Saturday, 23 July 2011

Homemade mini lathe ... ...

In my wood turning pursuits I've discovered that having a smaller lathe might be handy for, well smaller work, I plan to make my daughter a dolls house and no doubt I shall want some tiny spindles, which might be a little difficult on my lathe.

I've tried to turn very small things on it before, but it's a bit large and in all honesty it's designed for turning rather large bits of wood, so I set about looking for a cheap mini lathe, they are quite expensive for what they are, so then I thought about making one, and after looking at a few homemade mini lathes I realised I had just about everything I needed to make a small lathe.

Here's the power plant for the lathe -

I knew I'd find a use for this :-)
It's what's left of an old bench grinder, I modified it a few years ago to run a sharpening stone for a while, then I got a drill to power it and built a proper system for sharpening things, so the old bench grinder was left on a shelf, until now that is.

As it's an old bench grinder it has 2 speeds, off and on :-) it spins some where around 2000 rpm to 3000 rpm (give or take) it handles the load when turning a piece of wood quite well, and doesn't get too hot, I may at a later date make some kind of speed control for it.

I spent some time considering how to go about making a usable head stock, and tail stock, in the end I decided to use old chucks from a broken cordless drills as the head and tail stocks.

A bit battered from removing it, but it still works.


The end of the drive shaft was ground down using a file while it was spinning to keep it centred, then I threaded it with a tap and die set and basically screwed the chuck onto the shaft, in much the same way as it was fixed to the drill, this makes for a very easy system for changing the way you mount wood to the lathe, you can use a threaded screw or you could trim down one end of the wood and fix it straight into the chuck.

I've basically tried to make a smaller version of my lathe, which can turn wood up to a metre in length and about 50cm in width, the mini lathe can go to about 30cm in length and about 10cm in width, I've already used it to turn a couple of things :-) it worked better than I expected.

The tail stock is built to slide back and forth, which makes it easy to accommodate different lengths of wood, it's kind of how my larger lathe works.

The tail stock -

It's a bit hacky, but it works :-)

You can see the idea, the tail stock slides back and forth along the 2 bars, and is clamped down with a bolt and a wing nut for easy adjustment, it doesn't look very pretty, but it doesn't matter as long as it works.

I've used another old chuck for the tail stock, I did this because it means I can use various things as centres, in the picture I've poached the revolving centre of my big lathe. The 2 bars that the tail stock slides on are as centred as possible, I used a pendulum to find the right line from the head stock.

The tail stock chuck -

Looks a little odd, but does the job.

I've fixed this chuck the same way as the head stock chuck, just threaded it onto the threaded bar, and used bolts to keep it from moving. The chuck is fixed to an L shaped bracket, which I thought would be okay, but it turns out it had a little too much flex in it, so I added the white coloured brackets to give it a little more strength.

As I mentioned I poached the revolving centre from my big lathe for this, but I made an adapter so that I can easily remove the centre and fix it back onto the big lathe should I need to.

The revolving centre - 

A little large for this lathe, but it'll do.

I did originally make a dead centre for the lathe, but I found this to be a little problematic because it moved too much in the end of the wood, this might be down to a few things, but I figured using this centre was better anyway, turns out it is much better, although if it's not tight enough into the wood it makes a horrendous squeaking noise :-/ This centre is designed to just push on and off a peg, so I made the adapter the same way, out of an old 8mm socket, mainly because is was just about the right size to start with, the socket is meant for using in a cordless drill, so it's ideal for this and when I need to use the centre elsewhere I just need to tap it off with a small hammer.

The clamp for the tail stock is just a bolt and a wing nut, I used this as a way to make things easy to move about, my big lathe uses a similar method, all be it a much larger nut and bolt.

The clamp -

Simples :-)

You can see the ends of the white brackets I used for extra strength, I will at some point weld these to the other bracket, although at the moment there is a certain amount of spring in the brackets which means that when the clamp is tight it works a little like a spring washer and keeps it from undoing :-) so I might just leave it.

Here's a picture of the tail stock as it was originally -

Probably a little weak for this, hence extra brackets.
Here's the original centre as well -

Just a bit of threaded bar with a point ground in.

And here it is, drum roll please ;-) the Acme mini lathe -

Not pretty, but it works, bit like me ;-)

There are some things I want to add to it, for a start a tool rest, at the moment I'm using a block of wood, I'd rather have some kind of adjustable rest, but it'll do for now. I also need to work out an effective way to clamp it down to a work bench or even to the bed of my big lathe, but that's all for the future, at the moment things are screwed down and bolted but I will probably weld it where I can for extra strength, I want it to last as I have plans to use it quite a lot, for small work, like the light pulls I made to test it out.

The light pull -

Not a great picture.
Another light pull, made of Pear wood.

 My wife remarked that she didn't like the small plastic ends of the light cords in the bathroom so I made these to test out the lathe, one is made from part of an old towel rail and the other from a small piece of Pear wood, nothing special but it would have been a little hard to turn it on the big lathe, the light pulls are about 8cm long and about 1.5cm to 2.5cm thick, I could have turned them on the big lathe, but the tool rest would need some modification so as I could get it into the right place for turning small pieces, which to be honest I couldn't be bothered to do, and besides making this mini lathe was more fun ;-)

I've now added a rough tool rest to the mini lathe, and discovered the tail stock has a little too much play in it, so more tweaking is needed, I recorded a short video of the lathe working, it's quieter than I thought, I'm also using one of my haomemade Oland tools as well, can't be bad.



Thanks for reading.

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