What Did You Do Today (2017)

[Neil WyattModerator @neilwyatt]

For those who insist on using the technique, Tubal Cain also pointed out that any maths for calculating the infeed needed with an angled topslide was a pointless exercise.

• Advance the cross slide so the tool grazes the surface of the work.
• Zero the cross slide.
• Zero the angled top slide.
• Wind the top slide and tool well clear of the work.
• Advance the cross slide by the required depth of cut.
• Now apply cut using the top slide, when it reaches zero, you are at the required thread depth.

Neil

[Neil WyattModerator @neilwyatt]

Posted by Swarf, Mostly! on 14/08/2017 19:28:54:

The 'Tubal Cain' whose book I cited was the late T.D.Walshaw, a Brit. The 'Tubal Cain' who makes YouTube videos, aka 'Mr. Pete', is an American.

It seems necessary to point this out every so often.

I've got nothing against his videos but I wish he'd done a bit more research before choosing his pseudonym.

Brief research into the origin of the name makes it such an obvious choice I've come to the conclusion isn't fair to criticise anyone for using it.

Neil "Stub Mandrel" © ® ^TM Wyatt

[SillyOldDufferModerator @sillyoldduffer]

Posted by Nige on 14/08/2017 17:08:43:

…

I had wondered how to get the tool back to the beginning of the thread without it losing 'register' with the thread and my thought process had lead me to bless the existence of the tumbler reverse as that was an easy way to get the carriage back to the beginning without disengaging the half nuts at all! I had to read through 70 plus pages of Martin Cleave's 'Screw Cutting In The Lathe', which was delivered today, to find out that this is a big 'No No' !

…

Don't worry too much about reversing with the half-nuts engaged – it's allowed provided you withdraw the tool. The big 'no no' is cutting both forwards and backwards.

The main advantage of a thread dial is speed, not that they guarantee success. They don't always work – for example when cutting metric threads on an imperial lathe. Arguably they encourage mistakes as well. I've seen professional advice saying don't disengage half-nuts, I guess because it guarantees registration.

Final thought, one objection to reversing on older hobby lathes is that they often had screw-on chucks. Advice on threading from the golden age may well have been mindful that screw mounted chucks might unwind when the spindle was reversed.

Dave

[Swarf, Mostly!Participant @swarfmostly]

Posted by Neil Wyatt on 14/08/2017 20:33:30:

Posted by Swarf, Mostly! on 14/08/2017 19:28:54:

The 'Tubal Cain' whose book I cited was the late T.D.Walshaw, a Brit. The 'Tubal Cain' who makes YouTube videos, aka 'Mr. Pete', is an American.

It seems necessary to point this out every so often.

I've got nothing against his videos but I wish he'd done a bit more research before choosing his pseudonym.

Brief research into the origin of the name makes it such an obvious choice I've come to the conclusion isn't fair to criticise anyone for using it.

Neil "Stub Mandrel" © ® ^TM Wyatt

While I disagree with your opinion, I'd defend with my life strenuously your right to hold it.

But then your position as moderator makes you such a 'force majeure' that my statement is a bit of a vain gesture!!

Best regards,

Swarf, Mostly!

[duncan webster 1Participant @duncanwebster1]

Posted by SillyOldDuffer on 14/08/2017 20:35:25:

Posted by Nige on 14/08/2017 17:08:43:

…

I had wondered how to get the tool back to the beginning of the thread without it losing 'register' with the thread and my thought process had lead me to bless the existence of the tumbler reverse as that was an easy way to get the carriage back to the beginning without disengaging the half nuts at all! I had to read through 70 plus pages of Martin Cleave's 'Screw Cutting In The Lathe', which was delivered today, to find out that this is a big 'No No' !

…

Don't worry too much about reversing with the half-nuts engaged – it's allowed provided you withdraw the tool. The big 'no no' is cutting both forwards and backwards.

The main advantage of a thread dial is speed, not that they guarantee success. They don't always work – for example when cutting metric threads on an imperial lathe. Arguably they encourage mistakes as well. I've seen professional advice saying don't disengage half-nuts, I guess because it guarantees registration.

Final thought, one objection to reversing on older hobby lathes is that they often had screw-on chucks. Advice on threading from the golden age may well have been mindful that screw mounted chucks might unwind when the spindle was reversed.

