Jump to content

Recommended Posts

31 minutes ago, LittleWatchShop said:

I picked up another lathe...just because I guess.  I did not have a motor nor tail stock.  I scavenged a motor from an old sewing machine I had in the queue for the dump (whew, glad I woke up regarding that).

I think sewing machine motors are good replacements, here is one of my “bigger” small lathes with a frequency controlled sewing machine servo motor (brushless). I use the original 5mm rubber belts for the EMCO Unimat 3 even if this is a 550W motor, it works just fine.
I have the same rubber belts for my Geneva style lathes too, they are really cheap. Think they are just a 100mm in diameter rubber gasket.
 

Modified_Lathe.jpg

  • Like 1
Link to comment
Share on other sites

6 minutes ago, HSL said:

I think sewing machine motors are good replacements

Nice.  Long term, I am going to replace it with a PWM driven BLDC--an overall better solution I think.  I have to reverse my sewing machine motor buy wrapping the belt in figure 8.  I could take it apart and reverse the field winding but that is a hassle.  Happy with figure 8 for now.

Link to comment
Share on other sites

Yes, the brushed motors from a sewing machine usually runs "backwards"  those ones one just can flip them 180 degrees horisontal. Then it runs the right direction... On the brushless you just push a button for the rotation direction.

Link to comment
Share on other sites

1 hour ago, LittleWatchShop said:

Yeah, that was the first thing I did.  Just lacked aesthetics, so I put it back the way I had it and put the belt into a figure 8.  Once I transition to the BLDC, all problems go away!

Your is a watchmaker's lathe, so a powerful motor, belts etc are not important.  Very different from even an baby lathe like HSL's, on these you want to cut steel and the standard motor is easily not enough, there are other limiting factors, I know a old machinist that says "for each one his own". See if you can get to turn a cannon pinion to fit precisely the minute wheel, using just a graver. That is the kind of work it is made for.

  • Like 1
Link to comment
Share on other sites

The Geneva style lathes I mentioned above which I run with the same setup is an 8mm Lorch and a 6mm BMC, even if the motor is slightly more powerful, I think I get good enough control to cut a cannon pinion or two, even made a new axis for an escapement wheel the other day.
Guess I got a bit lazy with age and think new technology to control the revs is convenient, but I still think these rubber drive belts work just fine.
I add a romantic picture of the babies too. 

Lorch_BMC.jpg

  • Like 3
Link to comment
Share on other sites

You guys are heads and shoulders above me, but I am learning!

I have attempted a balance staff and failed.  Will attempt again.  I got close ?

The only pure success so far was to turn a couple of small brass rods down, leaving a head, to use as the pins in my Wave Cepter watch band.

I love these things.  Though I am an electrical engineer...I these mechanical things intrigue me and are a lot of fun.

Link to comment
Share on other sites

If you are going to work on vintage watches you probably quite fast will realize some parts is just not available any more, and one probably will turn a balance staff faster than waiting for one in the mail with some training.

I noticed you said your problems would be over when getting the setup fixed, I would say your problems are just beginning when you get the lathe running, it sometimes just can be so addictive your better half have to pull your away from it at 2 am. So, they might just begin ?

  • Like 2
  • Haha 1
Link to comment
Share on other sites

I'm probably not a good example but I make parts on my lathe pretty much every day for both vintage/antique and brand new (prototypes). I have a small 3 phase motor for my lathe with a countershaft; 3 phase power is ubiquitous here so no issue  99/100 I use two speeds, about 1500 rpm or 700. I use a cross slide for 99% of the work. Everything turned to size, +0.01mm on pivots which get finished in the Jacot after heat treatment. The little 3 phase is smooth as silk, there's a scope over the lathe, and a quick change toolpost on the slide*. I do use hand gravers, for cutting off balance hubs when restaffing, for cutting conical pivots and rivets, chamfering things sometimes, a quick retouch if the slide isn't mounted on a screw length etc.

 

The slide is a massive timesaver.

 

*the quickchange is a copy of a Dorian post, which I copied from a friend's when I was in school. It repeats almost without fail within 2 or 3 microns, spooky. Dorian stopped making it, but Horia makes a copy still. Worth every penny if you make your living with it.

Edited by nickelsilver
  • Like 2
Link to comment
Share on other sites

12 hours ago, nickelsilver said:

The quickchange is a copy of a Dorian post, which I copied from a friend's when I was in school. It repeats almost without fail within 2 or 3 microns, spooky. Dorian stopped making it, but Horia makes a copy still. Worth every penny if you make your living with it.

