How do I

[Martin WParticipant @martinw]

I’ve just about haddock enough of these puns but that’s enough carp-ing for now. If I get any more excited I will fall off my perch.

 

 

 

Martin

[blowlampParticipant @blowlamp]

Eel live to regret asking about this.

 

You could also drill the hole and roach it to size later.

 

If you drill too big, then just turn a slightly larger plug and put it on ice for a while.

When cool, it will drop into the hole and once the temperatures have stabilised, you will have a shrimp fit.

 

 

 

Martin.

[Martin WParticipant @martinw]

This could go on for dace and dace.

 

 

Martin

[blowlampParticipant @blowlamp]

Posted by Martin W on 20/11/2011 12:01:27:

This could go on for dace and dace.

 

 

Martin

 

 

Maybe even until oyster

 

 

Martin.

[Martin WParticipant @martinw]

Martin

 

You are evidently a dab hand at this and I can only flounder in your wake .

 

Cheers

 

T’other Martin

[TerrydParticipant @terryd72465]

Hi All.

 

I knew there was something fishy about this forum, now I know it.

Seriously if I may divert for a mo’, back to Wolfie’s problem. As you can see Wolfie, there are almost as many solutions to engineering problems as there are engineers! Some are simple, others more complex (just like said engineers perhaps – Just to clarify for the more sensitive souls on the forum, no offence or reference to any person living, dead or otherwise is intended ).

 

If you have limited resources you can easily
centre a drill on a round bar in the vice using a simple 150mm rule. I
use the mill for drilling accurate holes but there is no reason that
this method cannot be used on a bench drill. It is the same as the method referred to above by Mick above, but with pictures!

Support your bar in the vice nice and horizontal, use a small centre drill in the chuck then put a 150mm rule across the bar and lower the centre drill to capture the rule between it and the bar. If the rule is horizontal you are on centre so you can clamp and start the hole with the centre drill (that is important, a normal drill is liable to skid on top of the bar). If you think necessary, once centred replace the centre drill with a small slot drill to create a small ‘land’ on the bar before centre drilling to stop any chance of skidding. 

 

The method is quite sensitive and accurate enough for most purposes. Pictures can show it better so here are a few.

Drill set 0.2mm to left of centre

Drill set 0.2mm to right of centre

Drill set on centre

 

 

 

I hope that makes the technique clear,

 

(By the way, that mill vice was rescued from my garage fire in an awful state, I have de-rusted it in hydrochloric acid solution – as suggested by John W I think, in another thread,- refurbished it and it is now quite serviceable again.)

 

Best regards

Terry

Edited By Terryd on 20/11/2011 15:13:20

[michael coleParticipant @michaelcole91146]

Ah yes back to engineering.

The ruler method used by Terry is my fav method. If care is taken, starting with a end mill to make a flat , you can quite easy give to within 5 thou, which is all you need for 95% of cross drilling. If you have to be spot on then use a guide of the many types other posters used or an edge finder.

 

Mike

[WolfieParticipant @wolfie]

Cheers all. Nice to see that ruler perch on the job.

 

Edited By Wolfie on 20/11/2011 20:15:55

[TerrydParticipant @terryd72465]

p.s.

 

I also have a lathe tailstock vee centre, it is an original Boxford one and is quite accurate, but not really much more so than the ‘rule and eye’ method. When using the drilled bush method the drill can wander off by a few thou as it drills through. ‘Horses for courses’ so to speak.

 

Furthermore, the chuck in the picture is another ‘fire rescue’ job!

 

Regards

 

T

Edited By Terryd on 20/11/2011 21:26:52

Edited By Terryd on 20/11/2011 21:53:03

[chris stephensParticipant @chrisstephens63393]

Hi Guys.

Now that we off the puns, if you want the best (?) way to drill accurate cross holes, try this other way I do it. My DRO has provision for a number of “Zeros”, one of which I have set on zero on the fixed jaw of my mill vice. When I want to drill holes I just measure the diameter and dial in the radius on the DRO, then start the hole with a spotting drill, not a Slocombe/centre drill, followed by size required or pilot drill if large or an accurate sized hole is required. followed by final drill.

Easier to do than write, you do have DROs on your mill, don’t you?

chriStephens

 

[Les Jones 1Participant @lesjones1]

Hi Wolfie,

A variation on some of the methods suggested  that I use is to clamp the bar to be drilled in the machine vice so that it either does not reach the end or does not reach the top so a centre drill can be touched against the jaws. Then move the table towards the fixed jaw with a feeler gauge between the jaw and the centre drill. When the feeler gauge is a sliding fit between the jaw and the centre drill set the DRO to read zero. Repeat this on the moving jaw. (Must be THE SAME feeler gauge.) Note the reading on the DRO and divide this value by 2 (Or use the centre find function on the DRO) Now move the table so that the DRO reads the value from the divide by 2. I use the feeler gauge to save putting an edge finder in the chuck / collet. If you do not have a DRO you could use a digital vernier. Position the centre drill about the middle of the jaws. Measure the distance between each jaw and the centre drill. Add these two values together and divide by 2. Now move the table until the distance between the centre drill and the jaw is this value, (It will be the same distance to either jaw.) This method could also be used on a pillar drill but it would not be as easy.

 

Les.

Edited By Les Jones 1 on 21/11/2011 10:04:13

Edited By Les Jones 1 on 21/11/2011 10:06:07

[Author]

Posts