Dave

When you get confident and start screw cutting at speed you'll realise the advantage of disengaging the half nuts. Unless the lathe has a decent spindle brake you'll finish up with the tool in the chuck, as it doesn't stop dead when you hit the stop button. However when you're learning, leaving them engaged means one less thing to go wrong. With a Myford the leadcrew is 8 tpi, so you can cut 8, 16, 24, 32 tpi just dropping the half nuts in anywhere, again good for learning. Don't mess with the tumbler reverse, as this could disrupt the relationship twixt mandrel and leadscrew

[Anonymous]

For the first time I used a holder with a standard die on the Britan for cutting external threads:

The holder has an elegant spring loaded dog that disengages when a stop is reached, and re-engages the other way to unscrew the die when the lever is flicked to reverse the spindle. After a couple of trial runs at slow speed I cut the rest of the M4 threads at 500rpm.

Why was I using the die holder? Because I located three of my M4 Coventry diehead cutters, but was darned if I could find the fourth one.

Andrew

[JasonBModerator @jasonb]

Posted by Neil Wyatt on 14/08/2017 20:33:30:

Posted by Swarf, Mostly! on 14/08/2017 19:28:54:

The 'Tubal Cain' whose book I cited was the late T.D.Walshaw, a Brit. The 'Tubal Cain' who makes YouTube videos, aka 'Mr. Pete', is an American.

It seems necessary to point this out every so often.

I've got nothing against his videos but I wish he'd done a bit more research before choosing his pseudonym.

Brief research into the origin of the name makes it such an obvious choice I've come to the conclusion isn't fair to criticise anyone for using it.

Neil "Stub Mandrel" © ® ^TM Wyatt

Knowing the way Americans name themselves maybe he would have been better calling himself "Tubal Cain III" and then there would be no mixing him up with the previous two

[Joseph Noci 1Participant @josephnoci1]

Andrew, how does that die holder work? How does the dog latch work? Are the dies separate 'cutters' sort of like thread chasers? You mentioned it is with a 'standard die' and I understand that to be one of those solid circular disc type dies – so not sure how that disengages. I googled, but did not find anything useful – mostly I suspect because I do not know what to call the device?. An interesting bit of tooling.

Joe

 

Edited By Joseph Noci 1 on 15/08/2017 07:53:17

[SillyOldDufferModerator @sillyoldduffer]

Posted by Neil Wyatt on 14/08/2017 20:33:30:

Posted by Swarf, Mostly! on 14/08/2017 19:28:54:

The 'Tubal Cain' whose book I cited was the late T.D.Walshaw, a Brit. The 'Tubal Cain' who makes YouTube videos, aka 'Mr. Pete', is an American.

It seems necessary to point this out every so often.

I've got nothing against his videos but I wish he'd done a bit more research before choosing his pseudonym.

Brief research into the origin of the name makes it such an obvious choice I've come to the conclusion isn't fair to criticise anyone for using it.

Neil "Stub Mandrel" © ® ^TM Wyatt

Not seen the blockbuster film 'Noah' yet then? In it Tubal Cain is played to type by Ray Winstone, who does a very convincing line in baddies…

[Neil WyattModerator @neilwyatt]

Posted by JasonB on 15/08/2017 07:28:08:

Posted by Neil Wyatt on 14/08/2017 20:33:30:

Posted by Swarf, Mostly! on 14/08/2017 19:28:54:

The 'Tubal Cain' whose book I cited was the late T.D.Walshaw, a Brit. The 'Tubal Cain' who makes YouTube videos, aka 'Mr. Pete', is an American.

It seems necessary to point this out every so often.

I've got nothing against his videos but I wish he'd done a bit more research before choosing his pseudonym.

Brief research into the origin of the name makes it such an obvious choice I've come to the conclusion isn't fair to criticise anyone for using it.

Neil "Stub Mandrel" © ® ^TM Wyatt

Knowing the way Americans name themselves maybe he would have been better calling himself "Tubal Cain III" and then there would be no mixing him up with the previous two

[Russell EberhardtParticipant @russelleberhardt48058]

I don't see the problem. Tubal Cain wrote books and articles for ME, He never made Youtube videos. The man who makes Youtube videos usually refers to himself as Tubalcain, all one word so there shouldn't be any confusion.

Russell

edited to correct miss-typing

Edited By Russell Eberhardt on 15/08/2017 11:19:31

[NigeParticipant @nige81730]

In another thread I highlighted a minor problem in adjusting the compound slide. The hex head of the clamping bolt is rounded off because of its proximity to the slide which also necessitates the use of a small diameter washer. Wear on the the slot means the washer quickly becomes cup shaped! You can see the problem!

First thing was to change the hex bolt for a cap head bolt, then sort out a washer. The washer needs to be thick enough to resist squashing into the slot irregularities and fit up close to the edge of the slide at one end of the slot while still being wide enough to span as much of the slot as possible and give enough support to the bolt. I made some measurements and decided an eccentric washer would do the trick.