Don't get me started on toolsposts or I'll flood this topic to its drowning. I'm doing a serious market research to chose one for the 250mm swing lathe and came to learn many interesting things about most, if not all types available. In the meanwhile I've got a Multifix AA set, which is now available for the reasonable price of about USD100. It's a bit too small for the 250mm, and a bit too large for the baby lathe, although it works on both. Ideal on a 180 - 210mm swing mini lathe - which I don't have (for now). 

DSC_0427_copy_800x450.jpg.2d65ca37f2ef09252c32ac58fa642697.jpg

Link to comment
Share on other sites

I posted about this on another thread, but will revisit it here.

Using my lathe, I attempted to make this rather large staff for a stopwatch.  The challenge started with how to make the slot in the staff.  I attempted it with a dremel.  Very crude.  I thought about using the cross slide and a cutting wheel on the headstock, but, alas, there is no Z adjustment on my cross slide.  Thus I was unable to figure a way to adjust for the right depth of cut.  Maybe I am out in the weeds on this--dunno.

Some of these tools you guys are talking about might address the issue??

The stopwatch repair is not a value issue...just looked like an interesting problem to tackle!

2021-02-26 20_24_22-Photos.png

  • Like 1
Link to comment
Share on other sites

I love my WW bed Boley & Leinen lathe.

From turning staking tool punches in the first video, to gauging the wobble and eventual straightening of a Valjoux 7733 fourth wheel arbor in the last video. It can do it all!

I find using a countershaft in conjunction with a foot pedal controlled sewing machine motor keeps the torque up. There's also more control with tension on the pulleys/driving bands with a movable countershaft, I find.

  • Like 2
Link to comment
Share on other sites

19 minutes ago, Jon said:

I love my WW bed Boley & Leinen lathe.

From turning staking tool punches in the first video, to gauging the wobble and eventual straightening of a Valjoux 7733 fourth wheel arbor in the last video. It can do it all!

I find using a countershaft in conjunction with a foot pedal controlled sewing machine motor keeps the torque up. There's also more control with tension on the pulleys/driving bands with a movable countershaft, I find.

I have the same setup but use the large wheel off the sewing machine motor.  This gives me more torque.  I also use a leather belt I made from a thick boot lace.  Did a video on how to do this...on youtube.  Way more quite and lots of grip.

 

Link to comment
Share on other sites

2 hours ago, jdrichard said:

I also use a leather belt I made from a thick boot lace

Leather is a good choice.  I tried it sewn together with Power Pro braided fishing line (20lb) which works really nice threading a sewing needle.  But my piece of leather broke (it was some old scrap I had lying around).  Then I decided to try 3mm TPU which I use for 3D printing.  Will see how it goes.  I keep my eye out for the parts to make a setup like yours.

  • Like 1
Link to comment
Share on other sites

6 hours ago, jdrichard said:

I have the same setup but use the large wheel off the sewing machine motor.  This gives me more torque.  I also use a leather belt I made from a thick boot lace.  Did a video on how to do this...on youtube.  Way more quite and lots of grip.

 

The large wheel should give more speed, but not more torque. Probably the belt slips less on the larger pulley.

 

In the U.S. we used Habasit round belting in the school where I taught. It's heat weldable; of course there's a machine for it but you can weld it fine by heating a ~0.5mm strip of brass held in a vice, with a little torch, then press the two ends against opposing sides, they melt, and slide up to join. Hold till it cools, then trim the bead that's left. I have machines in the workshop with thousands of hours on their belt joined this way. Any good belting supplier should have it or know where to get it.

 

Leather is great too, less tolerant of pulley distance, but very good. If you have slippage issues rub solid beeswax on it as it's running. Seems counterintuitive but it works, better grip.

Edited by nickelsilver
Link to comment
Share on other sites

21 minutes ago, nickelsilver said:

The large wheel should give more speed, but not more torque. Probably the belt slips less on the larger pulley.

 

In the U.S. we used Habasit round belting in the school where I taught. It's heat weldable; of course there's a machine for it but you can weld it fine by heating a ~0.5mm strip of brass held in a vice, with a little torch, the press the two end against opposing sides, they melt, and slide up to join. Hold till it cools, the trim the bead that's left. I machines in the workshop with thousands of hours on their belt joined this way. Any good belting supplier should have it or know where to get it.

 

Leather is great too, less tolerant of pulley distance, but very good. If you have slippage issues rub solid beeswax on it as it's running. Seems counterintuitive but it works, better grip.

I agree with everything you stated, with the exception of the angular force transferred from the large pully to the much smaller pully; it will provide a greater force and thus more torque off the smaller pulley.  I am an electrical engineer, so I will need to ask my son the Mechanical engineer to see if i am "full of it" :).  Thanks for the advice.

