# Tips on selecting a lathe -will it thread



## Tin Falcon

On another thread no pun intended someone asked about the threading capability of the new south bend 8 x 18 lathe the following is based on my answer with a few more details added in. 

One serious consideration when purchasing a lathe is threading capability. How does the lathe create  the proper ratio between the lead screw and head stock. 





> Quote:
> Why does the #1001 SB need quick-change gears if it says that it can thread ?
> I have never threaded and do not know anything about the QC gears.
> Can someone enlighten us ?


Yes it will indeed thread!
In early days of of the screw threading lathe the only way to change the pitch of a screw being threaded is open the head stock cover, if it had one.( sometimes they were exposed) and change out the gears to set the ratio of gearing between the head stock spindle and the lead screw. these gears are furnished as a set with the lathe, Hence the term change gears and change gear set. 
a set will allow for all common threads to be made either imperial , metric or both.depending on the lathe.

Modern production lathes have a gear box with a series of levers or knobs that allow to change the ratio of gearing in the head stock quickly . 
this gearing also sets feed rate for automatic feeds. 

Modern hobby lathes may be a hybrid you can quickly change thread pitches with levers or knobs but within limits like imperial threads or feed rates or metric threads . if you need to change MODE open the box and switch change gears. 

the old way saves money on production cost but takes time to change out gears. 

A full featured QC gear box is an expensive option. but in a job shop where things change fast an furious it save production time and setup cost. 

the hybrid is a compromise it makes threading setup easier and faster and keeps costs reasonable. 

Some of the small hobby lathes like taig and sherline have no head stock gearing at all . this is an added option. 

Single point threading was one of the basic skills learned on the lathe in tech school for me. As a hobbyist one needs to decide how important the skill is and how important the threading capability of his or her lathe is. 

Added info:
Metric vs imperial most lathes I have seen are either designed to measure and function and are built either to be a metric machine or a  imperial machine. the difference is the lead and feed screws are made to either metric or imperial standards.  so if one has an imperial standard machine  and wants to thread you need a transposition gear of 127 teeth or in the case of the 7 x mini lathes a 21 tooth gear. and this gives a close approximation.

So the lesson here if wanting to do serious threading get a lathe built for what you work with or are comfortable with. some machines are built metric and only aproximate us decimal inches. The newer imports have corrected this and use inch based screws. 

CNC can be a horse of a different color. Look ma no gears. If the head-stock of a cnc lathe has a spindle sensor the computer can set the ratio of the spindle speed to the lead/feed screw electronically so you program in the numbers and the computer does the threading. just swith working units to metric or inches and the computer does the math
 I/we still recommend learning to thread with a manual machine. 


These are some things to keep in mind when selecting a lathe . Threading capability is one consideration. and selecting a hobby lathe can be tough. I learned to machine on a real lathe a modern south bend and a standard modern. full featured lathes with all the capabilities thereof. 
My first home lathe a grizzly 7x10  champagne  tastes on a ginger ale budget to say the least. The one advantage I had was a target of what a real lathe will do.I had to get what I could afford and not give away all capabilities . If I bought a taig (one of my first considerations) it would not thread at all. 

One must still consider things like budget accessories size of work to be done old iron vs import, swing and center to center size  available workshop space shipping weight shop location (Garage basement attic) and a few other things. I hope this helps the new folk. 




Tin


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## Tin Falcon

One of the factors to consider when purchasing a lathe is what accessories and tooling comes with the lathe. Check everything and  assume nothing. 
It is hard to define standard tooling. 
IMHO a well equipped lathe should have:
 3 jaw scroll chuck 
 4 jaw independent chuck
face plate 
Quick change tool holder 
machinable center
live center 
drill chuck or tail stock chuck 

the Basic Seig C2/C3 aka 7xs come with a three jaw and a center and a basic tool post.
a 9 x 19 has a, face plate, steady rest,  follow rest, and a woodworkers  cheap 4 jaw .

The point here is if a lathe costs say $ 600 and adding  the steady ,the follow rest  the face plate and a 4 jaw these will likely add up to another      $ 200.  then add shipping and in the case of Harbor freight add the extended warranty cost. so you are now close to the cost of a similarly equipped 9x19.

The other question is how much do you need or want the steady rest and follow rest. IMHO there is rely no place to put a steady on a 7 x 10 a 7 x 16 maybe. 
Other stuff: if you are turning on centers you need a machinable center and a drive dog as well as a drive plate or face plate with slots. You may also need mandrels. 

When using a face plate you need clamps a angle plate, and often a counterweight. 

You will need cutting bits. IMHO HSS is best for hobby machines 
right hand bit for turning LH bit for facing and a parting grooving bit. 

Drill bits.   Screw machine length will save spce on short lathes but are more expensive than jobbers length at least in sets. 

Buy or make a boring bar or bars generally use the largest that will fit. 

reamers will help smooth and size bores of cylinders . 
laps will refine cylinder bores. 

A scissors knurl will save on bearing wear. as apposed to a plunge knurl. 

A used lathe can come from stripped to well equipped so when looking at a used lathe take careful inventory. 


Tin


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## Tin Falcon

Another consideration  in lathe selection is how the chuck face plate etc mounted to the spindle on the head stock. 
1: theads. there are many sizes here. some are metric. make sure you can get upgrades and spares to fit the lathe unless you are prepared to make your own back plates. been there done it. 
2: bolt on. Works but do not expect quick set up changes. found on the seig C2/C3. 
3: D camlock there are several sizes these are rare on import hobby lathes . Nice if you can find a lathe with this mounting system.
4: L taper mount found on older industrial lathes. Do not recall seeing this mount on new imports. 

Warning a screw in chuck can screw off if the spindle direction is reversed unless there is some sort of locking feature to prevent this.

also a spindle that has a 5 morse taper will take 5c collets.
a 3mt will take 3c collets. 
Tin


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## Tin Falcon

lathes are sizes in terms of swing  or the largest diameter one can turn. this is USA definition.  The other important measurement is center to center lengths. 

