Critique our lathe choice

[MrRoboSteve]

I've been doing some research on a basic tabletop lathe for our team, and based on discussions around the web the one that's risen to the top is the Smithy MI-1237.

http://www.smithy.com/lathe-gear-drive/mi-1237/

Are there other lathes in a similar ($3200) price range that we should be considering?

[Cory]

I have heard good things about this lathe.

971 has it and I believe they are happy with it.

[RoboChair]

I would suggest looking at craigslist for bigger, older, used equipment that comes with the associated tooling to get you started. Tooling can set you back quite a bit if you don't have a really solid plan, even though that one comes with tooling it may not be fantastic. It's not a bad machine, but I wouldn't buy it for our shop.

We just bought 14,000 pounds of machines(5 machines) for $7,500 just by watching for a good deal on craigslist. They were all bare machines and had a few bits missing, but we have similar tooling already which helps and a lot of student labor to fix em up real pretty like.

So now I know what it's like to move 3 Bridgeport mills, a Hardinge HC lathe, and a 3-ton engine lathe 100 miles with 2 rental trailers and move them through a 34 inch doorway like a bad game of Tetris.

If you are looking for quality tooling at amazing prices, I would suggest you check out Shars.com I have yet to encounter any product from them that didn't beat the pants off a name brand price wise while delivering a quality product. They don't make the best, but the do come close.

These are just my opinions, but you can get a huge amount of machine for a STUPID price if you know what you need and have some patience.

I'm sorry if I went on rambling, I just have a lot of machine on the brain these last couple of weeks.

[asid61]

The lathe you've linked to looks pretty good, but I would say Cory's choice is the better bet. It appears to have a larger spindle bore, comes with a QCTP (among other things), and costs a lot less. Plus you can add on a collet set for pretty cheap.
The swing and center distance is smaller, but I doubt you'll be making 11" diameter parts or parts that are 30" long anyway. It's also lower power, but again I doubt you'll even be using 1.5HP with students running it. It's also easier to work with 120v single phase rather than purchasing even more stuff to get 220v.
The one you linked has an offset tailstock, which is a nice feature, but one I doubt you'll need it anyway.
Both show that the dials on the crossfeed are 0.002". I prefer 0.001" graduations, but it's definitely possible to just interpolate to that.

As RoboChair said, Craigslist is a good place to start. I got a medium-size garage mill with easily over $1000 in tooling for $1500. Bridgeports often crop up for less than $2000, less than $1000 if you're lucky/ patient. I'm on the lookout for a lathe for my team right now, but for $3000 I could buy pretty much any lathe I chose on there. My budget is less than $1000 for the team's lathe.
Like this: http://sfbay.craigslist.org/sfc/hvo/5088337161.html
You would need to see it in person, but at a glance it doesn't look too bad. Sure, you also need to buy tooling, but it's got the QCTP already and as such you would just need workholders and cutters.

EDIT: 4 mills and a Hardinge for $7500 is incredibly good. Although the 100mi drive would have been a dealbreaker for me lol. I had trouble just getting the 800lb benchtop mill into the garage.

[MrRoboSteve]

Thanks for the input. The option that Cory pointed out is intriguing.

I watched Craigslist for a while and had two issues with it:

1. Not a lot of metalworking lathes at prices we can afford in our area.

2. I know nothing about lathes and therefore can't judge whether something is a good deal, is fixable, etc. We're bootstrapping ourselves from no knowledge.

S

[Joe G.]

Originally Posted by MrRoboSteve

2. I know nothing about lathes and therefore can't judge whether something is a good deal, is fixable, etc. We're bootstrapping ourselves from no knowledge.

This was incredibly helpful to us when we bought our lathes, both used. We got two great machines. No one involved in the first purchase had any prior machining experience.

[ehochstein]

Originally Posted by MrRoboSteve

Thanks for the input. The option that Cory pointed out is intriguing.