I didn't have a piece of steel bar of sufficient diameter but I do have some large coach bolts the heads of which make a good start. I turned down the square behind the head, then faced off the dome of the head and put a chamfer on what would become the 'top' of the washer. At this point I removed the 'head' of the bolt with a hacksaw as I'm not confident enough to part this off at the moment.

The washer needed to have a clearance hole for 1/4"BSF bored into it but it needed to be closer to one edge than the other, eccentric in other words. I measured and marked the position of the hole and mounted the piece in the 4 jaw, centre drilled it then opened it out with a smaller drill and finally with a 1/4" drill.

I then faced off the washer to clean up the hacksaw marks and reduce its thickness. It was really close to the chuck jaws on the final cut.

Fits a treat, Jobs a goodun

Very pleased with this. Although it is a relatively simple task it allowed me to put a few techniques together to make my first useful article and improve the lathe a little.

From concept and donor bolt to finished article; two or three happy hours in the workshop

[OldironParticipant @oldiron]

Posted by Russell Eberhardt on 15/08/2017 11:18:38:

I don't see the problem. Tubal Cain wrote books and articles for ME, He never made Youtube videos. The man who makes Youtube videos usually refers to himself as Tubalcain, all one word so there shouldn't be any confusion.

Russell

edited to correct miss-typing

Edited By Russell Eberhardt on 15/08/2017 11:19:31

Agreed 100% Russell. Also Tubalcain always points out that he is not the British author.

[Anonymous]

Business meeting this morning. Flew the big glider this afternoon.

First half decent day this year that has coincided with a rostered day for me. Came off tow at 1500ft (money saved) and after a sticky couple of minutes climbed to cloudbase. Then bimbled past Bedford and Milton Keynes, eventually ending up at Bicester. Met a competition gaggle, at least a dozen gliders all in the same thermal as me. At least it was a well behaved gaggle, and they were lower than me. The plan was to go to HusBos (near the M1/M6 junction) but the sky looked iffy so I diverted to Northampton and then decided to go to Corby instead. Nice climb at Corby so back to Bedford and then over to Cambridge. Flew over my bungalow before landing. A nice bimble around a couple of hundred kilometres in a bit over 2 hours. Woohoo.

Andrew

[martin perman 1Participant @martinperman1]

Posted by Andrew Johnston on 15/08/2017 20:13:59:

Business meeting this morning. Flew the big glider this afternoon.

Then bimbled past Bedford

Andrew

And you didnt bother to wave as you passed over

Martin P

[JasonBModerator @jasonb]

Andrew what do you use for navigation? maps, follow roads, GPS or a bit of each.

J

[NigeParticipant @nige81730]

BIG glider competition starting at Lasham, possibly today and over next few days Andrew.

[Anonymous]

Martin: Sorry about that, to be fair I was north of the A421 to avoid the DZ at Cardington. On the plus side I saw the Airlander on its mast; first time I've seen it for real.

Jason: There's a moving map display in the glider but I can't see the darn thing, largely because the display gets washed out in the sun. And you can't mute the female who voices the warnings, so I often turn it off. We've got a simple GPS that I use as a goto, ie, distance and bearing. This also feeds into the variometer and a bar graph says you're going to make the next point, or fall short. I use the map quite a lot to check airspace and confirm my position. I know most of the area I flew over pretty well, and what features stand out, like Silverstone. Plus what features mark a particular town; for instance Northampton has a motorway (M1) hugging the west edge and a 600ft concrete tower in the SW corner of the town. The tower was built to test lifts, but is no longer used. It's now a listed building, fortunately not in the Pisa sense. In a glider you go where the clouds look good rather than in straight lines, so it's important to keep on top of the navigation.

Nige: Yep, the NOTAMs this morning listed a comp at Lasham and one at Sutton Bank. I'd be really impressed if the boys from Sutton Bank had made it this far south. The gliders were coming from the south west so I'd agree most likely Lasham.

At least I had a better day than one of the club single seater pilots who I helped push the glider out of the way. Not only was he cursing about not being able to stay up he'd had a pee bag malfunction resulting in wet trousers.

Andrew

[Anonymous]

Posted by Joseph Noci 1 on 15/08/2017 07:50:43:

Andrew, how does that die holder work? How does the dog latch work? Are the dies separate 'cutters' sort of like thread chasers? You mentioned it is with a 'standard die' and I understand that to be one of those solid circular disc type dies – so not sure how that disengages.

I didn't explain very well. The Coventry diehead and the die holder are different animals. This is a 1/2" Coventry diehead with dies for M6 in the closed position:

The diehead opens and moves the dies clear of the work either by pulling forward once a stop is reached or the plunger top left is pushed. The diehead needs closing before cutting each thread. The diehead takes four dies, in sets, as shown in front, in this case for a ¼" gas thread. Since I couldn't find one the four dies to make the complete set for M4 I had to use another method.

