I recently did some shopping at www.technobots.co.uk - ordered a lot of 
mixed small parts on Sunday, got an email Monday telling me that it had 
been packed, arrived today, Tuesday, with every part and exactly as 
ordered. Just a quick recommendation.



If anyone is looking for a CNC X3 mill, this one is (now) 1/3 of the 
arceurotrade price (but you'll have to pay duty and VAT, and service 
might be a problem):

http://cgi.ebay.co.uk/NIB-Sieg-Seig-KX3-CNC-milling-machine-QCTP-X3-X2-lathe_W0QQitemZ310076222153QQcmdZViewItem?hash=item310076222153&_trksid=p3286.m63.l1177


-- Peter Fairbrother

Peter Fairbrother wrote:
> I recently did some shopping at www.technobots.co.uk - ordered a lot of 
> mixed small parts on Sunday, got an email Monday telling me that it had 
> been packed, arrived today, Tuesday, with every part and exactly as 
> ordered. Just a quick recommendation.
> 
> 
> 
> If anyone is looking for a CNC X3 mill, this one is (now) 1/3 of the 
> arceurotrade price (but you'll have to pay duty and VAT, and service 
> might be a problem):
> 
> http://cgi.ebay.co.uk/NIB-Sieg-Seig-KX3-CNC-milling-machine-QCTP-X3-X2-lathe_W0QQitemZ310076222153QQcmdZViewItem?hash=item310076222153&_trksid=p3286.m63.l1177 
> 
> 
> 
> -- Peter Fairbrother

Interesting - how does this compare with the ArcEuro/JS offering?

On Tue, 19 Aug 2008 14:11:51 +0100, NoSpam 
wrote:

>Peter Fairbrother wrote:
>> I recently did some shopping at www.technobots.co.uk - ordered a lot of 
>> mixed small parts on Sunday, got an email Monday telling me that it had 
>> been packed, arrived today, Tuesday, with every part and exactly as 
>> ordered. Just a quick recommendation.
>> 
>> 
>> 
>> If anyone is looking for a CNC X3 mill, this one is (now) 1/3 of the 
>> arceurotrade price (but you'll have to pay duty and VAT, and service 
>> might be a problem):
>> 
>> http://cgi.ebay.co.uk/NIB-Sieg-Seig-KX3-CNC-milling-machine-QCTP-X3-X2-lathe_W0QQitemZ310076222153QQcmdZViewItem?hash=item310076222153&_trksid=p3286.m63.l1177 
>> 
>> 
>> 
>> -- Peter Fairbrother
>
>Interesting - how does this compare with the ArcEuro/JS offering?
I think that you will find that their's comes with drive electronics
which this one does not!

--

Richard

Email address is valid but remove burrs before sending!

On 19 Aug, 14:11, NoSpam  wrote:
> Peter Fairbrother wrote:
> > I recently did some shopping atwww.technobots.co.uk- ordered a lot of
> > mixed small parts on Sunday, got an email Monday telling me that it had
> > been packed, arrived today, Tuesday, with every part and exactly as
> > ordered. Just a quick recommendation.
>
> > If anyone is looking for a CNC X3 mill, this one is (now) 1/3 of the
> > arceurotrade price (but you'll have to pay duty and VAT, and service
> > might be a problem):
>
> >http://cgi.ebay.co.uk/NIB-Sieg-Seig-KX3-CNC-milling-machine-QCTP-X3-X...
>
> > -- Peter Fairbrother
>
> Interesting - how does this compare with the ArcEuro/JS offering?

I wondered what had happened to them <g>

Rush out and buy them all up, bargain of the century but please note
the following points:-

[1] Note the spindle in the you tube clip, this collet fixing is part
of the spindle and holds a range of 4 collets only,
If your tooling doesn't fit these collets then tough. It does not have
a separate R8 or morse taper.

[2] Note the operation of the air drawbar by a two way valve onto a
40mm or 50mm air cylinder direct onto the top casting.
Not having seen this in person but guessing that because it's so small
a cylinder and so close it can't use the normal method of stacked
Belville washers but relies on the air to pull the collet up.
No air and the tool falls out.

