drilling holes???

[tesseract]

Ok how would I do this and get it precisely right the complexity of this jig seems overwhelming.

I have a cylinder say about 2 inches in diameter and a length of about 4-5 inches.

Here is the easy part part I need three holes drilled equidistantly around the circumference this is not hard. The hard part is that I need them drilled at about a 30 degree angle with respect to the circumference and parallel to the top and bottom flat face of the cylinder can this even be done without a mill

The bad part is that the three holes only make a single so called layer of holes I need multiple sets running from one end of the cylinder to the other.

The holes would only be 1/8 inch in diameter and I need about 12 layers spread out across the length of the cylinder and and the holes of each layer would be offset from the previous by about 1/4 inch so I would end up with a spiral of holes.

told ya it was messy

any suggestions if I don't have a mill

 

[astroracer]

Get yourself another tube that will slip over the one you want to drill. Drill the hole pattern you want to replicate (one set of three) into the "sleeve". Use the sleeve as your drill guide, drilling one set of holes, then indexing it down the distance for the pattern spread and the 1/4" rotation.
You may need to drill and tap a couple of holes in the sleeve so it can be "locked" to the
one you want to drill.
I would suggest starting the drilled holes with a flat bottomed end mill to make a flat face for the drill to start on. If the endmill would work you could probably bore all of the holes with that.
Once you get your master made this work could be done in a vice.
Mark

 

[racingtadpole]

Can be done without a mill, but you will need a drill press
You'll need a pair of v blocks, a piece of angle iron, and a dressmakers tape.

Sit pipe in angle iron, draw a line down one edge. Thats your start point.
Take the dressmakers tape and measure the around the outside of the pipe using the line you just marked as your start/finish point, divide by 3 (can also be calculated mathematically if you are so inclined). Use the tape to mark the other two lines at the correct distances.
Use the angle iron to mark lines at those points.
Centre punch your first set of holes.
Now mark another set of lines 1/4" away from the lines you just made using the angle iron.
Centre punch 2nd row of holes
Repeat marking and centre punching until pipe is marked and punched with the desired hole pattern.

Set the table on the drill press to 30* using an angle finder and clamp pipe to table using the v blocks so its in the correct orientation.
Drill hole
Rotate pipe
Drill hole
Repeat until all holes drilled

A bit labour intensive but I wouldnt bother making a jig for 36 holes.

 

[Kevin54]

It's not as simple as it sounds. Astroracers got the right idea.

But the thing is...anytime that you drill a piece of metal that is on an angle, you need a flat spot to begin with. Just spotting the mark with a ***** punch then trying to drill, the drillbit will still want to walk on you. With a drill jig, it will prevent the drill from walking, but if the jig is made out of soft material, it may elongate the hole in the jig before you get done.

If it were me, and I didn't have a mill, I would go with a drill jig.

 

[bullnerd]

Material?
Wall thickness?
Tolerances?
Quantity?
Tools you have available?

 

[racingtadpole]

It's not as simple as it sounds. Astroracers got the right idea.

But the thing is...anytime that you drill a piece of metal that is on an angle, you need a flat spot to begin with. Just spotting the mark with a ***** punch then trying to drill, the drillbit will still want to walk on you. With a drill jig, it will prevent the drill from walking, but if the jig is made out of soft material, it may elongate the hole in the jig before you get done.

If it were me, and I didn't have a mill, I would go with a drill jig.

Very true, and quite often my biggest problem when I post in response to these types of questions is that nobody can see the instructional video that plays in my head.

 

[retrobuilder]

Invest is used or low cost cross slide with rotary table. No jigs required..even for drill press.

 

[larry_g]

Here is a picture (I hope) of what the op is trying to do. He has a couple of posts going on this problem. He is trying to drill into the cylinder, on a tangent, to insert the black dowel pin.

lg
no neat sig line

 

[Kevin54]

Invest is used or low cost cross slide with rotary table. No jigs required..even for drill press.

Even with a cross slide, that still won't help the fact that he is wanting to go in a cylinder on an angle. Without a flat spot the diameter of the drill, or without a drill jig, the problem will still exist of the drill walking off the side.

Another problem is that if the OP is going to use this as some sort of a shredding device. a round dowel isn't a good candidate for a cutter. It should be a square piece. A round dowel ground on an angle will give you a point while the rest of the dowel will just be pushing the material out.

 

[bullnerd]

Still need to know the material?

 

[retrobuilder]

Forget drilling- use an end mill or end mill to flat then drill/ream. A rotary table at 90 degree to the spindle will help.

EDM can also work well if the hole needs to be square..