---

From: drmico60
To: 7x12minilathe@...
Sent: Thursday, December 6, 2012 3:02 PM
Subject: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?

?

Hi John, Andy and others,
I have rechecked my measurements and still come up with Mod 2.2 for the spindle gears. John L's machine is a Real Bull from Amadeal whereas mine is a Sieg version of the minilathe. Is this yet another diifference between the two machines?
What is the origin of the OP's machine?
Mike

--- In 7x12minilathe@..., John Lindo wrote:
>
> Ian
> Andy is correct ??1.5 module.
> I went through the heartache of machining new Hi/Low gears out of brass.All the gears were to be fly cut??
> off??separate??arbors for each pair and brazing together after finish machining.
> This gear cutting project was due to braking one set of plastic gears while turning an??intermittent??cut at a 100 mm diameter.
> I bought another plastic set and decided to make my own.Out of brass.Silly mistake.
> After making 3 special high speed steel fly cutter bits and a boring bar holder to suit the small and large gears (although all 4 gears are 1.5 module)??
> and applied the correct??relief??angles etc.even used slitting saws to cut between teeth to the various root??diameters to help in metal removal.
> the chatter and banging (although feeding in several passes) seemed to be beating my Weiss mill (the Rolls of the Chinese mills) to pieces.I gave up.
> I still have the cutters if you want them.just send me a PM of your address.
> Also check out out of Hong Kong?? they have good offers.
> It's possibly better to buy the off the shelf steel gears and save your tooling and machines for other projects.
> Again,my Real Bull lathe runs fine with steel gears,but noisy,I was told that the noise will reduce in time,I am still waiting.
> I??regularly??apply lithium (white) grease through my cut out hatch.see link.and it does??quieten??it down.
>
>
> possibly the new brushless High torque lathes have not this problem gear problem.
> Who would of thought we could travel around the world after the Wright brothers barely got off the ground.
> Anyway.
> Also I drop oil directly onto the H/L shift mechanism through the??inspection??hatch.,note from the photos the other lube tube is oiling the plumber block of the feed screw.
> Again no need to remove the back cover.The plastic tube is attached to a nipple on top of the bearing block.
> Using an inspection cover you can also do regular greasing of the tapered roller bearings without having to dismantle the spindle.
> Regards
> John L
> Spain.
>
>
>
>
>
> >________________________________
> > From: Andy Franks
> >To: 7x12minilathe@...
> >Sent: Thursday, December 6, 2012 10:33 AM
> >Subject: RE: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?
> >
> >
> >??
> >Ian, I believe the gears inside the headstock are Mod 1.5.
> >??
> >You can check this by measuring the outside diameter of one of them in millimetres; preferably one with an even number of teeth. If that measurement is approximately equal to (N + 2) x 1.5 where N is the number of teeth, then they are Mod 1.5.
> >??
> >If I'm wrong and??they are a different Module, use the formula Mod = OD/(N + 2). The gears??are made in China, so don't expect it to work out exactly.
> >??
> >In terms of diametral pitch, Mod 1.5 is just under 17DP, so if you prefer to work in DP, 16 DP would work OK. Actually, these gears only have to mesh with each other so don't have to be to any particular standard, as??long as they are about the right overall??size.
> >??
> >Will it be difficult to cut the smaller gear without the cutter hitting the larger one to which it is attached?
> >??
> >Metal headstock gears are available from LMS. They are probably noisier than the plastic ones.
> >??
> >Andy
> >??
> >
> >
> >________________________________
> > To: 7x12minilathe@...
> >From: iannovak19@...
> >Date: Thu, 6 Dec 2012 06:31:07 +0000
> >Subject: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?
> >
> >??
> >Thank you for your reply. I am not so worried about the specs of the gears that are right behind the cover. I am looking for specs (pressure angle, diameter, spacing between gears, pitch diameter etc.) for the Hi-Low gears inside the cast spindle head stock.
> >
> >These gears are the most important for the lathe, and the most likely to break compared the the carriage travel speed adjustment gears.
> >
> >If they turn out to be straightforward to make with the help of the experienced instructors, it could be a valuable learning experience and a economic decision.
> >
> >Thank you,
> >
> >Ian
> >
> >--- In 7x12minilathe@..., SirJohnOfYork wrote:
> >>
> >> Metric. Module 1. Center hole is 12mm and on most lathes the keyway is
> >> 3mm (there were some 7x mini-lathes with 4mm
> keyways, check yours if in
> >> doubt.) Thickness is 8mm, but I made some using 5/16" thick plate that I
> >> happened to have handy and they work well.
> >>
> >> You can look at LMS to see the replacement gear sets here
> >> <> for the plastic and here
> >> <> for the steel sets, which list all of the
> >> factory gear sizes minus the two 80 tooth gears which are sold
> >> separately, here <> (plastic) and here
> >> <> (steel).
> >>
> >> Useful sizes not included on the older lathes are 21 and 32 tooth
> >> gears, with the 21 gear
> being most helpful for doing closer
> >> approximations of metric threads with a 16tpi leadscrew (or I believe
> >> inch threads with a metric leadscrew, not sure where you are located or
> >> whether you have a U.S inch or metric leadscrew machine.).
> >>
> >> LMS's Change Gear Page
> >> <> is real handy
> >> for finding workable gear combos for threads not listed on the machine
> >> labels or instructions, and for seeing how the 21 tooth gear can make
> >> for more accurate approximations and such. To see the A, B, C & D gears
> >> illustrated on that page, you need to first enter in a desired thread
> >> and click Calculate, then scroll down to see the pictures. There is a
> >> spacer that is normally behind the D gear than can be swapped to
> in
> >> front of it for those gear combos where an "any" gear is specified, so D
> >> will mesh directly with B (instead of with C as per normal).
> >>
> >> Cheers,
> >> John Z.
> >> York, Pa. USA
> >>
> >> On 12/5/2012 10:40 PM, Ian wrote:
> >> >
> >> > Hello. I have the resources to make my own metal gears in my machine
> >> > shop at school. I would like to be able to make my own set of
> >> > replacement Metal Gears for my 7x Mini lathe.
> >> >
> >> > I am looking for help in finding information about the dimensions and
> >> > specifications of the gears located in the head stock.
> >> >
> >> > Thank you,
> >> >
> >> > Ian
> >> >
> >>
> >
> >
> >
> >
> >
> >
>

