Here is a list of all the postings Keith Long has made in our forums. Click on a thread name to jump to the thread.
|Thread: grayson lathe rebuild|
Even easier - if you have the correct drive for the Grayson gears - is to drill a hole in the Myford gears to accept the Grayson pins. From the lathes.co.uk website early Myford gears (ML1 &2 era) used pin drive rather than a key anyway.
|Thread: Uploading photos on forum album|
Bob, click on "All Topics" just under this post, then choose "Website FAQs" - first topic heading as it's a "sticky".
|Thread: Calculating Epicyclic/Planetary gear ratio|
Rainbows - why are you looking to use 4MOD gears - those are enormous for the back gearing on a lathe. Drummond back gears are 14 dp - about 1.5 MOD and those are OTT. Myford back gears from what I read on here are typically 20 dp or approx 1.25 MOD. Forget the 285 Nm theoretical max. torque. If you succeed in getting that then assuming that you're still looking at a 30mm dia spindle, then you'll probably be be looking for a new spindle because the one you're using will have snapped or something else will have done. Step back from the design and do a reality check and look to see what other lathes of a similar size use.
I've just re-read your original post, and seen that your talking about a 25mm dia spindle at 285 Nm that certainly will snap or the tread that hold the chuck will! The Drummond lathes are 1 inch spindles so the same size to all intents and purposes. When folk break back gears on the Drummonds it's because they try and use the back gears to lock the spindle while they change the chuck, certainly not through cutting forces. On a lathe with a 25mm spindle I doubt that the tool post and tool would be able to generate that torque without failing or tearing out of the top or cross slide.
Edited By Keith Long on 18/05/2016 16:39:56
Hi Rainbows - no it's not you, looks like there is a mistake in the text (what a mistake in an old copy of ME - never!!). I think the formula should read j/d : j/d - h/b
Not sure where that leaves the calcs in the spread sheet as I can't remember what I put in there - it was quite a time ago.
The fancy fonts and the rather strange section line through the main pulley do take a bit of getting used to.
Edited By Keith Long on 16/05/2016 12:04:23
Info sent to those members who requested it - don't forget to check your "trash" "spam" or "junk" folders if it doesn't appear in your "inboxes"
Edited By Keith Long on 15/05/2016 10:31:16
PM me your e mail address and I'll send you a pdf of the article. The other good news is that all the gears in it are normal spur gears, no internal ring gears involved at all.
Rainbows, see if you can locate a copy of Model Engineer 1st April 1915. In there is a design for a epicyclic back gear, originally meant for a Drummond round bed, but applicable to any lathe with room in the inside of the main pulley, or could be adapted into a separate cassette fitted to the pulley. The article is by Bower-Lowe, and includes the formulae for calculating the gear ratios. The design works, I've got a version of it ready to fit to a round bed of about the same vintage as the design.
|Thread: How to seal a lathe headstock|
One thing I'm wondering is whether 30mm dia. is really adequate for a 150mm centre height lathe. At that size I'd be expecting 30mm minimum as the through bore. My IXL at that centre height has a 2" dia. nose thread for the chuck so I'm guessing at 2" min dia. for the spindle at the nose end (the lathe takes a 4.5MT adaptor)? If you hope to use the lathe at it's capacity remember chucks that size are getting very heavy as just a dead weight.
Also the seal arrangement as you've redrawn it is beginning to give a significant overhang to the nose of the spindle, mounting a chuck on a backplate will push the load further outboard even before you start adding the work piece.
Just my thoughts.
|Thread: Drummond M Headstock and Bed|
Unless there is excessive play in the bearings I'd leave well alone with the headstock apart from washing the bearings through with the diesel while turning the spindle by hand.The bearings are designed as a total loss system so you should flush any muck through as well. The first step would be to clean any debris from the oiling holes as you don't want that to go through the bearings. When the diesel comes though freely and is clean switch to a light oil - the 32 grade hydraulic oil from Machine Mart is fine, but you might already have something suitable that you use your other machinery.
