# Drummond B lathe



## wallace

I recently aquired a rough little B lathe. I'm struggling with the change wheels. The old guy that had it said he had never used it for screw cutting. I dont know how the wheels should be arranged to provide a slow motion when the feed is actuated. When I press the feed lever it goes to the right.
I had a look on the drummond group which is a horrible place to navigate.


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## bjm

Make enquiries on this site, very helpful group - Model Engineer


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## kenledger

What a beauty!!


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## Stanleymonkey

Do you have a box of spare cogs and gears that came with it? 

Are you able to turn it by hand and drive the cogs and gears - I only ask because assembling a gear chain and firing up the mains motor is going to be a risky process if you have it wrong.


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## Stanleymonkey

I have a different type of Drummond and it is a treadle drive. I will try an photograph the gears set up later and the sizes of the additional gears that came with it.


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## wallace

I got some advice from the guys on the drummond group. Apparently the previous owner was a mad man or genious.
He has the drive coming off the back gear and has modified the apron to give handwheel feed via an added on rack and a solid nut instead of a split nut


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## redhunter350

Have a look here Drummond (& Myford) M-Type Lathe
I realise you say yours is Type B but have a dig around, they are somewhat similar


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## MusicMan

Wallace,

There is a basic methodology for selecting drive gears. I have an old Boley with no instruction manual. Here is the spreadsheet I constructed to select the ratios for any feed (PDF copy sorry as spreadsheet files aren't accepted). If you have a 127 tooth gear you can cut either Imperial or Metric pitches with no compromise (if you don't, you can't). The example here is for an Imperial leadscrew for which you put the 127 gear as a DRIVEN gear, preferably the last in the chain, in order to get metric threads from an Imperial leadscrew.

The first thing you need is the leadscrew pitch. Just measure it, probably a threads-per-inch pitch for a Drummond. Then list the number of teeth in the gears that you actually have in your pile.

The next is the first two gears in the train. Since you mention that the drive is off the back gear, you will have an extra two gears on the left of the spreadsheet, which will be the back gear ratio, something like 1:4 (the numbers don't matter, could be 25 and 100 for example. 
Then you add the gears in the order in which they engage, the first one of each pair being the DRIVING gear the second the DRIVEN gear. 

The ratio column is optional, just might help in fiddling around to get ratios.

After the back gear, there will be a driving gear (1 in my table) which must mesh with the next driven gear (2). The latter is on a shaft that cn slide along the banjo. The banjo can also rotate to bring the two gears into mesh. Then there will be another gear on the same shaft as gear 2, which will be gear 3, the next driven gear. This in turn can be made to mesh with gear 4, the final driven gear. There is always a banjo that can be rotated, or a slide to translate the shaft, so that the gears can be made to mesh.

The final column will be the thread pitch (mm in the metric table, TPI in the Imperial). This is exactly the same as the the feed pitch when turning a cylinder. 

That's it. There's no great magic in selecting the gear pairs and often there are several combinations that will work. In general choose the combo that has fewer teeth on the driving gear and more teeth on the driven gear where possible. Some combinations might be excluded because of other bits of the lather or the shielding getting in the way.

PM me your address if you'd like a copy of the spreadsheet in xlsx format. If you aren't comfortable with spreadsheets, if you send me all the numbers of teeth on the gears you have, the leadscrew pitch and the back gear ratio I'll be happy to construct the table for you. 

Keith


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## wallace

Keith thanks very much for all of that, I think it will be a while before I've reached the level to be doing threads. The lathe seems to be set up to cut a left hand thread. The tail stock quill is rusted solid so it needs some tlc


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## clogs

Wallace 
there a couple of soft back books regarding setting and using metal lathes....
I canot rememeber the auther but he also did books on screwcutting , milling etc.....mine are packed somewhere....
they were excellant for ref..... 
as said go to modelengineer forum...very good for everything metal...also ask about the books, someone will know....
happy days with ur lathe....


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## OldWood

Stanleymonkey said:


> I have a different type of Drummond and it is a treadle drive. I will try an photograph the gears set up later and the sizes of the additional gears that came with it.


Just out of interest, SM, is that the round bed Drummond? I ask because as a small child my father had such that was treadle driven. My brother now has that machine. I remember using it in my teens to turn Meccano parts, but by then my father had changed it to a motor drive.


