# Lathe HELP



## RafaelMarujo (Feb 4, 2021)

Hey guys, so i bought this lathe a couple of days ago, and im in the process pf restoring it. I knew it had some problems and most of them I already adressed, except for one, every change gear is missing, and since im relatively new to machining, i dont knows how to make the calculations to figure out what i need. 
Can anyone help me out? Or better yet, teach me? Ive seen tens of videos about it, and still i get more and more confused 
Anyway thanks for any help you can give
The spindle gear is: 25 teeth
The final gear is :70 teeth
Im only cutting metric threads, i will attatch pictures


----------



## Braeden P (Feb 4, 2021)

RafaelMarujo said:


> Hey guys, so i bought this lathe a couple of days ago, and im in the process pf restoring it. I knew it had some problems and most of them I already adressed, except for one, every change gear is missing, and since im relatively new to machining, i dont knows how to make the calculations to figure out what i need.
> Can anyone help me out? Or better yet, teach me? Ive seen tens of videos about it, and still i get more and more confused
> Anyway thanks for any help you can give
> The spindle gear is: 25 teeth
> ...


if you can find the manual it should say what size change gears to use


----------



## DavidR8 (Feb 4, 2021)

I’m sure we can help you. 
Can you tell us make and model and provide some photos of the machine?


----------



## RafaelMarujo (Feb 4, 2021)

Braeden P said:


> if you can find the manual it should say what size change gears to use


That was my first idea, but i cant find anything on the lathe online, its a bilcia and i dont even know the sub brand because the lathe doesn't have any plaques.. 
Not even tony at lathes.uk could help


----------



## RafaelMarujo (Feb 4, 2021)

DavidR8 said:


> I’m sure we can help you.
> Can you tell us make and model and provide some photos of the machine?


Its a bilcia and i dont even know the model because the lathe doesn't have any plaques..
Not even tony at lathes.uk could help, ive emailed him


----------



## Braeden P (Feb 4, 2021)

we need pictures and i think we can find what model it is could it be one of these https://store.lathes.co.uk/print/b67


----------



## DavidR8 (Feb 4, 2021)

RafaelMarujo said:


> Its a bilcia and i dont even know the model because the lathe doesn't have any plaques..
> Not even tony at lathes.uk could help, ive emailed him



Can you post some pictures of the machine? There’s a chance it shares parts with some other machines.


----------



## RafaelMarujo (Feb 4, 2021)

DavidR8 said:


> Can you post some pictures of the machine? There’s a chance it shares parts with some other machines.


Im not home right now, but its exactly like this one i found online, with the change gear handle in front (i think some bilcias dont have it) 
I can send some pictures later, and thanks so much for helping me, im kinda desperate


----------



## Braeden P (Feb 4, 2021)

look up bilcia trp 536 see if those match.


----------



## RafaelMarujo (Feb 4, 2021)

Braeden P said:


> look up bilcia trp 536 see if those match.


Unfortunately they're not the same
Its amazing the lack of information about this brand that actually looks high quality


----------



## Braeden P (Feb 4, 2021)

yea that is what is messing me up


----------



## RafaelMarujo (Feb 4, 2021)

Braeden P said:


> yea that is what is messing me up


Well, what i can say is, im sorry to drag you down to the pit im in haha


----------



## Braeden P (Feb 4, 2021)

RafaelMarujo said:


> Well, what i can say is, im sorry to drag you down to the pit im in haha


its fine but this is going to be hard to find


----------



## RafaelMarujo (Feb 4, 2021)

Braeden P said:


> its fine but this is going to be hard to find


Isn't there a way to calculate the gear ratio by the already existing gears? If anyone knows the formulas we could just bruce force it


----------



## Braeden P (Feb 4, 2021)

probably others know how but im just a 12 year old with about 2 hours of machining time but that number will increase because i am getting my first lathe, good luck!


----------



## RafaelMarujo (Feb 4, 2021)

Braeden P said:


> probably others know how but im just a 12 year old with about 2 hours of machining time but that number will increase because i am getting my first lathe, good luck!


Im 24, and i just got my first real lathe, good luck with everything!!


----------



## T Bredehoft (Feb 4, 2021)

With an indicator you can put it in a gear, revolve the spindle exactly one revolution and determine what the per/revolution the saddle/tool advances. Then, of course, record that gear and it's advance.


