Unsiezing a Rotary table

[Adam HarrisParticipant @adamharris13683]

[Adam HarrisParticipant @adamharris13683]

I have a 10" rotary table that is seized. I have removed the worm screw mechanism and all bolts/screws and am left with the table base and top which are seized together. Being a high precision piece of equipment I am a little cautious of how to part them and was thinking of heating up the base first with a blow torch then drifting them apart with a piece of wood bashed with a heavy mallet. I have read that someone first tried to rotate the table with a 3 foot lever before drifting but I am worried about damaging the T slots. Furthermore it is a 10" beast and do not have anywhere easily found to bolt it down to that does not mind getting a bit damaged ( I am not going to use the Tom Senior table) . Any advice before I get to it this afternoon much appreciated! Adam

[Anonymous]

Personally I would only use heat as a last resort for precision equipment; and probably not even then! If it is that corroded then it is likely scrap.

I'd be inclined to liberally douse the thing with WD40/penetrating oil and wait. I'd bolt a length of steel flat on to the rotary table with proper snug fitting T-nuts so that the slots shouldn't get damaged. I wouldn't hesitate to bolt the rotary table to my milling table, but then again I've only got a tatty old Bridgeport. Having let the pentrating oil work I'd clobber the steel bar with a nylon/copper mallet.

First, of course, I'd make sure I actually have removed all the mechanism, locking devices, unseen screws etc.

Andrew

[Tim StevensParticipant @timstevens64731]

Before you light the blow torch, have a good look at it and make sure which bit actually fits outside the other bit. Heating up the inside part by mistake will make removal harder. And give it all a good squirt with penetrating oil – the proper stuff that smells a bit like ether, not WD40 or Duck oil. And if you can work out which half is the lighter, hitting that part will be more effective than the other way round, as you will have inertia on your side.

Go steady

Cheers

Tim

[Adam HarrisParticipant @adamharris13683]

Thanks. I was thinking of applying the torch to the base only, not in order to have the base expand therefore making drifting easier, but to gently "crack" apart the siezed gap which admittedly would work better if top and bottom were of different materials . I would let it cool down again before trying to drift. Do you think this would damage anything (I am thinking slight heat differential, not blasting it up to red hot or anything dramatic!)

[Adam HarrisParticipant @adamharris13683]

I could bolt it to the Tom Senior table but I think the M1 has a tendency to crack at the knee (hence was beefed up in the Major which i do not have) and that would be an utter disaster. I suppose I could try some gentle persuading and stop early if no progress. I do have a Meddings drill table where literally a great chunk has been broken out of the T slot and I am wary of doing this to the Tom Senior table or indeed the rotary table T slots

[Adam HarrisParticipant @adamharris13683]

Regarding WD40 I have of course done this 24 hours ago but the rotary table bearing surface is not easily accessible by spray

[Adam HarrisParticipant @adamharris13683]

I have thought about putting it in a very large metal pan and boiling it up with oil or chain lube (as i used to do to bike chains in my old biking days) but I have not yet found a big enough pan and actually the camping burner is not really sturdy enough to take the weight of it.

[Adam HarrisParticipant @adamharris13683]

Putting a steel flat along the rotary table slot , clamping it in place is a good idea for protecting the rotary table slots, bit then what about the slots of the table to which the base gets mounted. Maybe i just mount it to a piece of timber wedged across my trailer (wedged between the sides)

[Brian WoodParticipant @brianwood45127]

Adam,

Just a thought before you begin.

Does it have a spigot through the centre with some form of locking from the underside along the lines of the cheap versions?

I would also screw the body down to your workbench rather than clamping to machine tables, shock loadings can have nasty habits of doing damage elsewhere.

Best of luck

Brian

[MuzzerParticipant @muzzer]

Perhaps if you posted a picture of it, somebody could confirm how to dismantle it in the approved manner. Nothing worse than finally getting it apart only to discover the bolt / circlip etc you hadn't realised was there, especially if you generated(!) extra parts in the process.

[BazyleParticipant @bazyle]

I take it that it doesn't rotate at all. That implies there is something along the peripheral bearing surface that has rusted rather than the central spigot as you would have enough leverage to move that. I suggest continuing to make it rotate using very very very many light taps to try and break the rust bond. By applying the this force in a rotary direction you will be stressing the rusted part in shear which by the nature of the design will be strong.

If it is an american make you should post your query on PM and HSM where they have more chance of knowing th e make.

[Adam HarrisParticipant @adamharris13683]

Bazyle, thanks as always.

[JimmieSParticipant @jimmies]

Hi

I once heard of a home made vacuum bag working wonders in this type of situation which may be worth a go if/when all else fails.. Drench the table in penetrating oil before placing it in the bag. A quick google turned up some ideas for the bag design.

[Adam HarrisParticipant @adamharris13683]

Hi Jimmie that is a very very clever idea indeed and a great saving on the quantity of WD40/oil/kerosene. Thank you! Well anyway, thank you Andrew, Brian, Tim, Bazyle, Jimmie for your time – it was less seized than I feared and after mounting it on the milling table and gently exerting rotational leverage with a long piece of bar (actually the handle of a very large long adjustable wrench) it moved . I then unscrewed the oiling nipple and pumped the hole full of oil while rotating and gouging out swarf from the gap with the back of a stanley blade. Much pumping and much rotating and eventually the oil started to seep out clean. An astonishing amount of swarf was the culprit! So no blow torch, no wacking, but just overnight soaking in WD40 and leverage and now a very nice rotary table in my posession!

[Brian WoodParticipant @brianwood45127]

So a happy ending as well. It is always nice to hear the final outcome of brain storming.

It might though pay you now to remove the table completely and clean the inside very thoroughly as well, it might be full of dead coolant as well. You will only have shifted that which was jamming it and the next time it might lock up will undoubted be part way round a job which you really don't want to disturb

Brian.

[Adam HarrisParticipant @adamharris13683]

Thanks Brian. Will do

[wendy jacksonParticipant @wendyjackson]

when I was in the army, we used diesel. put the part in a bath of diesel for 24 to 48 oils. will free off parts. much better then wd40. michael

[Anonymous]

Posted by Adam Harris on 02/05/2015 17:24:01:

Well anyway, thank you Andrew, Brian, Tim, Bazyle, Jimmie for your time – it was less seized than I feared and after mounting it on the milling table and gently exerting rotational leverage with a long piece of bar (actually the handle of a very large long adjustable wrench) it moved . I then unscrewed the oiling nipple and pumped the hole full of oil while rotating and gouging out swarf from the gap with the back of a stanley blade. Much pumping and much rotating and eventually the oil started to seep out clean. An astonishing amount of swarf was the culprit!

Thought it might be, that and dried oil/grease/gunk.

Andrew

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