How to gently enlarge a bore (without using a lathe)

[RainbowsParticipant @rainbows]

[RainbowsParticipant @rainbows]

After moving house I decided to do a strip and repaint of my already partially disassembled drill press. One issue I had was taking the flange that clamps onto the post and bolts into the base. It took an absolute pounding with a soft faced hammer to edge it off its post.

I'm guessing it either warped with age/ constant stress of clamping or maybe the factory pressed them right on with a big machine. Either way I would Ideally like to not have to whack it with a hammer for half an hour to get it back on.

Skimming it out with the lathe is out cause I can't fit it on any currently available lathes. Scrubbing it with sandpaper sounds very tedious and not overly accurate.

Any advice?

[david sanderson 3Participant @davidsanderson3]

could you drive a wedge into the split and remove it when its back on the post

[RainbowsParticipant @rainbows]

I have a healthy phobia of wedging open cast iron parts on account of the sudden brutal breakages that can happen, that said if no better solution raises its head will probably gently try that

[Speedy Builder5Participant @speedybuilder5]

Just turn up a wooden plug 1/8" smaller dia than the bore, saw a slit down it thick enough for some emery cloth. Drill a hole through the centre of the block and mount it on a drill using a bit of threaded rod. Wrap a bit of emery around the block and clean it out with your hand drill. If you really want to go to town, get a lapping tool from your car parts shop.
BobH

[HOWARDTParticipant @howardt]

Find a suitable diameter flap wheel and use a hand drill.

[Neil WyattModerator @neilwyatt]

Clean it up, use plenty of lube and apply some heat to the casting.

Neil

[Mick B1Participant @mickb1]

I was gonna suggest a broom handle with wetndry to get out the scale and crap, but now SB5 has suggested similar but a bit more elaborate.

Then stick it in the oven at about 180 until it's heated through, and maybe it'll just slip on? If so, don't quench – just wait for it to cool.

Edited By Mick B1 on 04/08/2018 15:04:26

[JohnFParticipant @johnf59703]

As BobH says a wooden "lap" with emery but you can also add some foam rubber under the emery work well fo me for polishing the inside of tubes — metal removal is of course minimal.

John

One thing you need to be carful of is not to end up with a barrel bore — may be better to clean it up well and consider reducing the pillar diameter but I would try the wedge –carefully — first after a good clean up of both parts.

Edited By JohnF on 04/08/2018 15:22:30

[NigeParticipant @nige81730]

Also put a slight chamfer on both ends of the bore, give the post a good clean with fine emery cloth and oli. Clean thoroughly and lightly oil again.

[Noel MurphyParticipant @noelmurphy40921]

Remove the clamp bolt, put a piece of steel in the slot and replace the bolt from the other side. Tightening the bolt will push on the steel and open the slot. It's the same idea as the wedge, but might be a bit more controllable.

Noel

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