I watched Craigslist for a while and had two issues with it:

1. Not a lot of metalworking lathes at prices we can afford in our area.

2. I know nothing about lathes and therefore can't judge whether something is a good deal, is fixable, etc. We're bootstrapping ourselves from no knowledge.

S

I sent you an email that has a lot of good ideas for the Minneapolis area. If I were to suggest a good local spot for knowledge, I would go to Leonardo's Basement or the Hack Factory.

[asid61]

Originally Posted by MrRoboSteve

Thanks for the input. The option that Cory pointed out is intriguing.

I watched Craigslist for a while and had two issues with it:

1. Not a lot of metalworking lathes at prices we can afford in our area.

2. I know nothing about lathes and therefore can't judge whether something is a good deal, is fixable, etc. We're bootstrapping ourselves from no knowledge.

S

No knowledge could be bad. If any of the students of mentors know a machinist, they could critique a lathe before purchase. If you can't find somebody like that, then maybe new is the way to go.

This one looks pretty good:
http://minneapolis.craigslist.org/da...077388442.html
The person who owns it sounds pretty reasonable, so I'm sure they would let you give it a try to see what kind of cuts and to what accuracy you can make. Looking it up on Google, it sounds like a beast of a machine- several thousand pounds and a 7.5HP motor.
No tooling except a chuck and QCTP, but you can get tooling at that price.

EDIT: Joe's link above is a good guide.

[Jared]

Personally, I'd go for an old south bend or other older American lathe. We have a Grizzly lathe that's pretty terrible, and a smaller south bend that's pretty good. The Grizzly is less than ten years old and has over 1 entire turn of backlash on the cross slide.

Both of the lathes have 1.5" spindle bores, which is nice to have.
Cory's lathe has a quick change tool post with 5 holders.

Originally Posted by Cory

I have heard good things about this lathe.

971 has it and I believe they are happy with it.

I have no experience with this lathe, but I wouldn't recommend it because of the bizarre motor setup.

You can find an... interesting comparison chart on their website:




More seriously, the thing that's really weird about this lathe is that it gets you from 110-1800 rpm (or 50-850 rpm in low gear) without a gear change on a DC motor.

It's not a 3 phase with a VFD like in CNC machines - it's just varying the voltage of the DC motor to go slower. This means that you won't get torque multiplication through a gear reduction as you slow down, like you normally would. You also are changing your motor curve as you decrease voltage so that your torque at any given rpm decreases. You might actually get less torque at 110 rpm than at a much higher speed. Your 1.5 hp motor will act like a 0.1 horsepower motor if you set the speed to 110 rpm. You'll really notice this loss in power if you use a larger drill in steel, or if you're power tapping in the lathe. A slightly dangerous workaround is to set the rpm much higher than it should be, and let the load of the cutting slow down the spindle, but you'll end up tripping fuses/breakers quite often.

It also doesn't have a back gear. For FRC uses, where we're mostly turning aluminum, 850 rpm will work in most turning/parting operation, and it's where you'll get the most power from the lathe. However, there are definitely cases where you'll want to go faster.

My other concerns with this lathe would be quality/customer service. Some quick google searches show that precision matthews isn't well known for timely deliveries or assistance. People on the internet have had trouble with the motor/speed control burning out, which is hinted at in the manual:
"We suggest selecting the low speed. It provides stronger torque while operation."

It's not that big of a deal, but having to remove a bunch of screws to go switch pulleys, and no quick change gearbox might be annoying if you're used to having one.

[AustinSchuh]

Originally Posted by Cory

I have heard good things about this lathe.

971 has it and I believe they are happy with it.

Eh, it is ok. We originally got it because we could put it on a counter without a stand. It is way better than no lathe, but I'd consider looking for something a bit older and heavier if I were to do it again. One of our parents has put a lot of TLC into it, and that has helped.

[Michael Hill]

Here's a pretty good tutorial on checking out used lathes: https://www.youtube.com/watch?v=bP-rh6LfteU

(Also, watch some of his other videos, you can pick up some pretty neat tricks)

[RoboChair]

Originally Posted by asid61

No knowledge could be bad. If any of the students of mentors know a machinist, they could critique a lathe before purchase. If you can't find somebody like that, then maybe new is the way to go.

