Well after UPS losing the last chuck I bought the chucking cylinder has been doing nothing but spinning for the last 3 months. I however have just taken delivery of a nice new Pratt Burnerd 250mm Dia power chuck, complete with hard jaws. soft jaws and it even fits right on to my C8 bayonet fitting spindle nose

Hope to get a tube made up soon so I can start using it.
Hood

Tried the chuck on today so that I could measure for the drawtube length. The chuck looks small for some reason, think it must just be the shape of it as in the second pic you can see the normal shaped chuck below it which shows they are the same size, they are both 250mm Dia chucks.

Hood

This is turning into a nightmare for me
I have been trying for 3 days to find some seamless tube to make the draw tube but I am getting no where fast. I did manage to get one place that quoted me £150 for 1m of 70mm OD x 3.2mm wall but the spec of the material was different from their website. I have asked what the yield strength of the quoted material is and as yet no reply
 Fingers crossed I can get something soon, just cant believe how hard it is to get something like this. Plenty of places have the ideal size advertised online but when you enquire they dont have anything near it. The ideal for me would be 73mm OD with 4mm wall, I could then turn the end down to 72 and thread it for the chuck then turn the rest down to 70 or 71 to pass through the spindle and make up an adapter for the cylinder end. 2½ inch  NB pipe is the right OD but has just over 5mm wall but even trying to get a bit of that is proving difficult, if I bought 6M random length it would be easier but if 1M is £150 I dont fancy having to buy 6M

Hood

schedule 80 tube should be available.

Thats too heavy walled Wayne,that is if you are referring to Nominal Bore, 2½"  Sch40 is 5.16 wall
Hood

Well just like buses some suitable pipe came along in twos
A friend managed to source some 2.5 Inch NB Sch 40, I had to buy 2.65m but as it was only £55 for that I wasnt worried so told him to get it. A few hours later I got an email from a company I had emailed a few days earlier and they were offering the same tube but in the 1m length I requested and it was only £20 so more or less the same as the other place. I had already said to get the 2.65m so thats what I will be getting but its a big difference from the original price I had at £150/m for smaller dia and wall thickness tube
Hood

Sure it will be fine.    Just be careful setting your pressure!   


I need to start thinking of making a new tool turret for the Hardinge.   Got some material (EN24T) in to make the Curvic couplings, so thats a start!

The Sch40 will definitely be fine as I worked out the tube area left after the thread depth and the Yield strength exceeds the cylinders draw tube pull by over 4x so no worries there

I was lucky enough to get a brand new  coupling from Mark so thats one thing I didnt have to do

Hood

Got the drawtube machined today. The OD of the pipe was just over 73mm and I needed to turn down the first 80mm to 72mm Dia and thread 1.5 pitch, the other 820mm was turned down to 70mm to give clearance through the spindle bore (71.7mm) and the last 120mm of it was threaded, again with a 1.5mm pitch. I still need to make an adapter for the cylinder end and a locking nut for the chuck end but hopefully will get that done sometime this week.
Just had the phone so pics are crap as the lens is all scratched but heres a couple of pics, one of it on top of the wee conect lathe I am doing and the other with it screwed into the chuck. Really looking forward to getting the chuck fitted and I will again be able to take some heavy feeds.
Hood

Got the adapter made for the chucking cylinder, got the draw-tube fitted and chuck fitted then tested it out by working the hydraulic solenoids from the manual actuation on their ends and it worked fine.
 I only had 3 outputs spare on the PLC and they were wired up as sourcing outputs and as usual the relays for the cylinders were needing sinking inputs. Made up a wee relay board so I could then work the cylinder relays from the PLC, fitted and wired that and then altered the ladder in the PLC. I used two buttons I had on the panel that were for the front turret I used to have (one for indexing it and the other for the coolant). I have the buttons interlocked in the PLC with the spindle enable signal so I cant work the chuck unless the spindle is disabled.
 I took a couple of test cuts to see how things were performing and was very happy, took a 5mm DOC off of 70mm Dia EN8 at 0.35mm/rev and it cut beautifully. If I had attempted even 2mm DOC at 0.25mm/rev then the material would have been pushed into the manual chuck no such issues with this chuck .

Hood