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Best way to drill


Ron Altier

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 Is there a BEST way to drill a hole thru a cylinder that you have turned down. If you have a piece 8" long X 2" in dia and you want a quarter inch hole going completely thru it, is there a best way to accomplish a straight hole, end to end? My attempts were OK, but could be better. I know someone has a tip or two to share.

 

Thanks

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What is your current technique and drill bit material? What are the issues that lead you to the conclusion that you can do better?

For long straight holes I; 

1. use a jig; the above jig or one like it, clamped to the drill press table (table turned to vertical), cylinder clamped to the jig.

2. use the shortest, long drill bit you can find. Size the length of drill bit to the project, don't use an 18" long bit to drill an 8 " deep hole.

3. use the best alloy, I've found the cobalt drill bits are the stiffest, as an added benefit they had a high heat tolerance.

4. use the right speed; my chart says 3000 for softwood, 1500 for hardwood (twist drill bits) chart also states to reduce speed on end grain, so I would cut the speed about 10%.

   If you have to raise the drill press table to drill deeper holes (multiple times), clamp the bar that the table rides on (notched bar on the side of the column), this is to prevent the table from shifting side to side while lifting the table for another pass. One clamp low, another clamp just below the table mount.

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1 hour ago, Wichman3 said:

What is your current technique and drill bit material? What are the issues that lead you to the conclusion that you can do better?

For long straight holes I; 

1. use a jig; the above jig or one like it, clamped to the drill press table (table turned to vertical), cylinder clamped to the jig.

2. use the shortest, long drill bit you can find. Size the length of drill bit to the project, don't use an 18" long bit to drill an 8 " deep hole.

3. use the best alloy, I've found the cobalt drill bits are the stiffest, as an added benefit they had a high heat tolerance.

4. use the right speed; my chart says 3000 for softwood, 1500 for hardwood (twist drill bits) chart also states to reduce speed on end grain, so I would cut the speed about 10%.

   If you have to raise the drill press table to drill deeper holes (multiple times), clamp the bar that the table rides on (notched bar on the side of the column), this is to prevent the table from shifting side to side while lifting the table for another pass. One clamp low, another clamp just below the table mount.

I would also like to know how you are doing it now.

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13 hours ago, HandyDan said:

Getting it started dead center and strait is best can do.  Drill from both ends.  Sharp drill and clear the chips often.  Heat and chip build up are the enemy

 

4 hours ago, Steve Krumanaker said:

I would do it on the lathe. Start with a piece slightly over sized. Turn a tenon on either end. Chuck one end and drill about 1/2 way. Turn it end for end and repeat. Use the holes as your center and turn it round. I know you've already turned the cylinder, much better to drill first.

 

2 hours ago, lew said:

Using a short bit to go as deep as possible and then use a longer bit will help. Drilling from both ends as @Steve Krumanaker recommended is another excellent procedure. I keep the lathe speed very low and go very slow. 

 

ALL of the above.

For the bit get a good brand named bit with a full flute.  The longer flutes help to clear the chips better.

 

image.png.b64ed6273f4a6bb07d5fa2b1532fa97a.png

Edited by HandyDan
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2 hours ago, John Morris said:

Hey Ron, what's your accuracy standards? Is the hole for chord through a lamp base? Or do you need higher accuracy than that?

My wife has a favorite antique heavy aluminum cooking pots with a long wood handles. The handles have deteriorated over the years and I made a replacement. I drilled it on the drill press from each end and turned it round. The hole was not straight and it fit after some persuasion. So I was wondering..........is there a better way?

IMG_5630.JPG

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Like others have said, you can do this fairly easy on a lathe.  If you have a chuck that you can mount to taper into the tail stock, you can start the bore with a brad point or double point bit.  The reason for those bits is that they don't wobble out of the intended hole. After the hole starts, you can change into a long bit of any point as long as the bore size is the same.  You can advance the bit using the tailstock or if using a Shopsmith, you can advance the quill.  Of course, as you well know, you want to get your stock straight before boring or you may come out a side.  You can get some scraps to practice and when you get your technique down, you can do the real.  That handle looks fine and should last for many years.  

 

 

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