As mentioned earlier 7x10,12,14 and 9 x 19 are common hobby sized lathes. 
is bigger better. in most cases yes in general you can make small parts on big lathe but not the other way around. but beware. a 1/8 in brass  rod requires a speed of 9,000 rpm this may exceed the speed limit of a large chuck. and a large lathe may not run that fast.  so there are always trade offs. A good rule of thumb is get a little bigger that what you think you need  in swing . as far as cts it is hard to have too much. .
If you choose a larger lathe you may need a couple different sized chucks face plates etc. 
Also in general the larger the lthe the more real lathe features it will have and the less hassle changing tooling. 

get what you can afford.
what you have room for 
what you can move into your space safely. 
Tin


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## kvom

The tailstock drill chuck should take at least 1/2" bits, and up to 3/4" is better if the tailstock taper is large enough.  Many 3/4" chucks only go down to 1/8", and in this case you'd need a second chuck for the smaller drill bits.

For threading you need to either grind a 60-degree HSS bit, or buy a toolholder with inserts.  You also want a 60-degree thread gauge and a set of pitch gauges.

Pay attention to the spindle hole size; larger is better.  If you think you'll be machining long bars then position the lathe so that you can feed the bar through the back of the chuck through the spindle.


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## Tin Falcon

One of the most basic but confusing aspect of machining is holding the work. It is important when choosing a lathe  what choices you have in this respect. 

3 jaw chuck . this is probably the first work holding device that comes to mind for a lathe. It is quick and easy to use. It will never run true unless you have a set true chuck. a set true is more expensive and not common in the home shop. 
a 3 jaw is perfect for hex stock and general machining of round stock. good for a simple part like a hat bushing. 

4 Jaw chuck: more versatile easy to dial in a part. good for many odd shaped parts. and is great for square stock. It can be offset for eccentrics etc. Take a bit more time to clamp in the part. 

A   face plate allows one to clamp a part down . you will need clamps often a counter weight to balance things and sometimes a angle plate to hold the work. an old school but effective way to hold model engine parts. 

Turing on centers. the part is held between a center in the head-stock. A machinable center will ensure you are truly on center. and a center in the tail stock. you may need to adjust the tail stock for true center to prevent taper or kick it over to set a taper. a lathe dog is clamped to the part and the dog leg is inserted into a face plate or drive plate slot.  turning on centers is great for shafts.  a mandrel may also be placed on centers . a mandrel hold a part with a a hole in the middle like a gear blank or a cylinder. 

Collets. Indusrial lathes have a 5 morse taper in the head stock . this allows for 5c collet holders to be mounted in the head stock and allow for 5C collets. . smaller lathes with 3 MT tapers can accomadate 3c collets. 
5c collets are more common and have a greater size range . 3C only go to 1/2 in round. collets  come in various sets usually in 1/32 or 1/64 increments. 
you can only use a collet for the specified size with a little tolerances built in. 

collets save Z axis space hold the work truer than a 3 jaw hold the work all the way around and not just 3 or 4 points so good for tubing. 
collets are also made for hex stock and square stock as well as round. 
so a collet adapter is something to consider when purchasing a lathe. 

A steady rest hold a long part  so it can be machined .

a follow rest sits behind the cutting tool and supports long thin work as it is cut. it follows the cutter.

Tin


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## kvom

Some other options for workholding:

1) Soft jaws.  Some 3-jaw chucks have 2 piece jaws, so that the outer jaw can be removed and replaced with aluminum (or other soft material) versions.  These can then be bored out to hold a specific diameter workpiece.  The work can be removed and replaced without affecting runout as long as the chuck is not removed from the lathe.  This method is one of the best ways to hold and machine thin parts.

2) Jacobs rubberflex collets.  These are an older collet style where the collet is a stiff rubber with some metal "jaws" embedded.  Unlike 5C collets, the rubber allows a wide range of sizes per collet, and larger stock can be held.  Collets and chucks can sometimes be found on eBay.


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## Dunc1

While threading capability is great to have, on a practical basis on many hobby lathes it is difficult to practice. I have a mini & a 10 inch (5 inch center height) lathes. Both have threading capability (lead-screw, change gears, etc); however, their minimum speed (for the mini: add with adequate torque) is much too high to be able to thread. There is a reason that a Myford (and many others) has a back-gear to achieve speeds that are slow enough that everything is not happening quicker than I, at least, can think - let alone react. 

For the mini there are a number of plans out there to add a spindle crank to turn the lathe manually. For the larger lathe I am toying with the idea of adding a jack-shaft to the motor drive to reduce the speed. In the meantime, I have been using taps/dies.


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## Tin Falcon

Dunc: 
lets confine this thread to tips on selecting a lathe.

we can discuss  workarounds an modifications in there popper places. 

http://www.homemodelenginemachinist.com/f25/threading-mini-lathe-19305/#post199866

I invite others to add to this thread on lathe selection. 

If you want to share workarounds to the limitations of your lathe please post in the tips and tricks section. 
If you have modified  your lathe to improve it lets see that in the machine mod section 
I would like this to be resourse for those wanting to buy a lathe and hope to avoid a tangled thread. 
Tin


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## Tin Falcon

Another consideration in selecting a lathe is what kind of motor is mounted on the unit. also how does the operator control the spindle speeds. 

motors can span from 1/4 HP to several HP on an industrial  lathe . a 7x import lathe may have a 350 watt motor or a 500 watt motor depending on who is selling it. these lathes have variable speed dc motors to control speed. so one can change speed on the fly. 

Another common set up on hobby lathes is belt and pulley stop the machine loosen the belt move it an re tighten to get speed changes. 

Gear head machines use gears to set speeds.

Large industrial machines use a variable frequency drive to set motor speeds. 
and these vfds will translate  220 two phase power to industrial 3 phase. 

More power will increase productivity and production rates but beware while it is a nuisance to have a motor stall or a belt slip when overloaded a Multi hp motor will gladly bend things and suck an operator into the machine if something stupid happens. 
So more to think about.
Tin


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## Bastelmike

Some notes on Tins excellent explanations about lathes:

1. The distinction between faceplate and independent 4-jaw chuck isn't common in Europe. Most lathes have a European style combination faceplate, i.e. a faceplate with slots and 4 independent jaws that are easy to remove. This tool serves for most clamping needs and is usually the only clamping accessory found on large industrial lathes with swing > 30".

