman 12X36 that uses the 1-1/2X8, so the tooling is mostly interchangable. There may be a few other places where metric fasteners replace imperial. No big deal, I work with either and stock both.

If the price differential is not beyond your reach, you could do as well with a new Griz which comes with all the goodies you were asking about. Harbor Freight is another source, but it will require a lot of work to "bring it up to speed". But for the most part, the parts are interchangable. Good source for gears and the like. Balancing the costs is a call only you can make. But the Jet is not so rare, just a well finished version of a common machine. It is a much better choice than the 6X12, or whatever size bed.

The gearing is metric Modulus 1X20 degree. The same as most such machines. A really big issue is the 127/120 compound gear. That allows metric versus imperial threading. Such gears, steady rest, follow rest, and all the other goodies can be found at http://www.grizzly.com/. Tell them you have a G-1550, they'll be easier to get along with.

The belt does vary with machine delivery date and sometimes vendor. It is a Gates 5Mseries. Mine uses the 5M710, when I acquired a HF machine, it had a different length. As in, my spare wouldn't fit. The local supplier is Motion Industries. Another would be Dixie Bearings. Any vendor that carries the Gates line should be able to acquire. The 5M is the metric 60 degree cross sectional design, the 710, or whatever you have, is the length in MM.

A quick change (QCTP) tool post is highly recommended. As is a more stable compound base. The AXA series fits well, you could use a OXA if that's all you had. But with a little finagling... ... Avoid the BXA, the lathe is too small. My personal experience with tooling is mostly carbide for roughing, and tool steel for close tolerance work.

That isn't a book as such, but should be a good introduction.

Bill Hudson​
 

ARC-170

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Bill: Thanks so much for all the info! I really appreciate it. I'll look at the machines you mentioned. Maybe I can find a used G-1550.

How hard are the components to disassemble? Looks like the motor comes off with a few bolts. What about the rest of it?
 

Bi11Hudson

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I wouldn't expend a lot of effort looking for a G-1550. It went out of production(?) about 1994 when Grizzly replaced it with the G-4000. At half the price. A 1550 was made in Taiwan, a 4000 is still currently made on mainland China. There is a difference in quality, but I won't go there, I have too much bias.

The Jet is(was) the same source as the 1550, just different paint. Either is comparable to the other. But consider either to be in a higher dollar bracket than most of the other mentioned brands. That includes factory fitting and adjustment. Mine arrived in '92 (thereabouts) dead true with no measurable runout on the chuck. Look in http://www.hudsontelcom.com/BilzPage2.html for a tale about back gearing one with an old automotive transmission as parts donar. I think a GM, but not too sure.

I noticed in your photo what looks like the 127/120 metric conversion gears. If that's the case, the gears just got a lot cheaper. Now, below the large gear in the photo is what the Chinese consider a "banjo". Loosen the clamp screw and rotate that until the gears mesh. If it is what it looks like, that should get the threading up and running. Provided, of course, there isn't a burr or some other damage in the quick change box. And remember, the photo is a little dark and it's hard to be sure. On the center of the conversion gear is a clip in a groove on the shaft. Remove it and the gears, remembering which one is outside. You should then be able to see what's where. If any parts are needed, you can look at Grizzly, Harbor Freight, and most any machine that has a similar build. For what you want, find whoever has the lowest price.

As far as disassembly, common tools are all that's needed. The issue is getting it all back together true. The cross slide and headstock truth are the biggest problems there. The user's manual for a G-4000 will cover most of what is necessary. It is free to read on the Grizzly site. Just save to a file. The cross slide requires as much care as the headstock to get right.

For painting; I wouldn't. Unless it's been exposed to some chemical softener. Most of the bare metal I see in the photos is supposed to be bare. And kept with a little oil so it won't get rusty. You ever see a true machinist with clean hands? It's not like accounting. But then my old man was an accountant and his hands always had ink stains. That was back before computers, though. For cleaning, use a good "way oil" and a rag. For really nasty stuff, use kerosene and "scotch-brite" to scrub it. As a rule, avoid WD-40. The WD stands for water displacer. A good solvent but useless as a long term lubricant. The paint should be clean, but not so shiny as to comb your hair in the reflection. From what I see, just clean it up and don't worry about it.

