Drummond pre-B type lathe (1/4 scale)

Hi,

My new project is a 1/4 scale model of my own lathe - a Drummond Pre-B Type made in about 1910.

One of the conical headstock bearings has reached the limit of its adjustment, so I had the headstock dismantled to take dimensions to make a replacement. While the headstock was demounted and in bits I took the opportunity to make fully dimensioned drawings of the parts for future reference - and one thing led to another....

The obvious place to start is the bed. On the original, this is cast and to make a cast. Casting is not a process that I have access to, so I am going to mill/file the part from solid and fabricate some of the minor detail. Progress so far:

As you can see, I've a long way to go with this component...

Ian.

Having frightened myself with the thought of trying to machine the bed, I decided to start with something a little easier.

I spent yesterday evening flycutting some small slabs of stock to the desired thickness and then cut the 'blanks' that will become the compound slide, the cross slide and the saddle and filing them to shape.

Compound parts:

I machined the dovetails in the saddle, drilled and tapped the gib adjustment holes and filed the saddle to shape:

Judging from the effort that you seem to be putting into this project I am assuming that you will be motorising this miniature Drummond. In which case you will have a very nice watchmakers lathe.

Phil

Great project, Ian

Please keep the progress reports coming.

MichaelG.

Brilliant project! Keep us posted.

Rather than an electric motor, would you not perhaps use a foot motor, although small open crank horizontal gas engines were a thing used by some.

Ian S C

Ten he could set up a complete 1/4" scale sweat-shop complete and recruit a gang of toddlers to power it

neil

Phil,

As you (and Ian) have noticed, the intention is to make a working machine. I started on the assumption that it would be a nice, simple, straightforward project - it is a simple lathe with a total of about 12 moving parts, it must be a 'piece of cake' compared to a Gresley A4.

But when you start looking at the detail of the task it sort of grows

All the best,

Ian

Hi,

Today's progress - a bit of machining and drill/tapping to make the cross slide fit the saddle, and a little work with a needle file to shape the gib strip.

The parts (only one of the locating dimples has been drilled on the gib strip so far):

The cross slide fitted to the saddle:

Viewed from underneath:

The next challenge is to make a small Tee-slot cutter to produce the cross-slide Tee slots.

Ian

Even with an electric motor, it should be run from a line shaft with a fast and loose pulley, same as we had at school running the old Herbert lathes (1920s vintage).

Ian S C

A bit more progress:

The feedscrew for the cross slide machined out:

I also cut out the cross slide front plate. After threading the feedscrew, the cross slide and saddle could be fully fitted with the front plate and feedscrew. A small handle was quickly filed up to allow the operation to be tested:

View underneath:

I also roughed out the headstock - milled/hacksawed from a block:

That's looking great, Ian

MichaelG.

Indeed a great project.

That's neat. Keep on posting. Loving it.

How is it going with this very interesting project?

I have often entertained the idea of building a small machine, mill/lathe/shaper. If I would build one it would probably be a shaper and then I would make it large enough to be useful in cutting keyslots and such.

This is indeed an interesting project and I also would be interested to know how it is progressing, particularly as I have two Drummond pre-Bs, one on an original treadle stand. When I needed to replace a small cast-iron component I carved a pattern in lime-wood and found a small local foundry (in Derbyshire). For a small charge they made me two castings which I was then able to finish off at home. Would this approach work with your quarter-scale lathe bed?

Could Ian's real interest be in making large scale pens????????😈😈😈😈😈😈😈😈