First post, just a greeting from me and my new purchase

[PaulF]

Hi everyone, just wanted to say hello and tell you about my new purchase, its a viceroy TDS 1/1 GB (Metric). After studying the manuals and all the drawings that came with it, im a little confused to say the least.
Firstly the serial number is 12914m and the leadscrew lever is on the headstock, and not on the top of the gearbox as others i have seen, so is this a very early version????.
Secondly all the other machines i have seen seem to have 5 or 8 ranges on the dial gauge and lever, mine has 4!! so according to the transposed gearing table on the machine for cutting imperial threads, 7, 14, and 28 tpi requires both dial and lever to be set at 5. am i missing something here!!
( yes the 5th speed) well thats all for now and when i finally get the thing off the pallet and into position i will post a couple of pics and maybe some more questions!!!
Bye for now.

[Andy B]

Hi Paul, and welcome!

Some pictures would definately be useful to see what you have.
What drawings do you have? Do they have ML xxxxx numbers?
We might get a hint from these if it is some kind of 'special'.

Andy

[PaulF]

Hi, Thanks for the reply, I tooks some pics to show and it makes the old girl look a little tatty but i think its purely cosmetic, no damage to bedways apron etc so will just have to tidy her up a bit, will post more pics when in position cleaned etc.
As for the drawings i do have a lot, many duplicates so will list them incase anybody needs a copy. by the way my gearbox is on drawing
ML 115/900/M and says its the 2nd type!! anyway here goes
If there is A3 at the end it relates to the size of the drawing.
Size
ML100/100 A & B
ML100/200 A & B A3
ML100/300 A3
ML100/500 A3
ML100/600
ML100/700
ML100/800 A3
ML101 A3
ML102 A3
ML105 A3
ML105/100A/M A3
ML105/100B A3
ML105/100C A3
ML105/400B A3
ML110
ML110/300 A3
ML110/400 A3
ML110/400B A3
ML114 A3
ML115/100 A & B A3
ML115/900 A3
ML115/900 M A3 Shows my 4 speed gearbox
ML/119 A3
Un numbered but shows operating instructions for 4 speed gearbox
ML123 A A3
ML126
ML127
SK355 A3 showing Auto knock arrangement
ML128
The larger book of the two also covers the short bed and long bed wood lathe, The Sharpedge, Grinder, and polisher, all of which i have . and all part numbers and materals its made of.
Also have a full uk price list dated June 1984. Hope these may be of use to someone if i ever get a scanner!!
Now the pics, please dont be too hard on me!!!!

[Andy B]

Paul,

Looks like you've cleared out a school workshop to get that haul of Denford's!

I'd not noticed before, but if you look on Tony Griffiths' Denford page, there is a picture of a gearbox machine with the feed / screwcutting selection lever on the headstock, like yours is. So clearly not a 'special', it must simply be an early model.

Regarding your 4 dial positions, I can only guess that the early metric gearboxes used "1/2" of an imperial gearbox (which have 8 positions). Compared to the 5-position metric gearboxes, you are only missing a couple of threads at the 'large' end of the standard pitches:7mm, 5.5mm, so I would not have thought that this is much of a limitation for most metric usage.

Now, it could be that the ratios in the 4-position metric box left awkward gaps when using imperial transposing gears - and another guess is that the tranposing set you have (with its special guard) was supplied later, after the introduction of the 5-position boxes.
To check out my theory, I would need to confirm what the end-drive gears are on your lathe, and especially how many teeth the stud gears have.
Your plate shows 4 stud gears - A, B C & D.
The 5-position boxes had 7 stud gears - A(16t) B(18t) C(22t) D(24t) E(26t) F(27t) and G(35t).

Have you found my threadcutting calculator, here?
I will revise it to include 4-position boxes once I have all the necessary infromation.

