Major flaw in the world of engineering

[Nicholas FarrParticipant @nicholasfarr14254]

Posted by Ian P on 21/04/2023 14:32:55:

Posted by Andrew Johnston on 21/04/2023 14:22:34:

If the OP approaches suppliers with the same tone as the above rant then I am not surprised he got short shrift.

It's at times like this that one really misses the late JohnS.

Andrew

I miss John S all the time!

Ian P

Hi, I was talking to John at one of the exhibitions once, and we got on about some of the smart, I know it all, kind of people that used to be on here, and he said that he wound them up all the more till they made a fool of themselves. He certainly knew how to shot shrift those types.

Regards Nick.

[Ady1Participant @ady1]

Learning what to look for when buying stuff is yet another skill to be acquired

Just because it says what you are looking for doesn't mean it will be what you are looking for

Branding in particular can become a bit of a lottery because the brand has been sold to someone in Asia and they use cheesy steel instead of sheffield steel

Then there's the knock-offs wot say wot they're not…

Welcome to our world !

[Dave HalfordParticipant @davehalford22513]

I really don't get this post.

Things must have changed at RDG/Myford ( they are owned by the same family) 5 years ago someone would have been prepared to tell you to screw the plate onto the lathe spindle, measure the gap across the chuck back and turn a step in the edge of plate to match. That said I recently got a 125mm backplate for a Boxford with a 75mm chuck recess from them which had a recess over 80mm wide so fits a 75mm chuck after turning it down .

Amazon seems to like the Stan Bray 'Basic Lathework' book

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Paul, Chucks are precision pieces, and while the registers are technically all the same size for a given size and style of chuck, they still have a tolerance to the actual size depending on many things such as quality, so the ones they sell with the chucks fitted with backplates, are a matched pair, and of course the greater the accuracy of fit etc., the higher the price will be. While hobby machines are made to an affordable price, all engineering is made to a price, even in industry. so the more extreme the accuracy that is needed the higher the price is going to be.

Regards Nick.

[paul mcquaidParticipant @paulmcquaid48093]

Hi Mate.

The trouble is I haven't got that far yet, I needed a chuck to hold the bar to true the lathe first. I have only just been given it. and came with no chuck (or was lost) Can I ask a silly question? I noticed inside the spindle tube (At least I think that's what the bit the chuck screws onto is called?) there is a copper or brass ring. Is it supposed to be there or has it been jammed in by coming off something in the past? If it is supposed to be there what is it for If not how do I get it out as I am assuming its a taper?

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Paul, no I don't think that ring should be there, as the spindle does have taper at the front of the bore. Maybe someone used the ring as a backstop when doing some repetition work.

Regards Nick.

[paul mcquaidParticipant @paulmcquaid48093]

Do to you think It would be ok to tap it it out with a long tube like a drift?

[Nicholas FarrParticipant @nicholasfarr14254]

Hi David Halford, not much difference than B&Q/Screwfix, and many other joint companies. Of course dedicated Myford users will only buy Myford spears, Boxford users will only buy Boxford spares, Ford car owners Ford spares, I could go on and on.

Regards Nick.

[paul mcquaidParticipant @paulmcquaid48093]

Sorry everyone for not realising I needed to put down my personal information and have realised it come under settings instead of being labelled Personal Information. it is all completed now though. I hope I haven't offended anybody for my rant. I was Polite when I spoke to Myford, Not very happy with the lack of explanation.. But realised I wasn't going to get it sorted any other way so bit the bullet and paid the £150. So at least I can get on with learning how to check the trueness of the lathe now… Fingers crossed.

[Stuart BridgerParticipant @stuartbridger82290]

I do sympathise with the OP, it is a bit of a minefield getting started. I was lucky enough to have engineering apprenticeship under my belt. Although it was a 30 year gap to when I started my own workshop, the basics soon came back to me. Like others, I did a huge amount of research before getting out my wallet. I will admit to making mistakes with cheap tooling. The vice "bundled" with my mill was near to useless and I have upgraded a number of other pieces since. Is there a local ME club you could get advice from? Not knocking the advice here but a friendly face and eyes diretcly on the problem(s) can be very valuable.

[Stuart Smith 5Participant @stuartsmith5]

Paul

As others have said, you can fit the backplate to the lathe and machine it to fit your chuck.

