Quantcast

Looking for advice on getting a lathe

The Rocketry Forum

Help Support The Rocketry Forum:

Thorfire

Well-Known Member
Joined
Dec 29, 2013
Messages
236
Reaction score
31
I’m looking for a little guidance on putting a lathe in our shop. When I told my son to ask about using one at his Jr high, he found out they his school got rid of all the machines in their metals shop because of a lack qualified of teachers. Based on the projects I see us working on in the next few years I’d like to find something 40” between centers. Larger would be nice, but the size and weight of the machine could start being a factor…. For rocketry, we would be making parts for research motors, inter stage couplers (we have MD 54mm to 38mm and MD 75mm to 54mm planned for this years, and likely larger projects in the future) The possibilities I’m looking at right now are:
• New Enco / Birmingham/etc. Asian 13x40 lathe (about 800-900lbs, plus 200-300lbs for the stand).
o Plus - plug and play
o Minus – may not be the most accurate machine – a lot lighter that a 14” lathe, would eventually get drawn into getting a benchtop mill to go with it.
• Used 14 x40 lathe with about a year of use in a tech school (they just traded a couple in for larger ones). Comes with all tooling like a new one. 1700-1900 lbs.
o Plus - fresh check out and service from the dealer, plug and play, probably the best I could conceivably afford right now – about the same price as the new Asian ones.
o Minus – needs a 3-phase converter – extra$$, would eventually get drawn into getting a benchtop mill to go with it.
• Smithy Granite 1340 3-1 lathe mill combo (about 750lbs)
o Plus - plug and play, already has a milling machine, so no worries about that. Less expensive than one of the above lathes AND a new bench top Asian mill.
o Minus – may not be the most accurate machine – a lot lighter that a 13” Asian lathes, belt changes for speed changes, a lot of tooling (4 jaw chuck, steady rest, etc.) not included. questionable reviews of some 3-1 machines.
• Craigslist lathe
o Plus – likely half the cost or less of above options
o Minus – hard to find lathes in this size range, random availability may push us into not having one in time for this year’s projects.

My son Orion’s project last year:
https://www.flickr.com/gp/18181108@N05/4r72s5
 
Last edited:

patelldp

Well-Known Member
Joined
Jan 23, 2009
Messages
5,647
Reaction score
86
I’m looking for a little guidance on putting a lathe in our shop. When I told my son to ask about using one at his Jr high, he found out they his school got rid of all the machines in their metals shop because of a lack qualified of teachers. Based on the projects I see us working on in the next few years I’d like to find something 40” between centers. Larger would be nice, but the size and weight of the machine could start being a factor…. For rocketry, we would be making parts for research motors, inter stage couplers (we have MD 54mm to 38mm and MD 75mm to 54mm planned for this years, and likely larger projects in the future) The possibilities I’m looking at right now are:
• New Enco / Birmingham/etc. Asian 13x40 lathe (about 800-900lbs, plus 200-300lbs for the stand).
o Plus - plug and play
o Minus – may not be the most accurate machine – a lot lighter that a 14” lathe, would eventually get drawn into getting a benchtop mill to go with it.
• Used 14 x40 lathe with about a year of use in a tech school (they just traded a couple in for larger ones). Comes with all tooling like a new one. 1700-1900 lbs.
o Plus - fresh check out and service from the dealer, plug and play, probably the best I could conceivably afford right now – about the same price as the new Asian ones.
o Minus – needs a 3-phase converter – extra$$, would eventually get drawn into getting a benchtop mill to go with it.
• Smithy Granite 1340 3-1 lathe mill combo (about 750lbs)
o Plus - plug and play, already has a milling machine, so no worries about that. Less expensive than one of the above lathes AND a new bench top Asian mill.
o Minus – may not be the most accurate machine – a lot lighter that a 13” Asian lathes, belt changes for speed changes, a lot of tooling (4 jaw chuck, steady rest, etc.) not included. questionable reviews of some 3-1 machines.
• Craigslist lathe
o Plus – likely half the cost or less of above options
o Minus – hard to find lathes in this size range, random availability may push us into not having one in time for this year’s projects.

My son Orion’s project last year:
https://www.flickr.com/gp/18181108@N05/4r72s5
You want exactly what I have...a South Bend 13" x 6' bed (~42" long case capability). Can be had without tooling for ~$700-1,000 depending on your locale and may require a motor swap.
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
6,617
Reaction score
3,436
Location
Butte, Montana
Definitely not the Smithy. I have an older Jet 13x36, made in Taiwan, rather than the mainland. It's pretty decent, but I'm still fixing it up (everything's a project). I think the best choice of the ones you listed would be the 14x40 with all the tooling. The three phase convertor is not very expensive.
The older South Bend belt drive lathes were nice, but good quality new gear head lathes are very capable. I wish I had gotten a used school trade in like your second option. I did look at a South Bend with an 8 foot bed (total bed, not between center length) but I didn't have room for it.


