On Oct 14, 2011, at 11:16 AM, ralph_pattersonus wrote:

I think this is the project that was referred to...


--- In 7x12minilathe@..., "MERTON B BAKER" <mertbaker@...> wrote:

I have a 2" x 24" boring bar, which I used to do the cannons. Still a reach
on a 12x36, & requires a jig. I had a friend with a 2.5" dia. gun drill to
ease the labor. Mert


-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of "hanermo" - CNC 6-axis
Designs
Sent: Friday, October 14, 2011 7:51 AM
To: 7x12minilathe@...
Subject: Re: [7x12minilathe] Re: Finally, a project!




Agree 100% with Mert.

I could do it with a 7x - but would not.
It would involve building an external toolrest, and using a linear slide
to control the toolbit.
The linear slide, new, costs more than a 7x.
The work involved would be maybe 100 hours.. by my estimate.

I could do it with my 12x, but might not.
The bore is too deep for easy work.
Ie it IS doable, but far too big/heavy/hard/slow.

I would search for someone who has a 2" thick boring bar, and this is work
for industrial lathes in the 14x/3000 kg sizes, and above.
For my 12x I have a 1" one, and 1.5" ones are available.
Making one is not impractical, also.

Practical work sizes for a 7x are about 3" in steel, just like any lathe.
About half of nominal swing.
At a pinch, near nominal is doable, but very slow (everything is
relative.)

Boring that much metal on a big industrial lathe will probably take 3-4
hours.
12" deep means the cuts need to be light, maybe no more than 1 mm DOC or
depth, at a slow feed rate, to avoid excessive chatter.
If the total amount to be removed is say 6" or 140 mm, that means 70
passes at maybe 5 minutes per pass (could be a lot more, especially on the
later ones where rpm will be about 150).
You did not mention how thick the walls need to be, I guesstimeate at 0.5
inches.
That might be 350 minutes, or almost 6 hours.
Could be more.
Of course, the first 6" depth could be taken at 2-4 mm depths of cut, if
the lathe is a big enough one.

You will likely get your best price from a hobby semicommercial guy, who
will do it for 10-20-30$/hr.
They will take a full day, but wont be in a hurry, and the job might tax
their machines.
An industrial shop is likely to want 60$/hr x 3-4 hrs ..

Let us know how it goes, pics please ..


Rome was no built in a day. I was not the foreman on that job though,
and I
have advice. Keep your 7x12 for a while, buy a few books, (I'm making a
list, but there are some out there already) Play with your lathe, and
make a
few projects. Find something to make that turns you on, and if it's too
big
to fit on your 7x lathe build a working model that will. After 60 years
in
this game, I can say that if you are really interested, nothing can stop
you.

Mert

------------------------------------

Yahoo! Groups Links

--- In 7x12minilathe@..., george curtis <gcvisalia@...> wrote:

my bil is gonna put my lathe table together for me. we are wanting to know what
is best to protect the table, mdf, before we put the lathe on.
thanks,
?
george

--- In 7x12minilathe@..., "MERTON B BAKER" <mertbaker@...> wrote:

I have a 2" x 24" boring bar, which I used to do the cannons. Still a reach
on a 12x36, & requires a jig. I had a friend with a 2.5" dia. gun drill to
ease the labor. Mert


-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of "hanermo" - CNC 6-axis
Designs
Sent: Friday, October 14, 2011 7:51 AM
To: 7x12minilathe@...
Subject: Re: [7x12minilathe] Re: Finally, a project!




Agree 100% with Mert.

I could do it with a 7x - but would not.
It would involve building an external toolrest, and using a linear slide
to control the toolbit.
The linear slide, new, costs more than a 7x.
The work involved would be maybe 100 hours.. by my estimate.

I could do it with my 12x, but might not.
The bore is too deep for easy work.
Ie it IS doable, but far too big/heavy/hard/slow.

I would search for someone who has a 2" thick boring bar, and this is work
for industrial lathes in the 14x/3000 kg sizes, and above.
For my 12x I have a 1" one, and 1.5" ones are available.
Making one is not impractical, also.