2. Turning between centers:
Besides using a lathe dog there are 2 other possibilities. The first is to install the workpiece between the centers and then clamping it with the jaws of an independent 4 jaw chuck or (European style) faceplate. Again, this is standard on large lathes - I've never seen a 6" lathe dog.

There is another tool available for turning between centers, a "Stirnseitenmitnehmer", dunno an english word for this. Its attached to the lath spindle and it consists of a center and several spring loaded hardened wedges which grasp into the face of the workpiece. Advantage is, You can machine the complete OD of Your part in one pass; disadvantage it damages the face of your part.

3. Threading capability
Tin has written a lot about this subject, though I wonder whether its really very important for the small threads most of You usually cut. I find it very difficult to machine small internal threads with the single-point method. I once have cut an internal M10x0,8mm thread and found it very difficult to make. For small threads I use taps and dies, they are reasonably cheap.
If You need to machine large threads like M30 or larger or need something like ACME threads, You need threading capability - taps/dies this size are pretty expensive and only real large lathes develop the torque for these tools.

Mike


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## Bastelmike

Just a pic for a "Stirnseitenmitnehmer". Anyone in the forum who knows the english word for this?

http://www.google.de/imgres?imgurl=...pUOG4JcOzhAe_8YCwBw&ved=0CEQQ9QEwBQ&dur=10782


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## Tin Falcon

the top one is a live or ball bearing center used in the tail stock.
the cone type is a pipe center for supporting pipe or tube in the lathe . the bottom is a mutipurpose center set. for holding various size pieces.  center set

http://www.travers.com/skulist.asp?r=s&n=||UserSearch1%3Dlive+center+set&q=block+id+86715+and+class+level3+id+28974
Tin


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## Bastelmike

Hi Tin,

sorry, this is NEVER used in the tailstock. These are dead centers for the main spindle. Believe me there is no ball bearing inside.

The conical parts are to drive the part, they grip into your workpiece. You just need one of these tools in the main spindle and a live center in the tailstock to tun between centers.

Mke


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## MuellerNick

> Just a pic for a "Stirnseitenmitnehmer".



Also not knowing the proper term in English for it, I'd call it a "face driver".
There are no springs in them for the driving part, but three cylinders that allow the driving part to adjust to the maybe-out-of-straight face of the part driven. The only spring inside of it is for the center.

Also, you need a live center in the tailstock with a pressure gauge (at least, it is highly recommended) or any other means to adjust and control the force.


Nick


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## David Merrill

http://bbs.homeshopmachinist.net/threads/52364-Drive-centers

David Merrill


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## dman

Bastelmike said:


> Hi Tin,
> 
> sorry, this is NEVER used in the tailstock. These are dead centers for the main spindle. Believe me there is no ball bearing inside.
> 
> The conical parts are to drive the part, they grip into your workpiece. You just need one of these tools in the main spindle and a live center in the tailstock to tun between centers.
> 
> Mke



this is no entirely true. dead centers can be used in the tail stock if you have no other choice. tooling is expensive as we all know and you may not have a live center. you can use a dead center to support long work when you hold the part in the chuck if you use lube and light pressure. also, I was actually instructed in tech school to never use a live center for knurling. the pressure can damage the bearings. instead we used dead centers and a high pressure grease that was high in molybdenum content. some metals in lubes such as phosphorus, molybdenum, and I believe zinc form a chemical bond to metal parts. under pressure after the oil wedge breaks down the bonded metals will protect the surfaces. the part and center won't wear till the moly cote scrubs off. you still don't want to do this with your only dead center but if you have a couple of them and one is damaged or less true than the others its acceptable to use it in the tailstock if the situation calls for it. just remember the lube, run the rpm slow, and don't force the center into the part or it may bind, use light pressure or even leave slight slack. aka use common sense. 

that said I don't think I'd ever use two dead centers to run parts between centers. although the part can still be driven with a lathe dog and drive plate leaving the tailstock slightly loose to keep it from binding could mess up the roundness and part Finish.



> CNC can be a horse of a different color. Look ma no gears. If the head-stock of a cnc lathe has a spindle sensor the computer can set the ratio of the spindle speed to the lead/feed screw electronically so you program in the numbers and the computer does the threading. just swith working units to metric or inches and the computer does the math
> I/we still recommend learning to thread with a manual machine.



CNC threading is mostly for production. its a pain to program, setup and qualify the tool offsets for a single part so its not always good for hobby environments. and there is no good way to chase threads. if the part cant index to the spindle the same way every time you have no way to fix it if the part is removed from the spindle. you need to be able to gage the thread before you remove the first part (unless the part is expendable). also single point can be a good way to repair fasteners. not so easy on a CNC. 

with a manual machine picking up old threads is pretty strait forward. you can engage the QC gear box, lock the half nut and turn the spindle in the proper direction to pull out backlash. then with the compound rest set to the proper angle work it and the cross slide till the cutter is properly engaged in the threads. zero the cross slide and back off the compound rest and you're ready to chase the threads. on a cnc you have no way to know where the carriage is supposed to be for the spindle position to check alignment and no way to program the Chuck phasing to the thread. its a matter of balancing the tool z axis offset and the thread start z position. this also means doing multiple threads or other helical features on a lathe you have to do so by setting different start positions for each groove. for things like oil grooves in a bearing you may need to start the cycle several inches from the part to get multiple grooves (mills don't have this limitation if you are not tapping but lathes usually only have one or two commands to index the carriage to an exact spindle angle at full spindle speed and it doesn't have any spindle angle arguments, the hardware is there to do more but not the software.)


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## MuellerNick

> this is no entirely true.



It is entirely true, because bastelmike wasn't talking about dead centers, but a *drive center* (or face driver). And that one makes no sense at all in the tailstock. Unless you want to prevent work from rotating. And that would be quite uncommon for lathe work.


Nick


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## Tin Falcon

sorry for the confusion I see now what bastelmike posted is indeed a driving device face driver drive center whatever we call it and it is used in the head stock. to drive soft material that the teeth will grab. I know these are used for wood. What I posted is a different animal interchangeable live center used in the tail stock.  
Both of these are valuable tools for industry and enhance the capability of a lathe..
Tin


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## Noitoen

You usually see those markings on shafts an rotors that were subjected to a balancing operation.