It might be an idea to make it as a wheel rather than a crank, Charlie.

I have a crank, and unplug the lathe before using it, as a reminder to remove the crank before starting the motor later on. If I forget, the crank tries to whack me as the motor starts, at the same time as the lathe tries to turn upside down due to the imbalance. A wheel wouldn't hit me, and would be better balanced.

Andy


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

OK, looks like I need to make a hand-crank for the mini-lathe...

Thanks to all for their suggestions and comments!

Charlie

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

Hi, All,

I'm going to try single-point threading for the first time. I've read up on the procedure, and I figure the best way is to just jump in and give it a try. I'll initially make a 3/8-24 thread, only because it's big enough for me to really see the progress as it develops. But what I would really like to make for use after that is a 5 mm thread. These are, I believe, a 0.8 mm pitch. My goal is to make some thumbscrews to hold the gear cover on my lathe without having to use a hex key to get it off. My question is whether this is too fine a thread for me to do as a beginner? Are there any special tricks?

I guess it really doesn't matter; if I screw it up (pun intended), I'll just try it again.

Thanks,
Charlie

OK, looks like I need to make a hand-crank for the mini-lathe...

Thanks to all for their suggestions and comments!

Charlie

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

Hi, All,

I'm going to try single-point threading for the first time. I've read up on the procedure, and I figure the best way is to just jump in and give it a try. I'll initially make a 3/8-24 thread, only because it's big enough for me to really see the progress as it develops. But what I would really like to make for use after that is a 5 mm thread. These are, I believe, a 0.8 mm pitch. My goal is to make some thumbscrews to hold the gear cover on my lathe without having to use a hex key to get it off. My question is whether this is too fine a thread for me to do as a beginner? Are there any special tricks?

I guess it really doesn't matter; if I screw it up (pun intended), I'll just try it again.

Thanks,
Charlie

OK, looks like I need to make a hand-crank for the mini-lathe...

Thanks to all for their suggestions and comments!

Charlie

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

Hi, All,

I'm going to try single-point threading for the first time. I've read up on the procedure, and I figure the best way is to just jump in and give it a try. I'll initially make a 3/8-24 thread, only because it's big enough for me to really see the progress as it develops. But what I would really like to make for use after that is a 5 mm thread. These are, I believe, a 0.8 mm pitch. My goal is to make some thumbscrews to hold the gear cover on my lathe without having to use a hex key to get it off. My question is whether this is too fine a thread for me to do as a beginner? Are there any special tricks?

I guess it really doesn't matter; if I screw it up (pun intended), I'll just try it again.

