Backwards & Forwards

[Ginger Nut]

  I had my ML7 re-wired and reversing switch fitted recently I mounted the Dewhurst switch to casting this morning works like a dream. Two mates did the lecy work.

Here's the whole tale http://woolnwood.blogspot.com.au/2015/05/its-just-bump-to-left-and-bump-to-right.html

Oh raising blocks of Jarrah t lift it 40mm so cables could fit.

[Fergus OMore]

Glad things are running but why reverse a ML7 or a ML7 series?
The odds are that the chucks, catchplate and faceplate might unscrew in reverse. No problem with collets  and stuff secured through the spindle but I will NOT reverse my 3 phase motor otherwise.

Again, people say that the old Dewhurst is regarded as  electrically unsafe.

Maybe others will be able to correct me. Mine is ready for the skip.

Norman

[doubleboost]

I ran my Boxford with a inverter
This gives speed control & reverse
Never seen the chuck come loose
Did plenty of reversing cutting metric threads
John

[Sea.dog]

I have to agree with you John, I've run in reverse quite a few times on my AUD with no problems.
Graham

[philf]

Glad things are running but why reverse a ML7 or a ML7 series?

Norman,

It's very useful to be able to reverse the lathe if you're for instance doing metric screwcutting on an imperial leadscrew like on the ML7. Fortunately, screwcutting normally only uses slow spindle speeds and you're not cutting in reverse so there's little risk of the chuck unscrewing.

We used to have a Simonet lathe at work with screw on chucks. The chuck backplates had 2 or 3 slot's milled within a mm or so of the bore and a clamping collar squoze (is there such a word?) the backplate to the register on the spindle.

Cheers

Phil.

[Fergus OMore]

I'm glad to learn of success of others. Both my ML7( long gone) and my present S7B  suffered this problem. As I said, a chuck coming off the register and then the thread- and beginning to tip onto the lathe bed. I'm not very enthusiastic.

[doubleboost]

If I tighten a chuck on it will not come loose unless you do something stupid with it
John

[Ginger Nut]

I have two wood lathe one mini one standard only when I have had a large item on them and stopped them suddenly has the chuck started to spin off. These can be locked on with a grub screw or lock plate.

I doubt the ML7 would ever run at speeds to have the chuck come off as others have said, tests runs with an empty chuck hasn't budged it yet.

[Fergus OMore]

I'm sorry to have posted. This, I believed is a hobby, in which one shares  one's experiences.

If there is a problem in accepting my experiences, it is not important to me. So let's delete it?

[PekkaNF]

Actually I believe on certain lathe/motor combinations this can be a problem. I imagine heavy chuck and electric or mechanical brake or high gear ratio. Then again normal three jaw chuck with small piece and inverter drive with decent ramps probably will give no problems.

This circuit seemed to have a no-voltage-release, that should make things safer.

I never had Dewhurst switch but I have read some people touching it inadvertedly (usually walk-by or reaching something over the lathe). If very old and filled with debris then it's as much problem as any other switch. What makes it "electrically unsafe"?

Pekka

[Bluechip]

Norman is absolutely right. I've had Myfords since 1971 [ a ML7/T and a S7 ] and it's certainly possible to unscrew a chuck. Done it on quite a few occasions.

Happens usually when winding a die off a coarse thread eg. 1/2" BSW , M12 etc.

As posted earlier this is at low back-gear RPM so it does not drop on the bed.

I cannot comment about Boxfords, I have never used one.

Dave

[Fergus OMore]

Norman is absolutely right. I've had Myfords since 1971 [ a ML7/T and a S7 ] and it's certainly possible to unscrew a chuck. Done it on quite a few occasions.

Happens usually when winding a die off a coarse thread eg. 1/2" BSW , M12 etc.

As posted earlier this is at low back-gear RPM so it does not drop on the bed.

I cannot comment about Boxfords, I have never used one.

Dave

My experiences  and certainly whilst reversing die threading and tapping - hence my reference to preferring  the use of collets.

Again, my experience(s) with Boxfords was limited to having to spend my time- reaming out buggered tailstock poppets with my own reamer. Not the end of the world but a nuisance to have to mend the mistakes of others!

