Member postings for Gary Wooding

I made an additional point out of silver steel, which I sharpened to a nice point.

Absolutely fascinating, but what happened to page 159?

Its so easy to completely lose track of numbers that are bandied about, that people have no real concept of how big they are. Take the terabyte disk, for example. If you took one standard fag paper for each byte in a terabyte, and stacked them one above the other. How high would the stack be?

Don't calculate it, just take a gut guess.

It would be about 17,500 miles high!

Surprised?

I'll second those observations - the wind of change has blown it out of the doldrums.

You should also try levelling the bed with a precision level. This is to ensure the bed is not twisted.

Put the level on the saddle, across the ways, move it to one end and note the bubble position. Slowly move the saddle to the other end - ideally the bubble shouldn't move. If it does, bed is twisted, or worn, which, as far as the saddle is concerned, amounts to the same thing. Adjust the feet or whatever, to eliminate the twist.

Note, it isn't necessary for the bubble to show that its level, only that it doesn't move as the saddle moves along the bed.

Sorry Neil,

I must have missed something - who's Ken?

Anyway, yes, you can do it with one clock but, as you clearly stated, it creates problems. The only objection to the 2 clock method is that it requires 2 clocks. They don't have to be identical, just accurate enough, Second hand ones will do.

The suggestion in the original article was to mount the bar on a faceplate and trim the pillar, so it obviously must be possible to swing the bar.

The longer the bar the more accurate is the trammelling.

First thing, be careful about milling aluminium - some grades are very "sticky" and tend to build up on the cutting edges of tools. The usual advice is high speeds, but I've found just the opposite. I reckon the ali welds itself to the tool edge and higher speeds mean higher temperatures. I use slow speeds and paraffin or WD40 as a lubricant. Stop immediately if/when resistance is felt, and clear the ali buildup on the cutting edges before continuing.

To cut the pocket, I'd rough it out with a 10mm endmill, about 5mm deep at each pass. Then do the corners with a 6mm cutter (3mm radius), and then do a finishing pass all over.

Eric,

The normal digital angle gauge (Wixy type) has a claimed accuracy of 0.1 degrees, which translates to an error of almost 0.007" in 4". That's nowhere near good enough for a mill.

With regard to the MEW article, what's wrong with holding the pillar in the lathe chuck and taking very small cuts from the bar? Yes, I know its an intermittent cut but that shouldn't present any problems.

Hi Steven,

I can definitely recommend having DRO on a lathe, and I find the Z-axis one just as useful as the X-axis one. I fitted the BW Electronics wire system to my first lathe - its very compact and worked very well. When I upgraded to a bigger lathe the wire system was too small, so I fitted the normal glass scales. I wouldn't be without DRO now.

It's probably a silly question, but what is stopping you simply replacing the motor and using the original pulley?

Can you not change the Acceleration Time parameter? On my Mitsubishi VFD it's parameter 7. Parameter 8 is for the Deceleration Time.

Hi Bob,

I'm also using V21 PP. The first time I use Help it gives me the option of Online or Offline (with Online pre-selected). I've found that if it gets into the state of Online, then I can't find an option for Offline, unless I close and re-open the drawing.

I suspect that your error message is the result of using 2D shapes that are not closed. A shape can appear to have no gaps in its border, but still not be closed in the TCAD sense - it will appear to TCAD to be a series of lines/polyline/arcs etc. Use the Join Polyline tool to join them together (if you can't find its icon, look in the Modify pulldown).

Another little gotcher is when the shapes are closed but are on different workplanes. This is a strange feecher of TCAD where entities appear to be co-planar to the workplane but TCAD insists they are not. If this happens (and it can even happen when you are working entirely in 2D mode), switch to 3D mode, select the entities, then use Modify|Place on Workplane. You can then switch back to 2D if you like, but I normally keep in 3D mode.

A picture would help.

Thanks for that.

The offer email should include Jason's image instead.

I received an email advertising the Model Engineer subscription offer that includes a free gift of a Vargusb10bladesmhand

But what is it? Even the Vargus site sheds no light on it.

Posted by jason udall on 23/10/2014 09:09:01:

Watch out for distortion ..ideally you need a die to support far side..now how do we make the die...

Edited By jason udall on 23/10/2014 09:10:10

I'd make the die for this particular one-off from a small block of ally or hard plastic such as Nylon.

First drill a 5/32 round hole. Then, from a piece of 5/32 square silver steel turn up something like this on your lathe. Harden and temper it, and push it through the drilled hole.

Edited By Gary Wooding on 23/10/2014 08:16:44

Phil,

What sizes are the holes, and what thickness of what metal are they in? Are they through-holes or blind?

Yes, they were there every day.

I fancy making one for our 5" raised track - I reckon I'll have to design my own.