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## gus

Dunc1 said:


> While threading capability is great to have, on a practical basis on many hobby lathes it is difficult to practice. I have a mini & a 10 inch (5 inch center height) lathes. Both have threading capability (lead-screw, change gears, etc); however, their minimum speed (for the mini: add with adequate torque) is much too high to be able to thread. There is a reason that a Myford (and many others) has a back-gear to achieve speeds that are slow enough that everything is not happening quicker than I, at least, can think - let alone react.
> 
> For the mini there are a number of plans out there to add a spindle crank to turn the lathe manually. For the larger lathe I am toying with the idea of adding a jack-shaft to the motor drive to reduce the speed. In the meantime, I have been using taps/dies.



Hi Dunc,
For now,I make do with a 150mm Swing and 360mm between centres Japanese Watch-maker's Mini Lathe. I use taps with tapping head and Die Heads. For my mini model engine builds the above will do. I use machine taps which cost 2---3 times than hand taps. Tap and die threading with Tapmatic Oil produced very good threads. 
Going for a bigger lathe and mill is out of question due to very limited space in the balcony. Presently with just a mini lathe,mini Vertical Mill,13mm cheapy China Drill press and Bosch 8" Grinder makes complete requirement.
Work Bench with 4" Record bench makes the hacksaw/fitting dept complete.
Still trying to fit in a small band saw and it will be Taiwanese for long life.
After so many sessions manual hacksawing 1 1/2" bars,I find manual sawing
quite fun and gives good excercise.


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## jixxerbill

What are the advantages/disadvantages of a geared head and a belt driven ? My local supplier has a 13x40 jet with a stand for $4,400, but its a belt drive..thanks..Bill


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## Tin Falcon

Another tip I will mention here is Download the manual for any lathe you are seriously considering for purchase. It will tell you a lot about the lathe before you have the chance to look at a floor model . 
I assume you are talking about this one. 

BDB-1340A Belt Drive Lathe
http://www.misgroupinc.com/partfiles/M-321360A.pdf

Page 15 of the above manual explaines how speeds are changed and has a photo of the belts in the head stock. 

A geared head lathe will give faster spindle speed changes. 
you want to change speeds turn off the lathe and flip a lever or two and restart the lathe. 

A belt driven lathe you need to turn off lathe  open the head cover. release belt tension move the belt . apply belt tension close cover then start lathe. 

As far as advantages belts usually run smoother than gears. belts are easy to find and cheaper to replace. 

Also keep in mind most gear head lathes still have a belt going from the motor to the gear head. 
Tin


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## Tin Falcon

In the home shop of a newby or in a school lab it is a good idea to have some weak link on a lathe to protect the machine and to some extent the operator from a crash. 
on my south bend the belt slips if I get too greedy . the mini mill and lathe have a sacrificial nylon gear that breaks. on bigger lathes the pin that connects the lead screw and the drive shaft if it has one should have a brass taper pin installed . if a crash occurres the pin shears and protects the gears in the lathe head. so when you get a new lathe find out what safeties are built in . and add them if needed. A couple hours of preperation and modification can save big down the road. A $1 pin is a lot cheaper than replacing a couple of gears. 
Tin


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## gus

Tin Falcon said:


> Another tip I will mention here is Download the manual for any lathe you are seriously considering for purchase. It will tell you a lot about the lathe before you have the chance to look at a floor model .
> I assume you are talking about this one.
> 
> BDB-1340A Belt Drive Lathe
> http://www.misgroupinc.com/partfiles/M-321360A.pdf
> 
> Page 15 of the above manual explaines how speeds are changed and has a photo of the belts in the head stock.
> 
> A geared head lathe will give faster spindle speed changes.
> you want to change speeds turn off the lathe and flip a lever or two and restart the lathe.
> 
> A belt driven lathe you need to turn off lathe  open the head cover. release belt tension move the belt . apply belt tension close cover then start lathe.
> 
> As far as advantages belts usually run smoother than gears. belts are easy to find and cheaper to replace.
> 
> Also keep in mind most gear head lathes still have a belt going from the motor to the gear head.
> Tin



Hi Tin Falcon,
If Sakai ,Japan makes a gear lever shift mini lathe,I'll buy it. Right now with the belt drive,it is a pain in side to change speed. So I left it at 600 rpm.Now sort getting used to it.
With no electronics to worry about,I have peace of mind.


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## ConductorX

I have a question about threading abilities:

Two lathes: one listed as Variable Speed - the other as Gearbox

This is the specs listed:

Black is the variable speed and the red is the gear box lathe.  From these numbers I take it the Variable speed (black text) is a better lathe for cutting threads.  Is the difference highly significant based on the chores we would encounter to create model engines?  Or would either lathe suffice?

·         Leadscrew: 3/4"&#8211;12 TPI 
·         *Lead screw: 3/4" x 8 TPI*
·         Number of longitudinal feeds 9 
·         *Number of longitudinal feeds: 12*
·         Range of longitudinal feeds: 0.0023&#8211;0.013 IPR 
·         *Range of longitudinal feeds: 0.0022&#8211;0.0150 IPR*
·         Number of inch threads 33 
·         *Number of inch threads: 24*
·         Range of inch threads: 8&#8211;72 TPI 
·         *Range of inch threads: 8&#8211;56 TPI*
·         Number of metric threads 26
·          *Number of metric threads: 10*
·         Range of metric threads: 0.25&#8211;3.5mm 
·         *Range of metric threads: 0.5&#8211;3.0mm*


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## Tin Falcon

Those numbers you give are but one consideration.  What is better a green lathe or a red. HMM  
what size are the lathes how do you change the threading gears. ....
you need to look at the details when selecting a lathe but you can not forget the big picture. 
What size engines are you planning on building  ?
do you need to do a 72 pitch imperial thread or a .25mm metric or will a the 56/.5 do  .
there are many factors and trade offs to consider and ultimately you need to decide what is best for you.  Yes we can help. 
Tin