----------



## Braeden P (Feb 4, 2021)

RafaelMarujo said:


> Im 24, and i just got my first real lathe, good luck with everything!!


it runs and is a hardinge dv 59 110 volts which is rare and it is from my neighbors friend who has a  machine shop he likes that i am into machining so much he is giving it to me for free i feel so lucky! the lathe is a little second op lathe but weighs a lot of its size hope fully others will help you


----------



## RafaelMarujo (Feb 4, 2021)

Braeden P said:


> it runs and is a hardinge dv 59 110 volts which is rare and it is from my neighbors friend who has a  machine shop he likes that i am into machining so much he is giving it to me for free i feel so lucky! the lathe is a little second op lathe but weighs a lot of its size hope fully others will help you


The size doesn't matter as much as one may think, until now ive had a little atlas 10 inch wich has served me very well, and ive seen with my own eyes, stuff made with little lathes that are amazing, the experience is everything!!


----------



## Braeden P (Feb 4, 2021)

RafaelMarujo said:


> The size doesn't matter as much as one may think, until now ive had a little atlas 10 inch wich has served me very well, and ive seen with my own eyes, stuff made with little lathes that are amazing, the experience is everything!!


it is 9 inch swing 15 between centers but weight 1550 lbs so a lot of weight so it is sturdy


----------



## RafaelMarujo (Feb 4, 2021)

Braeden P said:


> it is 9 inch swing 15 between centers but weight 1550 lbs so a lot of weight so it is sturdy


Sounds good, it will last you many years if you take care of it! The next thing is getting a mill


----------



## Braeden P (Feb 4, 2021)

RafaelMarujo said:


> Sounds good, it will last you many years if you take care of it! The next thing is getting a mill


the next thing is a shop a two car garage that is packed full of stuff will get crowed and my neighbor needs parts machined and he does not have a lathe so that is the main reason and my dad is getting a shop built for him and me and my brother it should be done by spring


----------



## Lo-Fi (Feb 4, 2021)

Change gear calculators are what you need:









						Change Gears for Threading
					

This calculator determines the correct change gears for any thread pitch. Works for all mini lathes and HiTorque Bench Lathes.




					littlemachineshop.com
				








__





						Change Gears
					





					www.mibot.com
				




Though there are many more. It's not a straightforward single formula calculation and requires some iteration to get actual solutions.

It _looks_ from the photos to be a 4tpi leadscrew. Are the crossfeed and compound handles graduated in inch or metric?


----------



## RafaelMarujo (Feb 4, 2021)

Braeden P said:


> the next thing is a shop a two car garage that is packed full of stuff will get crowed and my neighbor needs parts machined and he does not have a lathe so that is the main reason and my dad is getting a shop built for him and me and my brother it should be done by spring


Nice man, good luck with all!


----------



## RafaelMarujo (Feb 4, 2021)

Lo-Fi said:


> Change gear calculators are what you need:
> 
> 
> 
> ...


Thanks thats what i thought 
I they're metric, its a spanish brand, made for the european countries


----------



## T Bredehoft (Feb 4, 2021)

Looks to be a 6 mm lead screw. one rev advances the carriage 6 millimeters.


----------



## kdtop (Feb 6, 2021)

I have a much smaller Atlas lathe and I ended up 3D printing change gears for it.  Surprisingly, they have lasted a couple of years now.

If you can't find the exact model number, then you may have to be more creative.   Do you have any gears for it now?  If so, then you can figure out the gear pitch (or, rather, the metric equivalent), pressure angle, and hub diameter.    I think the Machinist Handbook has detailed information.    If you don't want plastic gears, then you may have to cut some from metal, or look for gears online fitting your specs. 

I did some online research, and agree that there isn't much.  Here is what I did find

Manufacturer seems to be CEFERINO BILBAO
Here is an old catalog: https://www.worthpoint.com/worthopedia/vtg-ceferino-bilbao-catalog-bilcia-20-1856498703
Apparently the Spanish term for lathe is: torno paralelo.  I initially thought this might be manufacturer name, but it's not. 
Here is a manual on sale from ebay.  Looks like a lot of money for not much... https://www.ebay.com/itm/Nordic-Cef...erations-and-Maintenance-Manual-/172760547040  However, the first page is shown and it contains an address, included below.  I seemed to go down a rabbit hole pursuing the address
Here is another HM thread about Bilcia lathes:  https://www.hobby-machinist.com/threads/i-need-help.90093/




Best wishes,
Kevin


----------



## RafaelMarujo (Feb 6, 2021)

kdtop said:


> I have a much smaller Atlas lathe and I ended up 3D printing change gears for it.  Surprisingly, they have lasted a couple of years now.
> 
> If you can't find the exact model number, then you may have to be more creative.   Do you have any gears for it now?  If so, then you can figure out the gear pitch (or, rather, the metric equivalent), pressure angle, and hub diameter.    I think the Machinist Handbook has detailed information.    If you don't want plastic gears, then you may have to cut some from metal, or look for gears online fitting your specs.
> 
> ...