Practical work sizes for a 7x are about 3" in steel, just like any lathe.
About half of nominal swing.
At a pinch, near nominal is doable, but very slow (everything is
relative.)

Boring that much metal on a big industrial lathe will probably take 3-4
hours.
12" deep means the cuts need to be light, maybe no more than 1 mm DOC or
depth, at a slow feed rate, to avoid excessive chatter.
If the total amount to be removed is say 6" or 140 mm, that means 70
passes at maybe 5 minutes per pass (could be a lot more, especially on the
later ones where rpm will be about 150).
You did not mention how thick the walls need to be, I guesstimeate at 0.5
inches.
That might be 350 minutes, or almost 6 hours.
Could be more.
Of course, the first 6" depth could be taken at 2-4 mm depths of cut, if
the lathe is a big enough one.

You will likely get your best price from a hobby semicommercial guy, who
will do it for 10-20-30$/hr.
They will take a full day, but wont be in a hurry, and the job might tax
their machines.
An industrial shop is likely to want 60$/hr x 3-4 hrs ..

Let us know how it goes, pics please ..


Rome was no built in a day. I was not the foreman on that job though,
and I
have advice. Keep your 7x12 for a while, buy a few books, (I'm making a
list, but there are some out there already) Play with your lathe, and
make a
few projects. Find something to make that turns you on, and if it's too
big
to fit on your 7x lathe build a working model that will. After 60 years
in
this game, I can say that if you are really interested, nothing can stop
you.

Mert

> ----- Original Message -----
> From: "gwelo62" <gwelo62@...>
> To: <7x12minilathe@...>
> Sent: Thursday, October 13, 2011 3:03 PM
> Subject: [7x12minilathe] used minilathes
>
>
> > What is a fair price for a used micromark lathe? It looks almost unused.
> >
> > Are any of the US importers bringing in metric lathes?
> >
> >
> >
> >
>

--- In 7x12minilathe@..., "Jim Dunmyer" <jdunmyer@...> wrote:

Be aware that the present MM lathe is a 7X16 that sells for $795.00. It has
a 500 watt brushless motor and no gear shift, so is a bit quieter than most
others. The usual accessories are included: wrenches, change gears, and
outside chuck jaws. The tailstock is a cam-lock design, and there is an
OPTIONAL tachometer. The full info is here:
,9615.html

A year or so ago, MM sold a 7X14 lathe that had a slightly smaller motor
with a gear shift that uses metal gears. It's a bit noisier than the models
with plastic gears, albeit should be a bit more durable. The digital
tachometer was builtin and included, tailstock was camlock. It sold for
$595.00, and included the above accessories.

Both lathes are "True Inch", so there is no error in the cross-slide and
compound lead screws, the travel is .050" per revolution. Most others use a
metric thread that gives you pretty close to .040"/rev.

I bought my MM 7X14 in like-new condition from a fella who had picked it up
in a trade. Unfortunately, both of us confused it with the 7X16, so I paid
too much. However, I AM happy with the machine. My previous one was a H.F.
7X10, and the lack of "headroom" bugged me. I was otherwise quite happy with
the lathe.

To answer your question, the price would depend on which one it is. A fair
price for a like-new machine (to me) would be list minus $100.00 ->$200.00.

Dunno about metric lathes, but if you want to cut metric threads, you can
get "close enough" for many threads with the stock gears. Add a 21-tooth
gear into the mix and you can get "close enough" for a bunch more threads.
See:


In my experience, the MM lathes need the same TLC by the new owner as any of
the others of this genre.


<<Jim>>


----- Original Message -----
From: "gwelo62" <gwelo62@...>
To: <7x12minilathe@...>
Sent: Thursday, October 13, 2011 3:03 PM
Subject: [7x12minilathe] used minilathes

What is a fair price for a used micromark lathe? It looks almost unused.

Are any of the US importers bringing in metric lathes?