Steve Shannon
 

SCP

Well-Known Member
Joined
Jun 24, 2011
Messages
412
Reaction score
17
Don't rule out just buying a 3 phase motor and making your own converter. I have been running a few of my machines with a converter for decades.

What make is the one at the school?
 

Thorfire

Well-Known Member
Joined
Dec 29, 2013
Messages
236
Reaction score
31
Don't rule out just buying a 3 phase motor and making your own converter. I have been running a few of my machines with a converter for decades.

What make is the one at the school?
The school trade in is an Acra GH-1440A that was used there for a year. While I'm sure I could make a 3-phase converter, I don't realistically have the time to invest in it before we need this running. Static converters are about $300…
https://www.acramachinery.com/Manual_Machines/1400FEL-E.htm
 

MClark

Well-Known Member
Joined
Jan 21, 2009
Messages
2,696
Reaction score
773
Location
Glendale, AZ
I would suggest whatever you get hiring a machinery mover.
The money it costs doesn't go far in the emergency room.

I work for a gunsmith, our big lathes and mills run off phase converters..

M
 

FredA

Well-Known Member
Joined
Jan 19, 2009
Messages
2,170
Reaction score
347
I would suggest whatever you get hiring a machinery mover.
The money it costs doesn't go far in the emergency room.


Wise advice.
We rigged one of these bad boys....a vintage Sydney that was used to turn prop-shafts by the Navy.
Was not fun.
The two 8-ton forklifts we rented couldn't lift it off the flatbed.
Long story short, it became one of the scariest things I've ever done.

Lathe.jpg
 

chris m

Well-Known Member
Joined
May 24, 2013
Messages
1,834
Reaction score
5
Look at government salvage , or a university salvage like Purdue salvage look them to see what I'm talking about . Also a lathe is the only machine that it could build or rebuild it self or anything else
 

patelldp

Well-Known Member
Joined
Jan 23, 2009
Messages
5,647
Reaction score
86
It's the common bit of tool lore often discussed about lathes. Theoretically a lathe could clone itself if you have a milling attachment, collet closer, and unlimited capacity.
 

warnerr

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 4, 2011
Messages
360
Reaction score
44
dont worry about three phase- most if us have been using old school phase converters for years. today you can get inexpensive solid state variable frequency drives that happen to include two to three phase conversion- price 120 to 350 - tons on ebay, easy hook up. On lathe- look at bore through chuck- bigger opening is better! Weight is your friend. used american made better than new Chinese. Used with electronic controls- deluxe!
 

Binder Design

Sponsor
TRF Sponsor
Joined
Jan 18, 2009
Messages
1,820
Reaction score
232
It's the common bit of tool lore often discussed about lathes. Theoretically a lathe could clone itself if you have a milling attachment, collet closer, and unlimited capacity.
If only it were that simple. The bulk of a lathe is cast parts, namely the bed.
 

chris m

Well-Known Member
Joined
May 24, 2013
Messages
1,834
Reaction score
5
Yes and old school green sand casting and India blue you can .
 

BuiltFromTrash

Well-Known Member
Joined
Aug 7, 2014
Messages
305
Reaction score
2
You would still have to grind the ways. I say no-can-do. A lathe can't clone it's self.

As for advice, a lathe is a big expenditure. Get one that will last, has good accuracy. South Bend gear-head if you can. Also a digital readout is a nice accessory to have.
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
6,617
Reaction score
3,436
Location
Butte, Montana
You would still have to grind the ways. I say no-can-do. A lathe can't clone it's self.

As for advice, a lathe is a big expenditure. Get one that will last, has good accuracy. South Bend gear-head if you can. Also a digital readout is a nice accessory to have.
My comment was tongue in cheek, meant to be humorous, but some small lathes have heavy steel turned and ground bars instead of ways.



Steve Shannon
 

waywayanda

Well-Known Member
Joined
Feb 10, 2010
Messages
119
Reaction score
0
The thing to keep in mind is decent quality accessories (chucks, faceplates, collets & closer, steady rests, tool posts/holders, tooling, etc) can easily cost as much as the lathe. The more accessories that come with the purchase is money in the bank.
 

Binder Design

Sponsor
TRF Sponsor
Joined
Jan 18, 2009
Messages
1,820
Reaction score
232
Most important consideration: Through hole size. Everything else is further down the list.
 

FredA

Well-Known Member
Joined
Jan 19, 2009
Messages
2,170
Reaction score
347
Most important consideration: Through hole size. Everything else is further down the list.