Jezz thanks so much kevin, it looks like you went out of your way!!


----------



## RafaelMarujo (Feb 6, 2021)

kdtop said:


> I have a much smaller Atlas lathe and I ended up 3D printing change gears for it.  Surprisingly, they have lasted a couple of years now.
> 
> If you can't find the exact model number, then you may have to be more creative.   Do you have any gears for it now?  If so, then you can figure out the gear pitch (or, rather, the metric equivalent), pressure angle, and hub diameter.    I think the Machinist Handbook has detailed information.    If you don't want plastic gears, then you may have to cut some from metal, or look for gears online fitting your specs.
> 
> ...


Getting the gears isn't the problem because i can actually make them/buy them, the spinde gear is 25 teeth, and the last gear (right before the gearbox chagne lever) is 100 tooth... Both weird ratios (for ke at least, i was used to my atlas 10 inch


----------



## kdtop (Feb 6, 2021)

You mention a gearbox change lever.  So does this have a way to dial in the desired cutting gear pitch?  If so, then don't you just need to have a gear to connect from the spindle to the gearbox?  If your spindle has 25 teeth and the gearbox has 100, then this will effect a 25/100 = 1/4 speed change.  

KT


----------



## RafaelMarujo (Feb 6, 2021)

kdtop said:


> You mention a gearbox change lever.  So does this have a way to dial in the desired cutting gear pitch?  If so, then don't you just need to have a gear to connect from the spindle to the gearbox?  If your spindle has 25 teeth and the gearbox has 100, then this will effect a 25/100 = 1/4 speed change.
> 
> KT


Thats whay i firsy thought, just a simple idle gear, but theres a banjo (broken also, but easy to make) , that makes me think there should be a compound gear reduction


----------



## RafaelMarujo (Feb 6, 2021)

RafaelMarujo said:


> Thats whay i firsy thought, just a simple idle gear, but theres a banjo (broken also, but easy to make) , that makes me think there should be a compound gear reduction


As you can see here


----------



## Lo-Fi (Feb 6, 2021)

Compound gear reductions are often used to keep the physical size of the gear train down when cutting finer pitches. Doesn't have to be one way or the other, though. The banjos are used just as much for making trains of idlers. Looks like you've got plenty of room to take up there!


----------



## brino (Feb 6, 2021)

RafaelMarujo said:


> Isn't there a way to calculate the gear ratio by the already existing gears? If anyone knows the formulas we could just bruce force it



Great idea, but unfortunately there are a few other complications......

The math itself is not difficult, it's really just a string of fractions with "driving gear tooth count" on top (numerator) and the "driven gear tooth count" on the bottom (denominator).

The complications are:

1) how many intermediate gears? Without knowing the size and shape of the original banjo it's hard to guess the number of terms in the equation. Should the formula include 3 fractions? or 4 or 5? Some banjos are Y-shaped with slot for multiple gear axles.

2) down-stream gear box: you posted above a picture of a lathe identical to yours. It has a gear box with feed-change levers.
This will end-up being a "black box" on the output of your calculations. However, since you own this lathe you can look inside and count teeth on every gear. I did that on my lathes, really just to understand everything about them. I wiped off the gear and used a paint pen to mark the tooth where I started counting. This required a flashlight and mirror as well, to look thru the open bottom of my quick-change gear box (Southbend 9"). Of course I had the advantage of being able to verify them in a manual.

3) lead screw: Your picture shows that the lead screw looks very close to 4 tpi, but if this lathe was made in Spain, then it likely is metric, and
@T Bredehoft  may be correct that it is in fact 6mm. Knowing this is required to work out how far the carriage moves linearly for each rotation of the lead-screw. Perhaps a screw thread gauge can help you to tell the difference.

4) gears that are pinned together need to be calculated a little differently. These may appear as two gears with key ways that together run on a small bushing also with a key. With a pinned pair of gears the "input" gear is only a driven gear NOT a driving gear, therefore its tooth count appears only in a denominator. Similarly, the "output" gear of the pinned pair is only a driving gear and so its tooth count appears only in a numerator.

5) gear spacing; what is there physically room for? for the given gear module (or diametral pitch), can you fit a 50 tooth gear, 64 tooth? 84 tooth?
It is hard to know what options we are allowed to plug into the equation.


Please know that I am NOT trying to discourage you!!!
You CAN figure this out and we will *always *try to help!

One other idea is to look at other lathe manuals for a "similar" arrangement. Look for one that also has a 25-tooth gear on the spindle and the same lead-screw pitch; you might be able to use those threading/feed charts exactly as they are (depending on what gears fit your banjo). But also look for any others with a 50-tooth gear on the spindle....that would just require a driven gear with twice the teeth later in the gear chain.

