Pillar drill steel tube

I need to make one of my floor standing pillar drills considerably taller for a special long running job. What sort of "Tube" is used? I know its steel, I know its 2 3/4" diameter, but its not ERW. The surface finish is above the average stock material.Unlikely I would think to be ground? Advice welcomed with thanks Bob

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In days of yore it could be cast iron. I have one drill that I picked up from a cynical trader that still had the core in the hole! These days I would suspect centrifugally cast tube. It might be just as cheap to get a length of 2 3/4" or 70mm solid bright bar. Make sure the drill base is level and bolted down though :-)
I just measured the column of my tai/chi floor standing pillar drill and it's 80mm. The going rate for these seems to be £200 +VAT for a 1.1m chuck to base drill. How tall do you need?
Do you have a solid bench that the floor standing drill could be bolted to (or a custom made stand) That could get you another 3' or more, with no loss of rigidity.
Mark Rand RTFM

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The drill is an old Pacera that needs to be in a line of drills. So clamping to a bench is out. Annoying thing is I scrapped an ideal base from an old Elliott last summer, this had the cast base and the raised casting that the tube goes into. A similar one I have is great, the tube or pillar was in the casting right down to the floor, so a simple raising of the tube gave me the height of 1500mm under the drill with room to spare. There is a scrapper on Ebay that might do the job if the guy sends a photo of the base.
One possibility is to turn up an extension, but it might be as cost effective to locate a length of bar as you suggested. Oddly enough, another Elliott I have has exactly that, solid bar for the pillar, weighs a ton !!
I have also noticed that between different drill makes, the 2 3/4" pillar can vary by 15 thou which takes me back to wondering if they were ground bars.
I think I'd rather dig a hole in the floor (there's an idea ! )than lash out £200 for some Chinese import, no offence, but I have been there........ My huge old Kerry drill has so many controls, 3 morse taper, power down feeds etc it spoils you.
I should add I need to be able to turn the table vertical to accept a jig that holds flat steel bars to be tapped centrally on each end, so I also need room for the Tapmatic with a 2 morse taper and protruding 4mm tap Bob

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We have a nearly new Ajax floor pillar drill which is a rebadged Chaiwan import, but the Elliott Progress 3A in the corner is the beastie to play with!
They are horribly heavy, but superb if you really 'need' to do some serious drilling.
Picked up a load of free, nearly new 3 morse taper drills recently :-))
Re the tube, talk to one of the steel suppliers and see what they can do in ground finish tubing, or find a local engineering shop that might have something close to what you want?
You might even pick up a bit of stainless?
Peter -- Peter & Rita Forbes Email: snipped-for-privacy@easynet.co.uk Web: http://www.oldengine.org/members/diesel

Emimec wrote:
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Could you get something we call "precision tube"? It is cold drawn, not welded and has tight tolerances (that you will have to pay). Comes in a lot of diameters and wall thicknesses.
Nick

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I have the column from a Startrite bench drill under the bench, about 3' long from memory. There was also a bench mounting bracket (from a meddings drill that was supplied mounted to a bench instead of having a normal base). They've both been thee for a while "just in case", but as i haven't used them yet I'd happily swap them for something more useful. Might be a bit heavy to post though. Drop me an email if they are of interest and I can dig them out and send you a piccy.
Regards Kevin

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Many thanks, I also have a spare 3 foot column from a bench meddings, and the cast bases from 2 others, as well as several part butchered drill heads all kept, as you say "just in case". I will either see what I can locate in the way of another drill ( ebay has a couple of possibles) or take the route suggested and ask my steel supplier what he can come up with in the way of ground tube. One idea, is to mount the drill I have on some box section to raise the whole machine, but its a bit Heath Robinson and sods law everything dropped will hide under it !!!
I had planned to drill the longitudinal holes in the flat bars on the CNC mill, but typically the sample I was given was 500mm long and must have been the shortest example of work from this company, ever since I made the sample , most bars are 1500mm long, and few mills in my experience have a table travel that cope with that length, let alone drilling the ends of the bars. Bob

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Are the diameters of the bars small enough that the bars are handle-able?
What I'm thinking is a split clamp on a lathe cross slide drilled in place. Remove the tailstock. Then use either a fixed steady for support at the tailstock end or a V block on a pile of stuff or even a bandsaw/hacksaw roller if the bars are long enough.
Operation is the simple... Fit drill in chuck at headstock, clamp bar in clamp, drill hole. If holes are wanted that aren't centred, then offset the cross slide.
Mark Rand RTFM

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Problem almost solved thanks to information received on this newsgroup. I contacted my steel supplier, who suggested I contact another local supplier, Hub Le Bas tubes ltd. One phone call and they have in stock 2 3/4" diameter precision ground tube with a 5mm wall thickness for £10.80 a metre. Now the fun bit- it comes in 6 metre lengths !! Watch this space for a 4 metre length of tube offered for sale !!! Thanks Bob

Emimec wrote:
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You'll get more money with shorter pieces! :-)
Nick