Drilling depth

Hi team,

I will be making a shaft around 6mm diameter and around 130mm long. To keep the weight down I'm thinking of drilling out the centre but as we all know drills can wander off line. I can attempt to minimise this with a good quality drill, a good headstock~tailstock alignment, good collets and with lots of pecks.

With say a 3 or 4mm drill, how deep do you think I could sensibly go ? I'm not worried about the strength of the shaft, a little about eccentricity but more drill breakage.

Gerry

Think I'd be inclined to see if I could make the part from tube.

An alternative are these 6mm diameter stainless steel drinking straws, plenty long enough for your shaft, thin walled but very strong. I don't know what your shaft is for so it could be an alternative to drilling out a length of bar, and still give you the strength you need. I've been wracking my brains to find a use for these and now you have given me one use at least! Only problem now is going somewhere to buy them!

Ian

Using aluminium would likely be lighter than steel tube (but not those straws). That would allow drilling to ,say, 50mm quite easy. ‘About’ is a bit arbitrary - could you use a shaft thinned on the outside rather than internally?

Tell us what the shaft if for and we might be able to offer some suggestions.

Other than that, you should be able to drill in from either end as deep as the flutes on the drill go.

Edited By Hopper on 25/04/2020 12:46:25

Ian Johnson...'Only problem now is going somewhere to buy them!'

eBay has a variety of stainless straws / tube... couple of examples here:-

**LINK**

**LINK**

George.

Sovol give them away free with their 3-D printers. Would not accept a worthwhile offer on their ‘BIN or make an offer’ but sent out 2 packs of 6mm OD stainless steel straws and a cleaning brush (with one set only). Rather annoyed me!