Thanks,
Charlie

Ian
Andy is correct ??1.5 module.
I went through the heartache of machining new Hi/Low gears out of brass.All the gears were to be fly cut??
off??separate??arbors for each pair and brazing together after finish machining.
This gear cutting project was due to braking one set of plastic gears while turning an??intermittent??cut at a 100 mm diameter.
I bought another plastic set and decided to make my own.Out of brass.Silly mistake.
After making 3 special high speed steel fly cutter bits and a boring bar holder to suit the small and large gears (although all 4 gears are 1.5 module)??
and applied the correct??relief??angles etc.even used slitting saws to cut between teeth to the various root??diameters to help in metal removal.
the chatter and banging (although feeding in several passes) seemed to be beating my Weiss mill (the Rolls of the Chinese mills) to pieces.I gave up.
I still have the cutters if you want them.just send me a PM of your address.
Also check out out of Hong Kong?? they have good offers.
It's possibly better to buy the off the shelf steel gears and save your tooling and machines for other projects.
Again,my Real Bull lathe runs fine with steel gears,but noisy,I was told that the noise will reduce in time,I am still waiting.
I??regularly??apply lithium (white) grease through my cut out hatch.see link.and it does??quieten??it down.


possibly the new brushless High torque lathes have not this problem gear problem.
Who would of thought we could travel around the world after the Wright brothers barely got off the ground.
Anyway.
Also I drop oil directly onto the H/L shift mechanism through the??inspection??hatch.,note from the photos the other lube tube is oiling the plumber block of the feed screw.
Again no need to remove the back cover.The plastic tube is attached to a nipple on top of the bearing block.
Using an inspection cover you can also do regular greasing of the tapered roller bearings without having to dismantle the spindle.
Regards
John L
Spain.

________________________________
From: Andy Franks <andyf.1108@...>
To: 7x12minilathe@...
Sent: Thursday, December 6, 2012 10:33 AM
Subject: RE: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?


??
Ian, I believe the gears inside the headstock are Mod 1.5.
??
You can check this by measuring the outside diameter of one of them in millimetres; preferably one with an even number of teeth. If that measurement is approximately equal to (N + 2) x 1.5 where N is the number of teeth, then they are Mod 1.5.
??
If I'm wrong and??they are a different Module, use the formula Mod = OD/(N + 2). The gears??are made in China, so don't expect it to work out exactly.
??
In terms of diametral pitch, Mod 1.5 is just under 17DP, so if you prefer to work in DP, 16 DP would work OK. Actually, these gears only have to mesh with each other so don't have to be to any particular standard, as??long as they are about the right overall??size.
??
Will it be difficult to cut the smaller gear without the cutter hitting the larger one to which it is attached?
??
Metal headstock gears are available from LMS. They are probably noisier than the plastic ones.
??
Andy
??


________________________________
To: 7x12minilathe@...
From: iannovak19@...
Date: Thu, 6 Dec 2012 06:31:07 +0000
Subject: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?

??
Thank you for your reply. I am not so worried about the specs of the gears that are right behind the cover. I am looking for specs (pressure angle, diameter, spacing between gears, pitch diameter etc.) for the Hi-Low gears inside the cast spindle head stock.

These gears are the most important for the lathe, and the most likely to break compared the the carriage travel speed adjustment gears.

If they turn out to be straightforward to make with the help of the experienced instructors, it could be a valuable learning experience and a economic decision.

Thank you,

Ian

--- In 7x12minilathe@..., SirJohnOfYork <steelchipper@> wrote:

Metric. Module 1. Center hole is 12mm and on most lathes the keyway is
3mm (there were some 7x mini-lathes with 4mm

keyways, check yours if in

doubt.) Thickness is 8mm, but I made some using 5/16" thick plate that I
happened to have handy and they work well.

You can look at LMS to see the replacement gear sets here
<> for the plastic and here
<> for the steel sets, which list all of the
factory gear sizes minus the two 80 tooth gears which are sold
separately, here <> (plastic) and here
<> (steel).

Useful sizes not included on the older lathes are 21 and 32 tooth
gears, with the 21 gear

being most helpful for doing closer

approximations of metric threads with a 16tpi leadscrew (or I believe
inch threads with a metric leadscrew, not sure where you are located or
whether you have a U.S inch or metric leadscrew machine.).

LMS's Change Gear Page
<> is real handy
for finding workable gear combos for threads not listed on the machine
labels or instructions, and for seeing how the 21 tooth gear can make
for more accurate approximations and such. To see the A, B, C & D gears
illustrated on that page, you need to first enter in a desired thread
and click Calculate, then scroll down to see the pictures. There is a
spacer that is normally behind the D gear than can be swapped to

in

front of it for those gear combos where an "any" gear is specified, so D
will mesh directly with B (instead of with C as per normal).

Cheers,
John Z.
York, Pa. USA

On 12/5/2012 10:40 PM, Ian wrote:

Hello. I have the resources to make my own metal gears in my machine
shop at school. I would like to be able to make my own set of
replacement Metal Gears for my 7x Mini lathe.

I am looking for help in finding information about the dimensions and
specifications of the gears located in the head stock.

Thank you,

Ian

Uh... yes - sorry 'bout that..

andyf1108 wrote:

That's certainly true for the changewheels, Wam, but the query was about the hi/lo speed change gears inside the headstock, which I think are to a different module. Andy

--- In 7x12minilathe@..., WAM <ajawam2@...> wrote:

From this site:


The specifications for the gears used on the Mini-lathe are: module 1, 20??? pressure angle, 8mm face width, and a 12mm bore with a 3mm wide by 1.4mm deep keyway. Any gear that meets these specifications can be used on the lathe.

