开云体育

  1. 7x12MiniLathe
  2. Topics

Cutting with rotating cutter

 

Hi Roy
Thanks, I have now made an external lead screw crank.
Let see what happens after 144 teeth cuts on a 3.465 inch ? wheel .

Johannes Lavoll.

image0.jpeg

 

Your setup looks a lot like mine.? In addition to the crank, I made a replacement block that has pockets for thrust bearings.? That reduced the backlash quite a bit.? The OEM design has a lot of "slop" between the blocks and lead screw, which permits a LOT of backlash.
?
A custom-made washer the right thickness would do much the same thing.
 

The fitted thrust washer to reduce axial play was part of my overly elaborate sealing arrangement to keep swarf out of the control box.
?
Roy
 

Over the years, I've also considered doing this mod to add a crank to the end of the leadscrew, even though I've rarely had the "need" for this feature. But, in a recent hack, I did add a crank, but on the left-hand end of the lead-screw. (see photo). Just a thin metal arm secured underneath the cap screw that holds the plastic gear. Not sure if this arrangement is any better or worse than attaching a crank on the right-hand end of the leadscrew, but my hack did not require any permanent mods to the lathe, and can be quickly installed and removed if needed.
?
 

I have found that to get the best finish when turning I hand feed toward the head stock and power feed toward the tail stock.
By the way, high?speed?steel?is better than carbide on?our mini lathes.
For cutting thread I use a 9-inch diameter hand wheel that is secure to the spindle bore.
I have also made a modification to the change?gears to allow them to be adjusted easier.
Drawings and photos are available if you request, just email me.
Regards,
John Mattis (retired mechanical engineer)
(john.mattis@...)

On Thu, Feb 13, 2025 at 9:08?AM Walter Wpg via <walter.wpg=[email protected]> wrote:
Over the years, I've also considered doing this mod to add a crank to the end of the leadscrew, even though I've rarely had the "need" for this feature. But, in a recent hack, I did add a crank, but on the left-hand end of the lead-screw. (see photo). Just a thin metal arm secured underneath the cap screw that holds the plastic gear. Not sure if this arrangement is any better or worse than attaching a crank on the right-hand end of the leadscrew, but my hack did not require any permanent mods to the lathe, and can be quickly installed and removed if needed.
?
 

开云体育

I have a big dividing disk on the left side of my lathe. ?So no space for the crank.
However, after some days use, I will use my new crank much more.

IMG_3562

Johannes ? Lavoll. ? ? ? ? ? ? ?
? ?




On 13 Feb 2025, at 11:15, John Mattis via groups.io <john.mattis@...> wrote:

?
I have found that to get the best finish when turning I hand feed toward the head stock and power feed toward the tail stock.
By the way, high?speed?steel?is better than carbide on?our mini lathes.
For cutting thread I use a 9-inch diameter hand wheel that is secure to the spindle bore.
I have also made a modification to the change?gears to allow them to be adjusted easier.
Drawings and photos are available if you request, just email me.
Regards,
John Mattis (retired mechanical engineer)
(john.mattis@...)

On Thu, Feb 13, 2025 at 9:08?AM Walter Wpg via <walter.wpg=[email protected]> wrote:
Over the years, I've also considered doing this mod to add a crank to the end of the leadscrew, even though I've rarely had the "need" for this feature. But, in a recent hack, I did add a crank, but on the left-hand end of the lead-screw. (see photo). Just a thin metal arm secured underneath the cap screw that holds the plastic gear. Not sure if this arrangement is any better or worse than attaching a crank on the right-hand end of the leadscrew, but my hack did not require any permanent mods to the lathe, and can be quickly installed and removed if needed.
?
<IMG_20250213_105432.jpg>
 

开云体育

Hi Johannes. You don’t need an extra crank.

?

As your dividing disc uses the outer edge for measurement. Just drill a suitable hole in the disc, with a suitable bolt and handle, this can be attached when you need it and removed when you don’t.

?

??????????????? Ellis

?

?

?

I have a big dividing disk on the left side of my lathe. ?So no space for the crank.