As far as the control box on the Seven series( and the ML10???), I believe that the old stuff is suspect electrically and here, I am certainly ready to be advised- right or wrong.
Mine is '3 phase' and I used more modern  switches on earlier lathes.

One must now make one's own judgement.

Regards

Norman

[Ginger Nut]

I would ask why then are all new lathes & mills fitted with a reversing switch?

A simple fix or preventative is to use a grub screw in the backing plate mandrel area for when using the lathe under load as is done with wood lathes.


As for bumping the switch this for me became one area I had to be very aware of and is why it has been mounted where it has. If the lathe is stopped for other than a quick check then the main stop switch is turned off and during down time now the power switch turned off at the wall. Safety is paramount not just for myself but anyone who walks into my workshop/shed. Those who have no respect for safety have been told do not come near.

[Fergus OMore]

I understand your comments but let me try to explain?

The first point is that the ML7 is a very old model makers lathe and came- without any chucks. It came with a faceplate and hard and soft lathe centres. No more! If you wanted to have chucks, Myford supplied them as extras and NONE had back plates. My 4 chucks are all solid bodies.
Fitting grub screws or whatever is just as much- an accessory. Again, you have missed the fact that the ML7 is just as much a woodturning lathe as a metal turning lathe. Model engineers made their own moulds using simple rests. Sorry, but these are facts in what was- another world.

As for fitting a reversing switch to a mill or a lathe or a whatever, it is your choice and no model engineer worth his grubby finger nails didn't add his own accessories and modifications. I probably have 32gb worth of mainly Myford articles and a workshop full of either bought out or home made goodies.  I can say that a reversing switch on a mill was not put on for screwed chucks as per Myford lathes. If you want to do it- well, you can. The only screwed spindle was the one on the Westbury ones. Mills, at the time of the first Myford ML7's were a thing for the factory and the super rich an in shed or back of garage. I made my Westbury from homemade castings. Life was like that.

I must apologise for what might be 'trying to teach you to suck eggs' and this is certainly not my aim. I merely have corrected what appears to be misconceptions. There is no reason why you cannot do exactly what was done in the past on a lathe that was essentially out of World War 2.
Unquestionably, it will still give you excellent service and it can be restored to perform as well as more modern lathes. or better- because the documentation is still there where there is surprisingly little on more 'modern' lathes.

Enjoy yours as I do mine.

Norman

[Ginger Nut]

I understand your comments but let me try to explain?

The first point is that the ML7 is a very old model makers lathe and came- without any chucks. It came with a faceplate and hard and soft lathe centres. No more! If you wanted to have chucks, Myford supplied them as extras and NONE had back plates. My 4 chucks are all solid bodies.
Fitting grub screws or whatever is just as much- an accessory. Again, you have missed the fact that the ML7 is just as much a woodturning lathe as a metal turning lathe. Model engineers made their own moulds using simple rests. Sorry, but these are facts in what was- another world.

As for fitting a reversing switch to a mill or a lathe or a whatever, it is your choice and no model engineer worth his grubby finger nails didn't add his own accessories and modifications. I probably have 32gb worth of mainly Myford articles and a workshop full of either bought out or home made goodies.  I can say that a reversing switch on a mill was not put on for screwed chucks as per Myford lathes. If you want to do it- well, you can. The only screwed spindle was the one on the Westbury ones. Mills, at the time of the first Myford ML7's were a thing for the factory and the super rich an in shed or back of garage. I made my Westbury from homemade castings. Life was like that.

I must apologise for what might be 'trying to teach you to suck eggs' and this is certainly not my aim. I merely have corrected what appears to be misconceptions. There is no reason why you cannot do exactly what was done in the past on a lathe that was essentially out of World War 2.
Unquestionably, it will still give you excellent service and it can be restored to perform as well as more modern lathes. or better- because the documentation is still there where there is surprisingly little on more 'modern' lathes.

Enjoy yours as I do mine.

Norman

Norman seems your just the man I'd like to get all that information from regarding the ML7. Mine however was built in approx 1972 from numbers obtained.
Now about that time I was at school doing metal work on if I recall a Colchester lathe which funnily enough had reverse, yep stupid school bos would turn it on and off would fly a chuck or faceplate thank goodness sense was seen by the teacher and instant ban from class.

