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how to drill a concentric hole in a brass rod

02GF74 - 20/12/05 at 01:20 PM

I don't have access to a lathe otherwise it would be easy

Any tips on how I can drill a 1.5 mm hole concentrically in the centre of a 8 mm brass rod? (I have a drill press).

The tricky part is to align the drill with the centre and then keep it going along the axis.

bigandy - 20/12/05 at 01:31 PM

Could you mount the brass rod in the drill press chuck, and the drill in a vice? I.e rotate the workpiece, and keep the tool tied down....

Cheers
Andy

02GF74 - 20/12/05 at 01:33 PM

quote:
Originally posted by bigandy
Could you mount the brass rod in the drill press chuck, and the drill in a vice? I.e rotate the workpiece, and keep the tool tied down....

Cheers
Andy

err, right, that sorted then!!!

I have considered this but the problem remains the same: how to keep either the drill or work piece in the vice parallel to the thing that is rotating.

MartinDB - 20/12/05 at 01:44 PM

Is there room to fit the drill bit once the rod is clamped in place?

If so, how about, fit the rod in the drill's chuck, lower it as far as it goes and clamp in place then loosen the chuck and raise it and fit the bit?

Martin.

rusty nuts - 20/12/05 at 01:49 PM

Find someone with a lathe?

rsk289locost - 20/12/05 at 01:50 PM

Make a drill guide. Get a piece of thick ( say 2" ) scrap metal and drill a 1.5mm hole straight through it with your drill press. Then, without moving the guide, drill the same hole to 8mm but only to half ( 1" ) the material thickness. Now you can slide the guide on to your brass rod and the 1.5mm hole will support your drill bit and it will be concentric. If you see what I mean.

[Edited on 20/12/05 by rsk289locost]

02GF74 - 20/12/05 at 02:08 PM

quote:
Originally posted by rsk289locost
Make a drill guide. Get a piece of thick ( say 2" ) scrap metal and drill a 1.5mm hole straight through it with your drill press. Then, without moving the guide, drill the same hole to 8mm but only to half ( 1" ) the material thickness. Now you can slide the guide on to your brass rod and the 1.5mm hole will support your drill bit and it will be concentric. If you see what I mean.

[Edited on 20/12/05 by rsk289locost]

... htat is the way I am thinking. clamp vice to table with scrap metal; drill 8 mm hole so fit the rod in. then fit 1.5 mm drill and make the hole. need to figure out how to stop the brass rod from spinning!! (grub screw arrangement?)

alternativley thinkf of some sort of V-shaped jaw attachment.

Mix - 20/12/05 at 02:15 PM

Big Andy's response was correct if you are able to hold the rod in the chuck. The tendancy is for the drill bit to self centre if the work is rotating.

Mick

This asumes you have a drill press vice you can bolt to the table.

[Edited on 20/12/05 by Mix]

02GF74 - 20/12/05 at 02:25 PM

quote:
Originally posted by Mix
Big Andy's response was correct if you are able to hold the rod in the chuck. The tendancy is for the drill bit to self centre if the work is rotating.

yep - see what you mean; makes sense.

emsfactory - 20/12/05 at 02:40 PM

I have a lathe so I can drill it out if you want, youd have to post me it though.

02GF74 - 20/12/05 at 02:51 PM

quote:
Originally posted by emsfactory
I have a lathe so I can drill it out if you want, youd have to post me it though.

thanks for the offer. I'll give it a go myself first but if I find I am breaking too many drills or getting poor resilts I'll be in touch.

I've got 1m of rod to practice with (it is for making attachments for throttle cable)

Genesis - 20/12/05 at 04:41 PM

If it is for brake cable barrels then the hole doesn't want to be down the centre (axial) it what's to be radial through the middle.

Just dot it with a centre-pop and drill - providing it is near enough it will centre when it is in situ.

[Edited on 20/12/05 by Genesis]

caber - 20/12/05 at 08:00 PM

Make yourself a centering tool, basically a 90°v shape cut in plate with another plate fixed on the top bisecting the V, scribe at least two lines across the end of the workpiece sharpen a centre punch so you can feel the scribe marks when you are at the crossing give it a good wallop, The should find centre on th eend of the workpiece. If you don't have a proper vice for the drill press bolt a couple of bits of angle accross the work plate find a piece of scrap the same diameter as the work piece with a right angle end, fix the two angles at one end use the piece of scrap to get the workpiece vertical then clamp the other ends of the angle hard together, that should get you vertical in both planes, check with a square if it looks OK adjust the workplate so it sits with the drill landing on your centre punch mark you may need to re-clamp your angles to get it in the right place.

Drill gently with a sharp drill at the right speed and you should be OK. It is a bit of a long winded bodge but gives you a crude vice for your drill. If you decide to buy a proper vice that should come with V's cut in the jaws to hold tube vertically and horizontally make sure it fits the workplate correctly, i.e the bolt down slots in both vice and workplates are the same dimension otherwise it is worse than useless!

Caber :-)

02GF74 - 21/12/05 at 09:32 AM

these are the 3 bits I am trying to do.

the longer the concentric hole, the more difficult it is to make it concentric (the one on the right beingthe easiest)

accelerator cable

rusty nuts - 21/12/05 at 11:11 AM

Check out Peugeot/Citroen throttle cable kits. They don't supply a ready made cable ,it comes as a kit to fit all models . You use whatever fittings you need and cut the inner and outer cable to suit. HTH