Denford pillar drill

Do any floor standing pillar drill owners have any info/advice on how to separate a drill column from its base, This example is a Denford Viceroy.

The column looks somewhat rusted in but has had some penetration oil applied over a few months. I am hoping that the column is not screwed in!

One slight problem is that the small hole in the base that allows sight of the column from the underneath is not centred over the column, therefore the press mandrel only bears on a crescent shaped portion of the column.

I will try again making up a better mandrel from steel parts being 2 3/4 diameter billet to get into the hole in the base.

If that fails, what options do I have?

I would like to restore column and base but the two parts together are about 45Kg and for me are too much to easily move.

Pic 1 shows the general arrangement

Column appears to be held in socket of about 10 inches depth. Please tell me that it is not likely to be threaded or tapered!

Pic 2 shows rear of base with the two securing flat ended grub screws removed.

Pic 3 shows 12 tonne press propped up on a tottering pile of bricks after first attempt to push out using turned hardwood billet.

Result - epic failure!

Oxy torch to heat the base?

Shine a torch into the holes to make sure there isn't another pair of grub screws inside. Quite common for grub screws to be anti-vibration locked by screwing another one into the first.

The torch might also show a thread.

My guess is years of rust in a joint too deep to be easily penetrated by oil. In which case, repeated cycles of strong heat. Berhard's Oxy Acetylene is best because it gets objects quickly up to high temperature but a blow-torch should do the job eventually. Needs to be a big one though - that's a lot of metal and the faster the base is heated the better.

Dave

I'm with Dave and Bernard, oxy/propane or a large propane blow torch. You may have to get it near red heat to break the rust. Or light a bonfire of wood, old pallets in the garden and set it in the middle. Good luck. Noel.

I think I would open out the bottom for better access, insert a piece of square hss crossways or a round drift, then shove it out with the jack

Put the pressure on then leave it for a while, like with a balljoint, coax it out with some hammer dinging and an aluminium protector

Got to support the flat part though, cast iron no likey tension, only compression

Put a plug in afterwards? if you want to

With that 12 ton setup you must be half way there

Edited By Ady1 on 30/07/2023 14:37:35

Hi, before I read Noel's post, I was thinking about heating it on a bonfire, but I'd build the bonfire first and then set the base on top and the light the bonfire, to gradually raise the temperature, instead of sudden heat. Once it got burning you can then add more wood, until you think it's hot enough, and then let the bonfire burn itself out and allow it all to cool down in the ashes, but you may have to it a dull red heat to do any good. When it's cool enough, pour a good deal of penetrating oil in that hole in the bottom and in those grub screw holes.

Regards Nick.

Edited By Nicholas Farr on 30/07/2023 15:35:41

Just wondering, why do you want to separate them ?

Could they not be cleaned up as they are ?

Re your second picture Martin. I can see the moving part of the press (bottle jack) is presumably pushing on the crescent shaped access to the bottom of the pillar, but what is in contact with the top (RH in picture) of the base casting?

I would suggest that you apply several tons force to the bottom of the tube to 'load up' the whole assembly, then use a lead mallet to 'shock' the rust into submission. Hitting radially around the tubular part whilst loaded will be beneficial.

Are you able to also apply a shock force axially by using a drift and hammer on the end of the tube as well (if there is access past the jack spreader plate).

Whilst heat (a lot of very hot heat!) would help, I foresee some issues with the practicality of manhandling something so heavy and too hot to touch. It is not as if its just going to slide out so you would still need the press, whilst its hot!

Ian P

I appreciate your point about the weight but might it be better to consider more how to move it around than how to take it apart? Especially as there is no need to separate the column and base for refurbishing it.

Can someone help you manipulate it into its eventual position and set it up?

Putting the table and head back on the column will be the hard bit, after all.

Thanks to all for the advice. I was hoping someone with similar Denford would chip in and confirm not screwed in or some sort of hidden fastening. I see no reason why it should be threaded and peering through the lock screw holes can see no evidence of threads or other means of attachment. Just an unnecessarily long collar with 8 or 9 inches of rusted metal column!

Unfortunately I do not have any access to welding gasses and totally take the point about heating to red heat, I just don't think it would be practical in my situation. The best I can manage is a 21/2 inch propane burner (as in picture). That isn't going to get 25Kg of cast iron to red heat, maybe 4-500c. I'm not sure if there would be sufficient gas flow for a larger burner, assuming such would be available.

