Pye MM

[AlanBeckett]

Not much progress today, it being Saturday. That appears to be fairly universal at the moment on the Forum. Is everyone taking advantage of the fine weather?
So, the next requirement was to measure the offset angle of the Detent compared with the flats for the switches.
I glued - araldite - the broken end sections back together so that I a section to grip on and measure, and fished out my Rotary Table. I then set up a square so that I could get the two flats vertical - see attached.
As far as I can tell it's between 6 and 7 degrees, and I think it's 7. So, that's the value I've put on the Drawing.
I've also tidied up the Dims a bit.
So, the next step I think will be to make a sample shaft, at least make the Detent square, so that I can see where the switch contacts really fall.

Alan

       

[Yorkie]

At first sight, at a casual glance it looks deceptively simple Alan, but the drawing shows that there's rather more to it than meets the eye!

Quite a challenge in fact.

[Retired]

Hi,

Rotary table Alan; my you are posh. Its interesting to see you take the "high tech" route and I'm keen to watch your progress. I'm too tight for such luxuries and resort to using high precision scrap; bits of paper and on a good day a sliding bevel.

Get stuck in Alan and go for it; why bother with a prototype because the first one will be interesting but the second one boring.

How do you intend to produce the flats and the offset square end; have you decided on a plan of action?

I like to see how others approach these tricky little projects as I hope to pick up some tips and I'm always willing to learn new techniques.

As David rightly states such a spindle would appear easy to make after all it's only a short length of 1/4" Dia rod but it is deceptive in it's simplicity. Have fun.

Kind regards, Col.

[AlanBeckett]

Col,

I bought it for myself as a Christmas presant a few years ago.
I'm pondering on a plan of campaign, but not tonight having just got back from Golborne.

Alan

[Tedzed1]

I must say Joe, now having seen the cabinet in the flesh, I am very impressed with your work.

[AlanBeckett]

So, onwards and upwards.

Sorry for not Posting on this Thread for some time, but I suffered a couple of setbacks, apart from Golborne. First I had to wait for some more bits to come, and then I dropped my camera onto the tiled kitchen floor. It didn't survive, so I've been learning how to drive my son's Sony Cybershot - see eBay Item 260897674335. This is a fairly fearsome beast which does all sorts of alarming things. I've got to Page 21 of 159 in the Manual and I can just about switch it on and take a picture, as you'll see when you look at some of my efforts. I hope to improve.

So, step one was to get the Rotary set up on the Milling Machine with its Tailstock. There's no need to clock it very accurately for this job so stick the Test Bar in, line it up and tighten down. I've been pretty generous with the distance because once I get to machining the flats I won't want to take it out until I've finished. However, I think I've been a bit too generous - we'll see.

Next I decided that I'd machine the four flats which form the detent. I machined these right off the end - about 1" - while keeping the material as close to the chuck as possible. First I machined one flat accurately. Then it was just a matter of machining the other 3 sides at 90 degree intervals. Apart from making sure always to rotate in the same direction it's not difficult. The picture isn't very good, and gives the impression that it's rougher tha it really is. However, it's also true that there is a slight taper to it, no doubt due to the amont of material I had hanging out. It's not a big problem as I only need 3/8" starting at the plain shaft.

Finally, in this Post, I stuck it in the Chipmaster and turned the end down and faced it off. The knob fits OK but there's a bit of shaft left exposed. I'm pretty sure of my measurements but I'll check.

To be continued.....

Alan

                       

[Mark R]

Golborne? a set back Alan! now that is harsh lol, nice work though!
cheers Mark

[AlanBeckett]

So, now for a trial fit.
In a nutshell, it fits.
However, a couple of comments:-
It doesn't pull out, so the combination of the knob, the detent spring and the very small difference in the diameters is enough to keep it there.
There's about 3/32" of endfloat on the shaft. There's enough overlap between the contact fingers and the switch blocks to cope, but it does seem a bit much, hence my comment above.
It really does click round very solidly. Actually click is the wrong word because there's no actual clicking noise as with a conventional switch, but it does feel very solid.

So, I think my next step will be a trial assembly of the panels so that I can mark up where the contact fingers fall and see how the postions compare with my Drawing. Also, I should be able to see if that improves the endfloat or whether I need to adjust anything.

More soon.

Alan

           

[Joe]

Thanks for the up-date. Very interesting, especially as I've never seen a rotary table before.

Keep up the good work.

- Joe

[AlanBeckett]

I've had a thunk and a bit of a measure. In the light of the endfloat I believe that the 0.51" dimension should be 0.5". It's logical like a lot of the others. They're really Imperial Fractions. Also, the hole in the knob is only about 0.47" deep. There will still be some endfloat, but slightly less.
I've also updated the Drawing. There was a duff dimension on the Detent, and I've made the Arrowheads a bit bigger for clarity.

Alan