[3] As Richard points out the ad does say no driver box, it actually
means no electronics.
The correct title for this machine is KX3-NU the Nu being the Chinese
designation for nude. These are made for shipping to internal
customers in China for different Chinese controllers to be fitted. The
build includes the ballscrew's, motors, couplings and cables but no
drive electronics or what they purposely?  miss out the auction, no
motor drive board.

Now this motor is a special 1000W 3phase DC brushless motor and
requires a special matching board to suit.
They can be sourced from Sieg and the Chinese motor supplier but
neither Sieg or the supplier will ship out of China for a machine that
should not have shipped out of China in the first place.
So you now have to replace the drive motor which is near impossible to
get a small enough motor to fit where the original one fits.

I know exactly what a NU designation machine consists of as both mine,
KX1 and KX3 were shipped over as NU machines for retro fitting but I
had the support of Sieg.

This is no sour grapes post as I am not affected by any UK sales.
I get paid by the Chinese for development and for support. Support BTW
that is based on a tightly regulated issue of serial numbers and owner
numbers. If it doesn't appear on my list then sod off..............

Ketan at 5' 2" [ which is very tall for a dwarf ] is big enough to
fight his own battles <g>

John S wrote:
> On 19 Aug, 14:11, NoSpam  wrote:
>> Peter Fairbrother wrote:
>>> I recently did some shopping atwww.technobots.co.uk- ordered a lot of
>>> mixed small parts on Sunday, got an email Monday telling me that it had
>>> been packed, arrived today, Tuesday, with every part and exactly as
>>> ordered. Just a quick recommendation.
>>> If anyone is looking for a CNC X3 mill, this one is (now) 1/3 of the
>>> arceurotrade price (but you'll have to pay duty and VAT, and service
>>> might be a problem):
>>> http://cgi.ebay.co.uk/NIB-Sieg-Seig-KX3-CNC-milling-machine-QCTP-X3-X...
>>> -- Peter Fairbrother
>> Interesting - how does this compare with the ArcEuro/JS offering?
> 
> I wondered what had happened to them <g>
> 
> Rush out and buy them all up, bargain of the century but please note
> the following points:-
> 
> [1] Note the spindle in the you tube clip, this collet fixing is part
> of the spindle and holds a range of 4 collets only,
> If your tooling doesn't fit these collets then tough. It does not have
> a separate R8 or morse taper.
> 
> [2] Note the operation of the air drawbar by a two way valve onto a
> 40mm or 50mm air cylinder direct onto the top casting.
> Not having seen this in person but guessing that because it's so small
> a cylinder and so close it can't use the normal method of stacked
> Belville washers but relies on the air to pull the collet up.
> No air and the tool falls out.
> 
> [3] As Richard points out the ad does say no driver box, it actually
> means no electronics.
> The correct title for this machine is KX3-NU the Nu being the Chinese
> designation for nude. These are made for shipping to internal
> customers in China for different Chinese controllers to be fitted. The
> build includes the ballscrew's, motors, couplings and cables but no
> drive electronics or what they purposely?  miss out the auction, no
> motor drive board.
> 
> Now this motor is a special 1000W 3phase DC brushless motor and
> requires a special matching board to suit.
> They can be sourced from Sieg and the Chinese motor supplier but
> neither Sieg or the supplier will ship out of China for a machine that
> should not have shipped out of China in the first place.
> So you now have to replace the drive motor which is near impossible to
> get a small enough motor to fit where the original one fits.
> 
> I know exactly what a NU designation machine consists of as both mine,
> KX1 and KX3 were shipped over as NU machines for retro fitting but I
> had the support of Sieg.
> 
> This is no sour grapes post as I am not affected by any UK sales.
> I get paid by the Chinese for development and for support. Support BTW
> that is based on a tightly regulated issue of serial numbers and owner
> numbers. If it doesn't appear on my list then sod off..............
> 
> Ketan at 5' 2" [ which is very tall for a dwarf ] is big enough to
> fight his own battles <g>

Aha! We live and learn.

Good to know someone here knows what he's talking about, as it seems I 
don't.

-- Peter Fairbrother

> > Ketan at 5' 2" [ which is very tall for a dwarf ] is big enough to
> > fight his own battles <g>
>
> Aha! We live and learn.
>
> Good to know someone here knows what he's talking about, as it seems I
> don't.
>
> -- Peter Fairbrother- Hide quoted text -
>
> - Show quoted text -

"YES" !!

