Lang Junior Lathe

I have taken possession of a new 'old' lathe, a very hefty Lang Junior 6.5" from the 1950s, and have a query as to gearbox change wheels. The lathe has twin systems, a fixed set of wheels from headstock down into the gearbox, which I have not revealed yet, behind covers visible in this picture, and I do not know quite what they connect to in the screw cutting gearbox.

Then, there is further provision for externally mounted change wheels, to the exterior of the screw cutting gearbox, a banjo and three mounts for wheels.

I have no change wheels with the lathe, and from dry, dusty state of the architecture here, I am uncertain this lathe ever had them. Neither does it have a thread dial indicator.

Only guidance from a Lang Junior Owner's Manual states that change wheels were used for Whitworth and Metric threads, and that when the lathe was not being used for screw cutting that these were to remain unengaged.

This has suggested to me that the inner wheel train connects down not to the lead screw but to the power shaft, but it is by no means certain until I do a bit more dismantling.

Have any members any knowledge of this lathe, or such a system, which seems to me a bit of an oddity.

It is not easy to understand this, without further steps.

The gearbox information plate has no screw cutting guidance, only cutting speeds, surfacing and sliding.

It has six speeds, set by twin levers, and runs in a full oil bath.

Any help will be much appreciated.

Many thanks.

Chris Mills.

Edited By CHRISTOPHER MILLS 1 on 10/02/2016 10:51:52

Greetings Chris!

This is getting really serious, you will need at least a couple of rooms at the BM soon! Not too fearful having the gears missing, you have the "banjo", that is the really hard to get hold of part. I hope Ell approves! As usual you have impeccable taste, you have picked yet another fine maker. Will PM you soon.

Phil

There are some good pics on http://lathes.co.uk/lang-junior/ which I am sure you have already seen, and it does look like there are two ways of driving the screw cutting/feed box. Never seen anything like it, but it is only metal, you will soon sort it out. Woody might know!

Phil.

Presumably you have already taken the obvious course of rotating the chuck to see the ratio between it and the two exposed shafts for each setting of the relevant levers, and to the leadscrew. So all you are really asking is whether anyone has this lathe and has already worked out a screwcutting chart.

As it seems a rare machine that is unlikely. However when you provide the relevant ratios of leadscrew to lower shaft and spindle to upper shaft we will probably be able to work out the gears you need to make common threads.

Also as you are one of the lucky owners perhaps you can provide Tony at lathes.co.uk with a decent picture of the feeds chart.

Hello Phil,

Your faith in me is touching! And yes, it is a serious case of a specialisation madness that is beginning to overwhelm him!

But Chris needs to do a little research and perhaps some measuring as Bazyle suggests to see what turns and when. My immediate thought is that there is a shaft out of the gearbox, bottom, and another back in, top, the intermediate stud on the banjo would carry a gear to connect them. But then surely that would just act as an idler and take no part in the maths of whatever ratio the other two gears are in.

Seymour Engineering who have taken over the interests of Lang might be able to tell Chris what this arrangement is about, the handbook that Tony Griffiths was able to provide made no mention of it at all and left him no further forward. It is indeed a puzzlement at this stage

Brian

Here is a better picture of my Lang Junior. Despite tired cosmetics, the lathe is in excellent shape, and shows no sign of real industrial use.

This was, after all, John Lang & Sons' hobbyist offering, weighing in at only 1.4 tons. It is the smallest lathe Lang made.

Everything on it is seriously chunky - the drip tray weighs over 200lbs, and, covered in oil, it took three men to manhandle it. The tailstock weighs about 100lbs.

It has an extra foot of bed on standard, @ 7 ft, and came with three chuck/faceplates, and a whole estate carload of cutting and drilling goodies, and tailstock chucks, centres, etc.

Bazyle, many thanks, and I will try your diagnostics when I am next with the lathe in a few weeks.

Phil & Brian - I think we are inching forward on the gearbox status quo.

Hi Woody, you didn't pop into town to buy this then?

http://www.ebay.co.uk/itm/Holbrook-Lathe-Fabrication-Metalworks-/272127259970?hash=item3f5c0c7542:g:iVIAAOSwzgRWt5y0

Nice machine, maybe a bit heavy, but not far to have to move it!

Phil

Come on Phil, take a look at the condition, I hope you are joking!

The headstock cover has been off for donkeys years and I can just imagine the state of it inside. We have had to sell the team of huskies as well in view of the non-snow this year so we have nothing suitable to haul it home with.

So I decided to pass on this, even Chris looked sideways.

Brian

Well it is a good job you looked closely, because I didn't actually notice that! Nightmare! Yes I was joking, and it seems VERY toppy to start the bidding @£800, Also it begs the question WHY are the covers off? I have no urge to buy any more lathes at the moment. There are people however, who just can't get enough of them!

Phil

Surely the input shaft is at the top, then there is an idler (on the banjo) with the output shaft at the bottom. With this sort of arrangement there is normally a lever on the gear box to disengage the lead screw when only the auto surfacing/facing is required.

Frank

Frank, Many thanks. There is no obvious lever to set between lead screw and feeds power shaft. The only control lever addressing these is a right/left reverse feeds/threads lever on the headstock, beneath the main spindle speed levers. This has left and right, and, I am guessing, a neutral in between, whereby the gearbox is disconnected from the headstock. Here is a picture showing it set to 'right'.

Apart from this, there is nothing on the gearbox itself, aside of two main positional levers which set the six speeds. Only Lang guidance in the Owner's Manual says that when not using the lathe for threading, that the change wheels on the external part of the gear box must be left disengaged. This suggests to me that the lead screw is normally unengaged, and that it only comes into operation when it has change wheels attached. That might suggest the spindle is primarily connected not to lead screw but power feed shaft.

Here is another shot, which shows all control levers together - two main spindle speed levers on headstock, little feeds/threads lever between them, two main speed selectors on gearbox, and main clutch control lever. With prime information on the gearbox information plaque being only feed and cut speeds, my initial conclusion is that the lead screw does not work at all without external change wheels mounted, and that power from the spindle goes primarily through the power feeds shaft. I will know more next time I see the lathe in a couple of weeks from now, when I will take off a few covers, and see better what troubles us.

Christopher, i have a Laing lathe and if you want to contact me i'll help out with change wheel information etc.

Regards

Mike Young

Mike,

Many thanks, I have sent you a personal message. I look forward to hearing from you, about Lang change wheels.

Chris.

This is my first time on a,forum so be gentle please, I have a lang junior 6.5 inch the same or very similar to the lathes in this thread,I am trying to restore it there is I hope a manual for this machine some where .I,ve looked on Tony,s site but can,t find a manual, does anyone here have a manual that will help with the restoration?

Cheers Paul

Hello Paul,

Try looking at the pages for a Lang Junior on Tony's website for at least a description of the lathe. He does sell handbooks too so again look for one for the Junior. Not cheap mind

Regards

Brian

Thanks Brian, I have looked at Tony's listing

But the info on the lang junior seems to be for a later model lathe

A j6 I think ,when I googled this lathe it seems quite modern in comparison to my model. I have emailed Tony a few times but got no response,someone on this thread mentioned a manual so I thought it was worth a shot

The original poster Chris says he has a manual. He hasn't posted since Sept 2019 so hope he is ok and a PM might reach him, or the moderators might have a way of contacting him. It seems he moved on to a Karger lathe only a few months after getting the Lang.