Can’t drill through lathe stand base plate

[John CoatesParticipant @johncoates48577]

I have made a swarf/splash guard for my Barker from the clear plastic
screen off an old sun bed held rigid by two metal L brace pieces

One uses an existing 6mm hole in the base plate and I went to drill and tap a new hole for the other using my Bosch power drill. Well this is proving less simple than I thought. I can't get any drill bit to bite and cut. I've tried TiN and cobalt but nothing is working.

The base plate is 3/32 or 2mm steel

Is it because I am just not exerting enough pressure, unlike a drill press?

[John CoatesParticipant @johncoates48577]

[Roderick JenkinsParticipant @roderickjenkins93242]

Have you tried a small pilot hole first?

Rod

[David Clark 13Participant @davidclark13]

Try switching the drill to forward instead of reverse?

regards David

[SiddleyParticipant @siddley]

I'd try a pilot hole too. Are you working from an awkward position that prevents you getting any real force behind the drill ? if so, can you rearrange things to get a better angle ?

Nice bike BTW

[Clive HartlandParticipant @clivehartland94829]

Will the drill, drill through any other materiel? Check the end of the drill and see if it has a positive cutting lip as i recently bought some that had a negative angle!

Clive

[Nicholas FarrParticipant @nicholasfarr14254]

Hi John, drilling a 6mm hole through a 2mm thick piece of steel with a pistol drill shouldn't take an extreme amount of effort. A small pilot hole will help, but it is not absolutely necessary. You may be trying to dril with a too high enough spindle speed and or blunt twist drills. Assuming your drill has a speed control, try it at around 200 to 300 RPM while keeping firm pressure on to the drill.

Regards Nick.

Edited By Nicholas Farr on 16/12/2012 17:07:07

[John CoatesParticipant @johncoates48577]

Done it !

Stopped with the TiN and cobalt 3mm drills and used a normal black jobber 3.5mm and it bit and made the pilot hole. Didn't tap in the end just made it 6mm and put a nut on the other side

The Bosch is hi-speed but did try it a different speeds but they just weren't biting

Anyway that's done, now onto making a chuck guard. I'm fed up of swarf flying off around the garage and getting near the bikes

[John CoatesParticipant @johncoates48577]

Posted by Siddley on 16/12/2012 15:15:09:

Nice bike BTW

It is and I soooo wanted to get out on it this weekend but domestic chores got in the way. Am now hoping the better weather stays

[Peter TuckerParticipant @petertucker86088]

Hi John,

I have found when drilling tough steels the helix angle of the drill bit is too acute and grinding this back at the cutting edge facilitates drilling (similar to backing off to drill brass, but not to 0 rake). Hope this helps.

Good luck.

Peter.

[David LittlewoodParticipant @davidlittlewood51847]

It's easy to forget the precise mechanics of what happens when you drill with a jobber drill. The chisel edge in the centre of the drill has a huge negative rake and will not cut the metal; it has to gouge it out by plastic deformation. The force needed to do this can become very large indeed as the drill diameter (and hence the size of the chisel edge) increases. Using a pillar drill, the leverage applied by the feed handle is substantial. and one might not realise just how substantial; using a hand-held drill, the force has to be applied by you pushing it.

As you found, a pilot hole (sized about the same as the width of the web on the larger drill) will remove the need to force the chisel edge into the steel and make the job much easier.

David

Edited By David Littlewood on 16/12/2012 19:57:10

[TerrydParticipant @terryd72465]

Hi John,

A jobbers HSS drill these days is usually made from cobalt high speed steel and TiN is simply a coating for HSS drills, not an alloy. See here,

Regards

Terry

[Ady1Participant @ady1]

Drilling through steel by hand teaches you a great deal about the mechanics of drilling and the grinding of drill bits, always drill a pilot hole if you can

Most of us just rely upon the high speed and high torque pressure of a drill press to drill holes

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