This YouTube video shows the process:

**LINK**

Stuart

[JasonBModerator @jasonb]

You don't want to be holding a bar in a chuck to "true up the lathe" either use a MT2 test bar that fits into the spindle's tapered socket or turn a bar between centers and then measure the bar

Edited By JasonB on 21/04/2023 15:46:53

[Dave WoottonParticipant @davewootton]

I miss the late John S, bought a shaper the other day and kept smiling to myself as I thought of what he would say. Remembering one of his comments about shapers ( which he had no time for) " Shapers are wonderful things, they stop the floor escaping until you can find a proper machine to take it's place"

Clever and funny man.

[not done it yetParticipant @notdoneityet]

Posted by paul mcquaid on 21/04/2023 15:31:43:

Sorry everyone for not realising I needed to put down my personal information and have realised it come under settings instead of being labelled Personal Information. it is all completed now though. I hope I haven't offended anybody for my rant. I was Polite when I spoke to Myford, Not very happy with the lack of explanation.. But realised I wasn't going to get it sorted any other way so bit the bullet and paid the £150. So at least I can get on with learning how to check the trueness of the lathe now… Fingers crossed.

Paul,

I just, out of interest, looked for your profile (does not require specific personal information) but it is blank. I think you may need to adjust some settings to make it visible to the general membership.

Toolstation fairly recently opened an outlet nearby (previously the closest was about ten miles away) just off the same road but about half a mile apart – so I now have an alternative to Screwfix. I use either only as a source of cheap bits and pieces.

T’other day when I went into Screwfix for some odds and ends, I found they had no stock for one item, it would take a day to arrive and would I like to order it. My reply was that I would check out Toolstation for that item and mentioned each piece was about 20p cheaper. The Screwfix lady said fair enough and then added that the cost difference was because Screwfix supplies were of better quality. I just smiled and commented that while her claim was true – to beat Toolstation (on quality) was not really so much to shout about.🙂

I don’t buy much, from either outlet, even if I am only looking for just above average quality.

[Kiwi BlokeParticipant @kiwibloke62605]

Posted by JasonB on 21/04/2023 15:45:50:

You don't want to be holding a bar in a chuck to "true up the lathe" either use a MT2 test bar that fits into the spindle's tapered socket or turn a bar between centers and then measure the bar

Well, it depends on what is meant by 'true up the lathe'. If going through a full set-up process from scratch, it's quite involved, as are the tests (eg Schlesinger). However, for a final test of the machine's ability to turn parallel, a couple of turned collars on a length of bar, held in the chuck is absolutely fine. The chuck need not hold on centre, or truly axially, but must hold without slop. I've seen a video on the unreliable net that suggested that the 'two collar test' be done with tailstock support. Oh dear…

[JasonBModerator @jasonb]

Well a test bar should get it set up well enough to machine a backplate then the chuck used if you want to do a parallel (without tailstock support) test.

Two collar test can also be used for setting the tailstock as little point in turning down a full length of bar and ensures mimimal wear on the tool.

[Kiwi BlokeParticipant @kiwibloke62605]

^^^^^ Agreed!

[paul mcquaidParticipant @paulmcquaid48093]

[Nick WheelerParticipant @nickwheeler]

Posted by paul mcquaid on 21/04/2023 15:31:43:

Sorry everyone for not realising I needed to put down my personal information and have realised it come under settings instead of being labelled Personal Information. it is all completed now though. I hope I haven't offended anybody for my rant. I was Polite when I spoke to Myford, Not very happy with the lack of explanation.. But realised I wasn't going to get it sorted any other way so bit the bullet and paid the £150. So at least I can get on with learning how to check the trueness of the lathe now… Fingers crossed.

Just checking it requires more knowledge, skill and judgement than you currently have, which is proved by your chuck experiences.

Put the effort into actually using the machine to make some simple parts appropriate to your requirements for buying it. Then you'll be in a better position to fiddle about with the alignment, assuming that it's even necessary – I bought my lathe 8 years ago, and the installation procedure was to carry it down the cellar steps, stagger across the floor, plonk it on the bench and plug it in. It's never been bolted down, and the parts produced have always worked well enough.