Andy Franks wrote:

Ian, I believe the gears inside the headstock are Mod 1.5.
You can check this by measuring the outside diameter of one of them in millimetres; preferably one with an even number of teeth. If that measurement is approximately equal to (N + 2) x 1.5 where N is the number of teeth, then they are Mod 1.5.
If I'm wrong and they are a different Module, use the formula Mod = OD/(N + 2). The gears are made in China, so don't expect it to work out exactly.

In terms of diametral pitch, Mod 1.5 is just under 17DP, so if you prefer to work in DP, 16 DP would work OK. Actually, these gears only have to mesh with each other so don't have to be to any particular standard, as long as they are about the right overall size.

Will it be difficult to cut the smaller gear without the cutter hitting the larger one to which it is attached?
Metal headstock gears are available from LMS. They are probably noisier than the plastic ones.

Andy




To: 7x12minilathe@...
From: iannovak19@...
Date: Thu, 6 Dec 2012 06:31:07 +0000
Subject: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?





Thank you for your reply. I am not so worried about the specs of the gears that are right behind the cover. I am looking for specs (pressure angle, diameter, spacing between gears, pitch diameter etc.) for the Hi-Low gears inside the cast spindle head stock.

These gears are the most important for the lathe, and the most likely to break compared the the carriage travel speed adjustment gears.

If they turn out to be straightforward to make with the help of the experienced instructors, it could be a valuable learning experience and a economic decision.

Thank you,

Ian

--- In 7x12minilathe@..., SirJohnOfYork <steelchipper@> wrote:

Metric. Module 1. Center hole is 12mm and on most lathes the keyway is 3mm (there were some 7x mini-lathes with 4mm keyways, check yours if in doubt.) Thickness is 8mm, but I made some using 5/16" thick plate that I happened to have handy and they work well.

You can look at LMS to see the replacement gear sets here <> for the plastic and here <> for the steel sets, which list all of the factory gear sizes minus the two 80 tooth gears which are sold separately, here <> (plastic) and here <> (steel).

Useful sizes not included on the older lathes are 21 and 32 tooth gears, with the 21 gear being most helpful for doing closer approximations of metric threads with a 16tpi leadscrew (or I believe inch threads with a metric leadscrew, not sure where you are located or whether you have a U.S inch or metric leadscrew machine.).

LMS's Change Gear Page <> is real handy for finding workable gear combos for threads not listed on the machine labels or instructions, and for seeing how the 21 tooth gear can make for more accurate approximations and such. To see the A, B, C & D gears illustrated on that page, you need to first enter in a desired thread and click Calculate, then scroll down to see the pictures. There is a spacer that is normally behind the D gear than can be swapped to in front of it for those gear combos where an "any" gear is specified, so D will mesh directly with B (instead of with C as per normal).

Cheers,
John Z.
York, Pa. USA

On 12/5/2012 10:40 PM, Ian wrote:

Hello. I have the resources to make my own metal gears in my machine shop at school. I would like to be able to make my own set of replacement Metal Gears for my 7x Mini lathe.

I am looking for help in finding information about the dimensions and specifications of the gears located in the head stock.

Thank you,

Ian

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

Yahoo! Groups Links

That's certainly true for the changewheels, Wam, but the query was about the hi/lo speed change gears inside the headstock, which I think are to a different module.  

Andy

--- In 7x12minilathe@..., WAM  wrote:
  

 From this site:


The specifications for the gears used on the Mini-lathe are: module 1, 
20° pressure angle, 8mm face width, and a 12mm bore with a 3mm wide by 
1.4mm deep keyway. Any gear that meets these specifications can be used 
on the lathe.

Andy Franks wrote:

    

Ian, I believe the gears inside the headstock are Mod 1.5. 

You can check this by measuring the outside diameter of one of them in millimetres; preferably one with an even number of teeth. If that measurement is approximately equal to (N + 2) x 1.5 where N is the number of teeth, then they are Mod 1.5. 

If I'm wrong and they are a different Module, use the formula Mod = OD/(N + 2). The gears are made in China, so don't expect it to work out exactly.

In terms of diametral pitch, Mod 1.5 is just under 17DP, so if you prefer to work in DP, 16 DP would work OK. Actually, these gears only have to mesh with each other so don't have to be to any particular standard, as long as they are about the right overall size.

Will it be difficult to cut the smaller gear without the cutter hitting the larger one to which it is attached? 

Metal headstock gears are available from LMS. They are probably noisier than the plastic ones.