Taking the headstock apart isn't difficult, but there are things to watch out for with setting the bearings back up again. You should find information about that on the Yahoo Drummond group, not sure if it's in the files section or whether you need to search for the relevant thread, asking the question there should come up with an answer for you.
Wolfie - is item 130742885849 on E-Bay anything like you're looking for?
|Thread: Thread ID|
Giving us the diameter would help, but probably 1/2in. UNF (20tpi) one of the two common standards for replaceable chucks on electric drills.
|Thread: The International Brotherhood of Drummond/Myford M-Type Owners|
M type - lead-screw 8 tpi (1/8 in. pitch stated in the manual)
Drummond round bed lathe - lead-screw 10 tpi Whitworth form ie 3/4 in BSW.
|Thread: What Did You Do Today (2016)|
Beaten to it by Rod!!
How would you fit one of those on to a lathe!
Edited By Keith Long on 19/04/2016 16:29:53
|Thread: Myford ML7 long bed drip tray / other parts|
As to the tray, it might be worth looking in your local garden centre or similar for the trays that go under plant pots or grow-bags. I've got a couple (for lathe trays) that are about 37 in. long x 14 in. wide x 1.25in. deep. Made from plastic (polyprop in think) so impervious to oils and water, and over here in the UK at least, cheaper than getting steel sheet and fabricating one.
|Thread: Flat belts|
If they're the sort of clip with a joining pin across then the instructions that I had suggested squeezing the teeth into the belt in a vice with the two halves of the connector joined by the pin. The danger of doing each half separately is that you then cant get the pin in, and have to take it apart and start again. I don't think the clips take too kindly to repeated removal and re-fitting, they usually come in a longish length and you cut off enough to do the belt.
Having got the clips onto the belt then you beat them down with a hammer and block as needed to get as smooth a joint as you can.
|Thread: Recommissioning lathe size of hole to cut for belt|
You have a PM.
Gordon, have a look at Dexion Speedframe. Pretty sure that used metal connectors that fitted into the tubes with plastic inserts. For "temporary" structures you used to just knock them together with a mallet, but for more permanent set-ups it advised drilling and putting a fastener through to pin everything in place.
Also just found this link which might be what you're after, steel core, nylon coated.
Edited By Keith Long on 12/04/2016 16:45:11
|Thread: Recommissioning lathe size of hole to cut for belt|
Martin, if you look on the lathes.co.uk website at the Drummond pre 1921 3.5" small lathes sections, you'll just be able to make out the travelling steady originally meant for your lathe - it's a rather peculiar "F" shaped affair. The top slide on your machine is not the original, is the cross slide still as Drummond intended, if not you might find you have to make a travelling steady to suit.
|Thread: What steel for cylinder head stud|
Ian - it would be worth checking the thread form on one of the other head studs to verify that it is BSW and not UNC (or even possibly metric). BMC and later BL used a right concoction of threads in their engines and you can't always judge by the spanner sizes, I believe that there are some fittings with metric threads and imperial a/f heads and nuts. As the MGB engine is (assuming 4 cyl not 8) just another version of the B series it would be well worth making sure.
I used to have a sports car which used a Riley 1.5 engine, so I've been up to the elbows in the oily bits of a B series more than once!
Cylinder head stub on B series, most likely 8.8 or even 12.9 grade ht steel - they have a serious job to do and they get hot. The helicoil or other thread insert is the way to go. If you really want to make a stud with an oversized end then 7/16s isn't big enough. The 3/8 bsw is 16 tpi and 7/16 14 tpi, so you'll need to get rid of all the 3/8 thread. The tapping drill for 7/16 is smaller than the resulting hole in the block so you need to be looking at least one size up on 7/16 anyway.
Edited By Keith Long on 09/04/2016 14:54:42
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