Wow, thanks guys, kind words indeed. When I started this project, I didn't really know what I was taking on. I didn't realise I'd be so close to the limits (in terms of size) of the Bridgeport; I just figured "it'll do it, no bother"... but, well, I've learned a lot along the way - some as a result of "suck it and see"; but lots more from all of you out there who've either commented directly; or who've I've liberally stolen techniques and knowledge from your own threads. Without this website, I couldn't have come as far as I have, in the relatively short "actual machining time" that I have.
Truly:
Soooo anyway, I wasn't going to show the making of a spigot, 'cos it should only take 1/2 hour & be dead straightforward, right?
Yeah, right.
First up, I decided - perhaps unwisely - to use some scrap steel I happen to have. I think it used to be a hydraulic ram. I've no idea what it is, but it's pretty tough. It makes cool smoke though:
So; chop it down to 1" over the whole spigot length; then cut a .600" long nose to 0.825", which is threaded with a 1/2" BSP die in a monster die holder:
Using lots of oil, I power-tapped at 17rpm up to the last couple of turns, which were done by hand. Then, part the piece off. I'd hope to show a nice action shot of that, but the cutting oil can obscured the view. Shame, it made good smoke...
Moving on, I have a piece of steel pipe I'd tapped internally; so, chuck that up, and screw the spigot into it. I realised at this point I'd forgotten to relieve the end of the threads with the parting off tool, doh!, so it didn't quite sit true to the shoulder. Still, near enough..... The end is turned down to 0.750" for the pipe to slide over, then progressively drilled out to 5/8":
That should have been the final operation on the lathe, except for this one I needed to cut that shoulder... I used my ER32 collet chuck because it's pretty damn accurate, once you've found the best position for it in the 3 jaw. TIR was less than 0.002". I'm not sure if I get a prize for "The most chucks in use simultaneously" - the ER32 chuck in a 3-jaw in a 4-jaw....
Final actual operation is to use the dividing head on the mill to cut the flange into a hex shape, so I can graunch it up with a spanner. It turns out a 19 will fit perfectly:
So, there we have them:
I should probably explain the black one.... it wasn't deliberate, my 19/32" drill went blunt in the middle of it (probably a lack of oil + not pushing it consistently enough); I did keep trying to push it through, but when the whole thing changed colour & the cutting oil ignited, I figured it was dead... Fortunately, I have enough other drills that I could bin that one & carry on... eventually, I got it cut. The heat had definitely hardened the metal though, it was noticably more difficult to mill the hex...
Anyhoo - here they are, three little piggies all in a row:
And with some pipes on:
Turns out there's not quite enough room for a jubilee clip on that leftmost pipe, I'll have to mill a tiny (0.5mm at a guess) relief just to squeeze it in. Also, there's not enough space between the pipes to allow 2 jubilee clips to pass each other, so one of the tubes (probably the middle one) will have to be pinched "high"... There are 3 solutions to this dilemma: 1, use a thinner wall pipe; 2, next time, leave more space between the pipes; 3, make a longer spigot for the middle pipe, to allow the clip to sit further outboard. In the picture, the pipe is being pinched over the "bolt" section, which I'm not totally happy with.