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## Trextr7monkey

Hi I saw this on the Drummond lathes page which is probably best place as there’s lots of these machines about. The ingenuity of former owners is a story always to be investigated.
There’s a book by Sparey which can be picked up on. E bay which runs through all of the basics as well as showing how capable they can still be. If you haven’t got the full set of gears 3 d printing is the way to go as it gives quieter running gears for reasonable outlay.


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## Stanleymonkey

OldWood said:


> Just out of interest, SM, is that the round bed Drummond? I ask because as a small child my father had such that was treadle driven. My brother now has that machine. I remember using it in my teens to turn Meccano parts, but by then my father had changed it to a motor drive.



Sorry - this one has a flat bed.


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## MusicMan

wallace said:


> Keith thanks very much for all of that, I think it will be a while before I've reached the level to be doing threads. The lathe seems to be set up to cut a left hand thread. The tail stock quill is rusted solid so it needs some tlc



There should be a reversing lever in the gear train that will select forward/neutral/reverse. It may the the plunger at the bottom left of the first picture.
For right hand threads (or slow feeds from right to left) the tool moves from right to left (towards the headstock) when the drive is engaged. The engaging lever looks like the one on the left hand side of the carriage. It's usually a little better to feed towards the headstock when simply cutting, as it's a better direction for the bearing loading.


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## wallace

There is a reversing leaver for the B but I dont have it, by all accounts its a rocky horse item. 

A bit of aluminium bodge to level things up a bit











The head stock and back gear shaft






One thing that has really impressed me is the quality of the castings, straight out of mould with no fettling






A previous owner has put a row of 3 sealed bearings in one side of the head stock, they are japanese so might be good quality






One thing I'm undecided is what colour to do this. Should I stay original and paint it black or my usual grey with red innards. I should I get a bit crazy, I've always liked the colour of coronet lathes.
I always had an itch to line a machine, like what was done on big stationary engines like crosleys.


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## wallace

This is the back of the apron, I dont have a clue what its supposed to look like but theirs been some tinkering






I took the motor and switch off, its quite a nice thing. I have a nice little 3 phase brooks motor that will be perfect for this. I'm going to rig it up through a vfd











Did a bit aluminium filler






And made some bits nice and clean






I stuck the chuck in some evaporust and then wire wheeled it











For the life of me I couldnt get the lead screw to bits, I thought it would either unscrew or just slip off. But I could not get it to move. It spins freely 






Why would a head stock need to moved out of line






I ordered some paint and I think there must of been a failure to communicate, I asked for RAL 3O32 which is a dark ruby red, but what I got was 3O22 which is salmon pink


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## Trevanion

wallace said:


> Why would a head stock need to moved out of line



Taper turning!


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## AES

Trevanion said:


> Taper turning!



Trevanion beat me to it! Quite useful, but on my Chinese Mini Lathe anyway, it's a right PITA to get the tailstock back exactly in line again! don't know about the Drummond though.


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## marcros

wallace said:


> This is the back of the apron, I dont have a clue what its supposed to look like but theirs been some tinkering
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> I took the motor and switch off, its quite a nice thing. I have a nice little 3 phase brooks motor that will be perfect for this. I'm going to rig it up through a vfd
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> I stuck the chuck in some evaporust and then wire wheeled it
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> For the life of me I couldnt get the lead screw to bits, I thought it would either unscrew or just slip off. But I could not get it to move. It spins freely
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> Why would a head stock need to moved out of line
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> I ordered some paint and I think there must of been a failure to communicate, I asked for RAL 3O32 which is a dark ruby red, but what I got was 3O22 which is salmon pink



Pink it is then! Colour decided.


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## wallace

Oh I get it, if you werent turning between centres. Wouldnt it be easier to do it with the cross slide


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## Trevanion

wallace said:


> Oh I get it, if you werent turning between centres. Wouldnt it be easier to do it with the cross slide



It would be used for quite long, shallow tapers. By consequence a deeper taper would be less length because it’s traversing more _across _the material rather than along its length so it’s easier to do those with the top slide.

If that makes any sense


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## wallace

Seems strange to move the head stock, I can move the tail stock on my wood lathe for off centre work or for doing long tapers.


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## Trevanion

wallace said:


> Seems strange to move the head stock, I can move the tail stock on my wood lathe for off centre work or for doing long tapers.



You can do that on a wood lathe between centres because the work isn’t held as rigidly as a metal bar in a three-jaw chuck, on a metal lathe it wants to hold the bar in line with the headstock with very little play possible.