-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of my340sixpak
Sent: Friday, October 14, 2011 8:21 AM
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: Finally, a project!


LOL, SKY HOOKS,, LOL, plus the chuck jaws would slam the bed 3 or 4 times a
rotate ;)

--- In 7x12minilathe@..., Andrew Franks <andyf1108@...> wrote:

For a hobby lathe, that's major engineering, and I'd farm it out. It won't

fit over the cross-slide (or even over the carriage). And to bore it, you
would need a boring bar 12" long, so to start at the outer end, your
toolpost would need to be at least 24" from the headstock end of the
workpiece, and would need skyhooks for support.

Andy




To: 7x12minilathe@...
From: wy3xinsc@...
Date: Thu, 13 Oct 2011 22:37:18 +0000
Subject: [7x12minilathe] Finally, a project!






I finally have a project where I'm hoping to use my mini-lathe, to make

some of the parts at least.

Question- and I hope nobody thinks this is a dumb one..

My lathe is a 7 x 12. Is it practical (or even possible) to turn and bore

a piece of 1018 steel round stock that is precisely that size? (7" round by
12" long). That's the largest piece of the project. All other parts I have
no doubt about the lathe being useable. If it won't work, I'll have to farm
out at least that one part.

Admitted, I think I'll have to buy a new chuck large enough to accept this

stock (if such a chuck exists, which is my next question), but will the
lathe do this job without destroying itself?

Thanks, -Web in Myrtle Beach, SC

------------------------------------

Yahoo! Groups Links

-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of "hanermo" - CNC 6-axis
Designs
Sent: Friday, October 14, 2011 7:51 AM
To: 7x12minilathe@...
Subject: Re: [7x12minilathe] Re: Finally, a project!




Agree 100% with Mert.

I could do it with a 7x - but would not.
It would involve building an external toolrest, and using a linear slide
to control the toolbit.
The linear slide, new, costs more than a 7x.
The work involved would be maybe 100 hours.. by my estimate.

I could do it with my 12x, but might not.
The bore is too deep for easy work.
Ie it IS doable, but far too big/heavy/hard/slow.

I would search for someone who has a 2" thick boring bar, and this is work
for industrial lathes in the 14x/3000 kg sizes, and above.
For my 12x I have a 1" one, and 1.5" ones are available.
Making one is not impractical, also.

Practical work sizes for a 7x are about 3" in steel, just like any lathe.
About half of nominal swing.
At a pinch, near nominal is doable, but very slow (everything is
relative.)

Boring that much metal on a big industrial lathe will probably take 3-4
hours.
12" deep means the cuts need to be light, maybe no more than 1 mm DOC or
depth, at a slow feed rate, to avoid excessive chatter.
If the total amount to be removed is say 6" or 140 mm, that means 70
passes at maybe 5 minutes per pass (could be a lot more, especially on the
later ones where rpm will be about 150).
You did not mention how thick the walls need to be, I guesstimeate at 0.5
inches.
That might be 350 minutes, or almost 6 hours.
Could be more.
Of course, the first 6" depth could be taken at 2-4 mm depths of cut, if
the lathe is a big enough one.

You will likely get your best price from a hobby semicommercial guy, who
will do it for 10-20-30$/hr.
They will take a full day, but wont be in a hurry, and the job might tax
their machines.
An industrial shop is likely to want 60$/hr x 3-4 hrs ..

Let us know how it goes, pics please ..


Rome was no built in a day. I was not the foreman on that job though,
and I
have advice. Keep your 7x12 for a while, buy a few books, (I'm making a
list, but there are some out there already) Play with your lathe, and
make a
few projects. Find something to make that turns you on, and if it's too
big
to fit on your 7x lathe build a working model that will. After 60 years
in
this game, I can say that if you are really interested, nothing can stop
you.

Mert

--- In 7x12minilathe@..., Andrew Franks <andyf1108@...> wrote:

For a hobby lathe, that's major engineering, and I'd farm it out. It won't fit over the cross-slide (or even over the carriage). And to bore it, you would need a boring bar 12" long, so to start at the outer end, your toolpost would need to be at least 24" from the headstock end of the workpiece, and would need skyhooks for support.