Please don't give up. That looks like an amazing lathe.

-brino


----------



## DavidR8 (Feb 6, 2021)

Is an Electronic Lead Screw an option here?


----------



## RafaelMarujo (Feb 6, 2021)

Lo-Fi said:


> Compound gear reductions are often used to keep the physical size of the gear train down when cutting finer pitches. Doesn't have to be one way or the other, though. The banjos are used just as much for making trains of idlers. Looks like you've got plenty of room to take up there!


With the 6mm pitch leadscrew,, would 25/100 make the correct pitches?
I dont know because the lathe doesn't have any charts, they're e all missing


brino said:


> Great idea, but unfortunately there are a few other complications......
> 
> The math itself is not difficult, it's really just a string of fractions with "driving gear tooth count" on top (numerator) and the "driven gear tooth count" on the bottom (denominator).
> 
> ...


Omg brino thank you so much, i agree with everything you said, and i have lookes for similar lathes with 25 teeth gear spindle, but the 50 tooth gear is a genious idea and i will try to search tomorrow! 
Either way I'm going to count every gears in between and try to make a schematic of all the existing gears and see if i you guys can help. Thanks so much!!!


----------



## Blair (Feb 20, 2021)

RafaelMarujo said:


> Hey guys, so i bought this lathe a couple of days ago, and im in the process pf restoring it. I knew it had some problems and most of them I already adressed, except for one, every change gear is missing, and since im relatively new to machining, i dont knows how to make the calculations to figure out what i need.
> Can anyone help me out? Or better yet, teach me? Ive seen tens of videos about it, and still i get more and more confused
> Anyway thanks for any help you can give
> The spindle gear is: 25 teeth
> ...


Check this guy out, he has helped me out alot and he has a program called Ride the gear train, he will set you up and teach you about gear ratios


----------



## brino (Mar 7, 2021)

@RafaelMarujo

I am almost finished an excel chart for your lathe....it already covers 14 of the 15 most common metric threads.

I have come up with gear ratios to allow it all to work, however, there will still be some figuring on your end.
To fully detail it, I'd need to build a model of your lathe (either real or in CAD) with the shaft spacing, banjo,  and gear sizes all mocked-up.
That would allow me to check exactly what gears actually physically fit on your lathe.
However, that's easier for you to do on your end......"sweat equity" if you will...

Still for me to do:
i) finish the last 1 of 15 (0.35 mm pitch),
ii) I need to double-check the entire thing,
iii) I came up with one more question.....

Actually, two outstanding questions for you......

1) are you okay with me publishing the schematic you PM'ed me for your gear layout?
I'd like this posted so maybe it can help others, either by working thru it as an example, or for those with a similar lathe.

2) Are the existing 25-tooth gear on the spindle and 100-tooth gear on the gear-box input perfectly in line?
If you placed a straight edge against the side of the 100-tooth gear does it also perfectly contact the side of the 25-tooth gear?
Your 100-tooth gear seems to be on a key (see below).
Can that 100-tooth gear be placed in different positions on the shaft (ie. to the left or to the right)?

Thanks,
-brino


----------



## RafaelMarujo (Mar 16, 2021)

brino said:


> @RafaelMarujo
> 
> I am almost finished an excel chart for your lathe....it already covers 14 of the 15 most common metric threads.
> 
> ...


Hello brian, im so sorry for the late response, i have been super busy at work and barely come here anymore, and somehow i stopped receiving email notifications somehow? 
Anyway, to answer your questions yes you can use anything i sent to help others, i just wanna be able to help people in need, just like you! 
To answer the alignment question, is cant remember but as soon as i get home i will check and send some pictures, and ill know for sure... 
Everything about the lathe as been restored, the only thing im missing is the banjo and the gears, and i cant wait to have them! Once again thank you so much for your time and help, and i hope everything is good with you and your family in these troubled times... 
Thank you Brian! 
Rafael Marujo


----------



## brino (Mar 16, 2021)

RafaelMarujo said:


> im so sorry for the late response, i have been super busy at work and barely come here anymore, and somehow i stopped receiving email notifications somehow?


No worries.



RafaelMarujo said:


> Anyway, to answer your questions yes you can use anything i sent to help others, i just wanna be able to help people in need, just like you!



Great. I'll be back with some more info for anyone following along.



RafaelMarujo said:


> Everything about the lathe as been restored, the only thing im missing is the banjo and the gears



Nice, congratulations. 
What have you turned so far?



RafaelMarujo said:


> thank you so much for your time and help



I am very glad to help. 
Reviewing this info every few years helps keep it in my brain.

-brino


----------

