Member postings for ega

Speedy Builder5:

According to the late D H Chaddock the best-known use for old hacksaw blades is conversion to tooth rests on tool grinders - another reason for having a Quorn!

The OP asked for advice about "general use" but the key to hacksaw heaven is selecting the right blade for the particular job and I would recommend having at least three frames ready for use.

When I first bought Loctite products they were the only ones of their kind and information about storage and use was hard to come by. Later, I was able to get hold of their 1996/97 Design Handbook of 450+ pages which was rather more than I needed! Numerous brands are now available and I can recommend Truloc partly because the makers actually reply to requests for help.

John Haine:

If you are in the UK would you let us have some details about the CBN wheel, please?

Thanks for the excellent coverage of your build.

paul 1950:

Adjustable feet - which didn't get thrown out with the bath?

Good on you for not chucking the spanners!

Woodworkers use them for soaking circular saws in solvent (but not by the seashore!)

Edited By ega on 19/12/2015 11:17:26

Lambton:

My apologies; I clearly misread what you wrote. Needless to say, I agree with what you say to Robbo.

Thinking about this I wondered whether the spindle lock is or should be engineered so as to give way before either the backgear key and the woodruff key.

This is an area where prevention is very much better than cure.

Lambton:

Good point - although my understanding (and reading of the diagram in the S7 manual) is that it is the bullwheel that is keyed to the spindle by the woodruff key (H22); the pulley is connected to the bullwheel by the backgear key (H5).

So, ideally should we be looking for a method that doesn't involve the pulley, the bullwheel or the backgear? Perhaps by gripping the spindle tail in some way?

Incidentally, the manual does stress the need for cleanliness and to oil the spindle register.

OuBallie:

ARQ? A new abbreviation to me I fear.

Presumably not Are Rubies Quaint?

Iain Downs:

Just a thought. Is your spindle intended to be drilled through the whole or part of its length and, if so, how will you do this?

John Baron:

I've been hanging my handbag on that pin and did wonder what it's real purpose was!

Seriously, however, I do invariably use the spindle lock for removing chucks that are willing to come off but in the case of a stuck chuck would prefer to immobilise the spindle as directly as possible; as you no doubt know, the pulley into which the lock pin goes is connected to the spindle via the bullwheel ie indirectly.

Is it the case that the ML7 doesn't have a spindle lock?

Posting pictures on the site is rather like treadling a lathe - clunky and hard work but good for the soul. I believe the drill is to put the pictures in an album and then use the camera image to insert into the post. If you discover how to put text into the post *after* the picture please let me know! It does seem to help to size photos appropriately.

Edited By ega on 12/12/2015 15:25:03

Presumably oxidisation of the oil is unlikely to occur if the air is excluded as it would be on a well-fitting chuck.

Iain Downs:

An alternative to using a steady would be to find someone with a larger lathe which will accept your bar for centre drilling purposes leaving you to do the bulk of the job yourself.

Anyone offering to do this would need to have some idea of your location (no public profile).

Bazyle:

It's certainly a useful "gadget" (when needed) but, as I said, not my own invention. If the editor thinks it suitable I could submit a dimensioned drawing of my version for the Myford Super Seven; the idea would also work on the ML7.

From what I have read there does seem to be a real danger of damaging the bullwheel if abused and I feel more comfortable with the Sparey method. I suppose that in extremis one could always machine the chuck off!

OT: the other "thing" is the fixing point for the latch on the GHT headstock dividing attachment which, for me at least, was a major project some years ago. GHT was standing on the shoulders of J A Radford, whom he considered a very quick worker, but I don't think even JAR would call his original device small.

What actually happens when a chuck "sticks"? And is a steel backplate more prone to do so than cast iron?

My understanding is that metal to metal contact allows some sort of welding or sticking to occur, hence an oil film prevents this. My guess is that the problem arises at the register/shoulder, which should be a close fit, rather than the thread. Other things being equal, anti-seize compound no doubt is more effective but the presence of thick grease (or cardboard) might affect the accuracy of the mounting.

Purely by the way, an eminent woodturner, the late Peter Child, recommended a thick leather washer to prevent screw-on chucks from unscrewing when run in reverse.

I realise that the modern tendency is to secure the chuck by bolts, etc but I do value the ability to change chucks rapidly (or, indeed, to use the headstock taper).

Edited By ega on 12/12/2015 11:42:16

Bill Wood 2:

Thank you for your interest. A couple of photos: the first shows the spanner installed on the S7 spindle, the second the device itself with the loose pin which engages in one of the holes in the bullwheel. When used in earnest, I interpose a bit of brass between the projection on the spanner and the lip of the headstock.

The spanner was just sawn and filed up from a scrap piece of 8 gauge MS, hence the redundant hole. The pin is a bit of HT material but MS would do.

I will send you a PM with more information.

Bazyle:

I take it that you are advising against putting a cold male MT into a warm lathe spindle, a topical point in view of the recent thread about use of the headstock taper. I suppose the workers who stand a mug of hot tea on top of the tailstock might need to take care, too!

On the oil on threads point, I recall that an eminent woman cyclist was once asked what single piece of advice she would give to the world and replied "Grease all threads!". I believe she did her own maintenance.

Bazyle:

Fair comment, although if I am too slow in stopping the spindle the plastic ball is not going to damage the bed but only my fingers!

The reason for making the tommy bar of reasonable length was that I also use the chuck on my larger lathe where there would be full and unimpeded rotation; I wanted to have enough leverage to resist the torque of tapping large coarse threads on the bigger machine.

I have had my share of stuck chucks on my Super Seven, but much less so since adopting the practice of a quick squirt of oil on the register and thread when changing chucks. These items should, of course, be kept scrupulously clean.

I have also seen the suggestion that a chuck which has been used for heavy or intermittent cuts should not be left on the spindle overnight (the chuck should, perhaps, also be loosened at intervals during the job).

Prevention apart, there are two requirements for removal: immobilising the spindle and safely applying releasing torque to the chuck. Lawrence Sparey has very good advice on these points in his little book "A Man and his Lathe", in particular his design for a spanner to lock the mandrel without risk of damage to the backgear. I could post a photo of my version of this if anyone is interested. His suggested way of rotating the chuck is via a bar gripped in the jaws.

In my view there should be no objection to my posting a short extract from the book but I would like a nod from management before doing so.

Frances IoM:

Sorry if I wasn't clear about this. The tommy bar is held in one hand and the tap advanced into the work on the sliding support until it starts to cut whereafter the tommy bar is simply used to resist the cutting torque. Once the spindle has been halted the lathe is put into reverse and the tap withdraws onto the sliding support; any tendency for the chuck to rotate is again resisted by lightly holding the tommy bar.

Essentially a manual operation, but with clear advantages over the use of a drill chuck in the tailstock.

Correction: the stated capacity is M4 - M12 but in practice the chuck will not close down sufficiently to hold the shank of my M4 taps and, yes, I have used a drill chuck with these!