Member postings for Richard Parsons

Stub The whole lathe is a ‘Bittser’. The head and tail stocks are ‘from a ‘Britannia –The pre war (Kaiser Bills one) UK trade name for Lorch. The pulley with its dividing head is from a Swiss Boley as is one of the beds (I have 3) one the Normal (a Lorch), one Extra long (by Boley ) and the third one, a very short bed was made by me and finished ground by a well known defence company. The rest of the bits; collets, Jakot (Jacot) tools, centres (mostly damaged) wax chucks etc were in the box. Lots of them were made during the unpleasantness with 'Ole Shickelgruber'. It cost me £125 cash. Since then I have made drill chucks, fling rest, and other bits and bobs.

Ah Stub - mine has the word ‘Jakot’ stamped on it in a tombstone type. It also has an eagle and a swastika on it. I think it was ‘liberated’

Rdgs

Dick

Niko what lathe have you got? I would use my 6mm Lorch, very sharp tools highly polished, as I approached the 0.45mm I would start No2 cut Pillar files and a No6 cut dead smooth pillar/pivot file. I would finish using a well made burnisher.

Given a choice I would use annealed Pivot steel (Try Walsh & Co). If not silver steel and plenty of Dortan 25 neat cutting oil, but burnish dry or with traditional lubricant - spit.

I would make the gear wheels fit the arbours and not the other way round.

regds

Dick

Ps

Niko there is another way which is to use a Jakot tool.  You will probably need one to make the pivots at theends of the arbour.  

Edited By Richard Parsons on 28/02/2012 13:52:30

Ian Hi You have a 'Continental' 3 phase unit. It is marked 380 Volts 3 Phase. On the Continong they calculate thr RMS voltage slightly different to us. We will say 440 Volts 3 phase they will say 380 volts 3 phase. I know it is confusing but It is the same blooming stuff.

Your single phase is 240 Volt over here is 230 Volts.

Best regards

Dick

These keys are normally tapped in from the threaded end. They often use a special jig/die to keep the key ‘fair’ in the slot. That is why the key is rounded the led in end and is usually a little oversized.

To get it out all the way suggested are valid except I would a narrow ‘Keyway’ cold chisel rather than a punch and would start my attempts with a pair of ‘Side Cutters’.

One gets a lot of these little devils in small chain saw engines.

Rdgs

Dick

PS do not use _Paul_'s die trick.  Dies do not cut being when being un-scerewed! 

Edited By Richard Parsons on 26/02/2012 10:37:58

Edited By Richard Parsons on 26/02/2012 10:39:15

You cannot make the assumption that it is for Whitworth thread forms. There are a set of 60° threads which are also inch standard. These are the ‘Unified’ threads (UNC/NC, UNF/NF/SAE). These are American.

Rdgs

Dick

I acquired a decent stock of such files many years ago. I do not know what speed the thing should run at. Anyone help?

Rdgs

Dick

Edited By Richard Parsons on 24/02/2012 16:31:18

Peter The origins of M.E. threads are a bit of a mystery. There are TWO variants available today these are the 40 TPI and the 32 TPI. Both are in the Whitworth thread form.

They were designed for simplicity of manufacture and for use in thin materials. Most model engineer’s lathes of the pre-war period had 8TPI lead screws. With a 40 or a 32 TPI threads you can ‘drop in’ anywhere. There may have been a coarser thread of 24 TPI but it may have been lost. For ME size bolts from ¼” up I use BSF (as I have the taps and dies). Foe smaller than ¼” (6mm downwards I tend to use the now illegal BAs.

The third set of threads, called ME are the 26 TPI threads. These are the ‘Brass’ or ‘Birmingham Brass’ threads. These are used on most boiler fittings. The 26TPI ‘Birmingham Brass’, which are again in the Whitworth thread form, should not be confused with the old 26TPI Standard Bicycle threads which have a different thread form. I will not go into them here, except to say that taps and dies of this series are marked with a letter ‘C’.

Finally The BA series threads which were introduced at the turn of the last centenary. Here the sizes run from the largest ‘0’ BA down to ‘24’ BA. They are said by the authorities to be inch standard and therefore forbidden in The EU. BA threads are not inch standard. The starting size ‘0’Ba is 6mm with a 1mm pitch with a 47.5° angle. The smaller sizes have a pitch which is 90% of the size larger so, 1BA has a pitch of 0.9mm, 2BA 0.89mm and so on down to 25 BA which has bar diameter of 0.25mm. If you want more look here.

Do not let your local authority know you have BA sizes they will do their nuts according to them (even now) all Non metric threads are illegal!! You try to tell them that and unless you have several £1000 to throw away they will throw the book at you.

Edited By Richard Parsons on 08/02/2012 07:23:18

Hope it helps

Dick