I've rambled on enough here. Look to my website for some insights to the machine and what it is capable of. EDIT: As an afterthought, the photos of the machine down the road don't show the inside of the gear train. It looks good though. And, if it has all the goodies you need, should do the job. But if you're considering it, look beyond the "brand". Perhaps an older Atlas or Craftsman 6 inch machine would do as well. Some work to get up to speed, but made in the U.S. and still highly regarded by anyone that has one.

Bill Hudson​
 
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ARC-170

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Bill: Thanks!
The lathe I came across needs some work to get up to speed. It sounds like you're telling me it looks pretty good and I won't need to spend a ton of money to get it going.

I can buy a new G0768 or G4000 for about $1500 so the CL one is not really a deal to me. He doesn't really have much extra than what a new lathe comes with, either. I was thinking of offering $700-900 for it. I don't like to pay more than 1/2 to 2/3 of new when buying on CL. The seller is upgrading so maybe he's desperate to get rid of it. However, is he asking a fair price?

One of my purposes in asking in the forum is I'd like to know what a fair price is for a smaller machine like this. I also want to get a mill, but cannot go full size; I don't have enough room and need to mount this safely on a rolling tool chest or shop-build wood table. So my budget is limited as well. The CEO (Wife) needs to be consulted and give her blessing!

I'm not really concerned about a particular brand; I'm fine with anything that is decent and has parts and tooling readily available. I've learned quite a bit about what to look for and pricing on this site and hope to continue to do so!
 

Bi11Hudson

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#7
I really cannot give an estimate in dollars. It has been 20+ years since I bought the Griz. And almost that long since I bought a HF copy. I am medically retired from my mill job and have been scrambling for income since. And that over 10 years ago. I would say what is the spindle thread? M39x4 or 1-1/2-8 will effect your ability to find tooling. I found the Craftsman with the same thread as the Griz. That allowed interchange of many fixtures. And ease of finding more.

I do have my Griz up for sale, but not officially. My thoughts are that I want considerably more for it as used than a new one from HF costs. And most of the people that would be interested don't know or recognise the difference. Those that do understand the difference would want a larger machine. I can't, because I'm in a wood framed structure that was built in 1905. The Craftsman 12x36 is about as heavy as I dare. The Griz is about the same weight. I'm stuck because I can't have more weight.

As far as what you're asking, just keep in mind that you are located in a place more conductive to "horse trading" than I am. The deep south has a much lower factor of machine tools than your area. And much less free income. The issue comes down to why you want such a machine. If a small one will do what you want now, what about when you grow larger. Such a small machine could end up an albatross if you acquire a larger machine. Bottom line $700. If it goes over $1000, walk away. A $1000 machine can be found, if you're patient. And if you can stand the weight and size. I found some when I first started looking (1990) but they were far too heavy. And some could be had well under a kilobuck in those days. Of course, I was working in those days and had more "disposable" income.

Any discussion figured in dollars gets into my politics which are conservative as all get out. So I prefer not to go there. Any machine is always better than no machine, so it comes down to what you want to do. My eMail is bhudson at hudsontelcom dot com if you need to talk further about what I have little patience for. That being what can be acquired for how many dollars. No need to tie up board capacity for that off topic discussion.

Bill Hudson​
 

rwm

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#8
I recently sold my Jet 9 x 20. It was in near perfect condition and had a DRO added. Also, NO RUST. I sold it for $1000. That lathe for $1400 is a joke.
One issue with this lathe is the lead screws are metric but the dials are imperial. There is a cumulative error of .004" per revolution of the cross slide. It took me a year to figure that out. I would recommend looking at the Atlas or South bend lathes. You could find a nice one for $1000.
Robert
 
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ARC-170

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Update: I offered $800. He came down to $1200. I can get a grizzly delivered with tax for about $1400. I typically don't like to pay more than half of new, especially on CL. I'll keep looking.
 
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