Member postings for Gary Wooding

You were right, it was Adblock. I must remember to switch it off next time I look at an album.

By the way, is the massive list of all albums in any particular sequence? It appears to be random to me.

Gary

I think, maybe, that this is another Firefox incompatibility feature: I see no arrows at all. I've tried pressing Ctl-A to see all controls, but there are no arrows or buttons visible at all.

For what browsers does it actually work?

Or perhaps there is another method of looking at albums, other than clicking the Albums button at the top of the screen,

Gary

Is there a way to view consecutive photos in an album without the need to go back to the thumbnails in order to choose the next one? In other words, is there a "Next" , or "Prev" button that I haven't found?

Gary

"Nose grease" also works well - you simply wipe your finger and thumb down the side of your nose, where it meets your cheeks, then wipe the same finger and thumb along the saw blade. You can misplace a candle, but your nose is always handy.

Gary

If you want to saw intricate shapes in metal, there is really no substitute for piercing.

The photo shows the offcuts from a job, one offcut is 0.8mm brass sheet and the other is 3.0mm stainless steel sheet, both were cut using a 6/0 piercing blade - that's .007" thick and .014" deep.

Sizes of piercing saw blades can be found HERE

Gary

What you want is a Piercing Saw. They are are not very expensive, and the blades are remarkably cheap. If you've never used one before, be prepared to break lots of blades. Here's a place you can get them *LINK*

Yak,

It's not necessary to level both ends of the lathe - it's sufficient to adjust one end (choose the easiest) so that it matches the other. A lathe doesn't need to be actually level - lathes on ships can't be level, but they work OK because they have no twist in the bed.

If the headstock end is the most difficult to adjust, run the carriage up the headstock and place the level on it. Move the carriage towards the tailstock and watch the level. If it moves more than you like, adjust the tailstock end to compensate. When the bubble movement is acceptable, tighten the bolts and check again. If it's still OK, you're done. You're not seeking to level the bubble, you're only trying to make it the same all along the bed.

This is a well known problem with TCs PDF facility, the solution is to instal a separate PDF writer. The one I use is called PrimoPDF. It's free and instals as a virtual printer; it works for any program that can print.

The Android/IOS clinometer apps I've looked at imply a resolution of 0.1 degrees, which corresponds to approx. 1.75mm/mtr. Not really precision, or am I looking at the wrong apps?

The divisions on a typical precision precision level are marked as 0.05mm/mtr. or 0.0005"/10". A plumb bob displacement of 0.5mm (which is about as accurate as you could hope to be) would need a suspension string about 10mtrs long for equivalent accuracy.

The objective in levelling is to ensure that the lathe bed is not twisted; if the bed is twisted then everything you cut on the lathe will be tapered to some extent.

Perhaps the easiest way is by the use of a precision level. You place the level, at right angles to the bed, somewhere convenient on the saddle which you then carefully move from one end of the bed to the other while observing the bubble. There is no requirement to centralise the level, but you must ensure that it doesn't vary along the bed. Any movement in the bubble indicates a twisted bed. You adjust the bolts and or shims until you are satisfied.

Unfortunately, precision levels are not exactly cheap, and are not needed very often, so its probably best to borrow one if you can.

There are methods that don't need a precision level, but they are not so straightforward.

If, when placed on its male dovetail, without the gib strip in place, it...

1. Doesn't rock when each corner is pressed down, and

2. The critical surfaces are relatively horizontal in both directions,

then leave it alone, otherwise machine it where appropriate.

My late mentor advocated redrawing everything in CAD before cutting metal. I heed his advice; its amazing how many errors are revealed.

Gary

John, yes, I missed that bit.

Without having a centre for the headstock, why not put a bar in the chuck and turn a conical point on it - it's bound to be on the centerline. Of course, it will lose its accuracy when removed from the chuck, but it's very easy to sharpen it again.

Unless, of course, the headstock centre is really needed for other things - like turning between centres.

If you really want to align the tailstock to the spindle, why not put centres in each and match the points? Or am I missing something here?

Gary

Thank you MichaelG.

I was, indeed, thinking with my DRO hat on; as soon as I took it off my confusion disappeared.

The article about the use of the Ickey Ball was very interesting.

Gary

Michael,

I know and understand toolmaker's buttons,and how they are used. Essentially they are bolted approximately in the correct position then adjusted until accurate measurements indicate they are correctly positioned. The machine tool is then aligned to the correctly positioned button. This was the method used before the advent of DROs.

Now days we line the machine tool up to some appropriate datum point on the work piece, then set the DRO appropriately. If the datum point was correctly located then the DRO allows us to accurately position the work piece to any other relevant position.

What I don't see is how a conventional or conical button assists in this - how do you place the button accurately in the first place? relative to what? If the required datum point just happened to be a correctly positioned button, then fine, but that is very seldom (never?) the case.

I can see how the spinning laser can position the conical button accurately below the spindle centre, but how do you place it where you want it in the first place? If its in the right place, then fine, if its not then how does the spinning laser help?

Gary

John,

As I mentioned before, I understand how it works, and how, if the conical button is placed in exactly in the right position, the inclined rotating laser beam "magnifies" the displacement error. What I don't understand is how you place the conical button exactly in position on the work piece.

It seems to me that the whole point of using a laser is that it allows you position the work piece relative to some specific feature that already exists: an edge, corner, or hole, for instance. How does the conical button assist in locating that feature?

Gary

Thanks Ian, but as I said in my original post, I understand all that. What I don't see is the use of the solid cone that was shown in the CAD drawings used to illustrate how the laser circle deviated from the horizontal if the cone wasn't concentric with the spindle.. There was discussion on whether a ball would perform any better than a cone - for what purpose? Certainly a ball would self centre in a hole, but would offer no more accuracy than the described laser circle.

Like I said, I don't understand the purpose of a real, solid, cone.

Gary

I've obviously missed something about the cones and the inclined rotating laser.

I see how the rotating laser indicates when the cone is not directly below the centre of rotation, but I don't see how you place the cone directly over the required datum point of the work piece.

I thought Mr. Gelbart's method of adjusting the laser circle diameter to pretty much coincide with the circumference of an existing hole, reducing the circle to a point to indicate an edge pretty much did it all. As did the edge "V"s for indicating the spot for cross drilling a cylinder.

I'm sure somebody can tell me what I missed about the cone.