Really, why?
Most lathes I see are not very big wrt through-hole size.
Trying to get one big enough for 75mm is hard....more is near impossible without spending a ton of coin.

You can make an internal spindle that expands to grasp the tubes on the inside this allows you to cut all the groves near the chuck.
We do this for all our motors from 54->150mm.
Makes length a don't care too which is nice.
 

Binder Design

Sponsor
TRF Sponsor
Joined
Jan 18, 2009
Messages
1,820
Reaction score
232
You can make an internal spindle that expands to grasp the tubes on the inside this allows you to cut all the groves near the chuck.
We do this for all our motors from 54->150mm.
Makes length a don't care too which is nice.
I was the one who showed the good doctor how to do that, but I told him to keep it to himself. The fixtures are a pain. Not good for production speed.
 

FredA

Well-Known Member
Joined
Jan 19, 2009
Messages
2,170
Reaction score
347
I was the one who showed the good doctor how to do that
I think we both did then...and the reinforcement convinced him to do it.
Agree that it's a bit painful, but allows you to make motors longer than the bed and larger than the through hole.
I don't think anyone on this thread, besides yourself, is thinking mass production.
 

mrwalsh85

Well-Known Member
Joined
Apr 30, 2012
Messages
1,012
Reaction score
139
Most important consideration: Through hole size. Everything else is further down the list.
Mike is right. I have a Logan Model 200 in the garage. I picked it up because I build 1/12 scale live steam locomotives. While I'm happy with it, I've already run into a few snags.

First and foremost, the through hole size. I have to machine axles for the steam engines and they are typically 1" round. Talk about a show stopper. Thankfully I'm still within my 4:1 length to diameter ratio (sticking out of the chuck) so I can still do it.

I still have the original motor on it, which requires me to move the motor brushes in order to reverse it (this threw me off at first, but I figured it out). It can bog down, which I don't think it should.

I picked mine up used on Craigslist. $700 including a boatload of tooling. It was mounted to a nicely built workbench with drawers. Loading that was a pain. Motor and mount came apart from the lathe bed easily. Two-man job. It was advertised for $900, but once I called the guy, he realized that I was deaf and asked if I knew his son (who is deaf also)... So he hooked me up. Small world.

As far as wear, as long as you understand the wear on your lathe, you can do anything.
 

warnerr

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 4, 2011
Messages
360
Reaction score
44
The bore through chuck limits how big a long item item you can naturally turn without resorting to some fancy inside holding system- thats why i suggested used system as the larger bores get pricy. wish i had known before i purchased a 12in new Chinese.... freight costs not too bad.... ebay has lots of lathes listed.... dont let the three phase be a showstopper (see my prior post) ... this tool will outlast you... so reach a bit.
 

BuiltFromTrash

Well-Known Member
Joined
Aug 7, 2014
Messages
305
Reaction score
2
My comment was tongue in cheek, meant to be humorous, but some small lathes have heavy steel turned and ground bars instead of ways.



Steve Shannon
Lol. I am a bit dense sometimes.

I did not know that. Learn something every day!
 

cherokeej

Well-Known Member
Joined
Feb 16, 2009
Messages
835
Reaction score
51
That "thru-hole size" is called the spindle bore. Be careful here. That 13-40 may only have a 1 7/16" spindle bore, which means a 38mm case won't fit, so a special set-up would be required for working with longer ones.

Get the biggest, best machine your wallet and shop space will allow. (Cuz believe me, what ever you get, you're going to want a bigger one. It's a part of human DNA.) Three phase is a non-issue. Cuz if you're worried about the cost of a phase converter, you're gonna mess yourself when you start buying tooling for a lathe.

Someone mentioned maybe finding a South Bend for around $1K... Good luck. In the shop I worked in, I had an old SB 16-60. Sweet machine!! Oooooh... Don't I wish. Today, I have a 12-36 Taiwanese POS that was manufactured when I was in junior high school. It turns.

As mentioned, make sure you get the accessories that should come with the machine. A steady rest, a follow-rest, a 3-jaw scroll chuck with both inside and outside (or reversible) jaws, and a independent-4-jaw chuck should come with the machine. If they don't, the cost of acquiring them separately might prove prohibitive. Extra accessories to ask about (with a used machine) are a tail-stock chuck, a live center, dead centers, lathe-dogs, and a quick-change tool post.

One thing that won't come packaged with the machine is the experience to use it. Be careful. No long sleeves. Ever. Clear swarf with the chuck dead still. Those curls are double-edged razor blades. One set of fingers to a customer.

Most of all be safe, wear glasses, and have fun.
 
Last edited:
Top