Andy

[PaulF]

Hi Andy.
Thanks for the prompt reply, I had another tinker out in the garage tonight, fitted the imperial quadrant with a 54 spur gear and 48 drive gear, it Needs some fettling as the retaining collars for the drive gear are home made and not very well done, but all works.
Further to your question, I have checked the drive gear on the metric set and that has 66 teeth, and i have 4 metric spur gears A, B, C, and D. But also have gears with only teeth numbers marked on them and they are as follows, 21, 27, 2x48, 52, 54, and 49. Hope this helps.
Also when cutting imperial threads should the back gear be in or out, as with the metric table this does make a difference?? and the Imperial plate does not say.
I have found your threadgear calculator and think its a brilliant thing.
Thanks again
Paul.

[Andy B]

Paul,

Can you just confirm the following;
a) Do your gears marked A-D have 16, 18, 22 & 24 teeth respectively? If not, how many?
b) Are your end-drive gears (metric setup) all the same as identifed in my calculation sheet, i.e:
'IN' position- studgear driving 64t idler driving 24t, then 66t idler driving 66t g/box input (24t joined to 66t idler)
'OUT' position - studgear driving 64t idler, 22t driving 66t idler driving 66t g/box input (22t joined to 64t idler.
Knowing this is critical to getting the calcs right!

Also when cutting imperial threads should the back gear be in or out....

Do you mean back gear? That usually refers to the gearing used to get lower spindle speeds.
When using the imperial conversion set, you will have removed the metric quadrant and sliding (IN/OUT) gears, and just have the transposing quadrant, stud gear, 127/135t gear pair and the 48t gear fitted on the gearbox input - so no IN/OUT to worry about. but you will need to print off a new imperial setting table, once we've worked out what it should say!

Andy

[PaulF]

Hi andy,
Thank you again for getting back to me, in answer to your questions here are the following answers.
A) The gears marked A to D have the following number of teeth, 16, 18, 22 & 24 teeth respectively.
B) the gearing for the metric setup is as follows, 'IN' position- studgear driving 64t idler driving 24t, then 66t idler driving 66t g/box input (24t joined to 66t idler)
'OUT' position - studgear driving 64t idler, 22t driving 66t idler driving 66t g/box input (22t joined to 64t idler.
I think this is the same as your calculator?
As far as the "Back gear is concerned, I think i was having a bad day . (think we all them from time to time)
Thanks again in advance
Regards
Paul

[Andy B]

Well, this proved to be an interesting little exercise, with a few 'red herrings' to catch me out!

I have worked out what the gearbox ratios must be in the 4-position box, and revised my calculation sheet to include them - here.

Now for the catches:
1) The number of teeth on the stud gears A-D as marked on your metric plate are not the same as the ones you have marked A-D.
From my calculations, for the 4-position box as marked on the blue plate on your lathe, the stud gears should be:
A=24t, B=21t, C=27t, D=30t
You have the first 3 anyhow, and the 30t is only needed for 5mm, 2.5mm and 1.25mm pitches. In a way it makes sense for the 'old' A to be 24t, as this is the standard stud gear for the English boxes.

2) With your transposing set, you cannot cut 6.5, 7, 13, 14, 26 & 28 tpi - which substantiates my previous theory as to why the 5-position box was introduced.
Attached is the transposing table for what you can cut.

Please do a few tests to make sure I've got all my figures right, and let me know if anything is wrong.

Andy

[PaulF]

Hi Andy
Thanks for going to these lengths for me and other Denford users!!! still getting to grips with the calcs and gears etc, as soon as i get the old girl sorted I will do a few tests and let you know!.
you and the other mods do a fantastic job for us, if your ever down my way i will buy you all a drink!!!!!!
will reply with TPI info as cut accoring to your calcs ASAP .
Just been away for a couple of days on a pressure management and hydraulics seminar!, so still have brain freeze
surprised there have been no other 4 speed owners contacting you for info, or am I the only one with a four speed gearbox?? may post another thread to find out, Thanks again
Regards
Paul

[Andy B]

As a follow-up - I haven't yet found an exact date for when the 5 speed boxes were introduced, but I have found a Modification Note (1765/70) from June 1970 that states "After the new 5 speed metric box had been produced......"

So we have a bit more of a clue.

Andy