Ketan Swali wrote:
>>> Ketan at 5' 2" [ which is very tall for a dwarf ] is big enough to
>>> fight his own battles <g>
>> Aha! We live and learn.
>>
>> Good to know someone here knows what he's talking about, as it seems I
>> don't.
>>
>> -- Peter Fairbrother- Hide quoted text -
>>
>> - Show quoted text -
> 
> "YES" !!

  Ouch!

Talking of things Sieg of which I don't know much, has anyone seen/used 
a C4 lathe? Any good?

Ketan, any plans to sell them?

-- Peter

On 20 Aug, 16:48, Peter Fairbrother  wrote:
> Ketan Swali wrote:
> >>> Ketan at 5' 2" [ which is very tall for a dwarf ] is big enough to
> >>> fight his own battles <g>
> >> Aha! We live and learn.
>
> >> Good to know someone here knows what he's talking about, as it seems I
> >> don't.
>
> >> -- Peter Fairbrother- Hide quoted text -
>
> >> - Show quoted text -
>
> > "YES" !!
>
>   Ouch!
>
> Talking of things Sieg of which I don't know much, has anyone seen/used
> a C4 lathe? Any good?
>
> Ketan, any plans to sell them?
>
> -- Peter

It had problems in the early days with the motor/board combination. To
the best of my knowledge, these have been fixed. Axminster and Chester
sell them. Regardless of what is said, it is a metric machine with
metric leadscrew. No tumbler reverse. The gear which turns it into an
imperial is open to question. The physical weight is good, overall.
After considering John Stevensons comments on this machine, ARC has
thus far decided it is better for Axminster and Chester to continue
selling them.

Ketan Swali wrote:
> On 20 Aug, 16:48, Peter Fairbrother  wrote:
>> Ketan Swali wrote:
>>>>> Ketan at 5' 2" [ which is very tall for a dwarf ] is big enough to
>>>>> fight his own battles <g>
>>>> Aha! We live and learn.
>>>> Good to know someone here knows what he's talking about, as it seems I
>>>> don't.
>>>> -- Peter Fairbrother- Hide quoted text -
>>>> - Show quoted text -
>>> "YES" !!
>>   Ouch!
>>
>> Talking of things Sieg of which I don't know much, has anyone seen/used
>> a C4 lathe? Any good?
>>
>> Ketan, any plans to sell them?
>>
>> -- Peter
> 
> It had problems in the early days with the motor/board combination. To
> the best of my knowledge, these have been fixed. Axminster and Chester
> sell them. Regardless of what is said, it is a metric machine with
> metric leadscrew. No tumbler reverse. The gear which turns it into an
> imperial is open to question. The physical weight is good, overall.
> After considering John Stevensons comments on this machine, ARC has
> thus far decided it is better for Axminster and Chester to continue
> selling them.

Over to you then John...

On 21 Aug, 19:45, Peter Harrison  wrote:
>
> >> Ketan, any plans to sell them?
>
> >> -- Peter
>
> > It had problems in the early days with the motor/board combination. To
> > the best of my knowledge, these have been fixed. Axminster and Chester
> > sell them. Regardless of what is said, it is a metric machine with
> > metric leadscrew. No tumbler reverse. The gear which turns it into an
> > imperial is open to question. The physical weight is good, overall.
> > After considering John Stevensons comments on this machine, ARC has
> > thus far decided it is better for Axminster and Chester to continue
> > selling them.
>
> Over to you then John...

Wot ?????????????

John S wrote:
> On 21 Aug, 19:45, Peter Harrison  wrote:
>>>> Ketan, any plans to sell them?
>>>> -- Peter
>>> It had problems in the early days with the motor/board combination. To
>>> the best of my knowledge, these have been fixed. Axminster and Chester
>>> sell them. Regardless of what is said, it is a metric machine with
>>> metric leadscrew. No tumbler reverse. The gear which turns it into an
>>> imperial is open to question. The physical weight is good, overall.
>>> After considering John Stevensons comments on this machine, ARC has
>>> thus far decided it is better for Axminster and Chester to continue
>>> selling them.
>> Over to you then John...
> 
> Wot ?????????????
> 

Any thoughts on the C4 that you might care to share.

