Author Topic: Reviving a Britan Lathe.  (Read 4774 times)

Offline dvbydt

  • Jr. Member
  • **
  • Posts: 61
  • Country: gb
Reviving a Britan Lathe.
« on: March 08, 2015, 04:46:02 PM »
 I had been looking for the later version of this lathe for  a while. Originally they were first made during WW2 and most that survive are the blue painted 3/4" versions. Nearly all of them have lead a hard life, producing maybe 3-400 turned parts a day for years. The one I purchased is from the early 1970's and is the squared off version painted light green.

Electrically all Britans had a three phase  two speed reversing motor and stepped pulleys  to give a reasonable speed range. Later ones incorporated a long lever at the front left which was a high/low mechanical speed  clutch.

The motor on this one had been replaced by a standard single speed three phase  one and the speed switch with a  rotary fwd/off/rev switch. A geared auxiliary motor drives the compressor for the bar feed, the hydraulic pump for power feed and the coolant pump.

The lathe itself was in rather a mess but showed little sign of any hard wear and had been stood idle for a while.

Some of the things I learned may be of use in general repair and renovation. Attached are a couple of pictures.

Ian

Offline RobWilson

  • Hero Member
  • *****
  • Posts: 1007
  • Country: england
  • Jack of all,master of nowt!
Re: Reviving a Britan Lathe.
« Reply #1 on: March 09, 2015, 02:09:04 PM »
Hi Ian

Interesting lathe , you going into mass production ?


Rob

Offline dvbydt

  • Jr. Member
  • **
  • Posts: 61
  • Country: gb
Re: Reviving a Britan Lathe.
« Reply #2 on: March 09, 2015, 04:28:58 PM »
Rob, thanks for taking an interest. No, not mass production, though that is what it is meant for. It is so quick and easy to set up that making above ten off is far quicker than on the lathe. I do occasionally need to such work for my customers. Additionally it can, if you wish, complete up to about 15 turning drilling, chamfering, tapping, threading and parting off operations on one setting.

Next post will be mastering a VFD for the main motor.

Ian

Offline Anzaniste

  • Full Member
  • ***
  • Posts: 207
  • Country: gb
Re: Reviving a Britan Lathe.
« Reply #3 on: March 09, 2015, 08:02:23 PM »
I've fanced one of these ever since I saw one in a machine tool dealers 20 odd years ago. Sadly at the time I had no place for it. Still haven't really but they're supe little bits Of kit..
Enjoy :clap:
Scrooby, 1 mile south of Gods own County.

Offline Pete W.

  • Hero Member
  • *****
  • Posts: 752
  • Country: gb
Re: Reviving a Britan Lathe.
« Reply #4 on: March 10, 2015, 06:17:24 PM »
Hi there, Ian,

Please forgive me if you are already aware of this but have a look at http://www.model-engineer.co.uk/forums/postings.asp?th=71997
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Offline dvbydt

  • Jr. Member
  • **
  • Posts: 61
  • Country: gb
Re: Reviving a Britan Lathe.
« Reply #5 on: March 12, 2015, 05:29:30 AM »
Posted here last night but it is not showing? Forgive the duplication if you get two for the price of one.

Anzaniste, it is a very interesting design, I will post a picture of the attachments in the next post.
Pete, yes thanks  I have seen that. Considering how many subcontractors had at least one of these, there is not much information on the net.

I wanted to return the controls to original as much as possible, so I made up a coaxial Fwd/Rev speed change switch. Details attached.
The motor was  standard 3 phase and delta connected1.1kW, 1420 rpm. The VFD a Teco E2 40 3NF rigged for 240 volts input.
The easiest to understand programming details were at :-  http://www.teco.com.au

Sorry, I am not very good with explanations but for those of you who are familiar with setting up VFDs, this is what I did.

Programming F19 = 2 and F20 = 6 allowed me to set F08@20Hz, F26@35Hz and F27@50Hz. This gave me three fixed speeds, so with the mechanical High/Low clutch, there is a choice of
six speeds.

Ian

Offline dvbydt

  • Jr. Member
  • **
  • Posts: 61
  • Country: gb
Re: Reviving a Britan Lathe.
« Reply #6 on: March 23, 2015, 06:41:21 PM »

So another couple of photos.
The black control is for fwd/stop/reverse and the top red is for the VFD speed change selector. The lower long lever is the mechanical clutch high/low lever. Speed range is from 60 - 2000 rpm without changing any belts. Being programmable, the speed range can be altered if a special need arises for a production run.

Tooling photo shows the tailstock turret with tap and dieholders. Main tailstock holders can have larger drills, taps and dies, drill chuck, ER collet chuck or live centre.

More to come when I get it cleaned down after getting brass swarf everywhere!

Ian


Offline dvbydt

  • Jr. Member
  • **
  • Posts: 61
  • Country: gb
Re: Reviving a Britan Lathe.
« Reply #7 on: April 20, 2015, 11:37:49 AM »
On Youtube with sound! The VFD controls the maximum amps on ramp up and down, so the motor will happily go from fast forward to fast reverse. Very
happy with how it all worked out.

     <a href="http://www.youtube.com/watch?v=LqES5CC6nKk" target="_blank">http://www.youtube.com/watch?v=LqES5CC6nKk</a>




Ian
« Last Edit: July 21, 2015, 04:07:31 PM by dsquire »

Offline RobWilson

  • Hero Member
  • *****
  • Posts: 1007
  • Country: england
  • Jack of all,master of nowt!
Re: Reviving a Britan Lathe.
« Reply #8 on: April 20, 2015, 12:45:15 PM »
Sounds fit and well Ian  :thumbup:

Rob

Offline dvbydt

  • Jr. Member
  • **
  • Posts: 61
  • Country: gb
Re: Reviving a Britan Lathe.
« Reply #9 on: July 21, 2015, 03:46:02 PM »
The original had a cast aluminium coolant and swarf guard which was missing on this machine, so I decided to make one from 3 mm sheet aluminium. I solved the corner problems using a 19 mm x 3 mm wall tube and cutting them on the lathe with a parting tool mounted on it's side. The sheet was cut to size and I used BrazeTech solder to join them all together. Quite solid. There was a splashguard cover with a plastic window originally but it got covered in coolant - it was not very good, so I did not try to put in a window. I undercoated them with Hammerite Special Metals Primer then Hammered Dark Green.

Ian