[OldironParticipant @oldiron]

Posted by Nick Wheeler on 22/04/2023 15:25:40:I bought my lathe 8 years ago, and the installation procedure was to carry it down the cellar steps, stagger across the floor, plonk it on the bench and plug it in. It's never been bolted down, and the parts produced have always worked well enough.

Exactly the right thing to do Nick. Many beginners read up on things far too technical for their own good. Its ok watching dozens of videos and reading lots of books but use the lathe or mill for a while to see what it actually does or does not do. If you do not have the very basics you will not grasp the more techy bits needed.

The very first mistake the OP did was buy a 4 jaw SC chuck. the second was not reading up on how to actually fit a chuck to a backplate. Easy to bang your nose when blundering around in the dark.

regards

[paul mcquaidParticipant @paulmcquaid48093]

The reason I bough a 4 jaw SC chuck, Is I had read they hold the round bars better than 3 Jaw and my work is not going to be light brass etc, but heavy stainless and maybe some Aluminium Round bar mainly and eventually maybe screw cutting for special bolts and bits.

[peak4Participant @peak4]

Posted by paul mcquaid on 22/04/2023 18:19:39:

The reason I bough a 4 jaw SC chuck, Is I had read they hold the round bars better than 3 Jaw and my work is not going to be light brass etc, but heavy stainless and maybe some Aluminium Round bar mainly and eventually maybe screw cutting for special bolts and bits.

So long as your round bar is actually round, then I'm sure you will be fine.
I do find mine holds the work quite tightly. The problems arise where the bar is rolled rather than drawn, and may be oval or otherwise out of round.
In that case you might need to change the orientation with respect to the 4 jaws to get it to grip evenly without wobbling.

Bill

[Mick B1Participant @mickb1]

Posted by paul mcquaid on 22/04/2023 18:19:39:

The reason I bough a 4 jaw SC chuck, Is I had read they hold the round bars better than 3 Jaw and my work is not going to be light brass etc, but heavy stainless and maybe some Aluminium Round bar mainly and eventually maybe screw cutting for special bolts and bits.

That's fair enough. The 3 jaw mayn't have the same grip, but it's horses for courses. I tend to find I need to use hex bar, both for models and railway work, plus I've never gone for records on cubic inches per minute metal removal. So the 3 jaw suits for me, with soft jaws to hold parts where there's not much to get hold of, and occasionally the 4-jaw independent for odd profiles and eccentrics. Hot-rolled black bar is something I've not seen in a while, though presumably it's still available.

I think it'd be quite unusual aluminium round bar work that the 3 jaw couldn't handle.

Edited By Mick B1 on 22/04/2023 19:23:36

[TrickyParticipant @tricky]

Posted by Mick B1 on 22/04/2023 19:22:15:

That's fair enough. The 3 jaw mayn't have the same grip, but it's horses for courses. I tend to find I need to use hex bar, both for models and railway work, plus I've never gone for records on cubic inches per minute metal removal. So the 3 jaw suits for me, with soft jaws to hold parts where there's not much to get hold of, and occasionally the 4-jaw independent for odd profiles and eccentrics. Hot-rolled black bar is something I've not seen in a while, though presumably it's still available.

You can hold hex bar in a 4-jaw SC chuck!

[SillyOldDufferModerator @sillyoldduffer]

Posted by Tricky on 22/04/2023 19:26:41:

Posted by Mick B1 on 22/04/2023 19:22:15:

That's fair enough. The 3 jaw mayn't have the same grip, but it's horses for courses. I tend to find I need to use hex bar, both for models and railway work, plus I've never gone for records on cubic inches per minute metal removal. So the 3 jaw suits for me, with soft jaws to hold parts where there's not much to get hold of, and occasionally the 4-jaw independent for odd profiles and eccentrics. Hot-rolled black bar is something I've not seen in a while, though presumably it's still available.

You can hold hex bar in a 4-jaw SC chuck!

Can it be done without scarring the bar?

In a hex bar the distance between flats is less than the distance between edges, so a hex has to be twisted at an odd angle to grip with four edges off-centre in the jaws.

Feels like a bodge to me because twisting risks crushing the corners of the bar without getting a proper grip on it. In comparison, a 3-jaw always grips flats perfectly, whilst an independent 4-jaw grips two flats solidly.

I'd expect to change chuck rather than hold hex in a 4 jaw SC, but perhaps it works better in practice than I imagine it will?

Dave

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