On 22 Aug, 00:22, Peter Harrison  wrote:
> John S wrote:
> > On 21 Aug, 19:45, Peter Harrison  wrote:
> >>>> Ketan, any plans to sell them?
> >>>> -- Peter
> >>> It had problems in the early days with the motor/board combination. To
> >>> the best of my knowledge, these have been fixed. Axminster and Chester
> >>> sell them. Regardless of what is said, it is a metric machine with
> >>> metric leadscrew. No tumbler reverse. The gear which turns it into an
> >>> imperial is open to question. The physical weight is good, overall.
> >>> After considering John Stevensons comments on this machine, ARC has
> >>> thus far decided it is better for Axminster and Chester to continue
> >>> selling them.
> >> Over to you then John...
>
> > Wot ?????????????
>
> Any thoughts on the C4 that you might care to share.

No.
I though Ketan had explained it OK and even pointed out who was
selling them in the Uk.

John S wrote:
> On 22 Aug, 00:22, Peter Harrison  wrote:
>> John S wrote:
>>> On 21 Aug, 19:45, Peter Harrison  wrote:
>>>>>> Ketan, any plans to sell them?
>>>>>> -- Peter
>>>>> It had problems in the early days with the motor/board combination. To
>>>>> the best of my knowledge, these have been fixed. Axminster and Chester
>>>>> sell them. Regardless of what is said, it is a metric machine with
>>>>> metric leadscrew. No tumbler reverse. The gear which turns it into an
>>>>> imperial is open to question. The physical weight is good, overall.
>>>>> After considering John Stevensons comments on this machine, ARC has
>>>>> thus far decided it is better for Axminster and Chester to continue
>>>>> selling them.
>>>> Over to you then John...
>>> Wot ?????????????
>> Any thoughts on the C4 that you might care to share.
> 
> No.

Oooooh. Abrupt!

> I though Ketan had explained it OK and even pointed out who was
> selling them in the Uk.

But we wanted to know more about what *you* thought about the C4. Or is 
that just as Ketan said, or can't you say?

For someone who wants a table-top lathe it seems to be the biggest and 
perhaps best equipped available at non-Myford prices.

The problems with the imperial conversion wouldn't affect those like me 
who work in metric anyway, and the lack of a tumbler reverse - well 
that's curious as the C3 has one, but I've never actually used it to cut 
a left-hand thread, and if the carriage and cross-slide drives reverse 
it won't often be a problem.

Of course if they don't reverse that would be a real problem - do they? 
Over to anyone who has seen and used one ...

-- Peter Fairbrother

On 22 Aug, 19:59, Peter Fairbrother  wrote:

> > On 22 Aug, 00:22, Peter Harrison  wrote:
> if the carriage and cross-slide drives reverse
> it won't often be a problem.
>
> Of course if they don't reverse that would be a real problem - do they?
> Over to anyone who has seen and used one ...
>
> -- Peter Fairbrother

To reverse the carriage and cross slide screws you need a tumbler
reverse. That's what they do and this machine doesn't have one.
Ketan did say as much.

John S.

John S wrote:
> On 22 Aug, 19:59, Peter Fairbrother  wrote:
> 
>>> On 22 Aug, 00:22, Peter Harrison  wrote:
>> if the carriage and cross-slide drives reverse
>> it won't often be a problem.
>>
>> Of course if they don't reverse that would be a real problem - do they?
>> Over to anyone who has seen and used one ...
>>
>> -- Peter Fairbrother
> 
> To reverse the carriage and cross slide screws you need a tumbler
> reverse. 

To reverse the screws, perhaps, but to reverse the motion no - there 
could well be gears in the carriage to do that.

Are you saying that you can only face cut under power feed in one 
direction?

That would be *highly* objectionable, and if I bought such a lathe I'd 
send it back immediately, as not having proper cross slide drive!



Though I have long had doubts about cross slide drives which run on the 
leadscrew rather than a seperate shaft.