Andy




To: 7x12minilathe@...
From: iannovak19@...
Date: Thu, 6 Dec 2012 06:31:07 +0000
Subject: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?

 



Thank you for your reply. I am not so worried about the specs of the gears that are right behind the cover. I am looking for specs (pressure angle, diameter, spacing between gears, pitch diameter etc.) for the Hi-Low gears inside the cast spindle head stock.

These gears are the most important for the lathe, and the most likely to break compared the the carriage travel speed adjustment gears.

If they turn out to be straightforward to make with the help of the experienced instructors, it could be a valuable learning experience and a economic decision.

Thank you,

Ian

--- In 7x12minilathe@..., SirJohnOfYork  wrote:
 

      

Metric. Module 1. Center hole is 12mm and on most lathes the keyway is 
3mm (there were some 7x mini-lathes with 4mm keyways, check yours if in 
doubt.) Thickness is 8mm, but I made some using 5/16" thick plate that I 
happened to have handy and they work well.

You can look at LMS to see the replacement gear sets here 
 for the plastic and here 
 for the steel sets, which list all of the 
factory gear sizes minus the two 80 tooth gears which are sold 
separately, here  (plastic) and here 
 (steel).

Useful sizes not included on the older lathes are 21 and 32 tooth 
gears, with the 21 gear being most helpful for doing closer 
approximations of metric threads with a 16tpi leadscrew (or I believe 
inch threads with a metric leadscrew, not sure where you are located or 
whether you have a U.S inch or metric leadscrew machine.).

LMS's Change Gear Page 
 is real handy 
for finding workable gear combos for threads not listed on the machine 
labels or instructions, and for seeing how the 21 tooth gear can make 
for more accurate approximations and such. To see the A, B, C & D gears 
illustrated on that page, you need to first enter in a desired thread 
and click Calculate, then scroll down to see the pictures. There is a 
spacer that is normally behind the D gear than can be swapped to in 
front of it for those gear combos where an "any" gear is specified, so D 
will mesh directly with B (instead of with C as per normal).

Cheers,
John Z.
York, Pa. USA

On 12/5/2012 10:40 PM, Ian wrote:
   

        

Hello. I have the resources to make my own metal gears in my machine 
shop at school. I would like to be able to make my own set of 
replacement Metal Gears for my 7x Mini lathe.

I am looking for help in finding information about the dimensions and 
specifications of the gears located in the head stock.

Thank you,

Ian

     

          

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

Yahoo! Groups Links

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---

From: Andy Franks
To: 7x12minilathe@...
Sent: Thursday, December 6, 2012 10:33 AM
Subject: RE: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?

?

Ian, I believe the gears inside the headstock are Mod 1.5.
?
You can check this by measuring the outside diameter of one of them in millimetres; preferably one with an even number of teeth. If that measurement is approximately equal to (N + 2) x 1.5 where N is the number of teeth, then they are Mod 1.5.
?
If I'm wrong and?they are a different Module, use the formula Mod = OD/(N + 2). The gears?are made in China, so don't expect it to work out exactly.
?
In terms of diametral pitch, Mod 1.5 is just under 17DP, so if you prefer to work in DP, 16 DP would work OK. Actually, these gears only have to mesh with each other so don't have to be to any particular standard, as?long as they are about the right overall?size.
?
Will it be difficult to cut the smaller gear without the cutter hitting the larger one to which it is attached?
?
Metal headstock gears are available from LMS. They are probably noisier than the plastic ones.
?
Andy
?

---

To: 7x12minilathe@...
From: iannovak19@...
Date: Thu, 6 Dec 2012 06:31:07 +0000
Subject: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?

?

Thank you for your reply. I am not so worried about the specs of the gears that are right behind the cover. I am looking for specs (pressure angle, diameter, spacing between gears, pitch diameter etc.) for the Hi-Low gears inside the cast spindle head stock.

These gears are the most important for the lathe, and the most likely to break compared the the carriage travel speed adjustment gears.

If they turn out to be straightforward to make with the help of the experienced instructors, it could be a valuable learning experience and a economic decision.