The picture showing the press and base was not taken under pressure. The base would have been further to the right with the upper and lower lips of the collar top pressed against the red cross beam and the mandrel from the jack piece to the bottom of the column inside the base.

I will have another go when I fabricate an accurately sized custom steel mandrel. I am wary of heating while attempting to press as I thought CoEf expansion for steel is greater than iron. Perhaps in this circumstance it doesn't matter. May also try using a 20 tonne jack unit, which are available at the same size. If it destroys the frame, then I know I have done my best!

As a unit, the base + column is just a bloody awkward, heavy, difficult to manhandle piece of kit and dragging it in and out of the garage numerous times as a single item to abrade, pressure wash, undercoat, paint the base and then phos acid, neutralise, wet'n'dry and polish the column would be a total, 100%, 24 carat, PITA.

But in the end, as suggested, restoring as a unit will be the reality if second pressing fails to work. By comparison, the head (without the 6 pole motor) and table are pathetic, tinny, lightweight items at a mere 30Kg a-piece or there-abouts, with the motor and accessories adding only another 15 Kg.

Hi Martin, one thing you should use though, is a piece of plate something like 16 to 20mm thick, with a close fitting hole for the column, to go between that narrow edge of the base and your press cross beam. If you are pressing straight onto the edge of the base, there is a real risk of fracturing it with such a lot of pressure just on a small area each side, and it could even damage the cross beam as well. Your jack may not work so well in a horizontal position, so it maybe better to life that end up a fair bit.

Regards Nick.

Edited By Nicholas Farr on 31/07/2023 08:14:15

You could drastically reduce the amount of times you need to move it by using more modern paint; if you use ordinary 2k paint from an automotive supplier, you won't need the undercoat, acid, neutralising or rubbing down. Just degrease, pressure wash, dry in the sun and two coats of paint brushed on about 30minutes apart. Leave it a couple of hours to dry in the sun before reassembling the machine. Polish the column first, and mask the bottom before painting the base.

NF - Eeek! Thanks, you are quite right. The column fitted exactly between the two bars of the brace so my thought processes suddenly ceased at that point. It will be an expensive piece of plate too...

NW - The health aspects of 2K paints as sprayed have put me off in the past, it had never occurred to me that 2K might be brushed. Thanks, I shall investigate that option.

For breaking stuck joints, I think fast heating rather than slow is required.

If the base is heated rapidly with a torch, the base starts expanding before any heat reaches the column, and the expansion pulls hard on the rust sticking them together. And if the base is then cooled quickly, it contracts and crushes the rust against the column. Both actions give the rust a hard time, which loosens the joint. Several hot-cold cycles may be needed.

Slowly heating the base and column together much reduces the stretch/crush action because the parts expand and contract at together at the same rate, giving the rust an easy ride.

Slow heating works if the joint is stuck by gummed oil, paint or loctite, which have to be burnt out.

Shock is more effective at breaking joints than a slow push with a hydraulic ram, but there's a risk of cracking cast-iron. Sharp raps with a big hammer often get stuff moving, though whacking stuff hard always makes me nervous! Anyone tried a jack hammer?

Dave

It looks to me that cleaning and painting as a unit would have consumed much less effort than you have wasted on it so far.

If it was originally a press fit, and you do manage to press it out, you'll eventually have to press it back in. This looks to be beyond the throat of your press. I'd buy 4 castors and a bit of plywood and make a trolley on which to move it around. I've got such a beast, and it's dead handy for all sorts of moving jobs. Last time was shifting a king size mattress, I could tip it on its side, but no way could I then drag it.

May I suggest you head over to the Denford Forum - **LINK** - where you can find drawings of the pedestal drills and components.

The bases are just a sliding fit for the column, retained by 2 off 3/8" BSW screws.

Andy,

thanks, wasn't aware of that site - very useful.

It looks as if what appears from outside to be a single socket may be two parallel collars, which is useful to know. As is how thin the casting walls are. Sooo glad I didn't start a-hammerin on it!

From measurements, it looks as if my version has an increased the length of lower collar, certainly downwards and probably upwards as well. A relief to know it was just a placement fit.