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## dman

ConductorX said:


> I have a question about threading abilities:
> 
> Two lathes: one listed as Variable Speed - the other as Gearbox
> 
> This is the specs listed:
> 
> Black is the variable speed and the red is the gear box lathe.  From these numbers I take it the Variable speed (black text) is a better lathe for cutting threads.  Is the difference highly significant based on the chores we would encounter to create model engines?  Or would either lathe suffice?
> 
> ·         Leadscrew: 3/4"12 TPI
> ·         *Lead screw: 3/4" x 8 TPI*
> ·         Number of longitudinal feeds 9
> ·         *Number of longitudinal feeds: 12*
> ·         Range of longitudinal feeds: 0.00230.013 IPR
> ·         *Range of longitudinal feeds: 0.00220.0150 IPR*
> ·         Number of inch threads 33
> ·         *Number of inch threads: 24*
> ·         Range of inch threads: 872 TPI
> ·         *Range of inch threads: 856 TPI*
> ·         Number of metric threads 26
> ·          *Number of metric threads: 10*
> ·         Range of metric threads: 0.253.5mm
> ·         *Range of metric threads: 0.53.0mm*



they both sound fine. I can't remember any time I needed a 72tpi thread or a .25mm or a 3.5mm I've done as coarse as 3mm and some odd ball ones like .8mm. I can't think of an application for 72tpi. even radio control models mostly go to 40tpi for small stuff. 56 for the smallest. 72 may be for watch hardware. but why would you want to single point that small? 

an 8tpi lead screw is easier to read the wheel than 12. but if he lathe with 12 tpi has a gearbox that can reverse direction with the spindle turning like on a hardinge toolroom lathe and index back to the same spindle angle it will be easier. really more information is needed but it sounds like both will do a fine job but if you need a .8mm pitch I'm not sure the  second lathe will have that option.


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## ConductorX

Both are Grizzlys - 9x19 and the 10x22

They are both the same price but the second one is heavier (shipping weight). I am leaning to the 10x22 gear drive simply because the VW brake drum is a bit over 9" diameter. I downloaded the manuals for both and plan to do some reading and study. 

Needless to say the lathe won't be exclusive to building model engines.

Thanks Tin and dman.
"G"


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## Tin Falcon

You will probably will be better off with the 10 x 22 you can not have too much x and z . it has a beefier frame a more modern design to  the gear box . a real american style 4 jaw chuck. a 1 hp motor vs the 3/4 of the 9x. 
a few folks have the 10 x 22 and it seems to be well liked. 

both lathes are belt drive.Open the door on the end of the head stock and change the belt locations to change the spindle speeds.  there is a variable speed version of the 10 x but it is %50 more. the 9X is used by a lot of HSM guys as well . the 4 jaw European style 4 jaw is not well liked. 
so if is the same money IMHO the 10 x 22 is the more favorable choice. 
Tin


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## Tin Falcon

A lathe accessory that gets lots of discussion is the quick change tool holder. 
Likely the most popular is the aloris wedge style . there are many companies making these in various quality points and price points. Aloris brand while being the standard for quality is a bit pricey for the hobbyist. the piston style works but I have heard of complaints with them. 
IMHO a QCTP is a must have and almost always used accessory for the lathe. they save lots of time and hassle in comparison to other toll holders. there are better QC tool holders but again pricey. 
Tin


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## ConductorX

I have a question that more than likely everyone already knows.  What the fuzzy is a Turret Lathe and how does it differ from the run of the mill everyday lathe.  I found a place here in Louisiana that has a variety of old machine tools for sale.  Craigslist seems to have still more.

Among them:
Southbend Precision Lathe 12" x 42" with taper attachment, collet draw bar and 3 jaw chuck.  Cat No: CL8145C

LOGAN TURRET LATHE - Logan Engineering Co. Turret Lathe, model 825. Q C Gear box, 24" center distance, 43" bed length, 1 1/2 - 8 x #3 MT Spindle nose, 25/32 Spindle bore, Std. Tailstock, flat bed, cabinet, 830 Lbs. Screw turret gears. 

The wildest looking thing (and cheapest) was the Rivett Model 112 Lathe.  No information, but it looks like a drill press laying on it's back.

I appreciate your time and patience.
"G"


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## Tin Falcon

A turret or capstan lathe has  a tail stock that holds multiple tools and rotates . it uses special tooling . it is typically set up for production  or multiple part work. the beauty is once set up you can make the same part over and over all day with the pull of a couple of levers . you can make screws bolts hat bushings etc. 

rivet lathes are real nice machines. 
as are south bends . but remeber with old machines CONDITION unless you are planning on a rebuild, but then you still need good bones.
Tin


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## Hopefuldave

Bastelmike said:
			
		

> Just a pic for a "Stirnseitenmitnehmer". Anyone in the forum who knows the english word for this?
> 
> http://www.google.de/imgres?imgurl=...pUOG4JcOzhAe_8YCwBw&ved=0CEQQ9QEwBQ&dur=10782



I've always known it as a 'drive centre', never used on in metalworking but they're common in woodturning.

Dave H. (the other one)


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## Hopefuldave

One topic that hasn't been touched on so far, metric vs inch leadscrew: pick the threading system you're likely to cut most, as thread indicator dials only work in their native units! An inch leadscrew will (unless you have a single-tooth clutch leadscrew reverse - see the thread "screwcutting simplified") mean metric threads have to be cut by stopping and reversing after each pass with the half-nuts engaged, or vices versa. Not too bad once you get used to it but a hassle on long threads.

Dave H. (the other one)


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## Tin Falcon

Good point dave . I did touch on this in the first post. 



> Metric vs imperial most lathes I have seen are either designed to measure and function and are built either to be a metric machine or a imperial machine. the difference is the lead and feed screws are made to either metric or imperial standards. so if one has an imperial standard machine and wants to thread you need a transposition gear of 127 teeth or in the case of the 7 x mini lathes a 21 tooth gear. and this gives a close approximation.
> 
> So the lesson here if wanting to do serious threading get a lathe built for what you work with or are comfortable with. some machines are built metric and only approximate us decimal inches. The newer imports have corrected this and use inch based screws.