Thank you,

Ian

--- In 7x12minilathe@..., SirJohnOfYork wrote:
>
> Metric. Module 1. Center hole is 12mm and on most lathes the keyway is
> 3mm (there were some 7x mini-lathes with 4mm keyways, check yours if in
> doubt.) Thickness is 8mm, but I made some using 5/16" thick plate that I
> happened to have handy and they work well.
>
> You can look at LMS to see the replacement gear sets here
> <> for the plastic and here
> <> for the steel sets, which list all of the
> factory gear sizes minus the two 80 tooth gears which are sold
> separately, here <> (plastic) and here
> <> (steel).
>
> Useful sizes not included on the older lathes are 21 and 32 tooth
> gears, with the 21 gear being most helpful for doing closer
> approximations of metric threads with a 16tpi leadscrew (or I believe
> inch threads with a metric leadscrew, not sure where you are located or
> whether you have a U.S inch or metric leadscrew machine.).
>
> LMS's Change Gear Page
> <> is real handy
> for finding workable gear combos for threads not listed on the machine
> labels or instructions, and for seeing how the 21 tooth gear can make
> for more accurate approximations and such. To see the A, B, C & D gears
> illustrated on that page, you need to first enter in a desired thread
> and click Calculate, then scroll down to see the pictures. There is a
> spacer that is normally behind the D gear than can be swapped to in
> front of it for those gear combos where an "any" gear is specified, so D
> will mesh directly with B (instead of with C as per normal).
>
> Cheers,
> John Z.
> York, Pa. USA
>
> On 12/5/2012 10:40 PM, Ian wrote:
> >
> > Hello. I have the resources to make my own metal gears in my machine
> > shop at school. I would like to be able to make my own set of
> > replacement Metal Gears for my 7x Mini lathe.
> >
> > I am looking for help in finding information about the dimensions and
> > specifications of the gears located in the head stock.
> >
> > Thank you,
> >
> > Ian
> >
>

Ian, I believe the gears inside the headstock are Mod 1.5.

You can check this by measuring the outside diameter of one of them in millimetres; preferably one with an even number of teeth. If that measurement is approximately equal to (N + 2) x 1.5 where N is the number of teeth, then they are Mod 1.5.

If I'm wrong and they are a different Module, use the formula Mod = OD/(N + 2). The gears are made in China, so don't expect it to work out exactly.

In terms of diametral pitch, Mod 1.5 is just under 17DP, so if you prefer to work in DP, 16 DP would work OK. Actually, these gears only have to mesh with each other so don't have to be to any particular standard, as long as they are about the right overall size.

Will it be difficult to cut the smaller gear without the cutter hitting the larger one to which it is attached?

Metal headstock gears are available from LMS. They are probably noisier than the plastic ones.

Andy




To: 7x12minilathe@...
From: iannovak19@...
Date: Thu, 6 Dec 2012 06:31:07 +0000
Subject: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?





Thank you for your reply. I am not so worried about the specs of the gears that are right behind the cover. I am looking for specs (pressure angle, diameter, spacing between gears, pitch diameter etc.) for the Hi-Low gears inside the cast spindle head stock.

These gears are the most important for the lathe, and the most likely to break compared the the carriage travel speed adjustment gears.

If they turn out to be straightforward to make with the help of the experienced instructors, it could be a valuable learning experience and a economic decision.

Thank you,

Ian

--- In 7x12minilathe@..., SirJohnOfYork <steelchipper@> wrote:

Metric. Module 1. Center hole is 12mm and on most lathes the keyway is
3mm (there were some 7x mini-lathes with 4mm keyways, check yours if in
doubt.) Thickness is 8mm, but I made some using 5/16" thick plate that I
happened to have handy and they work well.

You can look at LMS to see the replacement gear sets here
<> for the plastic and here
<> for the steel sets, which list all of the
factory gear sizes minus the two 80 tooth gears which are sold
separately, here <> (plastic) and here
<> (steel).

Useful sizes not included on the older lathes are 21 and 32 tooth
gears, with the 21 gear being most helpful for doing closer
approximations of metric threads with a 16tpi leadscrew (or I believe
inch threads with a metric leadscrew, not sure where you are located or
whether you have a U.S inch or metric leadscrew machine.).

LMS's Change Gear Page
<> is real handy
for finding workable gear combos for threads not listed on the machine
labels or instructions, and for seeing how the 21 tooth gear can make
for more accurate approximations and such. To see the A, B, C & D gears
illustrated on that page, you need to first enter in a desired thread
and click Calculate, then scroll down to see the pictures. There is a
spacer that is normally behind the D gear than can be swapped to in
front of it for those gear combos where an "any" gear is specified, so D
will mesh directly with B (instead of with C as per normal).

Cheers,
John Z.
York, Pa. USA

On 12/5/2012 10:40 PM, Ian wrote:

Hello. I have the resources to make my own metal gears in my machine
shop at school. I would like to be able to make my own set of
replacement Metal Gears for my 7x Mini lathe.

I am looking for help in finding information about the dimensions and
specifications of the gears located in the head stock.

Thank you,

Ian

From this site:


The specifications for the gears used on the Mini-lathe are: module 1,
20° pressure angle, 8mm face width, and a 12mm bore with a 3mm wide by
1.4mm deep keyway. Any gear that meets these specifications can be used
on the lathe.

Andy Franks wrote:

Ian, I believe the gears inside the headstock are Mod 1.5.

You can check this by measuring the outside diameter of one of them in millimetres; preferably one with an even number of teeth. If that measurement is approximately equal to (N + 2) x 1.5 where N is the number of teeth, then they are Mod 1.5.