Link to comment
Share on other sites

28 minutes ago, jdrichard said:

 angular force transferred from the large pully to the much smaller pully; it will provide a greater force and thus more torque off the smaller pulley. 

The other way around ?

  • Like 1
Link to comment
Share on other sites

2 hours ago, jdrichard said:

I agree with everything you stated, with the exception of the angular force transferred from the large pully to the much smaller pully; it will provide a greater force and thus more torque off the smaller pulley.  I am an electrical engineer, so I will need to ask my son the Mechanical engineer to see if i am "full of it" :).  Thanks for the advice.

C'mon, if I  understand correctly you're an engineer. Pulleys are levers (and gears are pulleys with teeth), the fulcrum remains the fulcrum. You're seeing the big pulley as a bigger "effort" and the smaller one as a smaller load, but it's reversed. For a pulley of 3.14" diameter a pulley of 1" diameter from the motor has a mechanical advantage. More torque, 1/3 the speed.

In a watch the barrel with 90 teeth drives the center pinion with 12 teeth, the pinion does 7.5 turn per turn of barrel, but you can stop the center wheel with a toothpick. Try stopping a fully wound barrel with a toothpick. Speed increase, torque decrease. It's why Accutrons wear themselves out- it's power from the (super fragile) escapement- by the time you're at the 3rd or center wheel there's almost limitless power. Torque increase.

 

On edit- electrical engineer, still, most of the old fart sparkies I know get leverage haha (joshin _ just a bit_).

Edited by nickelsilver
Link to comment
Share on other sites

17 hours ago, nickelsilver said:

C'mon, if I  understand correctly you're an engineer. Pulleys are levers (and gears are pulleys with teeth), the fulcrum remains the fulcrum. You're seeing the big pulley as a bigger "effort" and the smaller one as a smaller load, but it's reversed. For a pulley of 3.14" diameter a pulley of 1" diameter from the motor has a mechanical advantage. More torque, 1/3 the speed.

In a watch the barrel with 90 teeth drives the center pinion with 12 teeth, the pinion does 7.5 turn per turn of barrel, but you can stop the center wheel with a toothpick. Try stopping a fully wound barrel with a toothpick. Speed increase, torque decrease. It's why Accutrons wear themselves out- it's power from the (super fragile) escapement- by the time you're at the 3rd or center wheel there's almost limitless power. Torque increase.

 

On edit- electrical engineer, still, most of the old fart sparkies I know get leverage haha (joshin _ just a bit_).

Got all of that and in fact studied all of this in my first 2 years in university.  So big wheel to small wheel on the counter shaft can generate more torque at a lower angular velocity. ant then small wheel to Lathe big wheel retains this torque as the wheels are pretty much the dame diameter.  Sewing machine motor is a very small wheel but spins like hell.  gear changing on a 20speed bicycle is a physical model of all of this.

"Sparky" is used in aerospace for the aircraft electrical guys.

Link to comment
Share on other sites

21 hours ago, LittleWatchShop said:

Leather is a good choice.  I tried it sewn together with Power Pro braided fishing line (20lb) which works really nice threading a sewing needle.  But my piece of leather broke (it was some old scrap I had lying around).  Then I decided to try 3mm TPU which I use for 3D printing.  Will see how it goes.  I keep my eye out for the parts to make a setup like yours.

Great, thanks for the note

Link to comment
Share on other sites

Are you saying that on your countershaft you have a large pulley and a small pulley (that's normal), and you are driving the large pulley from a small pulley on your motor, then from the small pulley on the countershaft to the lathe? Yes, that would increase the torque coming from the motor, while reducing speed. The way I read it you had a large wheel on the motor.

Link to comment
Share on other sites

Just now, nickelsilver said:

Are you saying that on your countershaft you have a large pulley and a small pulley (that's normal), and you are driving the large pulley from a small pulley on your motor, then from the small pulley on the countershaft to the lathe? Yes, that would increase the torque coming from the motor, while reducing speed. The way I read it you had a large wheel on the motor.

That is exactly in...as i have shown in the youtube video attached.

  • Like 1
Link to comment
Share on other sites

1 hour ago, jdrichard said:

Force to stop the small pully in motion on the countershaft is much greater than the force to stop the large pully.....

Consider that when you try to stop a spinning wheel you introduce two more factors in the equation, friction and inertia. E.g. https://www.physicsforums.com/threads/flywheel-disk-brake-system.817113/

Now for a more basic example, try going uphill ona bicycle with a big gear at the crankcase, and a small one on the wheel. And then.. the other way around ?