-- Peter Fairbrother


That's what they do and this machine doesn't have one.
> Ketan did say as much.
> 
> John S.
>

Peter Fairbrother wrote:
> John S wrote:
>> On 22 Aug, 19:59, Peter Fairbrother  wrote:
>>
>>>> On 22 Aug, 00:22, Peter Harrison  wrote:
>>> if the carriage and cross-slide drives reverse
>>> it won't often be a problem.
>>>
>>> Of course if they don't reverse that would be a real problem - do they?
>>> Over to anyone who has seen and used one ...
>>>
>>> -- Peter Fairbrother
>>
>> To reverse the carriage and cross slide screws you need a tumbler
>> reverse. 
> 
> To reverse the screws, perhaps, but to reverse the motion no - there 
> could well be gears in the carriage to do that.
> 
> Are you saying that you can only face cut under power feed in one 
> direction?
> 
> That would be *highly* objectionable, and if I bought such a lathe I'd 
> send it back immediately, as not having proper cross slide drive!
> 
> 
> 
> Though I have long had doubts about cross slide drives which run on the 
> leadscrew rather than a seperate shaft.
> 
> -- Peter Fairbrother
> 

Here is a post I found in the Chester forums:

http://www.atfreeforum.com/chesteruk/viewtopic.php?t=176&start=21&mforum=chesteruk

Not as convenient as a lever operated tumbler reverse but it will do LH 
threading. Correct me if I am wrong but many of the lathes in this class 
don't have a tumbler reverse lever but can be persuaded to do LH 
threading by arranging the changewheels.

However, the power crossfeed seems a little more hinkey. According to 
the review here:

http://www.mini-lathe.com/m4/C4/c4.htm

The power transfer lever allows the leadscrew to either drive the cross 
slide along the ways or across them. When set to power the cross feed, 
the direction of movement of the slide depends upon the direction of 
rotation of the spindle. Thus I guess you would have to put the spindle 
in reverse to move the cross slide out.

It seems no lathe has the exact features you want and they are all 
compromises. It is perhaps no wonder that, in this size range, the 
Myfords are still so popular. They are very versatile. Except, of 
course, for this money you have to take a chance on the condition of a 
used Myford. That is your compromise.

Peer Harrison

Peter Harrison wrote:
> Peter Fairbrother wrote:
>> John S wrote:
>>> On 22 Aug, 19:59, Peter Fairbrother  wrote:
>>>
>>>>> On 22 Aug, 00:22, Peter Harrison  wrote:
>>>> if the carriage and cross-slide drives reverse
>>>> it won't often be a problem.
>>>>
>>>> Of course if they don't reverse that would be a real problem - do they?
>>>> Over to anyone who has seen and used one ...
>>>>
>>>> -- Peter Fairbrother
>>>
>>> To reverse the carriage and cross slide screws you need a tumbler
>>> reverse. 
>>
>> To reverse the screws, perhaps, but to reverse the motion no - there 
>> could well be gears in the carriage to do that.
>>
>> Are you saying that you can only face cut under power feed in one 
>> direction?
>>
>> That would be *highly* objectionable, and if I bought such a lathe I'd 
>> send it back immediately, as not having proper cross slide drive!
>>
>>
>>
>> Though I have long had doubts about cross slide drives which run on 
>> the leadscrew rather than a seperate shaft.
>>
>> -- Peter Fairbrother
>>
> 
> Here is a post I found in the Chester forums:
> 
> http://www.atfreeforum.com/chesteruk/viewtopic.php?t=176&start=21&mforum=chesteruk 
> 
> 
> Not as convenient as a lever operated tumbler reverse but it will do LH 
> threading. Correct me if I am wrong but many of the lathes in this class 
> don't have a tumbler reverse lever but can be persuaded to do LH 
> threading by arranging the changewheels.

That's fine, as I for one seldom if ever want to cut LH threads and 
don't mind a bit of razamagoo when/if I do.

> 
> However, the power crossfeed seems a little more hinkey. According to 
> the review here:
> 
> http://www.mini-lathe.com/m4/C4/c4.htm
> 
> The power transfer lever allows the leadscrew to either drive the cross 
> slide along the ways or across them. When set to power the cross feed, 
> the direction of movement of the slide depends upon the direction of 
> rotation of the spindle. Thus I guess you would have to put the spindle 
> in reverse to move the cross slide out.