Andy




To: 7x12minilathe@...
From: wy3xinsc@...
Date: Thu, 13 Oct 2011 22:37:18 +0000
Subject: [7x12minilathe] Finally, a project!






I finally have a project where I'm hoping to use my mini-lathe, to make some of the parts at least.

Question- and I hope nobody thinks this is a dumb one..

My lathe is a 7 x 12. Is it practical (or even possible) to turn and bore a piece of 1018 steel round stock that is precisely that size? (7" round by 12" long). That's the largest piece of the project. All other parts I have no doubt about the lathe being useable. If it won't work, I'll have to farm out at least that one part.

Admitted, I think I'll have to buy a new chuck large enough to accept this stock (if such a chuck exists, which is my next question), but will the lathe do this job without destroying itself?

Thanks, -Web in Myrtle Beach, SC

?

Rome was no built in a day. I was not the foreman on that job though, and I
have advice. Keep your 7x12 for a while, buy a few books, (I'm making a
list, but there are some out there already) Play with your lathe, and make a
few projects. Find something to make that turns you on, and if it's too big
to fit on your 7x lathe build a working model that will. After 60 years in
this game, I can say that if you are really interested, nothing can stop
you.

Mert

-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of nissan.370z
Sent: Friday, October 14, 2011 12:15 AM
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: Finally, a project!


Surely need a larger lathe for that. Sounds like you are very new to lathes
like myself. Find some smaller projects to do, so you can learn more about
lathes and machining. Ask questions along the way etc., this way later on if
you decide to buy a larger lathe you will know much more and be able to get
use out of it right away.

I was going to wait till I had more room for a used SouthBend lathe much
larger than the 7x12 I purchased or get a 10x20 to start, but didn't want to
spend the money on a larger lathe when I have never used one yet (nor don't
really have the extra room for a large lathe "yet"). I have many small
projects to do and hope by the time I buy a large lathe I will be somewhat
knowledgeable with lathes and machining. So the more expensive lathe gets
used more and I can enjoy it.

good thing is, if you later upgrade to a larger lathe; these small lathes
seem to hold their value VERY well as I have seen used ones selling for
recently. I want to convert mine to CNC when I get a larger one though.

--- In 7x12minilathe@..., "wy3xinsc" <wy3xinsc@...> wrote:

I finally have a project where I'm hoping to use my mini-lathe, to make

some of the parts at least.

Question- and I hope nobody thinks this is a dumb one..

My lathe is a 7 x 12. Is it practical (or even possible) to turn and bore

a piece of 1018 steel round stock that is precisely that size? (7" round by
12" long). That's the largest piece of the project. All other parts I have
no doubt about the lathe being useable. If it won't work, I'll have to farm
out at least that one part.

Admitted, I think I'll have to buy a new chuck large enough to accept this

stock (if such a chuck exists, which is my next question), but will the
lathe do this job without destroying itself?

Thanks, -Web in Myrtle Beach, SC

------------------------------------

Yahoo! Groups Links

-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of Web Williams
Sent: Thursday, October 13, 2011 8:18 PM
To: 7x12minilathe@...
Subject: Re: [7x12minilathe] Re: Finally, a project!


Thanks for all the suggestions. I guess I don't have much
choice but to farm this work out. Due to the nature of the
project (Coehorn mortar barrel) it's not possible (from a
safety standpoint) to substitute a tube and cap. The powder
chamber requires a certain amount of web to retain the
pressure.

Back to the grindstone, thanks everyone!!!

-Web (in Myrtle Beach, SC)


------------------------------------

Yahoo! Groups Links

-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of Charles
Sent: Thursday, October 13, 2011 7:34 PM
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: Finally, a project!


All good answers:

You are now being introduced to the "specsmanship" of lathe specifications.

