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Member postings for Bevel

Here is a list of all the postings Bevel has made in our forums. Click on a thread name to jump to the thread.

Thread: Lathe gear calculation
08/07/2021 17:21:36
Posted by SillyOldDuffer on 08/07/2021 16:46:43:
Posted by Bevel on 08/07/2021 16:01:03:
... I only have a limited number of gears ...

For fun we can have a competition. Nigel and Howard will apply pen and paper to simple fractions, Ian will adapt his BASIC program, and I will apply Python. Show working. Winner gets duffed up after school for being a nerd!


Haha LMAO great Dave love it!!

Looks like Ian has already done it chaps.

Never was a 39T Howard mate, bought machine brand new and only comes with what I listed in first post.

Just 20, 30, 40, 50, 55, 60, 63, 70,75 + 80.

Still chuckling here Dave wink

Thanks Pete I will keep them for future ref

08/07/2021 16:30:42

I most certainly do Ian buddy

08/07/2021 16:01:03

Afraid not Howard mate if it was that simple we wouldn't be discussing it lol.

That is what this is all about in first place I only have a limited number of gears and unfortunately 39T isn't one of them.

08/07/2021 10:59:57

Thanks very much Dave, just ordered the aforementioned literature by Mr Cleeve

08/07/2021 08:56:24

Back again

This is the illustration I have on my lathe, in charts quoted by your kind selves there are only 4 gears quoted when mine contains 5?

gear change.jpg

My understanding is z1 + z3 are drivers as they are transferring rotation onto other gears but where does this leave L as it transfers rotation to leadscrew?

Also never fully understood this one either, does it mean I can literally select any point on threading dial to cut these thread ranges? What does Mn relate to and is z =32T referring to the gear on end of leadscrew?


07/07/2021 18:51:45

Aha the penny dropped, Nigel you were spot on with your calcs I have a 40T pinion.

Guys ALL your help is invaluable and very much appreciated.

I will get that book/books for sure and further my understanding. All these machines I have used for so many years and never given any thought to what was actually occuring within. Until now as you are all most probably aware it's been a simple case of following chart and selecting levers to correspond, and to be frank if Warco gave a better selection of change gears with their lathes then I most probably would never have looked any further.

Hats off to you gents, this knowledge will eventually wilt in the age of CNC and mores the pity cos once it's gone it won't return. Excuse my pesimism but I see it every day, young men today are not as skilled as previous generations gone by, not thru any fault of their own but via a massive leap forward in technology.

A massive thanks to you for taking time and explaining it all in such great detail.



07/07/2021 15:08:35

Holy Sh*t guys, technical overload! crookcrook

Many thanks to you all for your input much appreciated.

Even tho I have a GCSE in mathematics and never been considered a dullard this is all completely over my head if I'm honest.

Ian T's computer program/ excel file formula sounds just the ticket but I'm lost there as he only lists 3 gears, where have the others gone lol?? How exactly do you set them up?

Nigel Graham 2 writes that this is just simple arithmetics but all this talk of drivers and driven, ratio's etc etc has my head swimming.

Must be simpler way to work out what I can achieve with what I have to hand and where I position everything surely.

Martin C my chart is slightly diifferent, I will take a pic and post it shortly

07/07/2021 09:31:18

Still don't understand where the second combo of 30/60 comes from?

Sorry it's most probably so simple but I can't see correlation at all smile d

07/07/2021 07:47:34

Reason I asked the question in first place was yes I do have the chart and I know how to use it but the chart states the combination listed above.

Trouble is I don't have a 65T gear and I need to cut a 2mm pitch thread. I need to cut a M14X2 thread and have a finishing die but need a base thread first. Hence the query.

I asked a similar question previously and the forum answered in spades and allowed me to cut a thread of 1.5mm pitch with the change gears available to a close enough tolerance for job in hand.

With that much more experience now I would like to learn the reasoning behind the calculations enabling me, hopefully, to work out myself what is possible for future projects. Even tho I am time served some 30 years ago I have always had use of geared lathes so change gears are relatively new to me tbh.

Nigel, to answer your question the lathe is a Warco WM250v in English and it has a 40T pinion.

06/07/2021 22:59:12

Ok guys many thanks for the advice, think a little browse for literature is called for eh Chris yes

06/07/2021 22:14:23

Hi Howard,

Many thanks for the reply but I've only partly got it.

I undertstand the ratio bit and also the conversion to metric to explain the 127 rule but in simpleton terms (sorry) if I was looking for 26tpi thread how would I calculate the nearest I could get with gears to hand?

How do I know in what order to place the gears etc as example below?

x - 70

30 - 65

60 - x

This is illustrated on lathe itself so I know it's correct.

06/07/2021 21:25:40

Hi All,

Asked a similar question some time ago but forgotten the answer.....doh!

Could some kind soul take 5 minutes and enlighten me on how to calculate lathe gear changes required for selective pitches please?

I can see on machine what gears I need but how exactly does this work out eg. my machine has 8tpi leadscrew, I have 20,30,40,50,55,60,63,70,75 + 80 gears. For a 26tpi thread I would need 70, 65, 30 + 60 gears but how does the maths work here exactly?

My previous thread a gentlemen mentioned the 127/100 rule, what does that mean and what bearing does it have on change gears?

Many thanks once again guys

Thread: Warco lathe mill attachment
10/09/2019 19:19:54

Thanks old mart, space is at a premium with my layout as is but maybe a shuffle is on the horizon.

10/09/2019 11:11:40

Guys as expected plenty of invaluable advice. Points taken from each and every one with thanks.

Stand alone it is then and I'll be sure to check out the SIEG suggested by Ron.

09/09/2019 13:29:07

Right I see what you mean, never really thought about that so thx.

They are currently running for just over £600. According to their ad they are the WM14 but obviously without the table.

Do you think the extra bunts is worth it?

09/09/2019 09:40:00

Hi All,

Thinking of adding a milling head attachment to my Warco WM250V, does anyone have any experience with this machinery who could offer advice and opinions please?

I won't be machining anything heavy duty and I use aluminium and acetal mostly with the occasional steel piece here and there. Granted a stand alone would be better but I'm restricted with space presently. Having said that if you have suggestions for a better alternative I'd be interested to hear it.

Thanks in advance your views are always valued and greatly appreciated.

Edited By Bevel on 09/09/2019 09:43:30


Edited By Bevel on 09/09/2019 09:48:34

Thread: Another anodising query sorry
28/07/2019 19:11:56

Sulphuric acid is pretty difficult to get your hands on these days, presumably becuase of all these bl**dy idiots we have here using it as a weapon.

I know of one product that uses 91% acid in its make-up and thats readily available so maybe a splash of that would be the answer eh

28/07/2019 18:58:48

Mark smith 20,

I have some pool chems here, could adding a teaspoon of PH minus into a spray bottle of de-io be what we are looking for?

28/07/2019 18:53:29

looks pretty darn good to me Neil

28/07/2019 16:22:11

Just ordered and received a stock bar of 6063 funny enough so good to go there.

If I use a fish tank aerator as somebody has advised won't I be introducing more air bubbles and stand a great chance of patches?

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