This one looks pretty good:
http://minneapolis.craigslist.org/da...077388442.html
The person who owns it sounds pretty reasonable, so I'm sure they would let you give it a try to see what kind of cuts and to what accuracy you can make. Looking it up on Google, it sounds like a beast of a machine- several thousand pounds and a 7.5HP motor.
No tooling except a chuck and QCTP, but you can get tooling at that price.

EDIT: Joe's link above is a good guide.

I second this post.

Looking at the machine linked there, it looks in good condition cosmetically. All the important bit are shiny and the price leaves plenty of room for tooling. Advice on moving a heavy machine like this, acquire a trailer or a large truck(Hertz Equipment Rental Center had some great trailer choices at less than 100 bucks for a 24hr rental), get your hands on a chain hoist or pallet jack for unloading, then throw as much manpower at it as you can. cautious application of chains, web straps, 4x4's, and steel pipe rollers can move just about anything.

[Cory]

Originally Posted by asid61

No knowledge could be bad. If any of the students of mentors know a machinist, they could critique a lathe before purchase. If you can't find somebody like that, then maybe new is the way to go.

This one looks pretty good:
http://minneapolis.craigslist.org/da...077388442.html
The person who owns it sounds pretty reasonable, so I'm sure they would let you give it a try to see what kind of cuts and to what accuracy you can make. Looking it up on Google, it sounds like a beast of a machine- several thousand pounds and a 7.5HP motor.
No tooling except a chuck and QCTP, but you can get tooling at that price.

EDIT: Joe's link above is a good guide.

That JET lathe is a piece of crap. We had that exact model in our shop and thankfully parted ways with it. It's also not a 16x40. It's a 13x40. Model is GHB-1340A, if I remember correctly.

Buying used is great if you can get quality older American (or German/Japanese/Korean) machines...the problem is most of those are not going to be classified as "tabletop". With $3,000 to spend I'd be looking at a used Monarch 10ee or Hardinge HLV-H, which are two of the greatest "small" lathes ever made...the problem is the 10ee is 3500 lbs and the HLV-H is 2200 lbs...ie not table top.

I would under no circumstances buy a used Chinese lathe (any small Grizzly/JET/etc). They're all made by the same factory with a different badge and they all suck.

[RoboChair]

Originally Posted by Cory

That JET lathe is a piece of crap. We had that exact model in our shop and thankfully parted ways with it.

Buying used is great if you can get quality older American (or German/Japanese/Korean) machines...the problem is most of those are not going to be classified as "tabletop". With $3,000 to spend I'd be looking at a used Monarch 10ee or Hardinge HLV-H, which are two of the greatest "small" lathes ever made...the problem is the 10ee is 3500 lbs and the HLV-H is 2200 lbs...ie not table top.

I would under no circumstances buy a used Chinese lathe (any small Grizzly/JET/etc). They're all made by the same factory with a different badge and they all suck.

I definitely agree with your principal Cory, but I have found some Chinese equipment that functions adequately before. It will never be the BEAST that a Hardinge HLV(mmm that dovetail way) is, but it being used may actually be better than buying a new one. Who knows exactly what you are getting new with a Chinese machine, but if you are buying off someone that really has used it regularly for some time they have had time to break it in and find fixes. They do require a lot more regular maintenance to be serviceable however. You will never catch me buying a new Jet/Grizzly/etc, but I might still check out an old one on the chance it may surprise me.

[theawesome1730]

Originally Posted by RoboChair

It will never be the BEAST that a Hardinge HLV(mmm that dovetail way) is, but it being used may actually be better than buying a new one.

Yes! This this this! TD has a Hardinge HLV-H and a Grizzly (or something similar) and there is no comparison. If you can afford it and have room, the HLV-H is about the best you can get. Way better than a new lathe unless you are spending tens of thousands on it.