Ouch! Could anyone be so stupid as to design a lathe like that? You 
can't even turn in both directions?

If this is so then the C4 is well off my list!

> 
> It seems no lathe has the exact features you want and they are all 
> compromises. It is perhaps no wonder that, in this size range, the 
> Myfords are still so popular. They are very versatile. Except, of 
> course, for this money you have to take a chance on the condition of a 
> used Myford. That is your compromise.

Maybe a Boxford? Not table-top, but ...


-- Peter

"John S"  wrote in message 
news:3537cc94-78a9-4d15-8bed-406fa21152bb@k37g2000hsf.googlegroups.com...
> On 22 Aug, 19:59, Peter Fairbrother  wrote:
>
>> > On 22 Aug, 00:22, Peter Harrison  wrote:
>> if the carriage and cross-slide drives reverse
>> it won't often be a problem.
>>
>> Of course if they don't reverse that would be a real problem - do they?
>> Over to anyone who has seen and used one ...
>>
>> -- Peter Fairbrother
>
> To reverse the carriage and cross slide screws you need a tumbler
> reverse. That's what they do and this machine doesn't have one.
> Ketan did say as much.
>
> John S.
>
A recent edition of one of the Village Press (USA) magazines had an article 
on adding a tumbler reverse to an imported lathe. Seemed a very good job and 
not terribly difficult.

Don Young (USA)

Peter Fairbrother Wrote: 
> Peter Harrison wrote:
> 
> That's fine, as I for one seldom if ever want to cut LH threads and
> don't mind a bit of razamagoo when/if I do.
> [color=blue]
> >
> > However, the power crossfeed seems a little more hinkey. According
> to
> > the review here:
> >
> > http://www.mini-lathe.com/m4/C4/c4.htm
> >
> > The power transfer lever allows the leadscrew to either drive the
> cross
> > slide along the ways or across them. When set to power the cross
> feed,
> > the direction of movement of the slide depends upon the direction of
> > rotation of the spindle. Thus I guess you would have to put the
> spindle
> > in reverse to move the cross slide out.
> 
> Ouch! Could anyone be so stupid as to design a lathe like that? You
> can't even turn in both directions?
> 
> If this is so then the C4 is well off my list!
> 
> 
> 
> -- Peter

If you spend time to read the mini lathe article you will see that it
has purposely been designed that way so with the spindle disconnected
and using reverse it has power feed in both directions for the milling
attachment.

I have never understood the fascination for power cross feed on a lathe
that only has 3 inches of movement anyway.
When you compare the number of small machines built to the ones with
power cross feed it must be a very low percent but it's never stopped
anyone from making parts yet.

It seem only of importance to armchair machinists and nit pickers who
wouldn't even buy one anyway.

P Riedie.


-- 
P Riedie
------------------------------------------------------------------------
P Riedie's Profile: http://www.rcgroups.com/forums/member.php?u=145351
View this thread: http://www.rcgroups.com/forums/showthread.php?t=911090

> Though I have long had doubts about cross slide drives which run on the 
> leadscrew rather than a seperate shaft.
> 
Why is this, Peter ?

-- 
Boo

> I have never understood the fascination for power cross feed on a lathe
> that only has 3 inches of movement anyway.

Surface finish ?

-- 
Boo

On 23 Aug, 10:43, Boo 
wrote:
> > I have never understood the fascination for power cross feed on a lathe
> > that only has 3 inches of movement anyway.
>
> Surface finish ?
>
> --
> Boo

Unless it has Constant Surface Speed you won't get a true finish as
the feed rates change with diameter.
However on only 3" if you can't wind steadily enough either take more
water with it or learn to do so.
It's not hard and only requires practice as you go hand over hand, no
jigs and fixtures needed and you get a nice warm feeling afterwards.
Either that you you have pissed yourself................

John S.