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## Jelly

wallace said:


> Seems strange to move the head stock, I can move the tail stock on my wood lathe for off centre work or for doing long tapers.



This is also generally the arrangement used on larger metal lathes where the headstock and bed are part of a single casting, or the mass of the headstock is simply too large for moving it to be a sensible design.

But because of the issue highlighted by Trevanion, this does mean that workpieces then have to be turned between centers, potentially resulting in an awkward order of operations, or neccesitating the use of a dedicated arbour of some sort if the piece can't be turned from a long piece of bar stock.

For this reason, many larger lathes have the facility to fit a taper attachment, which will cut shallow tapers by controlling the movement of the cross slide with an external slide which you can set using a sine bar.


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## wallace

I wasn't expecting for this little lump to take so long. I thought I'd do some bits in black oxide, luckily the old bottle of solution is still working.












I have so little space I'm spraying on top of a machine that has been waiting to be collected for a few months.











I found this nice little motor in my stash.
















I want to use a vfd for speed control so got my motor guy to dig out the star point and make it 2OOv


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## MusicMan

For taper turning you do turn between centres but displace the tailstock. You should find out what the calibration means on your tailstock. You can do a taper with the top slide set at the desired angle, but only a short one, the length of the slide. With an offset tailstock you can do one the whole length of the bed.

As AES says, getting it back exactly right is not trivial. The way you check it of course is to turn a long bar and see if it is tapered, adjust till it isn't. You need to do this on most lathes anyway.


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## Phil Pascoe

You wouldn't need to turn the whole length, you'd need only to turn a groove or a rebate at both ends and check they were concentric with the bar, surely? (I'm no metalworker.)


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## AES

Actually you're quite correct Phil.

I'm definitely not a real good machinist (I just learnt the basics during my apprenticeship and didn't do any more at all until I bought a lathe only about 10 years ago), but personally I find that it's actually much easier to turn a long taper for such purposes. 

That's because on my little Chinese Mini Lathe anyway (can't talk about other big machines), you end up making such really minute adjustments on the tail stock position that although wasteful (of material) and of time too, in the long run it's actually quicker/easier to turn the single long taper (which you're actually trying to rid of, of course).

But it may well be easier/quicker to turn just a groove at each end on a bigger machine, I dunno.


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## MusicMan

Phil Pascoe said:


> You wouldn't need to turn the whole length, you'd need only to turn a groove or a rebate at both ends and check they were concentric with the bar, surely? (I'm no metalworker.)


No, you have to have the turning tool at the same feed position at each and check that the diameters turned are the same. And you can't keep the tool at the same feed unless you turn all the way along the bar. (though you could turn down the middle part of the bar, then you could do the test just at the ends, and do it again easily after you adjust the tailstock).

All your test does is to check that your bar is concentric with your centre V.


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## MusicMan

Ooops I hadn't noticed that the adjustment was on the headstock, for tapers as said it is usually on the tailstock. Is there one on the tailstock too?

What does the headstock adjustment actually do? Does it translate the whole headstock assembly over, or is the back pinned and the adjustment rotates the headstock? If so it would be for ensuring that the lathe spindle is well aligned to the axis of the bed. I think it must be something to do with alignment.


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## AES

On my little lathe MM, the tailstock adjustment (in effect a single bolt) can move the tailstock in an angular fashion (around a single point - IF you're un/lucky!) or laterally (side to side). To say that adjusting it is extremely finicky is a major understatement! One of the shortcomings of the breed.


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## MusicMan

AES, It's quite easy on my robust Boley lathes. The motion is side to side rather than angular, but I don't think this part is a big deal.

What I do when I have a lathe properly set up is to put centres in headstock and tailstock and adjust till these are accurately touching. Before this, one has to align the main spindle to be parallel with the main bed slideway, or at least check that it is so. A lathe alignment bar is best for this.

My first metal lathe at home (I'd used plenty at work, and had got spoilt with a beautiful Schaublin) was a mini lathe and it frustrated the hell out of me, so I went to reconstructing prewar Boleys!


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## Wildman

just one word of caution for you, the traverse wheel is different in direction to most lathes thus if you turn it clockwise instead of moving the apron away from the chuck it does in fact wind the tool into the chuck. Most people at some time introduced a intermediate gear to reverse the direction to the norm


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