This is the alternative:

It takes standard split dies, in this case 13/16" diameter; there are holders for other sizes up to 1½". The die holder screws onto the front of the holder containing the dog clutch and trapping the split die ensuring it is square to the work. There are also adaptors to hold taps.

This picture shows the internals of a similar, but smaller, version:

Note the fixed tapered dog at the front and the spring loaded dog behind. When feeding in to cut a RH thread the dogs engage and stop the front of the tool from rotating. When a stop is reached the front of the tool continues to move forward, until the dogs disengage as the taper slips over the spring loaded dog. At this point the front of the tool spins and cutting stops. The spindle is then reversed, flick one switch and it is almost instant on the Britan. The front part then rotates the other way and the dogs engage as the taper can no longer slip past the spring loaded dog. The front of the tool then stops spinning, and since the spindle is reversed the tool unscrews itself.

I hope that make sense; it works very well and at 500rpm is very quick, no more than a few seconds per thread.

Andrew

[IanTParticipant @iant]

I was just on the way down the shed this evening when the door bell rang. It was the next-door neighbour who had just purchased a new 'Fitbit' thingy – looks like a very large wristwatch. The metal strap was too big and he'd watched YouTube and the "pins" should just push out – but his didn't. This didn't sound too hard to fix, so I said leave it with me and I'll see what I can do (he does take our bins in when we are out).

The pins looked to be about 1mm – which was confirmed by poking a bit of pivot steel into the hole – it fitted nicely and the pivot steel miked at 36 thou. So I gripped it in a pin vice and pushed but the pin didn't budge. Got the Optivisor out and noticed that there seemed to be screw heads – with very fine slots on one side. My smallest watchmakers fitted the hole but not the slots. Ok I finally thought – he mentioned YouTube, so I'll go check that.

It turns out that the 'screws' are actually split pins and they only push out one way. On Youtube the guy uses a darning needle (griped in a mole wrench) to do the job but that didn't appeal to me. I had the ER32 collet already on the EW so drilled a scrap end of brass 1mm, cut a slightly longer length of pivot steel (Dremeled it) and used another brass scrap (with a pre-drilled centre hole) as the backing plate – they were temporarily stuck to the vice jaws with double sided tape and with about an 1/8" of pivot steel sticking out, two pins were popped out (in the right direction) – the "screw" end is the end that will come out – so you push from the other end…

Like many "5 minute" jobs – it ended up taking well over an hour. However, it is good to get your bins taken in when you are out….

Regards,

IanT

[Martin WParticipant @martinw]

Ian

There is a bit of 'deja vu' for me in your post. Some time ago I was asked to shorten a watch strap for my neighbour. A similar story with tight pins so I too made a device, bits from the scrap bin, to shift them, picture below

 

It worked very well and he was pleased as no jeweller's fees were required just a bottle or two of my favourite beer.

Cheers

PS They water our hanging baskets and tubs when we are away.

Edited By Martin W on 17/08/2017 00:28:56

[Joseph Noci 1Participant @josephnoci1]

Andrew, thanks for the explanations on the die heads. Looks like a very useful bit of kit, and something challenging to DIY! Cannot easily get the loose dies but the split die head is worth a try.

Need to do a lot more digging though, as its not easy to work out from that pic how the gubbins works!

Thanks Andrew.

Joe

[IanTParticipant @iant]

A much more elegant solution than mine Martin.

Hopefully, I won't be called on to remove any more links again but I will pop the bits in on of my very useful small sealable bags, with a note to remind what they are for. The bits will still go back into the scrap box they came from but I've lots of similar odds and ends.

Regards,

IanT

[MuzzerParticipant @muzzer]

Joe – you'll find this helpful then – the original book by Alfred Herbert Ltd.

Murray

Edited By Muzzer on 17/08/2017 13:59:31

[SillyOldDufferModerator @sillyoldduffer]

Been outside unblocking a downpipe and choked soak-away in the rain. Tired, muddy, soaked, scarred (sat on a bramble), feeling my age, and full of adrenaline. Whilst about 12' up screwing the downpipe back on the wall the ladder slipped on wet paving and I ended up on the ground. Fortunately I landed on my head whilst wearing a flat hat so no damage was done. I've left the top fixing until I can get an assistant to help control the ladder. Just as well I stopped because the weather got much worse as I tidied up, including thunder.

Having a lathe came in handy though: a scrap aluminium turning was exactly the right size to support the bottom of the pipe at the right height. I'm hoping that in two or three thousand years some archaeologist will be baffled by finding precision metalwork in a 21st century drain. 'Obviously' he will say, 'quality was much better in the good old days…'

Dave

[Author]

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