I know a LOT to read through. 
Tin


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## Tin Falcon

One basic lathe operation and accessory I neglected to mention earlier is tapers and a taper attachment. 
there are three ways to cut a taper on a lathe.
1) using the compound.
2) tail stock offset.
3) taper attachment. 
And with modern cnc there is a fourth just program in a taper. 

there are plans out there to make taper attachments even for the 7 x10 lathes.

adjustable ofset centers can also be made to ease with the tail stock offset method . IIRC plans in appendix of the elmers engines book.

More late 
Tin


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## Tin Falcon

another accessory sometimes asked about and used is the tool-post grinder. as the name implies it is mounted to the tool post of a lathe . actualy it temporarily replaces the regular tool post. and instead of removing metal by cutting with a lathe tool the metal is removed by a spinning grinding wheel.

Like any other lathe accessory these com in various sizes price points etc. Entry level import grinders are about $150 for the single speed model and a little more variable speed. 

Grinding is just another method of metal removal. 
it is mostly considered a finish operation in other words machine in this case turn a part to a few thousands oversize then finish with a grinder. 
so why grind?
grinding allows you to work hard materials , like cutting tools hardened centers. hardened crankshafts.etc...


grinding allows for a better finish. a better finish is desired for things like shafts and lathe centers . a smooth finish does not wear as much against a bearing.

grinding takes small bites so careful control will allow for tighter tolerances. 

typical lathe tolerances are in thousands of an inch grinding tolerances in ten thousands of an inch. just make sure your mics read in tenths. hope this helps.
tin
__________________


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## Hopefuldave

RE toolpost grinding on the lathe, a little tip:

If the grinder can be mounted on the topslide (compound slide in the USA), swivel the slide around until it's almost parallel to the lathe spindle axis - if the angle between axis and topslide is 5.74 degrees (as accurately as you can set it, 5.75 is close enough  ) there is a 10:1 ratio between the topslide movement and diameter, so advancing the topslide 0.001" will take off 0.0001", allowing you a bit more control over grinding depth. Grinding cuts should be of the order of "tenths", not thou", it's a finishing process, not a roughing process 

Another tip: **cover the ways!** The grinding dust is incredibly destructive to machines, being a mix of fine metal dust and abrasive particles - I've used oily cloth (with a fire extinguisher handy) and a "hood" in line with the sparks, attached to my workshop vacuum, to try to keep the dust under control. I still need to go over the lathe afterwards in minute detail with a soft brush and vacuum though! Look at the hoods fitted to surface grinders for a few hints.

Yet another tip - it's good practice (and very much safer) for the work and grinding wheel to meet "head on", it prevents the wheel hogging into the work - and gives a better finish.

If the wheel and work are moving in the same direction and there's the slightest slack in the setup, the wheel and part will try to close up, possibly bursting the wheel; head-on they force themselves apart removing the load: a burst wheel is a bit like a grenade, but harder to remove the shrapnel, being non-magnetic`.

If your lathe doesn't run in reverse, the wheel wants to be running *anti-clockwise* for external grinding, *clockwise* for internal, both viewed from the tailstock. If it runs in reverse, grinder clockwise for both internal and external, and reverse the spindle for external grinding only, normal forward rotation for internal grinding. If concerned about a screw-on chuck loosening, don't be  - the loads in grinding are much, much lower than cutting loads! Belt and braces would be a drawbar through the lathe spindle, pulling on a "spider" against the chuck face, but not likely to be necessary, I'd think.

Just my ha'pennorth,
Dave H. (the other one)


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## Wizard69

Tin Falcon said:


> Those numbers you give are but one consideration.  What is better a green lathe or a red. HMM
> what size are the lathes how do you change the threading gears. ....
> you need to look at the details when selecting a lathe but you can not forget the big picture.
> What size engines are you planning on building  ?


I see this as critical, if the lathe isn't sized right for the jobs you expect to do you will end up frustrated.  People often buy too small and end up upgrading. On the flip side some lathes end up being bigger than they should be.   


> do you need to do a 72 pitch imperial thread or a .25mm metric or will a the 56/.5 do  .
> there are many factors and trade offs to consider and ultimately you need to decide what is best for you.  Yes we can help.
> Tin



This highlights one problem for beginners, that is not knowing what they need.   One thing to consider is that some lathes are easier to adapt for odd pitches than others.   Given a little ingenuity and maybe a few more gears almost any pitch can be achieve.   Well within the mechanical ability of the lathe to support that odd pitch.


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## Tin Falcon

> you need to look at the details when selecting a lathe but you can not forget the big picture.
> What size engines are you planning on building ?



This can be a horse cart situation. I strongly recommend deciding on a goal when starting in this hobby. There are hundreds of plan sets out there. pick one or few you want to build. the size of the  parts will determine what size machine is ideal to make the parts. 
but do not be dismayed. you want to get started you find a deal on a lathe and you buy it. but you see that that dream model is twice the size that your new lathe will handle. simple solution scale down the model. I have fiend that has a sherline and makes beautiful model half the size of mine. Also if you are fortunate enough to find a bigger machine scale the model up. 
this hobby is for fun and learning. machining is adaptive. no book no forum can teach it all. sometime you need to make a work around. 

as far as threading same thing read prints. and again adapt if needed. in most cases a 4-40 screw can be used in substitute for a 3-48 .

tin


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## Tin Falcon

The compound slide is a part of a lathe I neglected to mention and kind of took for granted as being standard part of a lathe. I would say many if not most lathes come with this feature. Everything from the humble  seig 7 x whatever up.  but many better quality small hobby lathes like the sherline and taig offer this as an option. 

My edestaal 5 does not have one but It is now cnc so not as important. 

the compound is used for :
short tapers
angle feed when threading
fine feed set the coumpound to ten degrees and .001 in feed on the compound is .0001 cross feed.
Tin


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## ZipSnipe

Speed is another factor when determining a lathe.

I have a 9x20 and my only complaint is it doesn't have a slower speed than 180 which makes for some standing hair on your neck threading.

Funny thing is I watched a guy on YouTube thread with the 9x20 running at 2000rpm and says he can't do it any other way.