Link to comment
Share on other sites

17 minutes ago, jdm said:

Consider that when you try to stop a spinning wheel you introduce two more factors in the equation, friction and inertia. E.g. https://www.physicsforums.com/threads/flywheel-disk-brake-system.817113/

Now for a more basic example, try going uphill ona bicycle with a big gear at the crankcase, and a small one on the wheel. And then.. the other way around ?

Correct.  feet pushing big wheel:).  All we need know is vector diagrams!!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Yes @SwissSeiko, most of us here are just hobbyist and some horological products are simply too expensive. For example, cleaning fluids. I think even you find L&R cleaning fluids expensive. But I haven't found anything that shines up parts like #111. So I just bite the bullet and fork up the $$$. Here in Singapore, a bottle of #111 is $180SGD. ($134USD) The Rinse #3 is the same price. Oils like 2ml of Moebius 9010 is around $45SGD. Imagine if you had to fill your car engine with 5 quarts of 9010! I have been using odorless kerosene to preclean my parts before putting them into the #111. The kerosene does such a fantastic job that I may use that in place of the Rinse #3. But I can do without the #111, but now its role is just a brightening agent.  So my cleaning regimen will be kerosene, #111, kerosene and IPA. I see how that works out. I might even re-distill my used IPA to save even more.
    • What works for you, is good enough for me. You and I have great interactions on here, and you've taught me some things! I guess I should approach things with the thought process that most of the users on here are probably doing this as a hobby. I find myself reading some posts and thinking, that's definitely not how I would do it. But I do this for a living, I have overhead costs, bills to pay, taxes, tooling costs ect., and to many on here, it's probably just fine to do it as is necessary to work. So I'm probably a little overzealous when it comes to finishing. You should know, we(for sure at least me) appreciate you. If someone chimes in on my posts, it's usually you, and you're a good chap!
    • Hi. Just curious. Is there an official service center for orient in your area?  I had a problem with my orient mako before. I was regulating the movement and lost focus on what I was doing. I accidentally hit the balance wheel . I had the same issue in finding parts for it so I ended up sending it to the official service center here in the Philippines.
    • I think it was HectorLooi that posted some information at the time that we were discussing what materials to use for cleaning jars in an ultrasonic machine. It was decided that steel jars transmit the cavitation bubbles better than glass or plastic, which was considered the worst as it absorbs their energy. So I've tried a few different cleaning solutions, mostly non-proprietary watch stuff. There is a thread I made last year experimenting , actually I might have tagged it onto someone else's thread,  I can't remember.  Just mirror residue and evaporation rates. 🤔 Elma pro ammoniated,  paraffin,  ligher fuel , Ipa, meths, and I think break cleaner was in there as well. Elma and paraffin have a very slow evaporation rate, probably days. Both have wetting properties and are far reaching, paraffin being very much so, if you're looking for a deep cleaning solution then paraffin soaks well and finds every nook, cranny and crevice. When I use paraffin which is usually if I hand or US pre clean then i place the parts on absorbant tissue  afterwards to soak up the excess then spin them off and use IPA or break cleaner to rinse them off after that a rotary wash with elma and ipa for rinsing . I don't use a US that much, really just if any wheels and pinion leaves are really gunked up, which is when I hang them on the little wire tree. I kind of base how i will clean by how dirty and gunked up the movement is. If it's bad the procedure will follow : soak in paraffin for a couple of hours, peg out plate and bridges and hand clean what I can with a small brush to remove the bulk. Then onto the USM, some parts that can be hung go on the tree like wheels etc,  others that can't go in a slow rotating mesh basket, all in paraffin, the USM  loosens the crap up . Then put them in a rotary basket, spin them in paraffin, spin off the excess, then in elma then 3 rinses in IPA. That's like the full valet, if the movement is really dirty. The parts that don't get that treatment are the balance complete and the pallet fork, which I really like to clean by hand.  Screws and springs I also won't put in a machine, too easily lost, these are easily cleaned by swishing them in a jar of whatever you fancy . If I get a really stubborn sticky hairspring, that will be removed for cleaning separately, brreak fluid is good for that or tetrachloroethylene. Thats one way to get rid of the mother in-law, at 85 yrs old mine is heart attack territory.....🤔....I could accidentally have an envelope with certain contents fall out of my jacket pocket onto her dining room table...accidentally....🤔
    • Yeah, that's the guy. I told him it's cheaper if I just send the pictures to my  mother-in-law directly. 😮 
×
×
  • Create New...