However, after some days use, I will use my new crank much more.
 

开云体育

Yes Ellis
I have made many disk with holes, however they are not precise enough.
So now I have 1502 x 2 steps to help me.
1/2 mm is also a step.

Johannes ? Lavoll. ? ? ? ? ? ? ?
? ?




On 13 Feb 2025, at 15:23, Ellis Cory via groups.io <ellis103@...> wrote:

?

Hi Johannes. You don’t need an extra crank.

?

As your dividing disc uses the outer edge for measurement. Just drill a suitable hole in the disc, with a suitable bolt and handle, this can be attached when you need it and removed when you don’t.

?

??????????????? Ellis

?

?

?

I have a big dividing disk on the left side of my lathe. ?So no space for the crank.

However, after some days use, I will use my new crank much more.
 

开云体育

That was my instant thought as well. Something like this:?

It won’t work as a crank AND dividing head for your use case, but for the times you need to crank the lathe by hand (like when making a large thread or worm gear ) ?it will work better than trying to get enough torque to do it with the lathe motor.

Christophe has a bunch of really elegant tools and builds.

On Feb 13, 2025, at 2:23?PM, Ellis Cory via groups.io <ellis103@...> wrote:

Hi Johannes. You don’t need an extra crank.
?
As your dividing disc uses the outer edge for measurement. Just drill a suitable hole in the disc, with a suitable bolt and handle, this can be attached when you need it and removed when you don’t.
?
??????????????? Ellis
?
?
?
I have a big dividing disk on the left side of my lathe. ?So no space for the crank.
However, after some days use, I will use my new crank much more.

--?
Bruce Johnson

The less a man knows about how sausages and laws are made, the easier it is to steal his vote and give him botulism.

 

开云体育

After some hours setting?up the equipment , ready to do the new cutting with leadscrew, (Thanks to Roy,)? I did? something XXXXXXX
Ok, so it is to be a lathe operator.
However, I tested it on something different , and I really liked the Leadscrew manual feeding.

I have made many disks with holes , many different setups,? and every time I think I have done the best.
Therefor is this lathe group being so interesting, a lot of new?ideas show up.

I needed to make a ratchet, 10 deg undercut, 60 teeth, so I first made the dividing disk,120 holes, in the lathe.
Moved it over to the Mill and did the job.?
(just remember to do the cutting on the correct side !!)

The picture shows the setup.


Johannes
Mexico







?

From: [email protected] <[email protected]> on behalf of Bruce J via groups.io <bruce.desertrat@...>
Sent: Thursday, February 13, 2025 14:27
To: [email protected] <[email protected]>
Subject: Re: [7x12MiniLathe] Cutting with rotating cutter
?
That was my instant thought as well. Something like this:?

It won’t work as a crank AND dividing head for your use case, but for the times you need to crank the lathe by hand (like when making a large thread or worm gear ) ?it will work better than trying to get enough torque to do it with the lathe motor.

Christophe has a bunch of really elegant tools and builds.

On Feb 13, 2025, at 2:23?PM, Ellis Cory via groups.io <ellis103@...> wrote:

Hi Johannes. You don’t need an extra crank.
?
As your dividing disc uses the outer edge for measurement. Just drill a suitable hole in the disc, with a suitable bolt and handle, this can be attached when you need it and removed when you don’t.
?
??????????????? Ellis
?
?
?
I have a big dividing disk on the left side of my lathe. ?So no space for the crank.
However, after some days use, I will use my new crank much more.

--?
Bruce Johnson

The less a man knows about how sausages and laws are made, the easier it is to steal his vote and give him botulism.

IMG_3782.JPG

 

开云体育

My picture disappeared someplace, so I send it again.


/johannes
Mexico
 

Nice work @johannes!? I had built something similar to your lathe/mill attachment, but I see some details in your mod that I'm going to incorporate into mine.? I like the idea of the plinth block.? Like yours I had initially designed it for the lathe but moved the whole contraption over to the mill.
?
Thanks for sharing!
?
Jeff

1 - 12 of 12