Drummond pre B type

[blackcat smithParticipant @blackcatsmith57530]

changewheels

[blackcat smithParticipant @blackcatsmith57530]

I have the offer to buy various changewheels for this lathe-1910 model-but am not sure which to buy and have not come across anything online to tell me which were supplied originally..
I am interested in screwcutting as much imperial as possible but especially ME..Whitworth..BSF..BA perhaps..You may have guessed by now I have no idea how to work out the ratios myself as I am one for who figures fall off the page! Anyone else interested I can let you know where they are.Unfortunately I think they will all get melted soon if not bought..Thank you
Jonathon

[Keith LongParticipant @keithlong89920]

Hi Jonathon

The official set of gears for this lathe were 20 teeth, 2off; 30 teeth, 2 off then one each of 35, 38, 40, 45, 50, 55, 60 and 65 teeth. An extra 63 teeth wheel was needed for cutting metric threads.

You'll find a stack of information about this and the other Drummomd lathes on the Drummond pages on the http://www.lathes.co.uk website, well worth looking up.

It would also be worth your while joining the Drummond lathes Yahoo group as there are a number of folk there who use the Drummond lathes as they are menat to be – not just as collectors pieces and have a lot of knowledge about the machines.

Keith

Edited By Keith Long on 14/04/2015 00:11:48

[blackcat smithParticipant @blackcatsmith57530]

Thank you Keith..It looks like I ve bought a whole set plus some that came with the lathe.I have seen the yahoo group but you have to have your email address on view so I shant be joining that! I ll ask the seller how to put their name onhere as a contact if anyone else is interested.Jonathon

[john carruthersParticipant @johncarruthers46255]

If you download NThreadP.exe you can enter your lead pitch and gears then it will work out a train for you…

http://www.denfordata.com/bb/viewtopic.php?p=2997

[blackcat smithParticipant @blackcatsmith57530]

That s just what I need John..Thank you..
The ebay seller is bdshorty if its of use..Always had good stuff from this one..

[Graham LoakesParticipant @grahamloakes84505]

Hello to all Drummond users.

I bought off ebay a few months ago a restored Type A, all ready to use (with a few adjustments) and it has been great. Freshly retired,now, I used to have access to a perfect Myford super 7. The Type A is quite remarkable even compared to the super 7.

Just one niggle on the Type A and that is the original 3 jaw chuck only has the 'outside' type jaws, not the usual type.

I expect to find a set to be difficult….

What other (Myford?) chucks fit the Type A please, or is it a case of making a backplate and adapting something of a suitable size?

Of course, if anyone has a spare set of normal jaws I would love to hear from you!

Graham.

[BazyleParticipant @bazyle]

Blackcat you can always make a special gmail or yahoo account to use on the yahoo group, or most likely your existing internet service will allow you to make some spare accounts.

The early Myfords used 23 & 73 gears to obtain metric threads if you happen to have them in your set. On the yahoo group there are photos of the brass plate giving the screwcutting combinations, including metric. However there is an error in one setting for 0.6mm ptch I think. Hundreds of these little plates made but I've not seen mention of this error as probably nobody has ever tried cutting it.

[blackcat smithParticipant @blackcatsmith57530]

Bazyle, thank you..On all counts..

[BazyleParticipant @bazyle]

Graham, must be more than 75% of all outside jaws have gone missing. I suggest just getting a 4 jaw which you will need anyway and using it for the larger items you wanted the 3 jaw outside jaws for. I'm not sure what other lathes use the same thread. Somewhere there is a ist of lathes and their threads I have seen before, but can only find an american one just now. I do know the round bed is NOT the same thread.

[Keith LongParticipant @keithlong89920]

Hi Graham and welcome to both this forum and the band of Drummond owners and users. With the A type or round bed, forget any connection with Myford, they has nothing to do with it apart from possibly assembling a few machines from castings supplied to them by Drummond as part of the deal when Myford were ordered to build Drummond lathes instead of their own Myford models as part of the war effort. Unless the spindle in your lathe has been changed the nose thread should be 3/4 inch 10tpi (3/4" BSW), but depending on the age of your machine it could be different as some early machines were made using the nose thread from what became known as the "pre B Type" and the "B type" in which case it might be 1" od by I think 12 tpi. Your best bet with chucks is either to find one with a much larger thread fitting and make an adaptor bush, or go for a plain back chuck and machine up a back plate. I've used both methods and it's not too hard, you just need to take care and not rush. As mentioned above the Drummond Yahoo group is well worth joining as there are a lot of folk on there all willing to share their knowledge and advice.

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