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## Tin Falcon

As mentioned earlier selecting a lathe can be confusing. and many of the marketing terms can be confusing or meaningless. we can all look at Google definitions and some of those are confusing so how do we sort things out. 

Here is my personal view on lathe terms.
Hobby lathe : a lathe marketed for home and hobby use. These lathes may or may not be suitable for model engine building especially some of the older ones. so do your homework use common sense and look before you leap. 
the unimat , craftsman 109 , Sherline  ,Taig , Seig c2 and c3 are all examples of hobby lathes.  In reality just about any lathe can be used for hobby use as long as it fits your budget ,shop space and needs for your style and experience  machining. 

Engine lathe this definition seems a bit undefined from what I have read. seems to be another term for a machinist screw cutting lathe. 

Screw cutting lathe simply a metal cutting lathe designed and built to do single point threading. 

Gap bed lathe . a lathe that has a removable piece of lathe bed near the head stock . removing this piece  allows for a larger diameter to be turned. .

Tool room lathe. these lathes are normally made to a somewhat higher standard than engine lathes. ie higher precision. they commonly have more tooling like a collet set and a taper attachment. You may need to take lighter cuts than on a engines lathe or other production machine. 

turret lathe . a lathe built to make the same part over and over all day. the tail stock has places for multiple tools . pull the lever and a tool cuts push the lever back and it advances to the next tool . typical set up by a machinist but may be operated by a less skilled operator. 
turret lathe often also have production cross slides that aid in the machining. These are also lever operated. 
the advantage is you can make a part in a few minutes  just by pulling the lever or levers. the disadvantage is more tooling and more setup time. 
but if you want to or need to make lots of copies of the same part this can be the way to go. 

captain lathe: very similar to above. 

down river tools sells plans for turret attachments and the tooling for them that can be mounted on various hobb lathes like sherling the seig c2/3 and the seig 9x19.
tin


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## mikbul

There's a guy on you tube threading with the 8X18


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## AnvilJack

I have bought and sold two lathes, and now bought a third.  I found that a Chinese manufactured lathe (same maker as my mill) has a product called a CQ6125 that seems to appear in a dozen different places, called something similar (Brand name of a retailer plus the CQ6125), but often with different accessories, tools, etc.

Here is the spec sheet for my unit  ($1300):
Lathe

22"x10" (550 x 250MM) QUICK CHANGE GEARBOX METAL LATHE W/STAND 
Industrial quality machine, perfect for general machining in tool rooms and workshop, maintenance and production shops, cast iron quick-change gear box makes threading easy, machine ground, hardened iron cast bedways and come with 4 ways tool post, it has long travel automatic power feed, includes stand cabinet&#8232;
specification: &#8232;
-distance between center: 550mm (22") &#8232;
-swing over bed: 250mm (10") &#8232;
-swing over cross slide: 156mm (6")  &#8232;
-spindle bore: 26mm (1")&#8232;
-taper of tailstock: MT3&#8232;
-tailstock spindle travel: 65mm (2-1/2")&#8232;
-number of longitudinal feeds: 9 (0.063-0.350mm/rev, 0.0025"-0.013"/rev)&#8232;
-thread cutting: 38 kinds (metric 0.25-3.5mm & imperial 8-72tpi)&#8232;
-range of spindle speed: 6 (125rpm-2000rpm) &#8232;
-motor: 750w (1HP)/240v/1ph (single phrase)&#8232;
-max. tool size to use size:10mm x 10mm (3/8"x3/8")&#8232;
-max. compound size travel: 95mm (3-3/4")&#8232;
-max. cross size travel: 145mm (5-1/2")&#8232;
-steady rest capacity: 6.35-50mm (1/4"-2")&#8232;
-follow rest capacity: 6.35-50mm (1/4"-2")&#8232;
-length of bed: 1050mm (41-1/4")&#8232;
-width of bed: 155mm (6")&#8232;
-height of bed: 200mm (8")&#8232;
*accessories includes: 
stand cabinet, 
splash guard, 
chip tray, 
5" 3-jaws lathe chuck, 
6" 4-jaws lathe chuck, 
8" face plate, 
dead center, 
fixed steady, 
travel steady, 
change gears, 
toolbox etc.&#8232;

*Shipping weight (all up): 298kgs


Now, I've unpacked this new toy, assembled the cabinet/stand unit, bolted the lathe to the stand, and started to prepare it for use.

I've checked the level of the machine with several highly accurate levels placed across and along the ways, and had to shim up the back of the lathe (concrete floor).  That seems to be OK now.

But I would never run my mill without bolting it down: this lathe cabinet/stand doesn't have facilities to bolt it to the floor.  Is that what you would expect?

I've run the tailstock up to the head stock, centres in each, and the two points meet by eye (and, on the way back the point of the centre in the tailstock seems to be at the tool height (right knife in tool holder). 

But, is this last process too imprecise (Yes, but how do you do this check properly?).

What other steps does one do to get the best set up of a new small lathe?

Also, I can comfortably hold 13mm x 13mm (1/2") tools in the tool holder: if I am managing the speed, depth of cut and rate of cut, using cutting oil when necessary, am I really silly to ignore this limit of 10mm tools?


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## gus

*CAPSTAN LATHE
*During the last two months of my trade school in 1963 , I was selected to set up a brand new Capstan Lathe and cut hex head screw blanks for the Open House Day. 
Gus survived and the Capstan Lathe too and we turned hundreds of hex head screw blanks.
The entire class qued up to cut some blanks with Gus guiding them.
We did not get to try out the quick release threading Die as the instructors felt we could ruin it.


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## radar

Would the LMS 7x16 lathe work for 3/4" scale live steam engines? I realize some wheels might need a larger lathe. 

Also the X2 mill that they sell- for other parts.


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## Blogwitch

Radar,

As you have already stated the size of the lathe, 7" swing. So I doubt if 3/4" scale would have wheels anywhere near that size, plus the x2 is a very well tried and trusted small mill, and much larger items that you will make have been made on such machines.

If you are contemplating buying new, then I would suggest you spend a week or two setting up the lathe and mill to perfection as they are only assembled at the factory, not set up. If you do that, they should give you a long service with no major problems, except maybe for your own lack of knowledge about using such machinery, that only comes with experience.