If I'm wrong and they are a different Module, use the formula Mod = OD/(N + 2). The gears are made in China, so don't expect it to work out exactly.

In terms of diametral pitch, Mod 1.5 is just under 17DP, so if you prefer to work in DP, 16 DP would work OK. Actually, these gears only have to mesh with each other so don't have to be to any particular standard, as long as they are about the right overall size.

Will it be difficult to cut the smaller gear without the cutter hitting the larger one to which it is attached?

Metal headstock gears are available from LMS. They are probably noisier than the plastic ones.

Andy




To: 7x12minilathe@...
From: iannovak19@...
Date: Thu, 6 Dec 2012 06:31:07 +0000
Subject: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?





Thank you for your reply. I am not so worried about the specs of the gears that are right behind the cover. I am looking for specs (pressure angle, diameter, spacing between gears, pitch diameter etc.) for the Hi-Low gears inside the cast spindle head stock.

These gears are the most important for the lathe, and the most likely to break compared the the carriage travel speed adjustment gears.

If they turn out to be straightforward to make with the help of the experienced instructors, it could be a valuable learning experience and a economic decision.

Thank you,

Ian

--- In 7x12minilathe@..., SirJohnOfYork <steelchipper@> wrote:

Metric. Module 1. Center hole is 12mm and on most lathes the keyway is
3mm (there were some 7x mini-lathes with 4mm keyways, check yours if in
doubt.) Thickness is 8mm, but I made some using 5/16" thick plate that I
happened to have handy and they work well.

You can look at LMS to see the replacement gear sets here
<> for the plastic and here
<> for the steel sets, which list all of the
factory gear sizes minus the two 80 tooth gears which are sold
separately, here <> (plastic) and here
<> (steel).

Useful sizes not included on the older lathes are 21 and 32 tooth
gears, with the 21 gear being most helpful for doing closer
approximations of metric threads with a 16tpi leadscrew (or I believe
inch threads with a metric leadscrew, not sure where you are located or
whether you have a U.S inch or metric leadscrew machine.).

LMS's Change Gear Page
<> is real handy
for finding workable gear combos for threads not listed on the machine
labels or instructions, and for seeing how the 21 tooth gear can make
for more accurate approximations and such. To see the A, B, C & D gears
illustrated on that page, you need to first enter in a desired thread
and click Calculate, then scroll down to see the pictures. There is a
spacer that is normally behind the D gear than can be swapped to in
front of it for those gear combos where an "any" gear is specified, so D
will mesh directly with B (instead of with C as per normal).

Cheers,
John Z.
York, Pa. USA

On 12/5/2012 10:40 PM, Ian wrote:

Hello. I have the resources to make my own metal gears in my machine
shop at school. I would like to be able to make my own set of
replacement Metal Gears for my 7x Mini lathe.

I am looking for help in finding information about the dimensions and
specifications of the gears located in the head stock.

Thank you,

Ian

Ian, I believe the gears inside the headstock are Mod 1.5. 
 
You can check this by measuring the outside diameter of one of them in millimetres; preferably one with an even number of teeth. If that measurement is approximately equal to (N + 2) x 1.5 where N is the number of teeth, then they are Mod 1.5. 
 
If I'm wrong and they are a different Module, use the formula Mod = OD/(N + 2). The gears are made in China, so don't expect it to work out exactly.
 
In terms of diametral pitch, Mod 1.5 is just under 17DP, so if you prefer to work in DP, 16 DP would work OK. Actually, these gears only have to mesh with each other so don't have to be to any particular standard, as long as they are about the right overall size.
 
Will it be difficult to cut the smaller gear without the cutter hitting the larger one to which it is attached? 
 
Metal headstock gears are available from LMS. They are probably noisier than the plastic ones.
 
Andy
 



To: 7x12minilathe@...
From: iannovak19@...
Date: Thu, 6 Dec 2012 06:31:07 +0000
Subject: [7x12minilathe] Re: 7x Lathe Transmission Gear Specs?

  



Thank you for your reply. I am not so worried about the specs of the gears that are right behind the cover. I am looking for specs (pressure angle, diameter, spacing between gears, pitch diameter etc.) for the Hi-Low gears inside the cast spindle head stock.

These gears are the most important for the lathe, and the most likely to break compared the the carriage travel speed adjustment gears.

If they turn out to be straightforward to make with the help of the experienced instructors, it could be a valuable learning experience and a economic decision.

Thank you,

Ian

--- In 7x12minilathe@..., SirJohnOfYork  wrote:
  

Metric. Module 1. Center hole is 12mm and on most lathes the keyway is 
3mm (there were some 7x mini-lathes with 4mm keyways, check yours if in 
doubt.) Thickness is 8mm, but I made some using 5/16" thick plate that I 
happened to have handy and they work well.