Actually, if you removed the saddle, you probably could get a 7 inch by 12
inch cylinder between centers going round and round. But about all you
could do is watch it.

Another way to look at lathe specifications is that you could turn something
12 inches long, or 7 inches diameter (with great difficulty), but not both.
Choose one.

Actually, the clearance over the ways is usually most meaningful when
needing to clear a large part while turning or boring a much smaller
diameter of it. Drilling a hole in a large disk is an obvious example. But
boring the cylinder hole in a steam engine casting is another. The size of
the casting may not clear the compound, but might clear the ways so you
would be in good shape.

Except for certain situations where you are willing to take on extra grief,
a good rule of thumb is to get a lathe with twice the swing of the largest
diameter you will routinely be turning.

Or for the occasional situation beyond the machine, find somebody with a
machine that is big enough.

Or find a way to design around it. For example, maybe what you need could
be handled with a length of tube somebody could cut and you could make end
caps to weld in. (I know that probably isn't a solution in your case, but
making a fabrication of more manageable parts is sometimes a solution.)

Chuck K.

--- In 7x12minilathe@..., "MERTON B BAKER" <mertbaker@...>
wrote:

Sorry, no. You are limited by the swing over the carriage, and, while it

is

theoretically possible to turn a 7" flywheel, you will find that getting

the

toolbit onto the surface is tricky, and necessitates rigging a special

tool

post. another limitation on large diameter work is power. Cutting rates
are in surface feet per minute, and the larger the diameter, the slower it
has to go. The Asian 7xs, as a rule, are not happy at slow rpms.

Mert



-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of wy3xinsc
Sent: Thursday, October 13, 2011 6:37 PM
To: 7x12minilathe@...
Subject: [7x12minilathe] Finally, a project!


I finally have a project where I'm hoping to use my mini-lathe, to make

some

of the parts at least.

Question- and I hope nobody thinks this is a dumb one..

My lathe is a 7 x 12. Is it practical (or even possible) to turn and bore

a

piece of 1018 steel round stock that is precisely that size? (7" round by
12" long). That's the largest piece of the project. All other parts I have
no doubt about the lathe being useable. If it won't work, I'll have to

farm

out at least that one part.

Admitted, I think I'll have to buy a new chuck large enough to accept this
stock (if such a chuck exists, which is my next question), but will the
lathe do this job without destroying itself?

Thanks, -Web in Myrtle Beach, SC



------------------------------------

Yahoo! Groups Links

------------------------------------

Yahoo! Groups Links

--- In 7x12minilathe@..., "nissan.370z" <ebandit@...> wrote:

I just got my Grizzly 7x12 lathe and it is my first lathe ever. It was dropped during shipping on its side. the package was roughed up with a few gouges in it. The Styrofoam inside was busted up a little on the head end but was still there. the splash guard is lightly dented and the tray has a good dent in the back just behind the spindle. I will post a picture or two also.

What should I look for that could also be damaged? Can it be knocked out of true? I have no lathe experience and do not want to try and learn on a damaged lathe. If it is ok should I get new parts from them or demand a discount or what of anyone had experience with this sort of issue before from any company.

Any advice is greatly appreciated. I may test it out and inspect closer in the morning because they asked me too do that and call back with any other details. I have only opened the box and took pictures and marked the shipping info before signing it. Have not did a close inspection yet.

--- In 7x12minilathe@..., "wy3xinsc" <wy3xinsc@...> wrote:

I finally have a project where I'm hoping to use my mini-lathe, to make some of the parts at least.

Question- and I hope nobody thinks this is a dumb one..

My lathe is a 7 x 12. Is it practical (or even possible) to turn and bore a piece of 1018 steel round stock that is precisely that size? (7" round by 12" long). That's the largest piece of the project. All other parts I have no doubt about the lathe being useable. If it won't work, I'll have to farm out at least that one part.

Admitted, I think I'll have to buy a new chuck large enough to accept this stock (if such a chuck exists, which is my next question), but will the lathe do this job without destroying itself?

Thanks, -Web in Myrtle Beach, SC