John S wrote:
> On 23 Aug, 10:43, Boo 
> wrote:
>>> I have never understood the fascination for power cross feed on a lathe
>>> that only has 3 inches of movement anyway.
>> Surface finish ?
>>
>> --
>> Boo
> 
> Unless it has Constant Surface Speed you won't get a true finish as
> the feed rates change with diameter.
> However on only 3" if you can't wind steadily enough either take more
> water with it or learn to do so.
> It's not hard and only requires practice as you go hand over hand, no
> jigs and fixtures needed and you get a nice warm feeling afterwards.
> Either that you you have pissed yourself................
> 
> John S.

Suppose I want to face 4mm off a 50mm dia surface in something hard.

Remembering that mine is a small lathe and can only take 0.25mm cuts in 
the hard stuff, that's 16 cuts. At 1mm per turn each cut will need about 
30 turns, 60 if only cutting one way.

That's 960 turns of the handle, and it gets tiresome real quick - damhikt.




As to using the leadscrew to drive a carriage  or cross feed, I just 
think it may be too much of a compromise - will the leadscrew still work 
properly as a leadscrew? Will the pin or whatever which rotates stick? 
will it cause the carriage to move?

I don't know the answer to either question, but I have doubts.

-- Peter Fairbrother

On 23 Aug, 20:33, Peter Fairbrother  wrote:

> As to using the leadscrew to drive a carriage  or cross feed, I just
> think it may be too much of a compromise - will the leadscrew still work
> properly as a leadscrew? Will the pin or whatever which rotates stick?
> will it cause the carriage to move?
>
> I don't know the answer to either question, but I have doubts.
>
> -- Peter Fairbrother

In which case ask Myfords, Boxford, South Bend, Emco and a host more
companies who did and in some cases still do employ this situation of
a combined lead and feed screw.

John S.

On 23 Aug, 20:33, Peter Fairbrother  wrote:.
>
> Suppose I want to face 4mm off a 50mm dia surface in something hard.
>
> Remembering that mine is a small lathe and can only take 0.25mm cuts in
> the hard stuff, that's 16 cuts. At 1mm per turn each cut will need about
> 30 turns, 60 if only cutting one way.
>
> That's 960 turns of the handle, and it gets tiresome real quick - damhikt> As to using the leadscrew to drive a carriage  or cross feed, I just
> think it may be too much of a compromise - will the leadscrew still work
> properly as a leadscrew? Will the pin or whatever which rotates stick?
> will it cause the carriage to move?
>
> I don't know the answer to either question, but I have doubts.
>
> -- Peter Fairbrother- Hide quoted text -
>
> - Show quoted text -


Peter

I have to say that, stopping the machine, reversing the direction of
the feed shaft, re-starting and re-engaging the feed 16 times is also
tiresome. I guess if I was going to do that job very often I would
have to consider if the compromise of using too small a lathe was
worthwhile. Although I have PCF on all my lathes, when facing
something where I want a good surface finish right to the centre, I am
more inclined to feed by hand. I can at least try to vary the feed
rate to match the surface speed. With practice and using the "hand
over hand" method one can produce a very good facing cut. With that in
mind, I agree with an earlier comment that PCF is somewhat overvalued
in small lathes. Lets be honest, it's a hobby (well it is for me) and
if we don't enjoy twiddling hand wheels we possibly need to look at
CNC anyway as we won't need to turn any hand wheels at all then.

This system for providing power feeds is well established, much used
and reliable. I have a couple of PCF Myfords and a Boxford which all
use a single leadscrew to provide power feeds, they all work
faultlessly and have done so for many years. All also work very well
as a "leadscrew" and produce accurate threads if I have taken the
trouble to correctly set up the drive train. Again, these days many
thread accuracy issues are down to compromises in trying to cut as
many imperial and metric threads as possible with a couple of change
gears (smaller are cheaper so 21 rather than 127) or with a simple
limited range gearbox.

In fact, my BH600 which has both a leadscrew and a power feed shaft
does tend to stick sometimes when I try and disengage it. I guess it
is all down to appropriate design and manufacture. In my experience,
the issue with sticking when disengaging feeds is much more prevalent
on feed screws with very fine threads, something which is often used
these days on the smaller, cheaper lathes. Trying to disengage the
feed on my old Naerok 920 when approaching a shoulder at speed was
guaranteed to provide an increased heart rate. I would also point out
that if facing, particularly with a hard material, good practice would
have the saddle locked anyway; supposing the facility is available of
course.

Regards

Keith