Member postings for Ajohnw

If you have the right sort of screw cutting indicator many metric threads can be cut using the it directly in much the same way as imperial threads. I assumed that your Vicroy would have one and that it's likely to be similar to a Boxford one. That works this way

Lathe parts can make this type of indicator or people could have a go at making one themselves. An M3 acme tap could be used to finish of the gears providing they aren't too thick for the size of tap used. It's best to cut slots at more or less the correct pitch first by hand. If the equipment is available it's simpler to just cut a gashed gear - straight teeth at an angle to suit the angle of the thread.

Must admit I have stuck to imperial because of the pain metric threads cause in this respect. The catch with indicators like this is the time it can take for the correct index marks to come round on some pitches.

The screw cutting nut can always be disengaged if the method I outlined is used. It helps when working up to a shoulder.

John

-

When these old lathes have a plain steel spindle running in a simple cast iron "bearing" tightened via a nut on one side in my view they generally don't retain sufficient accuracy to be called a lathe any more. There is usually too much play in the headstock bearing and often at some point when the bolt is used to tighten them up the castings crack. Ok for some one who just wants to produce vaguely round things. I did come across one where the owner always used something like a travelling steady and capstan lathe type tools. The headstock and other bits and pieces hardly matter than. People pay what are really silly prices for some lathes like this on ebay.

If the lathe has bearings, usually phos bronze much depends on how well they have been looked after and if there are problems if the new owner is prepared to make new ones. If that is needed they might well find that the bed needs lapping as well to get it back to a reasonable fit. Same with the slides.

However bad the lathe is heavy cuts will often give decent even good finishes on either type due to the wonderful cast iron they are usually made of. As a for instance one lathe I had briefly was fine with cuts of the order of 1 to 1 1/2 mm providing the feed was even. Run the tool back along the work though and more metal would be taken off - pretty badly.

My answer is not much. Personally if I tried it and the results were not reasonable it would be off to the scrap merchant or if not too bad I would point out that the new owner will probably have to use a file to finish work off.

John

-

There are some simple things that are better made than bought such as centre punches and drifts for knocking dowels out of things. Many items like that are made of air hardening steels these days and don't really measure up to the old way - hardened and tempered steels. Silver steel is suitable and easy to get. For slotted screws a hollow ground blade increases the grip by an extra ordinary amount. The rad of a 6in or 8in grinding wheel is about right for the hollow grinding.

A lathe type centre finder is can be useful for face plate work also 4 jaw at times. Pictures can be found on the web but they benefit from having stiff spring loading built in as well. Around 12in long over all is a decent length for one with say a 4in section with the female centre hole to hold the spring.

If you envisage fitting your own chucks a very precise dummy spindle nose is very useful. If the Viceroy is the same as the Boxford you need to cut the flanks of the thread correctly to size but omit the rounded end - normal way of screw cutting on a lathe. This means that the OD is undersized which help get the register correct in cases where the lathe doesn't have a different diameter register. A very short section of the register can be turned under size - say by 0.010in to help use it as a plug gauge when making back plates. The threads in the back plate are best cut entirely with a chaser. They crop up on Ebay regularly. Not sure how you will get on doing this on a metric lathe as the spindle might still be imperial. In that case you will probably have to reverse the lathe at the end of each cut. Best way to do that is often described on the web when metric threads are cut on an imperial lathe. It uses a screw cutting indicator in a particular way. Disengage, turn off, reverse and re engage when the indicator is where it was when disengaged.

You might find that College engineering produce a casting suitable for a Boxford/Viceroy face plate. They did do an excellent rotary table kit but unfortunately it was slimmed down to suit the gap in a Myford bed. Still better than most but not sure if they do it any more.

If I want a keyway in a bore I use a slotting attachment. They do the casting for these as well but as it's for a Myford tt needs packing up to the centre height.

Lots an lots of things can be made but some of the more ambitious ones such as a dividing head do need a T slotted cross slide. This chap can help with that if the machine lacks one

http://www.latheparts.co.uk/

He's always busy and can be hard to get hold of.

John

-

With GREAT care using a knife edge needle file WITH hopefully a plastic handle rather than a sharp end - hold said tube in some form of electric drill at a moderately slow speed.

You could jig this up to form a lathe of sorts - drill a hole in some piece of wood to suite the tube OD, saw in half. Lay tube in the wood as a support and drive it with the drill and file away. This should give you nice clean cuts. A knife probably will too,

John

-