From what I have read of the ML7 (I used to read UK Model Engineer regularly in the 60's & 70's) over the years it grew from a very standard start up lathe for model engineers/home hobbies sector but often was seen in small and large engineering shops I have a friend who did his apprenticeship on one in the 70's).
You could make your own attachments many of which became incorporated into Myford's optional extras.

Here's a question then "Why did Myford fit a motor which can be and through the manual gives great explanation of fitting and using a reversing switch let alone used to sell it??

[awemawson]

Ginger, all the Colchesters I've seen in schools and ex schools of that era had the 'L0' (or L00 on smaller lathes)  american short tapered nose, with a key to provide angular location and a screwed collar to hold it on. Reversing was never a problem, as the inertia of the screwed collar is small (anyway the locking spanner is huge!) and the inertia of the chuck and workpiece are irrelevant as the key prevents rotation. Later ones of course had the D1-4 camlock spindle nose.

[Fergus OMore]

I think the answer is so that the lathe can accept tooling other than that which is screwed on. There are things like boring heads, facing tools and a collets to name only a small fraction. Some can be bought whilst others can be made. I'm sure that you are aware that the ML7 used to be the total workshop rather than only one bit. With a vertical slide and a block of steel to pepper with holes and away one went

Is much of the old information still available? Can one set off today with an old lathe and use fabrication from blocks of steel?  Of course, it is. Again, there are lots of castings and drawings in the UK if not in Oz.

What has to be recalled is that vast projects like tool and cutter grinders, dividing heads and rotary tables have been made on a lathe only workshop.

I'm having to take a break for at least a month- wife's and doctors orders but feel free to drop me a note if you wish. Given a new year, I'll be 85, I might just help.

Meantime

My best wishes


Norman

[RobWilson]

Looking good Ginger Nut   

A handy feature to have on a lathe . 

I have been using Dewhurst drum  switches on my machines for years, my first ML7 had one , the Super 7 has one , been using that for 22 + years , my Boxford has one ,been using that a tad less about
19 years , my mill drill has a copy switch fitted , been using that at least 20 years ,,,,,,,,,,,and have NEVER I will say that again NEVER had a chuck unscrew and I hammer my machines at times .

To me not having the spindle reverse , is like having a car with no reverse gear  , it increases the  functionality of the machine .

And this NVR switch argument ,,,,,,,,,,,,,,,,bollocks !    what is the world coming to .      

Rob


edited for piss poor spelling 

 

[NormanV]

I have a Raglan lathe fitted with a Dewhurst switch, I was demonstrating the fact that it could be reversed and the chuck unscrewed and flew onto the floor narrowly missing my foot.

[vtsteam]

I don't have a reversible motor on my Craftsman lathe, which has screw on chucks, but wouldn't have qualms it if it did. It seems to me it's a matter of choice in outfitting your own lathe, and if you do set up reversing, it simply requires a reasonable amount of care to use it.

I wouldn't be without reverse in my tractor, or truck, or even an electric drill, but running these or just about anything else forward and then trying instantly to jump into reverse is a bad idea, and so generally discouraged. Likewise starting out in a high gear. Or overloading the capabilities of a mechanism. So knowledge is required, and familiarity with the equipment and limits.

I know that manufacturers of modern equipment/vehicles/tools try to add saftey features and lockouts.; But depending on some safety feature dulls the public's need to understand how things work, and what not to do. Knowledge prevents accidents in case a safety feature fails. Or if a person happens to use something older without those safety features.

As a matter of choice, it seems perfectly reasonable to me to either fit an older style reversing switch, or remove and replace an older style reversing switch depending on your own take on it, just as you can choose every other aspect of your shop tools. I don't believe there is a right and wrong for something like this, once the possible problems are already expressed, and people clearly accept the responsibility for their own safety in their own shop.

I run a chainsaw in the woods, after all. Plenty of possible safety downsides to that. And just about every other interesting thing I do in life.

[Bluechip]

I hammer my machines at times .

Oaf !!!!         

 is like having a car with no reverse gear 

Don't knock the arrangement. My mate had a BMW Isetta. OK it was not as fast as my Velo Clubman but it was warm, dry and it was no problem keeping a Woodbine alight .. 

Dave

[RobWilson]

I hammer my machines at times .

Oaf !!!!         


Dave