John


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## radar

Blogwitch said:


> Radar,
> 
> As you have already stated the size of the lathe, 7" swing. So I doubt if 3/4" scale would have wheels anywhere near that size, plus the x2 is a very well tried and trusted small mill, and much larger items that you will make have been made on such machines.
> 
> If you are contemplating buying new, then I would suggest you spend a week or two setting up the lathe and mill to perfection as they are only assembled at the factory, not set up. If you do that, they should give you a long service with no major problems, except maybe for your own lack of knowledge about using such machinery, that only comes with experience.
> 
> John



John, 
Curiously enough the largest I have seen the wheels is around 5 inches. 
I was mostly worried about these machines being rigid enough for that kind of work. I had planned on having my mentor help me with any set up and what not- making sure everything is aligned and the like. The dealer (Little Machine Shop) has a great reputation as far as quality and the like is concerned as well. The only other likely thing to happen is a Taiwanese Myford clone my come my way. 

-Dean


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## Blogwitch

R,

Don't worry, those two small machines are about the most popular two in the world, it 'seems' that about 50% of model engineers use one or the other or both, and you only have to look around to see what can be really made with them.

If you do start to get vibrations, it is usually to do with how you are using the machines, and experience will soon have you vibration free. You can't learn everything in a few weeks, and in my opinion, two to three years usually sees a very competent model engineer emerging, and you never cease learning.

Also, both these machines can be modified fairly easily and cheaply with new head bearings fitted, and the list goes on and on to what you can do to them to improve their machining capabilities. 
I took a mini lathe back to the basics a few years back as it was unusable because of a banana shaped bed (a very early machine), but when finished with, it was a fantastic, super accurate little machine.
I have recently bought an X2 mill that is destined to become a CNC machine, so I like them as well.

[ame]https://www.youtube.com/watch?v=GnL3ipa7JO8[/ame]


BTW, if you have a little bit of time on your hands, these three links are well worth watching as even though not for a smaller lathe, they do give a good rundown on what it is all about and how to achieve what you want. They also do a set for the milling machine.

[ame]https://www.youtube.com/watch?v=Za0t2Rfjewg[/ame]

[ame]https://www.youtube.com/watch?v=jXET1-g6CJA[/ame]

[ame]https://www.youtube.com/watch?v=3ue8XtStUBA[/ame]


John


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## Bentwings

Tin Falcon said:


> lathes are sizes in terms of swing  or the largest diameter one can turn. this is USA definition.  The other important measurement is center to center lengths.
> 
> As mentioned earlier 7x10,12,14 and 9 x 19 are common hobby sized lathes.
> is bigger better. in most cases yes in general you can make small parts on big lathe but not the other way around. but beware. a 1/8 in brass  rod requires a speed of 9,000 rpm this may exceed the speed limit of a large chuck. and a large lathe may not run that fast.  so there are always trade offs. A good rule of thumb is get a little bigger that what you think you need  in swing . as far as cts it is hard to have too much. .
> If you choose a larger lathe you may need a couple different sized chucks face plates etc.
> Also in general the larger the lthe the more real lathe features it will have and the less hassle changing tooling.
> 
> get what you can afford.
> what you have room for
> what you can move into your space safely.
> Tin



Well done!

Ok I’ll add one more thing probably more on mill than lathe but here goes.  Digital readouts. Yess the lathe can have then.
How necessary are they and how many decimal points?

I have an on going battle about this. I worked in a shop that had 4 brand new Bridgeport’s with three axis read outs that read 5 places or tenths. I can count on less than one hand the number of times this was of use. The standard .0005 was more than ok. The extra place was of value only on grinding machines.  This shop had iOS of the line every thing. We even had a brand new jig grinder. It did all the super close stuff. The guy that generally ran it was pretty creative in what he did.  I had used a gig bore but the grinder was something else.
Other shops I worked in had no read outs or .0005. At best.  Even that didn’t seem necessary if you had dial indicators and measuring tools. So what is the feeling on this?


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## SmithDoor

The new same South Bend Lathes they do not put back gears on the lathe.
You can not put the old South Bend tooling on new lathes or even buy tooling like tapper attachment.

I did know they are using plastic gears too.

Dave



Tin Falcon said:


> One of the factors to consider when purchasing a lathe is what accessories and tooling comes with the lathe. Check everything and  assume nothing.
> It is hard to define standard tooling.
> IMHO a well equipped lathe should have:
> 3 jaw scroll chuck
> 4 jaw independent chuck
> face plate
> Quick change tool holder
> machinable center
> live center
> drill chuck or tail stock chuck
> 
> the Basic Seig C2/C3 aka 7xs come with a three jaw and a center and a basic tool post.
> a 9 x 19 has a, face plate, steady rest,  follow rest, and a woodworkers  cheap 4 jaw .
> 
> The point here is if a lathe costs say $ 600 and adding  the steady ,the follow rest  the face plate and a 4 jaw these will likely add up to another      $ 200.  then add shipping and in the case of Harbor freight add the extended warranty cost. so you are now close to the cost of a similarly equipped 9x19.
> 
> The other question is how much do you need or want the steady rest and follow rest. IMHO there is rely no place to put a steady on a 7 x 10 a 7 x 16 maybe.
> Other stuff: if you are turning on centers you need a machinable center and a drive dog as well as a drive plate or face plate with slots. You may also need mandrels.
> 
> When using a face plate you need clamps a angle plate, and often a counterweight.
> 
> You will need cutting bits. IMHO HSS is best for hobby machines
> right hand bit for turning LH bit for facing and a parting grooving bit.
> 
> Drill bits.   Screw machine length will save spce on short lathes but are more expensive than jobbers length at least in sets.
> 
> Buy or make a boring bar or bars generally use the largest that will fit.
> 
> reamers will help smooth and size bores of cylinders .
> laps will refine cylinder bores.
> 
> A scissors knurl will save on bearing wear. as apposed to a plunge knurl.
> 
> A used lathe can come from stripped to well equipped so when looking at a used lathe take careful inventory.
> 
> 
> Tin


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