You can look at LMS to see the replacement gear sets here 
 for the plastic and here 
 for the steel sets, which list all of the 
factory gear sizes minus the two 80 tooth gears which are sold 
separately, here  (plastic) and here 
 (steel).

Useful sizes not included on the older lathes are 21 and 32 tooth 
gears, with the 21 gear being most helpful for doing closer 
approximations of metric threads with a 16tpi leadscrew (or I believe 
inch threads with a metric leadscrew, not sure where you are located or 
whether you have a U.S inch or metric leadscrew machine.).

LMS's Change Gear Page 
 is real handy 
for finding workable gear combos for threads not listed on the machine 
labels or instructions, and for seeing how the 21 tooth gear can make 
for more accurate approximations and such. To see the A, B, C & D gears 
illustrated on that page, you need to first enter in a desired thread 
and click Calculate, then scroll down to see the pictures. There is a 
spacer that is normally behind the D gear than can be swapped to in 
front of it for those gear combos where an "any" gear is specified, so D 
will mesh directly with B (instead of with C as per normal).

Cheers,
John Z.
York, Pa. USA

On 12/5/2012 10:40 PM, Ian wrote:
    

Hello. I have the resources to make my own metal gears in my machine 
shop at school. I would like to be able to make my own set of 
replacement Metal Gears for my 7x Mini lathe.

I am looking for help in finding information about the dimensions and 
specifications of the gears located in the head stock.

Thank you,

Ian

      

What he said! Cap Screw M6-1.0 X 8
(I had just looked it up yesterday...)

--------------------
Richard Brennan - San Leandro CA
--------------------

At 04:20 PM 12/5/2012, Chris Wood wrote:

The screw is an M6x8 button head socket cap screw.


Regards,

Chris Wood
<>LittleMachineShop.com
The premier source of tooling, parts, and accessories for bench top
machinists.
396 W. Washington Blvd. #500, Pasadena, CA 91103
(800)981-9663 * Fax (626)797-7934



From: 7x12minilathe@...
[mailto:7x12minilathe@...] On Behalf Of Michael Jablonski
Sent: Wednesday, December 05, 2012 3:05 PM
To: 7x12minilathe@...
Subject: RE: [7x12minilathe] What is description for the button head
screws used to replace the allen heads on cross and topslide handles?

Metric. Module 1. Center hole is 12mm and on most lathes the keyway is
3mm (there were some 7x mini-lathes with 4mm keyways, check yours if in
doubt.) Thickness is 8mm, but I made some using 5/16" thick plate that I
happened to have handy and they work well.

You can look at LMS to see the replacement gear sets here
<> for the plastic and here
<> for the steel sets, which list all of the
factory gear sizes minus the two 80 tooth gears which are sold
separately, here <> (plastic) and here
<> (steel).

Useful sizes not included on the older lathes are 21 and 32 tooth
gears, with the 21 gear being most helpful for doing closer
approximations of metric threads with a 16tpi leadscrew (or I believe
inch threads with a metric leadscrew, not sure where you are located or
whether you have a U.S inch or metric leadscrew machine.).

LMS's Change Gear Page
<> is real handy
for finding workable gear combos for threads not listed on the machine
labels or instructions, and for seeing how the 21 tooth gear can make
for more accurate approximations and such. To see the A, B, C & D gears
illustrated on that page, you need to first enter in a desired thread
and click Calculate, then scroll down to see the pictures. There is a
spacer that is normally behind the D gear than can be swapped to in
front of it for those gear combos where an "any" gear is specified, so D
will mesh directly with B (instead of with C as per normal).

Cheers,
John Z.
York, Pa. USA

On 12/5/2012 10:40 PM, Ian wrote:

Hello. I have the resources to make my own metal gears in my machine
shop at school. I would like to be able to make my own set of
replacement Metal Gears for my 7x Mini lathe.

I am looking for help in finding information about the dimensions and
specifications of the gears located in the head stock.

Thank you,

Ian

---

From: CLevinski
To: 7x12minilathe@...
Sent: Wednesday, December 5, 2012 7:57 AM
Subject: [7x12minilathe] Threading for the first time

?

Hi, All,

I'm going to try single-point threading for the first time. I've read up on the procedure, and I figure the best way is to just jump in and give it a try. I'll initially make a 3/8-24 thread, only because it's big enough for me to really see the progress as it develops. But what I would really like to make for use after that is a 5 mm thread. These are, I believe, a 0.8 mm pitch. My goal is to make some thumbscrews to hold the gear cover on my lathe without having to use a hex key to get it off. My question is whether this is too fine a thread for me to do as a beginner? Are there any special tricks?

I guess it really doesn't matter; if I screw it up (pun intended), I'll just try it again.

Thanks,
Charlie